CN112460593A

CN112460593A - Gas system of heating cover of cover type furnace and operation method thereof

Info

Publication number: CN112460593A
Application number: CN202011337639.0A
Authority: CN
Inventors: 王智炎; 蒋兴辰; 李光辉; 郑灵科; 张益龙
Original assignee: Lysteel Co Ltd
Current assignee: Lysteel Co Ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2021-03-09

Abstract

The embodiment of the application provides a bell-type furnace heating cover gas system and an operation method thereof, wherein the system comprises a gas pipeline and a bell-type furnace heating cover, and the gas pipeline is communicated with the bell-type furnace heating cover; in the conveying direction of the mixed gas, the gas pipeline is sequentially provided with a filtering device and a gas preheating mechanism, the filtering device is used for filtering dust in the mixed gas, and the gas preheating mechanism is used for preheating the filtered mixed gas. The dust in the mixed gas is filtered through the filtering device on the gas pipeline, and then the filtered mixed gas is preheated through the gas preheating mechanism, so that the salt substances in the mixed gas are in an aerosol state, and the probability of blockage caused by crystallization of the salt substances at the positions of elbows, reducing holes, valves and the like on the gas pipeline and a heating cover of the cover type furnace, which cause the change of the conductance of the mixed gas, can be reduced. Meanwhile, naphthalene and tar are in an aerosol state, and the viscosity is reduced, so that the probability of blocking caused by adhesion at the position with changed gas conductance can be reduced.

Description

Gas system of heating cover of cover type furnace and operation method thereof

Technical Field

The application relates to the field of steel coil production equipment, in particular to a bell-type furnace heating mantle gas system and an operation method of the bell-type furnace heating mantle gas system.

Background

The bell-type furnace heating cover gas system comprises a gas pipeline, a bell-type furnace heating cover and a smoke exhaust pipeline, wherein the gas pipeline burns gas through a burner of the bell-type furnace heating cover. After the gas is burnt in the heating cover of the cover type furnace, the gas is discharged out of the smoke discharging pipeline. The coal gas introduced into the coal gas pipeline is mixed coal gas consisting of blast furnace coal gas and coke oven coal gas. The mixed gas has a large amount of dust, tar, naphthalene and salt substances (existing in the form of aerosol). The substances block the heating cover pipeline of the cover furnace and accessory equipment (such as a gas electromagnetic valve, a manual valve, a burner, a reducing pipe and an elbow) to influence the continuity of the production of the heating cover of the cover furnace. The heating hood gas system of the bell-type furnace usually adopts a filtering device to filter the substances so as to solve the problem of blockage. However, in the actual use process, the problem of blockage of the heating hood pipeline and the accessory equipment of the bell-type furnace still occurs.

Disclosure of Invention

The embodiment of the application aims to provide a method for preventing a heating cover gas pipeline of a bell-type furnace from being blocked by a heating cover gas system of the bell-type furnace, so as to solve the technical problem that the heating cover pipeline and accessory equipment of the bell-type furnace in the prior art are blocked.

In order to achieve the purpose, the technical scheme adopted by the application is as follows: the heating cover gas system of the bell-type furnace comprises a gas pipeline and a heating cover of the bell-type furnace, wherein the gas pipeline is communicated with the heating cover of the bell-type furnace;

in the conveying direction of the mixed gas, the gas pipeline is sequentially provided with a filtering device and a gas preheating mechanism, the filtering device is used for filtering dust in the mixed gas, and the gas preheating mechanism is used for preheating the filtered mixed gas.

Preferably, the gas preheating mechanism is a gas heat exchanger, and a smoke exhaust pipeline connected with the heating cover of the bell-type furnace is connected with the gas heat exchanger and used for preheating the mixed gas.

Preferably, the smoke exhaust pipeline is also provided with an air preheating mechanism, and the air preheating mechanism and the coal gas heat exchanger are sequentially arranged in the smoke exhaust direction of the smoke exhaust pipeline;

the air preheating mechanism is provided with an air pipeline communicated with the outside and a combustion-supporting air pipeline communicated with a burner of a heating cover of the bell-type furnace.

