RU2509795C1 - Method of heating refractory masonry coke furnace battery - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry, particularly to coke chemistry and enables to put into operation the main coke furnace battery when building new coke chemical plants when it is impossible to heat the first (main) battery with coke gas. The method involves feeding heating gas into coke furnace chambers, heating and switching to heating on a constant scheme until intrinsic reverse coke gas is obtained. The battery has bottom or lateral supply of heating gas, the heating gas used being re-gasified liquefied propane-butane gas. Furnace burners are fitted with a screen and are mounted in the temporary inner hearth of the coke furnace with on the machine and coke side of the battery. Air is fed into the hearths through movable screens mounted on hearth windows which are made on the front of the temporary inner hearths or in pre-mounted doors of the coke furnaces. When switching to heating on a constant scheme, upon achieving temperature of guaranteed ignition of the propane-butane gas in all vertical flues, propane-butane gas is fed into a permanent coke gas distributing pipe which is temporarily shutoff from the reverse coke gas supply gas pipe through a pre-installed nozzle with a slide valve, said propane-butane gas being mixed with air fed from a bottom tunnel into units for feeding heating gas into each vertical flue or gas-feed channel.

EFFECT: invention reduces consumption of heating gas, provides uniform heating of the refractory masonry of coke furnace batteries with a limited choice of heat carriers without using external hearths and with the possibility of mounting coke furnace doors before heating begins.

1 tbl, 7 dwg

Description

Technical field

The invention relates to the field of coke chemistry, and can be used for heating and commissioning of coke oven batteries using liquefied propane-butane. The heating of the coke oven battery with liquefied gas (propane-butane) is mainly used when commissioning the lead (first) coke oven battery at a single enterprise, while there are either no other gas supply sources for heating, or they are not available in sufficient quantity. The method provides for the possibility of conducting heating through pre-installed doors of coke ovens, as well as switching the coke oven battery to heating with propane-butane gas according to a constant heating scheme, which greatly simplifies preparatory and commissioning work for putting the battery into operation, reduces the consumption of heating gas (propane-butane) .

State of the art

In the construction of coke oven batteries, refractory materials such as dinas and fireclay are used, which together with high thermal conductivity have a large coefficient of thermal expansion. When dinas is heated from ambient temperature to operating temperatures, the level of which is from 1150 to 1450 ° C, modifications of quartz (silicon dioxide, SiO ₂ ) pass from one to another with a change in the crystal lattice and volume of the product. The change in volume can be from 0.1% to 3.0%. Structural transformations of quartz in dinas products occur in the temperature range 117 ° C, 163 ° C, 230 ° C, 573 ° C, 870 ° C and can violate their strength. At a large thermal expansion of dinas at the stage of low-temperature (below 300 ° C) transformations of quartz and its modifications (tridymite and especially cristobalite), dinas is thermally unstable. These circumstances require the use of a special heating technology that allows you to strictly maintain the specified technological mode for raising the temperature of the refractory masonry of coke oven furnaces. Depending on the modification (phase-structural) degenerations of the dinas, the average daily temperature increase of the refractory masonry should be strictly observed according to the stages of heating. Depending on the particular warm-up phase, it is approximately 5 to 50 ° C per day.

After the completion of the construction of coke oven batteries or after major cold repair (reconstruction), it is required to heat their refractory masonry to operating temperatures. Different types of gases can serve as fuel for heating a coke oven battery: coke oven, natural, blast furnace, generator. During the construction of new by-product coke plants, when it is not possible to heat the first (head) coke oven battery with coke oven gas, it is proposed to heat and transfer to a permanent heating circuit with natural or liquefied gas (propane-butane) before starting up the battery (loading it with coal) and before receiving its own ( reverse) coke oven gas.

The use of the option of heating and further heating according to the constant scheme of the coke oven battery with liquefied gas (propane-butane) with its preliminary mixing with air and supplying the gas-air mixture to the gas supply pipelines when a pre-prepared gas-air mixture is fed to the burner is dangerous and difficult for the following reasons:

- 2-3 degrees of protection against an explosion of the installation and supply pipelines are necessary in case of violation of the gas-air mixture ratio;

- the option of diluting propane-butane with inert gases to achieve complete combustion of the gas mixture is very costly due to the high cost of these gases;

- requires a complex and expensive system for preparing a gas-air mixture and protection against cases of flame penetration deep into the burner or flame separation;

- the cost of the gas transportation system rises due to the increase in the diameters of the pipelines of the gas-air mixture in comparison with the diameter of the pipelines of the gas itself.

