What is pipe lining

5.5 Pipeline lining

The insulating coating of the pipeline in the pulling sections and in the underwater trench is protected from mechanical damage by a continuous lining - wooden slats.

Pipelines are lined to protect the insulation from damage during installation. The lining process includes the following operations:

sorting by length and cutting slats;

preparation of slatted carpet;

carpet wrapping pipes;

preliminary and then final strengthening of the lining with wire rod.

5.6 Pipeline ballasting

Ballasting, or weighting of the pipeline, is carried out during the construction of gas pipelines that have positive buoyancy.

To ballast the underwater section of the gas pipeline, cast iron ring weights were used in the amount of 216 sets, with a mass load of 450 kg.

Ballasting work is carried out in the following sequence:

• sets of cargo from the on-site warehouse are transported along the pipeline and laid out according to marks;
• the pipeline string is sequentially transferred by pipelayers to the lower semi-rings of loads;
• the upper half rings are installed on the pipeline;
• The half rings are connected with bolts and fastened with nuts.

To center the holes in the half rings of the weight, metal rods are placed when lowering the upper half rings of the weights.

5.7 Laying the pipeline

The essence of the method is to drag the pipeline along the bottom of an underwater trench from one bank to the other using a cable pre-laid in the trench.

The technological sequence of the main operations associated with laying by pulling is as follows: the pipeline is welded onshore into a thread, compressed, insulated, lined, and, if necessary, ballasted and equipped with pontoons; a launch track is arranged on which the pipeline prepared for laying is placed; a traction cable is laid along the bottom of the trench; drag the pipeline through a water barrier using tractors, winches or special devices; after the end of pulling, the actual position of the pipeline is monitored, the laid pipeline is tested and then backfilled.

Laying a pipeline by dragging it along the bottom of a water barrier is the most common method. Its advantages include the ability to carry out work without stopping shipping and at any time of the year, and the insignificant need for rigging and floating equipment. In addition, the pipeline is not subject to wave and wind loads during installation.

This method of laying the pipeline is recommended:

in the presence of a smooth topography of one of the banks in the crossing area, in which planning on this section is possible in accordance with the permissible bending radius of the pipeline when pulling it;

if it is necessary to lay a pipeline in summer through navigable water barriers;

if there is a sufficient size of the platform in the crossing area for the installation of a descent path;

sufficient strength of the pipeline being pulled, taking into account the impact of traction forces on it.

The pipeline can be pulled through the full length of the descent track or by successively increasing the strands (sections). The entire length of the dragged pipeline must exceed the width of the water barrier in order to ensure that pipes are joined dry in coastal areas without jumpers.

When dragging the pipeline, it is necessary to determine the values ​​of traction forces. In order to reduce the traction force when moving the onshore section of the pipeline during pulling, various descent paths are used, which should ensure unhindered transportation of the pipeline during the entire period of pulling work.

Depending on the length of the pipeline string being laid, its diameter and weight, as well as the topography of the coastal section, the descent path can be arranged as follows:

• coastal trench filled with water;

• with roller supports on a planned section in the crossing alignment;

• rail track with bogies

The dirt path is a planned strip of dirt at the crossing point on the right bank of the Vilyui River. The path is made rectilinear in plan, the profile of the path is planned so that it has a slope towards the reservoir. Even a slight tilt in the opposite direction creates a large additional force for pulling.

The laying of the siphon in the underwater trench is carried out by dragging along the bottom of the trench using pipe layers and bulldozers on the left bank of the Vilyui River.

For pulling through, a cable with a diameter of 48.5 mm is required in accordance with GOST 7669-80. The traction rope must have a manufacturer's certificate or a certificate of testing.

After the pipeline is laid in the riverbed, installation is carried out on the onshore sections of the crossing.

Before pulling and laying the pipeline, you must do the following:

• develop a trench in the river bed and on the edges,
• weld the lashes to the required length,
• carry out testing, insulation, lining, and ballasting of strands,
• install a traction winch with an anchor support.

• prepare the lashes for pulling, secure the end of the traction rope to the head,
• lay the traction rope through the water obstacle, secure it to the winch,
• place machines, mechanisms, equipment and means for safe work on the construction site and prepare for work;
• instruct workers and specialists, clearly distribute their responsibilities;
• check the interaction of all machines and mechanisms, communications and alarms;
• place the work control point so that an overview of the entire work area is provided;
• measure the depth along the underwater crossing alignment and check the compliance of the actual profile with the design one,
• check the water horizon and, in accordance with the horizon, measure the width of the crossing surface using geodetic instruments,

• determine the basic data of the reservoir necessary for the survey:

— flow speed

• maximum depth,
• water temperature.

Dragging the pipeline along the bottom of the trench is carried out in the following sequence:

1. The first strand of the pipeline is laid out along the transition axis.

2. Pipe layers are placed along the entire length of the string (according to the diagram) to relieve the weight of the pipeline on land.

3. After the first string of the pipeline is completely ready for installation, the traction cable is tightened and the slack is removed.

4. At the signal from the work manager, the traction winch is turned on, and the pipelayers lift the string to the calculated height.

5. The dragged string is accompanied by pipelayers until they leave work.

During the process of pulling the pipeline, all working stations must have two-way communication with the control point for complete coordination of the actions of the pipe layers and the traction winch. Commands for starting and stopping the pipeline, which are transmitted from the control point using portable radios and duplicated by conditioned signals, must be worked out in advance. After the transition is completely ready, a control inspection of the laid siphon is carried out along the trench profile.

Source: https://studfile.net/preview/6868913/page:9/

Pipe lining

Prices for services Implemented projects SP, GOST and other documents Related articles Definitions of terms

Lining pipelines and chimneys helps extend their service life, protect them from harmful chemical, mechanical and temperature influences, and save on expensive repairs and replacements. There are external and internal lining of pipes. Technologies and materials differ depending on what the pipe is made of and where it is used.

Granoeskport LLC offers lining of brick, steel and concrete pipes. We use high-quality materials that are highly resistant to environmental influences and production. With us, your equipment will serve for a long time and reliably!

For any questions, please contact the numbers provided in the header of the site.

Chimney lining - features, materials, purpose

The chimney lining has two main functions:

1. Providing protection from high temperatures.
2. Ensuring protection of the inner surface of the pipe from aggressive compounds in smoke and condensate.

The lining of brick and concrete pipes is carried out using refractory bricks or concrete, heat-resistant slabs, as well as complex compositions and mixtures. Our company uses fireclay bricks, concrete tocreting, silicon carbide mixtures, cement-fireclay mortars, etc. We also use acid-resistant mixtures based on liquid glass. We approach each individual case individually, based on the customer’s budget, his requirements and the characteristics of the pipe itself.

Pipeline lining - reliable protection against corrosion

Lining is needed not only for chimneys, but also for steel pipelines. In this case, the lining treatment protects the internal and external surfaces from corrosion, abrasive wear and material adhesion.