Preferably, the gas pipeline comprises a gas main pipe, a gas ring pipe and a gas branch pipe, wherein the gas main pipe comprises a first-stage main pipe, a second-stage main pipe and a third-stage main pipe which are sequentially connected and have gradually reduced pipe diameters; the gas ring pipe is arranged around the outer wall of the heating cover of the cover type furnace; the gas branch pipe extends from the gas ring pipe to a corresponding burner of the heating cover of the cover type furnace;

the filtering device is arranged on the primary main pipe, one end of the coal gas preheating mechanism is communicated with the tertiary main pipe, and the other end of the coal gas preheating mechanism is communicated with the coal gas ring pipe.

Preferably, the gas preheating mechanism and the air preheating mechanism are both arranged on the body of the heating cover of the bell-type furnace.

Preferably, the filtering device comprises a box body, and the gas inlet end and the gas outlet end of the box body are respectively communicated with the gas pipeline;

the box is provided with an air chamber and a filter element arranged in the air chamber, and the filter hole of the filter element is 80-200 meshes.

Preferably, filter equipment includes first filtering area and the second filtering area that can switch on with the gas pipeline alternative, and first filtering area and second filtering area all are equipped with the box.

Preferably, a valve on a gas pipeline between the gas preheating mechanism and the heating cover of the cover type furnace is a temperature-resistant valve.

The application also provides an operation method of the bell-type furnace heating cover gas system, which comprises the following steps:

filtering the mixed gas to remove dust in the mixed gas;

preheating the filtered mixed gas to ensure that salt substances in the filtered mixed gas are in an aerosol state, and naphthalene and tar are in the aerosol state and simultaneously reduce the viscosity;

and introducing the preheated mixed gas into a burner of a heating cover of the cover type furnace.

Preferably, the temperature of the preheated mixed gas is 170-250 ℃.

The bell-type furnace heating mantle gas system that this application embodiment provided filters the dust in the mixed coal gas through filter equipment earlier on the gas pipeline, then preheats the mixed coal gas after filtering through coal gas preheating mechanism, can make salt class material wherein be the aerosol state, reducible salt class material is in the gas pipeline and bell-type furnace heating mantle on elbow, reducing, valve department etc. cause the place crystallization of mixed coal gas conductance change and form the probability of jam. Meanwhile, naphthalene and tar are in an aerosol state, and the viscosity is reduced, so that the probability of blocking caused by adhesion at the position with changed gas conductance can be reduced. Therefore, the heating hood pipeline and the accessory equipment of the hood-type furnace of the heating hood gas system of the hood-type furnace are not easy to be blocked. The cover type furnace heating cover gas system is simple in structure and high in reliability, and can effectively solve the problem that a cover type furnace heating cover pipeline and accessory equipment are blocked.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic view of a portion of a gas system of a heating mantle of a bell-type furnace according to an embodiment of the present disclosure;

FIG. 2 is a schematic flow diagram illustrating operation of a bell jar gas system according to one embodiment of the present disclosure.

Description of reference numerals:

100. a gas pipeline; 200. a bell-type furnace heating mantle; 300. a smoke exhaust pipeline; 400. a valve;

110. a filtration device; 210. a gas preheating mechanism; 220. an air preheating mechanism; 230. a body; 240. burning a nozzle; 250. a gas ring pipe; 260. an air ring pipe;

221. an air line; 222. a combustion air line;