Starting up the first (head) coke oven battery at the plant after warming up without first transferring it to a permanent heating circuit is much more complicated due to the combination (in time) of the last heating stage with testing of coke oven machines and equipment, and the completion of a large amount of pre-commissioning work. Over a short period of time, a number of responsible actions are combined, such as: breaking the camera mirrors and removing temporary fireboxes, installing coke oven doors, installing plugs in the heating holes, loading the furnaces with a charge, purging the gas path with the gas blower in operation, transferring the battery to constant heating with a small and unstable amount of reverse coke oven gas. All these operations are performed when heating is carried out according to the temporary scheme of furnace loading (until they are transferred to constant heating). At the same time, 14-16 furnaces prepared for the first load are not included in the heating at all, but are loaded with coal and are included in the heating only after receiving the return gas (after switching to constant heating). Part of the accumulated heat of these furnaces is lost when disassembling temporary furnaces and installing doors before loading them with coal, which significantly reduces the masonry temperature during loading, reduces the rate of gas evolution from the first loaded furnaces, complicates the start-up of gas blowing and transferring the battery to a permanent heating circuit with its own ( reverse) coke oven gas. During these starting operations, breakdowns, breakdowns on coke oven machines and equipment, failures in the gas blower and gas path can lead to a risky, critical situation associated with a shortage of gas for purging gas pipelines and transferring the battery to constant heating with its own (reverse) coke oven gas.

The difficulty of heating the battery according to a permanent scheme with clean (not diluted with air) high-carbon gases (including propane-butane) lies in the fact that when they are heated in incandescent gas ducts (at a temperature of 800 ° C or more): corneas, upper zone the nozzle channels and burners are decomposing with intensive deposition of soot graphite on the surface of the elements, which leads to their rapid clogging of the heating channels and, consequently, to the heating failure.

A known method of heating furnaces using internal gas burners.

For example, a method is known for drying and heating vertical chamotte and dinas chamber shale furnaces (SU 136508, 1961). The method involves heating the furnaces using an injection gas burner installed in the lower part of the chamber.

However, the known method cannot provide a safe and high-quality heating of the coke oven battery, for example with propane-butane, since at minimum gas flow rates at the initial stage of heating, when air injection due to a gas jet is not provided within the limits necessary for high-quality and complete (smokeless) combustion of the heating gas , soot clogging of the nozzles of the regenerators occurs and the disorder of the battery heating process.

A known method of heating the refractory masonry of a coke oven battery using a gaseous heat carrier, the use of compressed air is recommended, the heat carrier is supplied to the heating channels and heat is heated by heat exchange between the hot nodes of the coke oven battery, and the masonry is heated using a gaseous heat carrier to a temperature of 250 ° C during high-altitude masonry, and the heating of new heating channels is carried out to a temperature of 500 ° C directly but after the completion of the construction of masonry (RU 2062282, 1996).

The known method is inconvenient to use, since partly heating has to be done in the repair process, partly in the process of laying the furnace.

Disclosure of invention

The objective of the present invention is to ensure uniform heating of the refractory masonry of coke oven batteries (with a limited choice of coolants) with regasified propane-butane, without the use of external furnaces and the possibility of installing doors of coke ovens before heating. Subsequent transfer to heating according to a constant scheme is carried out with propane-butane gas until the battery is started (loaded with coal) and its own (reverse) coke oven gas is obtained, using a safe method of mixing propane-butane gas with air to obtain a mixture of the required calorific value.

The technical result of the present invention is the commissioning of the lead coke oven battery during the construction of new coke oven plants when it is not possible to heat the first (lead) battery with coke oven gas, reduce the consumption of heating gas, ensure uniform heating of the refractory masonry of coke oven furnaces with a limited choice of heat carriers without the use of external furnaces and with the possibility of installing coke oven doors prior to heating.