For the lining of steel pipes and pipelines, we use flexible fluoroplastic, fluoroplastic varnish, rubber and composite compounds, polyurethane, polyethylene, etc. Thanks to this, we protect both the material from which the pipes are made and the liquids that move through them.

Our offer:

• affordable prices in Rostov-on-Don;
• high-quality materials - moisture-proof varnish LF-32LN made of fluoroplastic, fireclay, acid-, heat- and fire-resistant mixtures and solutions;
• assistance from professionals - specialists who have extensive experience and can offer quick results.

When lining chimneys, we rely on SNiP III-24-75. “Industrial ovens and brick pipes”, but at the same time we offer a personalized approach.

SP, GOST and other documents on the topic

Source: https://granoexp.ru/moskva/uslugi/futerovka/trub

What is lining?

For the construction of furnaces, only fire-resistant materials are used. But even they are not able to withstand high temperatures on their own for a long time, which when burning fuel reach hundreds of degrees. To protect the outer walls near the firebox from radiation, thermal or chemical influences, a lining is installed inside.

The first question that an amateur stove maker asks when he hears the word lining is what it is and what its purpose is. This is the shell that covers the inner surface of the combustion chamber. Thanks to its resistance to constant exposure to high temperatures, it allows the structure to last for a long time.

In the chemical-thermal system “medium-lining-material” the lining is a kind of mediator. When starting to lay the central part, it cannot be considered as a separate component.

You can arrange the lining in one of the following ways:

1. Installation of protective screens that reflect thermal radiation, but some of the heat will escape through the chimney to the street
2. Treat the internal surfaces of the combustion chamber with materials that have a low thermal conductivity coefficient

The main purpose of the lining is thermal protection, but not thermal insulation. These two concepts are completely different from each other. If the inner surface is insulated from heat, the heat will be constantly retained inside the combustion chamber and removed outside along with the smoke, significantly reducing the efficiency of the stove.

It is necessary to begin laying the lining after carrying out engineering calculations and deciding on the type of foam installation. In this case, the characteristics of all building materials used are taken into account.

Introductory video

Features of lining for various types of furnaces

For each type of furnace or heating boiler, the lining has certain features. Let's look at the most common options:

• Lining of metal furnaces
• Brick kiln lining
• Steam boiler lining

Lining of metal furnaces

If the combustion furnace is made of metal, the different thermal expansion of the materials must be taken into account. A small gap must be left between the lining and the steel, otherwise the constant fluctuation in the size of the iron walls will destroy the masonry.

The cavity left should not be empty. It is filled with one of the non-flammable materials, for example, basalt wool. Sometimes asbestos is used, but the stove must be located in a non-residential area.

When making the lining of metal furnaces, bricks are sometimes laid on both sides. The answer to the question about the feasibility of such a solution is justified as follows: the heating of the furnace improves and the level of safety increases. However, this approach is wrong:

• Brick has low thermal conductivity
• Brick has a heat capacity

Analyzing the above, we can come to the conclusion that lining metal furnaces on both sides will lead not to thermal protection, but to thermal insulation. Moreover, cooled air will not flow inside the furnace, which can lead to burnout of surfaces.

Read also about how to make a Swedish oven with your own hands

Brick kiln

The opinion that lining a brick kiln is much simpler than a metal kiln is erroneous. Such work also has some features, without taking into account which you cannot count on the long service life of the structure.

It is impossible to lay the lining close to the bricks that are elements of the outer walls. The reason for such consequences is the pushing out of the outer layers by the expanding inner layers. Cracking can be aggravated by the fact that clay has low adhesion rates and expands more than brick.

If the lining is of poor quality, this will lead to unpleasant consequences:

• Overheating of external surfaces will result in cracking of seams and the formation of cracks
• The latter, in turn, will cause carbon monoxide leaks into the room, but not into the chimney

In addition to the high-quality lining made from fireclay bricks, special attention is paid to the quality of the seams and the clay used. It is necessary to glue 2-3 bricks together and burn them at high temperatures. This action will allow you to clearly determine how the assembled structure will behave. If the results are not satisfactory, you will have to experiment with the composition and repeat the tests.

Steam boiler

Sometimes the lining needs to be laid not for classic fireplaces and stoves, but for combustion steam boilers. In this case, choose one of its 3 varieties:

• Heavy
• Lightweight
• Natrubnaya

Heavy lining and what it means is one of the exciting questions. They resort to it when boilers have weak shielding. Sometimes the temperature inside the furnace can exceed 1200 degrees, causing fires in external materials. It is necessary to lay out heavy lining from 2-3 layers of fireclay bricks. Such protection allows you to reduce the temperature outside to a safe 60-80 degrees.

If the brick is laid in just one layer, the lining is called lightweight. However, each of the belts must be supported by an intermediate beam or boiler frame. Then the surface of the heating installation is wrapped in non-flammable materials and covered with a metal sheet. Thanks to this combination, it is possible to reduce the outside temperature and increase the efficiency of the boiler room.

The simplest is the pipe lining. To arrange it, it is necessary to prepare a viscous non-flammable mass and apply it to the pipes in 2-4 layers. To make the structure better resist thermal expansion, a reinforcing mesh is laid.

Household lining: answers to common questions

More often, the lining is a laying of fireclay bricks, which will be in direct contact with the burning surface. However, a novice builder, faced with such a task for the first time, will ask himself a number of questions:

1. What is the best way to lay bricks?
2. How thick should the furnace lining be?
3. What should be the gap between the bricks and is it necessary at all?

When constructing classic stoves and fireplaces, it is enough to lay only one layer of lining. In this case, products measuring 25x15x6.5 cm are used - such a brick is considered standard.

Laying is usually done vertically. Nobody forbids making it horizontal, but most of the internal usable area will be lost.

Unlike classic brick, the thermal expansion of fireclay products is minimal. Therefore, there is no need to leave a large gap between them. A clay solution is used as a connecting link and a metal spike is installed. The use of cement-sand mortar is prohibited.

If the lining comes into contact with metal products, for example, a grate, a gap should be provided between them. Metal under the influence of heat will constantly change in size and can be pushed out, bend over time and even burst.

Materials used

Having learned what a lining is, it is necessary to take a closer look at the materials for its construction. The materials used for lining furnaces and boilers can be divided into three main classes:

• Class A - artificial or natural materials based on silica
• Class B - classic materials based on clay
• Class C - this includes all remaining options and various fire-resistant solutions

Specific examples

You can protect the inner surface of the combustion chamber using a variety of methods:

• Fireclay brick masonry
• Application of non-flammable mixtures
• Installation of protective screens

It is recommended to install screens when installing metal sauna stoves. In other cases, it is not effective, as it will lead to wasteful leakage of thermal energy.