120. a gas branch pipe.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

After the existing bell-type furnace heating cover gas system runs for a period of time, the problem that the heating capacity of the bell-type furnace heating cover is poor easily occurs, for example, the temperature is normally increased to 400 ℃ within about 3.5 hours, but the temperature is increased to 400 ℃ within 7-8 hours at present; or the gas flow of the single heating cover is not increased; or the electromagnetic valve and the manual valve are blocked by action and have to be opened fully, so that the phenomena of incapability of controlling air-fuel ratio, insufficient gas combustion and the like are caused. When the problems occur, the on-line bell-type furnace heating cover needs to be stopped for maintenance, lifted off the line, dredged and cleaned at the positions of valves, elbows, reducing diameters and the like on the gas branch pipes one by one, reinstalled, and then lifted on line. In this case, the production is stopped, the coil in the inner hood is cooled down again, and the heating hood is heated up again. Therefore, the cleaning workload is increased, the trouble is brought to the maintenance work, the production pause yield is reduced, the energy consumption is lost, and the quality problem under the condition that the steel coil is repeatedly heated is also caused, and the safe, stable, efficient and economic operation of the heating cover of the cover type furnace is seriously influenced.

The existing bell-type furnace heating cover gas system is only provided with a filtering device at a first-stage main pipe of gas, the filtering device utilizes a 80-200-mesh filter element, the filter element system is 304 stainless steel wound with a sintering net, and dust, a small amount of salt and coal tar are filtered through the sintering net. Once the filter screen is blocked to cause the pressure drop of the coal gas, the coal gas filter device is provided with two areas which can be switched for use without causing production influence. One region of the blockage requires servicing and cleaning of the filter element screen. Firstly, low-pressure nitrogen (0.4-0.5MPa pressure) is utilized for back blowing to remove dust on a filter element filter screen; then, salt and coal tar on the filter screen are removed by blowing and dissolving by utilizing the back blowing of low-pressure steam (the pressure of 0.2-0.5 MPa). Finally, hot water containing dust, salt and coal tar is discharged through the ash discharge port.

However, after the bell-type furnace heating mantle gas system runs for a long time, the problem that the temperature rising capability of the bell-type furnace heating mantle becomes poor, which cannot be solved by the bell-type furnace heating mantle gas system after the pipe network is blown, can occur. The inventor checks that the gas pressure of a gas pipeline is normal, the pressure in front of a burner gas electromagnetic valve of a heating cover of the bell-type furnace is normal, and the position of the burner has no pressure or is very low, so that the situation that the front of the burner is blocked is judged, namely the part of the gas pipeline close to the burner and the burner are blocked or one of the part and the part is blocked.

Before adding a new gas filtering device, sampling 0.5 kg of blockage in a gas pipeline in front of a field bell-type annealing furnace burner 240, and screening by using different sieves, wherein the distribution conditions are as shown in table 1:

TABLE 1 plug particle size distribution

	Sieve number	Weight percent (%)
			Less than 10 meshes	10	55.7
10-20 mesh	30	23.4
			20-40 mesh	50	10.8
40-60 meshes	60	4.5
			60-80 mesh	80	2.4
80-100 mesh	100	1.7
			The rest(s)		1.5

It can be seen that 96-97% of the coal gas dust can be trapped by the filter device when the filter element is selected to be 80 meshes. Therefore, the accuracy of the selection of the coal gas filtering device is more than 80 meshes.

At the same time, a sample of the plug was taken and analyzed by X-ray fluorescence analysis using a plug press, and the results are shown in table 2 below.

TABLE 2 sample of blockages in the front gas line of the heating mantle mixed gas burner of the bell-type furnace

The chloride content was 70.58% and SO as determined by fluorescence analysis₃The content of (A) is 10.56%, which indicates that the amount of sulfate and sulfite is large.

Burning the sample of the plug at 900 ℃, and weighing to obtain the 900 ℃ ignition decrement before and after burning, wherein the 900 ℃ ignition decrement is 81.11%. The loss of weight loss by ignition is mostly chloride, ammonia salt, sulfate and sulfite. The experimental results of the ignition loss are consistent with those of the fluorescence analysis.