The claimed technical result is achieved in that the method of heating the refractory masonry of the coke oven battery, comprising supplying heating gas to the chambers of the coke ovens, heating and switching to heating according to a constant circuit to obtain its own reverse coke oven gas, according to the invention, characterized in that the battery is made with a lower or with a side supply of heating gas, regasified liquefied propane-butane gas is used as heating gas, while the burners of the furnace are equipped with a screen and are installed in a temporary the first furnace of the coke oven from the machine and coke sides of the battery, through the kindling window made in the facade of the temporary internal furnace or in the pre-installed door of the coke oven, air is supplied to the furnace through movable dampers installed on the kindling windows the circuit, upon reaching the temperature set for loading the coal charge chambers, the constant distribution coke oven gas pipeline is temporarily discharged from the inlet coke oven gas supply pipeline, and to dividing previously set through the pipeline choke valve is supplied with propane-butane gas, which is mixed with the feed air from the bottom of the tunnel.

The problem is solved by the described method, including the supply of heating gas to the chambers of coke ovens according to a temporary scheme, heating in accordance with a given temperature regime and switching to heating according to a constant scheme to obtain its own (reverse) coke oven gas. At the same time, liquefied propane-butane is used as heating gas. The liquefied gas is first subjected to regasification in an evaporator-heat exchanger, then it is supplied to the burners, each of which is provided with a screen, and is installed in the temporary internal furnace of each coke oven on the machine and coke sides of the battery. Through a kindling window made in the facade of a temporary internal firebox or in a pre-installed door of a coke oven, a regulated air flow is supplied into the firebox in an amount necessary for stable combustion of a propane-butane gas torch during the entire heating process. The amount of air supplied to the furnace is regulated by means of movable dampers installed on the kindling windows and providing the possibility of changing the area of the through section of the kindling window during heating. The set temperature mode of heating is maintained by regulating the draft of the furnace and the flow rate of propane-butane gas supplied to the burners. Upon reaching the temperature of guaranteed ignition of propane-butane gas in all verticals, the permanent (design) distribution coke oven gas pipeline is temporarily removed from the supply coke gas return pipeline, and propane-butane gas is supplied to the distribution gas pipeline through a previously installed fitting with a valve. On a battery with a lower gas supply, in the lower plugs of each crosspiece, vertical holes (into each nozzle channel) are drilled to supply gas from the lower tunnel to the crosspiece (under natural vacuum in the heating system) to mix it with propane-butane gas . For this purpose, metal plates with calibrated holes are temporarily installed on the battery with a lateral gas supply for the purpose in the screening windows. An appropriate hydraulic mode is established in the heating system, which provides the necessary vacuum in the crosspiece of the nozzle channel (also in the cornea on the battery with side gas supply) for air intake from the tunnel for mixing with gas.

When using the option of conducting heating through pre-installed doors of coke ovens, a significant reduction in the volume of work and the need for materials is achieved - primarily due to the execution of temporary internal furnaces without facade walls, and the preparatory and start-up work performed after heating the battery is greatly simplified due to there is no need for disassembling the front walls of temporary internal fire chambers and synchronous installation of doors on heated stoves. When conducting heating through pre-installed doors of coke ovens, the consumption of heating gas (propane-butane) is reduced by reducing heat loss through the doors of coke ovens, compared with heat losses by the front walls of temporary internal furnaces along the front of the chambers, as well as reducing the volume of heated refractory masonry from -for the lack of front walls of temporary internal fire chambers. Since the main elements of the doors of coke ovens are made of cast iron and, therefore, are not subject to temperature deformations and wear in the operating temperature range, no negative consequences on the technical condition of the doors of coke ovens are possible.

Preferably, the heating is carried out for 65-70 days to a temperature of 1000-1050 ° C.

Preferably, the rate of temperature rise during heating is in the period of the first 32 days 5.5-6.5 ° C per day, in the period of 33 to 35 days 9 ° C per day, in the period of 36 - 39 days 12 ° C per day, during the 40s - 44 days 15 ° C per day, during the 45s - 47 days 18 ° C per day, during the 48s - 50s days 21 ° C per day, during the period 51st - 59th days 24 ° C per day, during the 60s - 62nd days 32 ° C per day, in the period 63-64 days 36 ° C per day and further at a rate of 48 ° C per day until the temperature (~ 800 ° C) is reached, which is necessary for the possibility of switching to heating according to a constant scheme.