When choosing brickwork, it is not recommended to use classic brick - it quickly collapses and requires replacement. Before the advent of fireclay materials, products of the M-300 brand were used. They are relatively reliable and durable, but still inferior in efficiency.

How to prepare the solution

It was previously mentioned that it is necessary to experiment with the mortar for laying the lining. To minimize the number of tests, it is recommended to prepare several options at once and fire them under the same conditions. Don't forget to label.

A solution prepared on the basis of brick dust and fireclay clay is considered widely popular. However, if only wood is burned in the stove, you can use a classic clay mixture with a small sand content.

Lining for stucco stoves

Classic stone or metal heating structures in baths are gradually being replaced by more modern and beautiful stucco stoves. They are built using the adobe method. For them, the lining can be made of fireclay bricks, but craftsmen recommend resorting to special mixtures:

• Mullite
• Fireclay
• Corundum

To use these compounds, it is enough to dilute them in warm water on site. The solution is applied to fire-resistant surfaces. After drying, the monolith will not crack.

About repairs

Nothing lasts forever, including the furnace lining. Before the start of the next heating season, it is recommended to inspect surfaces and restore damaged areas.

It is recommended to use a mixture based on aluminous cement and fireclay powder as patches. First, the mass is applied to the damaged areas, and then dried with an open flame. The last stage should begin after a week. If you rush, the renewed surface can quickly collapse again.

A little about industrial lining

The main difference between industrial and household linings is the structure of the fireclay bricks used. In the first case, it will be exposed to high temperatures, and therefore requires additional pressing during the production process. They are much more expensive, but can withstand thermal shock.

Let's consider the most optimal ratios of such characteristics as material-density-temperature:

Material	Density kg/m3	Maximum operating temperature °C
Chamotte	1800-2000	1300
Kaolin is dense	2400-2500	1400
Vermiculite	150-250	1100
Basalt wool	100	750
Clay brick	1600	700

In industry, linings perform much more practical functions than in everyday life:

• Reduces the temperature of external surfaces
• Protects furnace walls from thermal destruction
• Reduces heat loss
• Does not allow furnace materials to come into contact with chemical compounds or molten metals

Let's sum it up

Having familiarized yourself with the various features of arranging linings for various types of furnaces, you can safely get to work. However, neglect of the considered rules can significantly affect the reliability and durability of heating structures.

Source: https://otoplenie.site/sistema/chastnyj-dom/pechi/futerovka-chto-eto-takoe.html

Lined pipes

One of the areas among the production capabilities of the TechCo company is the lining of pipes and containers with polyurethane.

The peculiarity of polyurethanes is their exceptionally high physical and mechanical properties, which in some parameters are superior not only to all types of rubber, but also to metals. Compared with metals, they provide a reduction in product weight, reduced noise during operation, less intensive wear, and are not subject to corrosion. Polyurethane gives products such useful properties that are not achievable with conventional rubber.

Lined pipes are excellent for transporting highly abrasive ore slurries such as copper, phosphates, zinc, nickel, kaolin, gold, iron, manganese, tungsten chrome, titanium, magnesium, etc. They are also used for dewatering, wellbore filling, sludge removal, and tailings placement.

In order to order pipeline lining, send a request using the feedback form on our website.

Our company also produces tanks and containers for storing products for various purposes, and manufactures non-standard equipment according to customer drawings and requirements.

Advantages of lined pipe:

• Reliable protection of the metal base (pipe) from intense abrasive wear;
• Excellent abrasion resistance;
• Operability at temperatures from - 50 to 80 0C;
• Good ability to withstand high pressure;
• Provides resistance to hydrolysis, air humidity, weather conditions, ozone and microorganisms, good resistance to aging;
• Excellent performance in the presence of oil, hydrocarbon compounds, solvents, acids, alkalis;
• Are not subject to oxidation and minimize corrosion;
• High resistance to shear deformation and rupture;
• Increased permeability of the transported product due to increased sliding (smooth internal surface with a low coefficient of friction) and resistance to sticking;
• Increased pipe service life;
• Provides significant cost savings when replacing;
• The number of leaks (cases of depressurization) of the pipe is reduced;
• Environmental friendliness;

One of the areas among the production capabilities of NPP Unicom-Service LLC is polyurethane.

Lined pipes are excellent for transporting highly abrasive ore slurries such as copper, phosphates, zinc, nickel, kaolin, gold, iron, manganese, tungsten chrome, titanium, magnesium, etc. They are also used for dewatering, wellbore filling, sludge removal, and tailings placement.

In order to order pipeline lining, send a request using the feedback form on our website.

ADVANTAGES OF LINED PIPE:

• Reliable protection of the metal base (pipe) from intense abrasive wear;
• Excellent abrasion resistance;
• Operability at temperatures from - 50 to 80 0 C;
• Good ability to withstand high pressure;
• Provides resistance to hydrolysis, air humidity, weather conditions, ozone and microorganisms, good resistance to aging;
• Excellent performance in the presence of oil, hydrocarbon compounds, solvents, acids, alkalis;
• Are not subject to oxidation and minimize corrosion;
• High resistance to shear deformation and rupture;
• Increased permeability of the transported product due to increased sliding (smooth internal surface with a low coefficient of friction) and resistance to sticking;
• Increased pipe service life;
• Provides significant cost savings when replacing;
• The number of leaks (cases of depressurization) of the pipe is reduced;
• Environmentally friendly.

DIMENSIONAL DESIGN POSSIBILITIES:

Pipe lining

Lining pipelines with polyurethane is the best way to protect pipeline metal from the negative effects of transported materials, as well as the environment. To perform lining, pipes are divided into separate sections up to 10 meters long and flanges are mounted at the ends of the sections. Pipe lining is carried out both from the inside and from the outside.

The most reliable way to protect pipes from the inside is to install a polyurethane liner into the pipe. This liner is manufactured using special equipment and fixed inside the pipe using the hot-fitting method or using a special adhesive.

Lining of pipes from the outside can be done in several ways:

• Spraying a liquid polyurethane system onto the surface of a pipe with its subsequent polymerization
• Pasting the pipe with polyurethane sheets, fixing the sheets with adhesives and subsequent sealing of the seam

Lining the internal surfaces of pipes with polyurethane using aluminum oxide will increase the service life of the coating several times. Lined pipes provide maximum wear resistance compared to rubber lining, which reduces the cost of subsequent linings.

Production of wear-resistant polyurethane linings for almost any transfer or storage equipment: chutes, chutes, bunkers and trays.