The two tests show that the main components of the visible blockage are chlorine salt, ammonia salt and sulfite, (the content unit is% or percentage), so that the filtering device in the existing cover type furnace heating cover gas system can not effectively filter the salts in the mixed gas in practice. On the basis of the above, the inventor has found that the filtering device is usually positioned on a gas primary main pipe of a gas pipeline, and the filtering device is far away from a heating cover of the cover type furnace, and is usually about 200 meters away. When the mixed gas passes through the filtering device, the salt substance is in an aerosol form, so that the filtering device cannot form effective filtration. On the one hand, the temperature of the mixed gas is gradually reduced when the mixed gas passes through a longer gas pipeline. On the other hand, various salts in the mixed gas are easy to crystallize in the places where the flow conductance of the mixed gas changes due to elbows, reducing holes, valves and the like of the gas pipelines and the heating cover of the bell-type furnace, water in the gas is easy to volatilize, and the salts can also crystallize in the elbows, the reducing holes, the valves and the like. In addition, the tar and naphthalene in the mixed gas have relatively high viscosity, are easy to adhere to crystals, and cause blockage at elbows, reducing holes, valves and the like.

On the basis, the inventor designs a cover furnace heating cover gas system. Referring to fig. 1 and 2, the embodiment of the present application provides a bell-type furnace heating mantle gas system, which includes a gas pipeline 100 and a bell-type furnace heating mantle 200, wherein the gas pipeline 100 is communicated with the bell-type furnace heating mantle 200; in the conveying direction of the mixed gas, the gas pipeline 100 is sequentially provided with a filtering device 110 and a gas preheating mechanism 210, the filtering device 110 is used for filtering dust in the mixed gas, and the gas preheating mechanism 210 is used for preheating the filtered mixed gas so that salt substances in the mixed gas are in an aerosol state and naphthalene and tar are in the aerosol state and the viscosity is reduced.

The structure of the bell-type furnace heating cover gas system is similar to that of the existing bell-type furnace heating cover gas system, namely a gas preheating mechanism 210 is added on the basis of the existing bell-type furnace heating cover gas system. The gas line 100, the filter 110 and the bell jar heater 200 of this embodiment may be constructed as in the prior art bell jar gas system. The positional relationship and the connection relationship of the gas line 100, the filter assembly 110 and the bell jar heater 200 may be similarly arranged with reference to the existing bell jar gas system. Of course, the structures, positions and connection relationships of the gas pipeline 100, the filtering device 110 and the bell jar heating mantle 200 may be adjusted according to actual requirements.

Both blast furnace gas and coke oven gas carry dust. Although blast furnace gas is dedusted by the dry method, the blast furnace gas also carries dust. Dust is brought by coke oven gas through a coking process, dry desulphurization is carried out on the coke oven gas, and dust is also brought by pulverization of a desulfurizing agent. The filtering device 110 is used for filtering dust in the mixed gas.

The gas pipeline 100 feeds the filtered mixed gas into the gas preheating mechanism 210 for preheating, and then feeds the preheated mixed gas into the burner 240 of the heating cover 200 of the bell-type furnace through the gas pipeline 100. The gas preheating mechanism 210 may be a heat exchanger separately provided with an external preheating device as a heat source, such as an electric preheating heat exchanger and a gas heat exchanger. Of course, a heat exchanger can be used in conjunction with the bell jar furnace 200, for example, the flue gas exhausted from the bell jar furnace 200 can be used as a heat source to preheat the gas.

After the filtered mixed gas is preheated by the gas heat exchanger, the temperature is increased, the salt substances in the mixed gas can keep an aerosol state, and meanwhile, the naphthalene and the tar are in the aerosol state and the viscosity is reduced. Therefore, the probability of the salt substance crystallizing and blocking at the places where the mixed gas conductance changes, such as the elbows, reducing diameters, valves 400 on the gas pipeline 100 and the bell-type furnace heating mantle 200, and the like, can be reduced. Meanwhile, naphthalene and tar are in an aerosol state, and the viscosity is reduced, so that the probability of blocking caused by adhesion at the position with changed gas conductance can be reduced. Therefore, the pipelines and the accessory equipment of the bell-type furnace heating cover 200 of the bell-type furnace heating cover gas system are not easy to be blocked. After the tar, naphthalene and salt substances enter the bell-type furnace heating hood 200, the tar, naphthalene and salt substances are combusted in the bell-type furnace heating hood 200, the temperature is high, and meanwhile, the pipe diameter of the smoke exhaust pipeline is thick, so that the smoke exhaust pipeline is not easy to block and can be discharged after the subsequent process.