In order to use propane-butane gas in heating according to a constant scheme, it must be safely diluted with air to a calorific value of 3500-4000 kcal / m ³ , which corresponds to a volume content of 13-15% propane-butane gas and 87-85% air in the mixture (upper limit explosive concentration of propane-butane gas mixed with air is 8.65% vol.). As an option for such safe dilution, mixing propane-butane gas with air directly at the entrance to each nozzle channel (at the crosspiece of the nozzle channel) on batteries with a lower gas supply, and at the entrance to the corneum (in the riser in front of the cornea cannon) on batteries is proposed. with lateral gas supply.

The claimed method can be implemented, for example, using devices, the design and installation diagram of which is illustrated below.

Brief Description of the Figures

Figure 1 - temporary internal firebox, laid out of fireclay bricks inside each coking chamber of a heated battery (option without installing the doors of coke ovens);

Figure 2 is an embodiment of the use of a coke oven door instead of a front wall of a temporary internal firebox;

Figure 3 - burner for burning propane-butane gas in the internal furnace, installed in each furnace from the machine and coke side of the battery;

Figure 4 - burner with a screen mounted on it, made in the form of a stainless steel mesh;

Figure 5 - movable damper that regulates the air supply, placed in a kindling window made in the front wall of the temporary internal firebox in front of each burner;

6 is a General view of the gas supply unit for heating the furnace through the kindling hole in the front wall of the temporary internal firebox;

7 is a General view of the site of mixing propane-butane gas with air when heated according to a constant scheme on batteries with a lower supply of heating gas.

General detailed description

In each particular case of heating, the following process parameters are calculated depending on the volume of the refractory masonry and the number of furnaces in the coke oven battery:

- heating gas costs for the heating stages (for one burner and for the whole battery, calculated on the basis of the known need for energy consumption to maintain a given temperature increase and calorific value of liquefied propane-butane);

- diameters of the supply and distribution pipelines within the entire unit;

- diameters of the burner pipes;

- calibrated cross-sections for supplying propane-butane gas to the sub-wall collectors and from these collectors to the crosses of the nozzle channels (on batteries with a lower gas supply) or to the corners (on batteries with a lateral gas supply);

- openings for air in plugs of crosspieces (on batteries with a lower gas supply) or in windows of degraphization (on batteries with a lateral gas supply);

- hydraulic mode in the heating system, providing the necessary vacuum in the crosspiece of the nozzle channel (on batteries with a lower gas supply) or in the cornea (on batteries with a lateral gas supply) for air intake from the tunnel for mixing with propane-butane gas during heating according to a constant scheme ;

- diameters and number of holes in the perforated part of the burner.

With appropriate calculations, the necessity of heating the chimney to create traction and discharge in the side burs of the battery is also taken into account.

At the preparatory stage, a warehouse is being built to store the required amount of liquefied propane-butane and its regasification unit, including evaporator-heat exchangers for transferring the coolant from a liquid to a gaseous state. Manufacturing of auxiliary devices and equipment, including burners and dampers. The masonry configuration of the temporary internal firebox does not depend on the type of coolant used.

A general view of the masonry of the temporary internal firebox is shown in figure 1, while under pos. 1 the hearth line of the furnace is indicated, pos. 2 is the arch line of the furnace. The kindling windows of pos. 3 are made with the maximum possible, based on the structural features of the stoves of a particular battery, the area of the passage section. In this case, the kindling window of pos. 3 can be made directly in the door of the coke oven, which closes the chamber after completing the masonry of the inside of the temporary furnace, as shown in Fig. 2. In this case, the masonry of the front part of the temporary firebox is not performed, the cast-iron door casing, pos. 4, is made with a heating hole, pos. 5, which, after completion of the heating process, is closed with a cast-iron lid. A hole is made in the lining of the coke oven door, which in its dimensions corresponds to the kindling window, item 3, and after the completion of the heating process, this hole is laid with refractory brick.

At the stage of preparatory work, a temporary gas supply pipeline for gas supply for heating the battery from the regasification unit to the chimney and to the battery from the machine and coke side is mounted. Burners of a special design are installed in the furnace of the coke oven battery through the windows provided for them in the internal furnaces or in the doors of the coke ovens pos. 3.

The implementation of the method is illustrated below.

The design of the burner used, illustrated in figure 3, is quite simple and is a welded structure of pipes of various diameters.