Application of polyurethane lining:

Purpose	Advantages	Property of polyurethane
Abrasion protection	Reduced equipment repair costs, reduced downtime for frequent replacement of short-lived rubber/steel linings	Polyurethane has excellent resistance to abrasive wear. Test
Protection against material sticking and freezing	There is no need for constant labor-intensive mechanical cleaning or complex vibration mechanisms. Polyurethane is easy to clean.	Polyurethane has a low coefficient of adhesion and a smooth, non-porous surface. Test
Shock absorption, impact protection	Under conditions of a combination of abrasive wear and medium impact loads, polyurethane lining is more durable than rubber	Polyurethane has good elasticity and resistance to impact loads

Thus, in many cases, polyurethane lining has advantages over other lining materials:

• rubber lining
• lined with high molecular weight polyethylene
• steel lining
• lining made of stainless steel.

The use of polyurethane lining is especially effective when several problems combine, for example: wear and freezing of wet material on a steel or rubber lining, or wear and cracking of a plastic lining. Additional advantages of polyurethane lining over metal lining are reduced noise levels and low weight.

Types of polyurethane lining:

Lining type	Maximum lining dimensions	Lining thickness, mm	Lining installation method
1300 x 2300 mm (possibly larger on request*)	4-150 mm	Bolted connection, glue
Polyurethane on a flexible metal mesh base	1220x3050 mm	8-150 mm	Bolted connection
Polyurethane on a rigid metal base	1250x2000 mm	10-200 mm	Bolted connection, welding
no restrictions	1-20 mm	Sputtering

* Upon request, it is possible to produce linings in the form of large-sized polyurethane sheets with a thickness of 8 mm, including non-standard shapes. Used in cases where a seamless sealed lining is required. The length and width of such sheets is practically unlimited.

Scope of application of polyurethane lining:

We have accumulated significant experience in using polyurethane linings, and the most effective protection has proven to be on the following types of equipment:

• lining of chutes, chutes, ore passes;
• lining of bunkers, containers;
• lining of bodies of heavy-duty vehicles and mining dump trucks (with small material size);
• lining of vibrating trays, vibrating feeder trays;
• lining of screen decks;

Source: https://5geo.ru/lined-pipes/

What is Lining

Lining - 1. open
Same as: lining. 2. A facing layer of fire-resistant, chemically resistant and heat-insulating material, which covers the inner surface of metallurgical furnaces, steam boilers, ladles, etc.

Lining in the Encyclopedic Dictionary:

Lining - (from German Futter - lining) - protective internal lining (for example, from bricks, blocks) of furnaces, fireboxes, pipes, containers, etc. There are fire-resistant, chemically resistant and heat-insulating linings, and according to their chemical composition - acidic and main

The meaning of the word Lining according to Ushakov’s dictionary:

LINING
(te), lining, pl. no, w. (those.). 1. Action according to verb. line Furnace lining. 2. Internal lining, lining of chimneys, furnaces for melting metals, made of refractory materials.

The meaning of the word Lining according to the Brockhaus and Efron dictionary:

Lining - Furnaces in which metals are heated during various metallurgical processes are made of materials that ensure their strength and stability - brick, cast iron and iron. But all these materials are not able to withstand the high temperature at which these processes take place, the inevitable temperature fluctuations and the influence of the chemical reactions that accompany them.

In view of this, all working spaces of the furnaces that come into contact with metal or high-temperature gases are lined from the inside with a layer of fire-resistant and chemical-resistant materials, which protect the rest of the furnace from destruction. This internal fireproof clothing of furnaces is called their lining. For F.

Various rocks or clay are used, moreover, either in the form of individual stones (natural or artificial), or in the form of a plastic mass. All lining materials are divided into three classes: A) materials, the main part of which is silica. B) materials the main part of which is clay (hydrosilicate of alumina) and C) mixed materials not suitable for classes A and B.

Class A materials are: 1) natural (in the form of stones hewn from pieces of rock) and 2) artificial (in the form of bricks pressed from pre-crushed rocks). The following are used as natural stones: a) in the form of solid stones—sandstones, quartz, pudding (conglomerate)—for F. blast furnaces. siliceous shale - for fiery furnaces. granite - for stoves that do not develop the highest levels of heat.

b) in crushed form - ganister (quartz grains containing 1-7% Fe 2 O 2 and Al 2 O 3, bound by clay matter), which goes to F. Bessemer converters. Artificial siliceous F. is made in the form of so-called silica bricks.

To do this, finely ground, pure quartz is bound with 1-2% lime or clay substance and pressed into bricks, which are fired to white heat (fuel consumption is three times more than when firing ordinary building bricks). Under the influence of heat, these bricks swell somewhat, but under the influence of sharp temperature fluctuations, they crack easily.

Class B lining materials are used exclusively in their artificial preparation, since natural hydrosilicates of alumina lose water when heated. This type of material includes: a) bauxite brick.

To prepare it, natural alumina hydrate, containing an admixture of iron oxide and known as bauxite, is taken, fired, crushed, mixed with a small amount of water and fresh refractory clay, molded into bricks, which are fired again, and shrink significantly.

b) ordinary refractory (fireclay) brick, consisting mainly of refractory clay with an admixture of lean substance (burnt fireclay), which prevents drying out and cracking, to which clay is very prone. Fresh fireclay mass or ground fireclay bricks that have already been in use are mixed with enough fresh fireclay to form a thick dough.

For the sake of simplicity, sometimes quartz grains (the size of peas) are mixed into it, and in special cases - grains of graphite, coke or charcoal. An admixture of fine quartz flour, iron oxide, alkalis, etc. reduces the fire resistance of bricks. The following refractory materials belong to Class C: 1) basic heels, 2) coal bricks and 3) refractory mortars.

The main are partly iron oxides: ores, hammer scale, slags rich in iron oxide and (in modern times) chromium iron ore in the form of so-called chromium bricks. Practice has shown, however, that the degree of fire resistance does not compensate for the high price of the latter.

Bricks made of lime or magnesia, or both of these substances at the same time, are widely used as the main lining materials. dolomite is used for this purpose which is fired in cupola furnaces until white heat, at which point it begins to float.

After cooling, it is ground, sifted, mixed with 3-8% clay (previously dehydrated by boiling) and molded into bricks, sometimes used directly in the form of a plastic mass. Both the mass and the bricks are, however, subjected to a new firing before being used. Even more durable are magnesite bricks, made from magnesite fired until it melts, ground into flour and pressed on a hydraulic press.

The molded bricks are heavily fired. Magnesite mass (mixed for cohesion with tar, soluble glass, etc.) is used on the F. packing and directly. lime bricks for F. but they turned out to be unsuitable.