According to the bell-type furnace heating cover gas system provided by the embodiment of the application, the gas pipeline 100 is firstly filtered by the filtering device 110 to filter dust in mixed gas, and then the filtered mixed gas is preheated by the gas preheating mechanism 210, so that salt substances in the mixed gas are in an aerosol state, and the probability of blockage caused by crystallization of the salt substances at places where the flow conductance of the mixed gas changes due to elbows, reducing holes, valves 400 and the like on the gas pipeline 100 and the bell-type furnace heating cover 200 is formed can be reduced. Meanwhile, naphthalene and tar are in an aerosol state, and the viscosity is reduced, so that the probability of blocking caused by adhesion at the position where the gas conductance changes can be reduced. Therefore, the pipelines and the accessory equipment of the bell-type furnace heating cover 200 of the bell-type furnace heating cover gas system are not easy to be blocked. The gas system of the heating cover of the cover furnace has the advantages of simple structure and high reliability, and can effectively solve the problem of blockage of the pipeline and the accessory equipment of the heating cover 200 of the cover furnace.

In one embodiment, referring to fig. 1 and 2, the gas preheating mechanism 210 is a gas heat exchanger, and the smoke exhaust line 300 connected to the heating mantle 200 of the bell jar furnace is connected to the gas heat exchanger for preheating the mixed gas.

The flue gas temperature of the heating cover 200 of the bell-type furnace reaches about 1000 ℃, the smoke exhaust pipeline 300 connected with the heating cover 200 of the bell-type furnace is connected with the coal gas heat exchanger to be used as a heat source to preheat the filtered coal gas, the heat of the smoke exhaust pipeline 300 connected with the heating cover 200 of the bell-type furnace for exhausting the flue gas is fully utilized, extra energy is not required to be provided for the heat exchanger, the energy is saved, and the equipment maintenance and the process cost are saved.

In one embodiment, referring to fig. 1 and 2, the smoke exhaust pipeline 300 is further provided with an air preheating mechanism 220, and in the smoke exhaust direction of the smoke exhaust pipeline 300, the air preheating mechanism 220 is arranged before the gas heat exchanger; the air preheating mechanism 220 has an air line 221 communicating with the outside and a combustion air line 222 communicating with the bell jar heating mantle 200.

The air preheating mechanism 220 and the gas heat exchanger are sequentially arranged in the smoke exhaust direction of the smoke exhaust pipeline 300; the flue gas duct 300 leads from the bell jar furnace heating mantle 200 through the air preheating mechanism 220 and the gas heat exchanger in that order. The air preheating mechanism 220 may be an air heat exchanger. The bell-type furnace heating mantle 200 may be correspondingly provided with an air loop, external air enters the air preheating mechanism 220 through an air pipe 221, enters the air loop 260 after being preheated in the air preheating mechanism 220, a combustion air pipe 221 is communicated with the air loop 260, and the preheated air enters the burner 240 of the bell-type furnace heating mantle 200 through the combustion air pipe 221.

The invention is arranged that the flue gas passes through the air to preheat the air, and then the coal gas passes through the coal gas preheater to preheat the coal gas. Because the mixed gas has high preheating temperature and is dangerous.

If the temperature of the flue gas of a certain bell-type furnace heating cover 200 reaches about 1000 ℃, the preheated air is preheated to about 300 ℃ and 400 ℃ through the air preheating mechanism 220. The preheating temperature of the mixed gas is also proper and reaches about 170-250 ℃, and the preheating temperature is lower than that of the preheated air.