Heating gas (propane-butane), from a temporary gas pipeline, through a gas outlet from a temporary gas pipeline, pos.6 enters the main burner pipe, pos.7, located along the axis of the coking chamber and connected to the outlet through a flange connection pos.8. In the main pipe pos. 7, at an acute angle to its axis, parallel to the plane of the coking chamber hearth, two outlet pipes of a smaller diameter, pos. 9, are welded, which serve to supply gas directly to the gas outlet pipes, pos. 10, which are parallel to each other and perpendicular to the plane of the hearth coking chambers. In the gas outlet pipes, item 10, coaxially drilled, in a row, one below the other, small-diameter gas outlet holes, item 11, so that the jet of exhaust gas is directed towards the axis of the main pipe, item 7. At the same time, at the free ends of the main pipe pos. 7 and exhaust pipes pos. 10, plugs pos. 12.1, pos. 12.2 are hermetically welded.

Through the kindling window, item 3, a directed air flow enters the firebox, which, as it were, cuts the gas jets of the burner, and provides the mixture of gas and air required for high-quality combustion due to the intersection of the air flow with gas jets.

On each burner, after its installation in the coking chamber, before starting heating, the screen pos.13 is hung, which is a rectangle of metal mesh (preferably stainless steel) bent in three places so as to lean under the force of its own weight in the poses closed by caps. 12.1, pos. 12.2 the upper ends of the exhaust pipes of the burner pos. 10 and press against both exhaust pipes of the burner pos. 10 from its front side below all the gas outlet openings pos. 11. With this arrangement, during heating, the screen will be constantly in a red-hot state from the burning torch, and if the torch unexpectedly goes out (is blown out), the propane-butane gas stream will ignite again in contact with the red-hot screen grid and combustion will resume. The required level of air flow, at which sufficient air is supplied from the external environment for stable flame burning, is ensured by closing the kindling windows of pos. 3 in the internal furnaces or in the doors of coke ovens with movable shutters separately shown in Fig. 5. In the masonry of the facade of the temporary fire chamber, between the rows of bricks forming the lower and upper borders of the kindling window, item 3 (or above the upper and lower edges of the hole item 5 in the cast iron casing of the door of the coke oven pos. 4), the upper guide pos. 14.1 and lower support-guide pos. 14.2 metal corners. In this case, between the upper and lower corners of pos. 14.1 and pos. 14.2, respectively, two symmetrical gate leaves are installed - the left pos. 15.1 and the right pos. 15.2, which are metal sheets with slots made in them under the main burner pipe, pos. 7 and welded handles . Thus, both flaps abut from the bottom in the reference-guide angle pos. 14.2 and together with it are fixed vertically by the guide angle pos. 14.1. Thus, each leaf receives one degree of freedom in the form of horizontal movement (in the plane adjacent to the front of the temporary firebox, or in the plane adjacent to the front of the heating hole, pos. 5 in the cast-iron door casing, pos. 4) with a change in the area of the passage section of the kindling window and the corresponding change in the flow of atmospheric air supplied to the temporary firebox.

During the heating process, the set temperature mode is maintained by adjusting the draft (total draft of the chimney and vacuum in the chimney fumes) and the flow rate of the heating gas. The total gas flow to the battery and separately to the coke and machine sides is regulated by valves on a temporary gas pipeline. There are also latches pos.16 for shutting off the gas supply to each burner separately, as shown in Fig.6. On all burners in the furnace of the battery from the machine and coke sides, the gas volumetric flow rate is controlled by installing interchangeable diaphragms in the flange connections of item 8 immediately before each burner. Replaceable diaphragms of various flow cross sections create a local narrowing of the flow, which ensures a change in the volume of gas entering the burner per unit time.

The proposed technology of heating with propane-butane gas according to the coke oven gas supply scheme with continuous heating is as follows:

- the distribution gas pipeline of coke oven gas is temporarily removed from the supply gas pipeline of the reverse coke oven gas (including from the gas heater);

- a fitting with a valve crashes into the distribution gas pipeline, through which pure (undiluted) propane-butane gas is supplied;

- in the bottom plugs, pos.17 of each crosspiece at the gas supply, holes 18 are drilled into each vertical (into each nozzle channel) for supplying air from the lower tunnel to the crosspiece (under natural rarefaction) to mix it with propane-butane gas supplied into the crosspiece through a calibrated section from the subsurface collector pos.19 (for a battery with a lower gas supply), as shown in Fig.7;