Coke turned out to be incomparably better , prepared as follows: dry coke, low in ash content, is ground into flour, mixed with tar or coal tar (up to 20%), stuffed into molds, and after removing from them, dried slowly (over two weeks) on low heat. heat and then fired in hermetically sealed muffles without air access. Taking into account its lightness, coke brick is no more expensive than fireclay and serves very well, except, however, in those cases when, due to the nature of the metallurgical process taking place, it is exposed (at high temperature) to the action of oxidizing gases, iron-rich slag or molten, carbon-poor iron. Refractory mortars used to fill joints when laying refractory bricks belong to the same class of lining materials. They are usually given a composition similar to that of the bricks themselves. For basic phosphorus, solutions are made from calcined dolomite or magnesite, cemented with resin, or from calcined, ground, sifted, and water-moistened magnesite. Sometimes dolomite milk or simply dry magnesite flour is used as a solution. Mortars for non- main stones are mixed with water from ground sand, lime, blast furnace slag, glass, fireclay, etc. The seams should be as thin as possible, for which purpose the bricks are carefully rubbed together before laying. In some metallurgical processes, furnace filtration not only protects the walls, under, and roof of the furnace working space from destruction by heat, but also itself participates in chemical reactions, helping to obtain a product of the desired qualities. V. Knabbe. Δ. .

Definition of the word “Lining” according to TSB:

Lining (from the German Futter - lining, lining)
is a protective internal lining of thermal units and their parts (furnaces, fireboxes, ladles, hogs, pipes, etc.), as well as chemical apparatus, pickling baths, etc.

It is made from bricks, slabs, blocks, concrete, ramming masses, etc. shotcrete mass. Depending on the purpose and type of material, F. can be fireproof, acid-resistant, or heat-insulating. F.

sometimes also called external protective cladding of unit elements, if heat flows, aggressive agents, etc. act on these elements from the outside.

Source: https://xn----7sbbh7akdldfh0ai3n.xn--p1ai/futerovka.html

Why is furnace lining needed in Suvorov and Suvorov-M boilers?

Lining buckets is the main method that significantly increases their service life. In most cases, it is simply necessary.

Protective lining is applied to the exterior and interior of attachments to protect them from heat. We are primarily talking about ladles used to pour steel. The lining also protects equipment from mechanical damage. Buckets of bulldozers and excavators especially need this.

Immediately after applying the protective lining to the attachment, it becomes clear how effective it is. This is especially noticeable in the example of buckets of machines working with stones.

Polymers/PE

The advantages of polymer lining include:

• speed.
• lightness of the material.
• eliminating sticking.
• surface tightness.

And the safety of the material allows it to be used to create tanks for the food industry.

It is applied for:

• body structures of transporting vehicles.
• various containers and pools, septic tanks.

Polyurethane/PU

Due to its high durability, it is used for gumming anti-corrosion surfaces in metal structures and brick buildings (as waterproofing).

After lining with PU, the structure becomes insulating due to the non-porous properties of the material. In addition, the substance has the following properties:

• strength,
• elasticity,
• resistance to UV rays.

It is used for boxes and chutes, buckets of loading machines, dump truck cabins, skips, concrete mixers, pipelines, hydrocyclones and scrubbers, electric centrifugal pumps, screen bottoms in:

• production of military and naval equipment;
• mining, oil and gas industries;
• approved for use in food industry factories.

Polyethylene/PE

If the main problem is not equipment failure, but the sticking of raw materials, then PE will be an excellent choice for gumming.

Due to the perfectly smooth plane of polyethylene sheets, as well as the low adhesion and good fastening, the material slides without difficulty and sticking becomes impossible.

Used for lining:

• bunkers,
• gutters,
• tanks for unloading,
• truck cabins,
• propeller blades,
• funnels in machines, various containers and elevators.

Compared to other facing materials, polyurethane lining lasts on average 5-6 times longer.

Metal furnace lining

The peculiarity of metal furnaces is that the thermal expansion rates of metals are not the same. Therefore, a small space must be left between the combustion and lining layers. This will prevent the protective layer from being destroyed when the size of the metal part changes.

In this space, special materials with non-flammable properties, such as asbestos or basalt wool, are usually placed. The use of asbestos is permissible only for structures located in non-residential premises. But there shouldn't be any air there.

To make a metal furnace as safe as possible, the boiler is often lined on both sides at once. Through this step, the best heating is achieved. But this point of view is partly correct. This is explained:

• High heat capacity of brick;
• Low thermal conductivity of brick.

This combination of properties is a guarantee that the heat will not escape beyond the firebox, and will subsequently be removed with the escaping smoke. But with double-sided lining of the furnace wall

begin to burn out due to lack of air necessary to remove thermal energy.

Therefore, a double-sided lining for a metal furnace is a measure for thermal insulation, not thermal protection. But cooled air masses must be able to flow to the combustion chamber.

The furnace lining is a necessary component of its long-term and safe operation. But it must be carried out in strict accordance with the basic rules and using high-quality and suitable materials.

Source: https://www.tproekt.com/cto-takoe-i-dla-cego-nuzna-futerovka-peci/

Subsea oil product pipelines

Work on drying, cleaning and insulating pipeline strands is carried out at the construction and installation site. Insulation and cleaning machines arriving at the construction and installation site must be carefully inspected, checked for completeness with working tools and checked at idle speed.

Before starting work, the insulation cleaning machine must be adjusted to the diameter of the pipeline being insulated. The insulation cleaning machine must be equipped with a device for removing static electricity from the surface of the insulating tape being wound and grounded.

The section of the construction and installation site along the path of the insulation cleaning machine must be planned so that there are no bumps, holes, stumps or other obstacles in the path of movement of its support wheel. To prevent damage to the edges of the pipe, you should use a special device in the form of a conical nozzle, which is fixed to the end of the pipe before installing the insulating cleaning machine on the pipeline.

Insulating tape in its original packaging must be transported to the construction and installation site in vehicles covered with an awning. Rolls of insulating tape and protective wrapping are not allowed to be thrown during loading and unloading.

Adhesive primer and solvents are transported in hermetically sealed barrels. It is necessary to store adhesive primer and solvents in separate rooms or under a canopy in compliance with fire safety rules for fuels and lubricants.

Insulating materials should be stored in places protected from the sun and precipitation at temperatures from -40° to +45° C. Rolls of insulating tape should be stored in a vertical position at the ends in no more than three rows. Insulating materials entering the site must be accounted for and labeled.

At air temperatures below +10°C, before carrying out insulation work, imported polymer tapes must be kept for at least 48 hours at a temperature not lower than +15°C.

Unpacking of rolls of insulating tape from the factory packaging should be carried out immediately before applying them to the pipeline at the construction and installation site.

The pipeline is cleaned and insulated using a self-propelled insulation and cleaning machine.

Reinforced insulation of pipeline strings with a diameter of 1220 mm or more with polymer tapes in two layers with protective material wrapping is carried out by a team of 13 people: a pipe-laying operator; cleaning machine operator; cleaning machine operator assistant; insulation machine operator; insulation machine operator assistant; insulator Labor productivity per shift is 254 m.

• laboratory testing protocol for insulating materials;
• magazine for the production of insulation work;
• act for acceptance of pipeline insulation work.