Meanwhile, according to the existing air-fuel ratio, the air quantity is one time of the coal gas quantity, and the newly added coal gas preheater has smaller volume, so that the investment of the coal gas heat exchanger is not large.

In one embodiment, referring to fig. 1 and 2, the gas pipeline 100 includes a gas main pipe and a gas branch pipe 120, the gas main pipe includes a first-stage main pipe, a second-stage main pipe and a third-stage main pipe which are connected in sequence and have gradually decreasing pipe diameters; the gas ring pipe 250 is arranged around the outer wall of the heating cover of the cover type furnace; the gas branch pipes 120 extend from the gas ring pipe 250 to the corresponding burners 240 of the heating mantle of the bell type furnace; the filtering device 110 is disposed on the first-stage main pipe, one end of the preheating mechanism is communicated with the third-stage main pipe, and the other end is communicated with the gas loop pipe 250.

This design makes preheating mechanism set up before coal gas branch pipe 120, and the pipe diameter everywhere of the main pipe of coal gas is thick relatively on the one hand, is difficult to take place blocking phenomenon, and the pipe diameter of coal gas branch pipe 120 is less relatively, takes place blocking phenomenon easily, and the quantity of coal gas branch pipe 120 is relatively more moreover, if set up preheating mechanism and preheat then the cost is relatively higher at every coal gas branch pipe 120.

In one embodiment, referring to fig. 1 and 2, the gas preheating mechanism 210 and the air preheating mechanism 220 are disposed on the body 230 of the bell jar 200.

The whole system is compact in structure, and the gas preheating mechanism 210 and the air preheating mechanism 220 are both arranged on the heating cover 200 body 230 of the bell-type furnace, so that the heat loss of the preheated gas and the preheated air due to long-distance transportation can be reduced. Especially, if the preheated mixed gas is transported for a long distance, the heat loss is too much, and the temperature is reduced, salt substances, tar and naphthalene can be separated out to block the pipeline again.

In one embodiment, referring to fig. 1 and 2, the filtering apparatus 110 includes a housing, an inlet end and an outlet end of which are respectively communicated with the gas pipeline 100; the box is provided with an air chamber and a filter element arranged in the air chamber, and the filter hole of the filter element is 80-200 meshes.

The filter holes of the filter element are 80-200 meshes, so that dust can be effectively filtered and removed, and the probability of blockage in front of the burner 240 is reduced.

In one embodiment, the filtering device comprises a first filtering area and a second filtering area which can be alternatively communicated with the gas pipeline, and the first filtering area and the second filtering area are both provided with a box body.

The filtering device comprises two filtering areas which are respectively communicated with the gas pipeline and can be alternatively controlled to be communicated through corresponding valves. Each filtering area is provided with an independent filtering component, namely a box body and a corresponding filter element. When one of the filtering areas needs to be cleaned or maintained, the pipeline communicated with the gas pipeline can be closed, and the other filtering area is communicated for filtering. The design can ensure that at least one filtering area is in a working state capable of filtering, so that the heating cover gas system of the bell-type furnace cannot be stopped and overhauled due to cleaning and maintenance of the filtering device of the single filtering area, and the production efficiency is improved.

In one embodiment, referring to fig. 1 and 2, the valve 400 on the gas line 100 between the gas preheating mechanism 210 and the bell jar heating mantle 200 is a temperature resistant valve 400.

Various valves 400 are arranged on the gas pipeline 100 between the gas preheating mechanism 210 and the bell-type furnace heating cover 200, and the valves 400 are replaced by high-temperature-resistant-grade valves 400 so as to meet the requirement of conveying preheated mixed gas, prolong the service life and improve the reliability. In one embodiment, the gas pipeline 100 between the gas preheating mechanism 210 and the bell-type furnace heating cover 200 is insulated to avoid the temperature reduction of the preheated mixed gas therein, and further reduce the probability of blockage before the burner 240.