- on a battery with a lateral gas supply, metal plates with calibrated openings are temporarily inserted in the window for decarbonization (decarbonization) for air to enter the cornera for mixing with propane-butane gas entering the cornera from a permanent gas pipeline through a calibrated diaphragm installed after the reversing valve;

- calibrated cross-sections for supplying propane-butane gas to the subsurface collectors and from these collectors to the crosses of the nozzle channels, as well as the air holes of pos. 18 in the corks of the crosses of pos.17 and in metal plates in the windows of decanting are selected by calculation;

- an appropriate hydraulic mode is established in the heating system, which provides the necessary vacuum in the crosspiece of the nozzle channel of the battery with a lower gas supply (or in the cornera of the battery with a side gas supply) for air intake from the tunnel for mixing with gas.

The calculated gas-air mixture obtained in the cross (in the cornea) should consist of 15-16% propane-butane gas and 84-85% air and have a caloric value of about 4000 kcal / m3 (lowest calorie content).

Table 1 shows a specific example of a phased continuous heating of the refractory masonry in accordance with the claimed method.

Table 1 An example of a graph for warming up a coke oven battery Warm-up phase Day from the start of warm-up Set temperature rise per day, ° C The set temperature, ° C Propane-butane consumption by stages of heating, t 1st stage of heating (28 ÷ 88 ° C) + chimney heating one 6 34 fifty 2 6 40 3 6 46 four 6 52 5 6 58 6 6 64 7 6 70 8 6 76 9 6 82 10 6 88 2nd stage warming up (88 ÷ 166 ° C) eleven 6 94 one hundred 12 6 one hundred 13 6 106 fourteen 6 112 fifteen 6 118 16 6 124 17 6 130 eighteen 6 136 19 6 142 twenty 6 148 21 6 154

Warm-up phase Day from the start of warm-up Set temperature rise per day, ° C The set temperature, ° C Propane-butane consumption by stages of heating, t 22 6 160 23 6 166 3rd stage of heating 166 ÷ 202 ° C) 24 6 172 38 25 6 178 26 6 184 27 6 190 28 6 196 29th 6 202 4th stage of warming up (202 ÷ 388 ° C) thirty 6 208 455 31 6 214 32 6 220 33 9 229 34 9 238 35 9 247 36 12 259 37 12 271 38 12 283 39 12 295 40 fifteen 310 41 fifteen 325 42 fifteen 340 43 fifteen 355 44 fifteen 370 45 eighteen 388 5th stage of warming up (388 ÷ 679 ° C) 46 eighteen 406 300 47 eighteen 424 48 21 445 49 21 466 fifty 21 487 51 24 511 52 24 535 53 24 559 54 24 583 55 24 607

Warm-up phase Day from the start of warm-up Set temperature rise per day, ° C The set temperature, ° C Propane-butane consumption by stages of heating, t 56 24 631 57 24 655 58 24 679 6th stage of warming up (679 ÷ 1015 ° C) 59 24 703 420 60 32 735 61 32 767 62 32 799 63 36 835 64 36 871 65 48 919 66 48 967 67 48 1015 Total: 1363

As can be seen from the table, the method is characterized by the continuity of the process and a quite acceptable consumption of affordable and cheap heat carrier - liquefied propane-butane.

Thus, the claimed method can be implemented using fairly simple devices, which simplifies the method as a whole, ensures the continuity and uniformity of masonry heating in the absence of external furnaces for heating and the need to combine in time a large number of starting operations for putting the battery into operation.

Claims (1)

A method of heating the refractory masonry of a coke oven battery, including supplying heating gas to the chambers of coke ovens, heating and switching to heating according to a constant scheme to obtain its own reverse coke oven gas, characterized in that the battery is provided with a bottom or side supply of heating gas, using heating gas regasified liquefied propane-butane gas, while the burners of the furnace are provided with a screen and are installed in the temporary internal furnace of the coke oven from the machine and coke sides of the battery, Without a kindling window, made in the facade of a temporary internal firebox or in a pre-installed door of a coke oven, air is supplied to the firebox through movable dampers installed on the kindling windows, when switching to heating according to a constant scheme, when the temperature set for loading the chambers of the coal charge is constant, the coke oven gas pipeline is temporarily discharged from the inlet coke oven gas supply pipeline, and to the distribution gas pipeline through a previously installed fitting with a hearth valve tsya propane-butane gas, which is mixed with the feed air from the bottom of the tunnel.

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