At air temperatures below +3°C, the pipeline surface is dried using a drying unit. The pipeline in front of the insulation machine is heated to a temperature of +15° - +45°C. A drying unit, for example type ST 1224, contains two ovens and is equipped with an autonomous, unified power unit. The furnaces are mounted on the pipeline sequentially and are connected to each other by an articulated joint. The front furnace is connected using an intermediate frame to a trolley suspension mounted on a pipelayer hook. The same pipelayer is used to tow the power unit of the drying unit along the ground parallel to the pipeline. Fuel and air are supplied to the furnaces from the power unit via flexible arms. The operating mode of the furnaces is monitored through the open ends. During normal operation of the furnace, the flame makes a full revolution around the pipeline, without leaving the ends of the furnace body. During the drying process, the combustion process is controlled and regulated, preventing soot from covering the surface of the pipeline. If there is moisture, snow or ice on the surface of the pipeline, the duration of stopping the drying unit should not exceed 1.5 - 2 minutes. If the pipeline overheats, the furnace burners are extinguished by closing the fuel valves of the drying unit. Thawed soil accumulates in the lower part of the oven. It is periodically removed with the scraper included in the installation kit.

Subsea pipeline lining

Lining of underwater pipelines is carried out in order to protect insulating coatings during transportation, installation of sections and when laying pipelines. The lining is made with wooden slats with a cross-section of 20÷50 mm on pipelines with a diameter of up to 426 mm and 30÷60 mm on pipelines with a diameter over 426 mm, the length of the slats is at least 2 m, or with lath-wire carpets. The lining can be continuous, in which the entire surface pipes around the circumference are covered with slats, and non-continuous, when the slats on the surface of the pipes are laid at intervals equal to the width of the slats. Depending on the methods of laying pipelines and their operating conditions, lining can be carried out along the entire length or in individual sections of the pipeline. When laying a pipeline by dragging along the bottom of trenches, the lining must be continuous along the entire length of the siphon, and when laying an unballasted pipeline using the free-immersion method, the lining can be not continuous and produced in separate areas, for example, in places where cables are attached, where damage to the insulation is possible. Slatted wire carpets are rolled into rolls before delivery to the construction site. If possible, the placement of rack-and-wire carpets and packages of racks along the pipeline, as well as clamps or wire twists for fastening the lining to the pipeline, is carried out directly from vehicles. When lining with rack-and-wire carpets, the pipeline is wrapped with this carpet every 60 - 100 s. When lining a pipeline The work is carried out using separate slats in the following technological sequence:

• slats are laid out on two ropes or belts made of technical rubber in an amount sufficient to cover 3/4 of the circumference of the pipeline;
• slats on rubber belts are brought under the pipeline, pressed against its surface, and after placing the rest of the slats under the belts, they are dispersed on the surface of the pipeline so that the slats rest along the pipeline with their ends;
• the slats are secured to the pipeline with wire twists every 1 m, the ends of the twists are tucked under the lining strip so that they do not unbend when pulled through;
• After installing the twists, the ropes or rubber belts are removed and used to line the next section.

During the lining process, the pipeline string is supported by a pipe layer, while slats are placed where the pipeline rests on pads.

Underwater pipelines at crossings within the boundaries of the high water horizon of at least 1% probability are designed to prevent ascent.

If the calculation results confirm the possibility of the pipeline floating, then the following is provided:

• on the channel section of the crossing - concrete coverings or special weights, the design of which should ensure their reliable fastening to the pipeline for laying a siphon by dragging along the bottom of an underwater trench;
• in floodplain areas - single loads or anchor devices.

Ballasting of subsea pipelines

Prefabricated reinforced concrete ring weighting material of the UTK type is made of B20 grade concrete with a density of 2.3 t/m3 and consists of two symmetrical half rings, which are mounted on a pipe along a wooden lining and fastened with steel bolts. Characteristics of UTK type weighting materials.

All ballast weights must be marked indicating the weight of the load in air and the volumetric mass of the material. The internal surface of reinforced concrete loads must be flat and smooth without any protrusions of concrete or exposed reinforcement that could damage the insulating coating.

Loading, unloading, storing and laying out half-rings of weighting materials is carried out by truck cranes or pipe-laying cranes using mounting loops. When storing, reinforced concrete elements of ring weights, sorted by grade and set, are placed on wooden pads 80 mm high and 100 mm wide. The pads are placed vertically next to the mounting loops, one on top of the other. Reinforced concrete elements are stacked in stacks no more than 2.5 m high.

Fasteners are delivered to the construction site before ballasting begins. In accordance with technical conditions and building codes, connecting elements must be painted with paints and varnishes of groups II and III or bitumen primer before they are installed in the structure.

Before ballasting begins, control weighing of 2-3 loads from each batch is carried out and a report is drawn up. In addition, check:

• availability of passports and certificates for ballasting weights;
• integrity of cargo and presence of mounting holes;
• marking indicating the volume and weight of ballasting weights.

The construction and installation site must be pre-planned. When installing weights on two or more strings, the distance between the strings must ensure the passage of pipelayers and vehicles for welding, installation and insulation work, as well as laying out weights.

Before ballasting the pipeline with prefabricated weights, the strings are numbered with paint and marks are made on the lining where the weights will be installed. The lower and upper halves of the weight couplings are laid out parallel to the prepared pipeline strands in two rows along the pipe axis. In practice, mainly two methods of weight ballasting are used.

When using the first method of ballasting, the pipeline string is lifted using a pipe layer and then, using any traction mechanism, such as a tractor, the half-coupling weights are placed under the places marked on the pipe. When using the second method of ballasting, the string is transferred using pipe layers to the lower halves of the load couplings, laid straight on the construction and installation site.

Before fixing the installed coupling halves to the pipeline, check the size of the gap between the lining and the pipe and, if there are gaps of more than 5 mm, place additional slats of the required size under the inner surface of the coupling halves.

For alignment, metal rods are placed in the bolt holes of the upper coupling halves during installation, which, when lowering the upper coupling halves onto the pipe, enter the corresponding holes in the lower coupling halves. After alignment is completed, the rods are removed, the upper and lower halves of the weight couplings are connected to each other with bolts and nuts.

After tightening, the bolted connections are coated with paints and varnishes of groups II and III or bitumen primer.

Concreting of underwater pipelines can be carried out in the following main ways:

• concrete coating of individual pipes under basic conditions;
• concrete coating of the pipeline with a monolithic reinforced concrete coating using formwork in the field.

Concrete coating of a pipeline in the field is carried out in two stages: first, the areas between the layings are concreted, then, after removing the formwork and end caps, the remaining sections are concreted. Acceptance of finished concrete-coated pipes is carried out based on the results of incoming, operational and acceptance inspections.

When accepting finished concrete-coated pipes, the following is controlled:

• appearance;
• geometric dimensions of reinforced concrete pavement;
• concrete strength; concrete density;
• weight of concrete pipe;
• crack opening width;
• correct application of markings;
• waterproof for pipelines operating in aggressive environments.

Source: http://proofoil.ru/Underwaterpipeline/Underwaterpipeline28.html

Lining of PTFE pipeline parts: what is important to know about this

Comprehensive pipeline protection is one of the most popular services. You can protect pipes from any damage, environmental influences and chemicals using conventional fluoroplastic lining. Now many companies offer this service, so industries have plenty to choose from.

Process Features

Classic lining with fluoroplastic is not a difficult job. In general, a specialist simply applies a certain composite to those areas of the product that he must protect from exposure to an aggressive environment and damage. It is worth noting that such a procedure can be ordered both for completely new pipeline parts and for products that have already been in use for some time and have become unusable.

In order to restore parts, you do not need to specifically hire a specialist who will do the repairs. Few people know, but the composite partially restores metal products, so using fluoroplastic in your practice is very profitable.

This material helps to restore the functionality and consumer properties of any part, as well as extend the service life without new breakdowns and destruction for a relatively long period.

How is the PTFE lining procedure performed?

This is a fairly simple procedure that can be quickly completed by a specialist. When lining a pipe with fluoroplastic, the master reliably protects the metal product from moisture getting into it and the development of corrosion processes. Pipe lining also protects the metal from the effects of various chemical reagents.

As a result, the procedure gives the following results:

• dielectric permeability;
• resistance to the lowest and highest temperatures from -190 to +260 degrees;
• partial or complete restoration of the functionality of the product;
• improvement of pipe characteristics;
• extension of service life.

Increasingly, various companies or private customers are using PTFE linings from an advantageous point of view, since they make it possible to put both new and old equipment into use for many years.

In addition, lining significantly saves money and time on replacing damaged or completely broken equipment that can no longer be restored.

You can be 100% confident in products that can be lined, since specialists guarantee complete operational reliability, strength, high pipeline efficiency and good quality.

Main characteristics of fluoroplastic

Fluoroplastic is a very convenient and beneficial material for lining, which has high resistance to chemicals, low wear rates, non-flammability and dielectric properties. PTFE is not afraid of high temperatures, so pipes with this coating can be used in absolutely any conditions. As a rule, lining with fluoroplastic is carried out in industries in the form of molding, spraying, gluing to pipe walls, and free installation.

As a rule, if the master knows that lined pipes will be used at low temperatures. He simply glues a sheet of fluoroplastic to the metal. However, it is necessary to use high-quality glue with high resistance to chemicals and temperatures.

Places for attaching fluoroplastic may be different. Everything depends on further operating conditions, but the properties are the same. This is wear resistance, immunity to chemicals and temperatures. Such protection of pipes will help extend their service life and avoid problems with restoration.

If you are interested in a good result, consider our information.

Source: https://skyprom.ru/news/futerovka-detaley-truboprovoda-ptfe-chto-ob-etom-v/

Lined pipelines

Pipeline sections lined with polyurethane (pipes, bends, fittings) are designed for moving abrasive and chemically aggressive materials in gravity and pressure pipelines.

Main characteristics of polyurethane coating:
1. Anti-corrosion layer.
2. High resistance to mechanical damage.

3. Highly resistant to chemicals, electrical damage, humidity and ultraviolet rays, and does not age in various environments.

4. Ideal anti-adhesion of the protected surface.5. Environmentally neutral.6. High resistance to abrasion - much higher than that of steel pipes.7. High elasticity and resilience of the composite reduces the power of water hammer.8. Low thermal conductivity reduces the need for thermal insulation.9. Reduces maintenance costs due to an increase in the service life of the pipeline several times.

10. Reducing noise during transportation.

Purpose of polyurethane lining: 1. Reducing slip resistance due to the low roughness of the polyurethane lining.

2. Reduces the drop in gas and liquid pressure, which increases the efficiency of pipeline transportation.

3. Excellent anti-corrosion coating.

4. Reduced contamination such as rust, no sediment, which is a problem for unprotected pipes.
5. Significantly lower weight compared to steel or cast iron (6 times lower).

     Lined pipes are excellent for transporting highly abrasive ore slurries such as copper, phosphates, zinc, nickel, kaolin, gold, iron, manganese, tungsten chrome, titanium, magnesium, etc.

They are also used for dewatering, wellbore filling, sludge removal, and tailings placement.

     Lining pipelines with polyurethane is the best way to protect pipeline metal from the negative effects of transported materials, as well as the environment.

     To perform lining, pipes are divided into separate sections up to 10 meters long and flanges are mounted at the ends of the sections.

Pipe lining is carried out both from the inside and from the outside.

Lining of pipes from the outside can be done in several ways:

• Spraying a liquid polyurethane system onto the surface of a pipe with its subsequent polymerization,
• Pasting the pipe with polyurethane sheets, fixing the sheets with adhesives and subsequent sealing of the seam 
• Lining the internal surfaces of pipes with polyurethane using aluminum oxide will increase the service life of the coating several times.

Lined pipes provide maximum wear resistance compared to rubber lining, which reduces the cost of subsequent linings.

Pipeline elements lined with polyurethane

Source: https://sibkraspolimer.ru/rukava/truboprovody-futerovannye.html

What is a furnace lining and why is it needed?

Furnace lining

To find out what a lining is and why it is needed, you need to understand that in any furnace, when fuel is burned, a high temperature is generated. Exposure to high temperatures leads to changes in the structure and properties of the material. The materials from which the stove is made, although most are fireproof, also need protection.

External, internal protection

Protecting the internal walls of the firebox can be done in several ways:

• Firstly, you can use protective screens that can absorb most of the radiant fluxes. The screens installed inside the firebox affect the heating of the flue gases, so most of the heat will be removed through the chimney.
• Secondly, the inside of the firebox can be lined with fire-resistant, low-thermal conductivity material.

Thermal protection and thermal insulation - there is a difference

There is a huge difference between thermal protection and thermal insulation principles. With thermal insulation , the heat generated in the work area is not removed anywhere. This is what thermal insulation is for.

In contrast, thermal protection is designed to protect a specific area from the thermal radiation of the working area. From all that has been said, it becomes clear that thermal protection is not at all intended to preserve heat.

Fireclay brick

Fireclay brick

If external protection in the form of a screen in heating boilers, the use of this method will be very wasteful, since most of the heat will be spent completely in vain. But this method is perfect for installing sauna stoves.

Previously, under the USSR, most private owners were familiar with simple building brick GOST 530-95 . This brick is intended for the construction of industrial and residential buildings and in no way for use in furnaces and heating boilers. By the way, many still use it to build furnaces and boilers.

Many craftsmen at that time managed to get a brick of this GOST, but of a higher grade M - 300 , in the popular expression “kiln”. This brick lined the furnace part of the furnaces to protect against high temperatures.

Later, fireclay bricks GOST 390–96 .

Our information: fireclay materials are made from clay mixed with fired clay powder and then fired at high temperatures.

The use of fireclay is the lining

Due to the fact that all fractions have a homogeneous chemical composition, all fireclay products have a high degree of heat resistance and do not crack when exposed to high temperatures.

Lining the combustion part with fireclay material to protect the heating unit from the effects of high temperature in the combustion part is called lining.

Manufacturing lining and material properties

In production, in metallurgy, the lining of an induction furnace is made using special, pressed fireclay bricks. They are very wear-resistant, do not shrink and withstand thermal shocks well. The use of fireclay bricks made it possible to achieve great cost savings and greatly reduce the cost of the metal production process.

Induction oven

Induction oven

The table shows the properties of some refractory materials

Material	Density kg/m3	Maximum operating temperature °C
Chamotte	1800-2000	1300
Clay brick	1600	700
Vermiculite	150-250	1100
Basalt wool	100	750
Kaolin is dense	2400-2500	1400

Household problems - lining as a solution

In everyday life, people usually have to solve simpler problems. At the very last stage, the burning of the coals, the bottom of the metal stove overheats, sometimes red hot. A man decides to cover the overheating wall from the inside with his own hands.

But even in this case, you have to decide to what level to lining, whether to leave a gap and how to secure the bricks?

Specifically in this situation, the issue can be resolved as follows:

• If the width of the firebox allows, fireclay bricks of a standard size are laid along its perimeter - 250X150X65 mm. In this case, the brick is laid flat against the wall. Can be laid vertically with a height of 250 mm or horizontally with a height of 120 mm.
• In order to securely fix the bricks together, a simple method is used. Using a grinder, a cut is made in part of the joint, and the bricks are held together using an inserted metal spike of a suitable size.

Lining device: temperature and metal

Particular attention should be paid to the fact that the thermal linear expansion of metal is much greater than that of brick. Therefore, all metal parts exposed to heat must have free space for expansion.

Our information: the absence of a gap between the metal wall of the furnace and the lining leads to destruction of the lining.

When installing this lining, the gap is sealed with basalt or kaolin wool, twisted into bundles, cords or in the form of a compressed sheet. Asbestos can be used for this purpose.

Wrong defense. Consequences

This picture occurs very often. The metal stove is lined with bricks using clay mortar, and without any gap. This is motivated by ensuring safety and improving the heating of the furnace.

Metal stove with brick lining

This is completely misleading!

• Firstly, brick is very heat-intensive .
• Secondly, brick has low thermal conductivity . What happens during operation of such a furnace?

The brick simply plays the role of thermal protection.
The main heat generated by the stove simply flies out into the chimney due to excess in the firebox. In addition, the absence of a gap prevents the penetration of cooling air to the metal walls of the furnace, which definitely leads to their burnout, and the expansion of the metal will lead to cracking of the brick protection.

As a result, carbon monoxide will begin to enter the room.

Not always brick: lining mixtures

Recently, “modeled” sauna stoves of various shapes have become very popular. Basically, such stoves are installed in bathhouses made in a stylized “fairytale style”. Such stoves are made using an ancient method called adobe.

After the clay has dried naturally, the oven is fired from the inside using firewood. The outer part is burned using blowtorches until a crust forms. It is very convenient to line such furnaces using special compounds.

These can be dry mixtures:

• Fireclay.
• Mullite.
• Corundum.

These compositions can be perfectly used for the on-site production of various refractory products, including linings. A solid, monolithic lining made from these materials far exceeds in quality seam furnace linings made with fireclay bricks.

On-the-job lining

Currently, there are a number of technologies in which lining or restoration of the lining is carried out without stopping the furnace. The compositions are applied by “spraying” directly onto a hot surface or by gunning.

Our information: shotcrete is a method in which concrete or other mixture is applied layer by layer to a structure using compressed air and a special shotcrete installation.

This method is mainly used in production, which allows lining work to be carried out, if necessary, without stopping the production process.

Brick kiln: problems with overheating

We have already considered the need for lining the combustion part of metal stoves, but what about brick stoves? What happens to brick kilns when they are overheated?

Cracks in a brick kiln

There is a concept - thermal cracking . This phenomenon applies both to the material of the stove itself and to its seams.

• The inner walls of the furnaces, heating up from the hot gases produced by the burned fuel, expand and begin to expand the outer “cold” walls.
• The outer walls of the furnace act as a “bandage”, maintaining the dimensions of the furnace and maintaining its integrity.
• The more the oven heats up, the thinner the “bandage” becomes, which is already under heavy loads, and therefore becomes even less durable.
• When the furnaces “overheat,” the outer walls begin to “move apart” under internal pressure.
• Cracks form and even individual bricks break.

Local solution: main disadvantages

It is worth noting that in a brick kiln clay is used to connect the bricks together. Therefore, either the seams themselves or the contact with the bricks rupture due to low adhesion. In any case, a seam in which a mortar with a high sand content was used will expand significantly more than a brick.

This situation is further complicated by the fact that the thermal coefficients of bricks and joints generally differ greatly from each other. This is understandable, because the bulk of the furnace solution is prepared directly on site. Stove makers primarily strive for the plasticity of the solution to the touch and the absence of cracking when drying and compressing.

Our reference: the correct assessment of the mortar for compliance with the bricks used can be checked as follows. Two bricks are held together with a solution; after drying, the test block is calcined in an oven, followed by an assessment for adhesion, cracking and peeling.

Methods and options for preparing the right solutions

Of course, this method requires a certain amount of time, because it is not a fact that you will get the required solution the first time.

Therefore, if you still decide to use this testing method, prepare several “blocks” for testing with different solutions. Then all you have to do is choose the most optimal one. The main thing is not to confuse and forget which solution is which.

Another good option is to use the most common clays for the solution, mixed with powder made from ground bricks.

If you use only firewood when burning, the use of special fireclay clays with a high content of kaolinite is not entirely advisable, since the temperature of the firewood is not sufficient for kaolin to sinter into mullite. But if you use coal, then this option will be completely justified.

Lining: no more questions

Having considered this issue, we can conclude that the lining of stoves used for domestic purposes mainly represents protection of the stove structure from the destructive effects of high temperatures. This is a kind of screen that prevents the heat flow of an open fire from directly affecting the walls of the stove.

Unlike “household” linings, industrial linings, for example, the lining of an induction furnace, are intended to significantly reduce heat losses, protect the furnace casing from direct exposure to high temperatures and protect against direct contact with molten metal.

Having considered this issue, we hope you will draw the right conclusion, which will help you when building stoves with your own hands.

Source: http://SdelaiKamin.ru/uhod-za-pechyu/futerovka-pechi-chto-eto-i-dlya-chego-115