In one embodiment, referring to fig. 1 and 2, the bell jar gas system further comprises an underground flue and a flue gas blower in communication with the flue gas duct 300. The design is more convenient for smoke discharge.

The present application also provides a method of operating a bell jar gas system, with reference to fig. 1 and 2, comprising the steps of:

filtering the mixed gas to remove dust in the mixed gas;

and introducing the preheated mixed gas into a burner 240 of the heating cover 200 of the cover furnace.

The operation method of the bell-type furnace heating mantle gas system can be suitable for the bell-type furnace heating mantle gas system, and can also be suitable for other bell-type furnace heating mantle gas systems, such as industrial kilns with gas users being mixed gas of blast furnace gas and coke oven gas or pure blast furnace gas and smaller gas burner 240. According to the operation method of the bell-type furnace heating cover gas system, the filtered mixed gas is preheated by the gas heat exchanger, so that the temperature of the mixed gas is increased, salt substances in the mixed gas can keep an aerosol state, and meanwhile, naphthalene and tar are in the aerosol state and the viscosity of the mixed gas is reduced. Therefore, the probability of the salt substance crystallizing and blocking at the places where the mixed gas conductance changes, such as the elbows, reducing diameters, valves 400 on the gas pipeline 100 and the bell-type furnace heating mantle 200, and the like, can be reduced. Meanwhile, naphthalene and tar are in an aerosol state, and the viscosity is reduced, so that the probability of blocking caused by adhesion at the position with changed gas conductance can be reduced. Therefore, the pipelines and the accessory equipment of the bell-type furnace heating cover 200 of the bell-type furnace heating cover gas system are not easy to be blocked. After the tar, naphthalene and salt substances enter the bell-type furnace heating hood 200, the tar, naphthalene and salt substances are not easy to block the smoke exhaust pipeline because the tar, naphthalene and salt substances are combusted in the bell-type furnace heating hood 200 and have high temperature, and meanwhile, the pipe diameter of the smoke exhaust pipeline is thick, so that the tar, naphthalene and salt substances can be discharged after subsequent treatment.

In one embodiment, the temperature of the preheated mixed gas is 170-250 ℃.

The temperature can ensure that the salt substances in the filtered mixed gas are in an aerosol state, the naphthalene and the tar are in the aerosol state, the viscosity is reduced, the temperature of the preheated mixed gas is not too high, the probability of explosion of the preheated mixed gas is reduced, and the safety is enhanced.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A heating cover gas system of a bell-type furnace is characterized by comprising a gas pipeline and a heating cover of the bell-type furnace, wherein the gas pipeline is communicated with the heating cover of the bell-type furnace;

2. The bell-type furnace heating mantle gas system of claim 1, wherein the gas preheating mechanism is a gas heat exchanger, and a flue gas line connected to the bell-type furnace heating mantle is connected to the gas heat exchanger for preheating the mixed gas.

3. The bell-type furnace heating mantle gas system of claim 2, wherein the flue gas duct is further provided with an air preheating mechanism, and the air preheating mechanism and the gas heat exchanger are arranged in sequence in a flue gas direction of the flue gas duct;

the air preheating mechanism is provided with an air pipeline communicated with the outside and a combustion-supporting air pipeline communicated with a burner of the heating cover of the bell-type furnace.

4. The bell-type furnace heating mantle gas system of claim 1, wherein the gas piping comprises a gas main pipe, a gas ring pipe and a gas branch pipe, the gas main pipe comprises a primary main pipe, a secondary main pipe and a tertiary main pipe which are connected in sequence and have gradually decreasing pipe diameters; the gas ring pipe is arranged on the outer wall of the heating cover of the bell-type furnace in a surrounding way; the gas branch pipe extends from the gas ring pipe to a corresponding burner of the heating cover of the bell-type furnace;

5. The bell jar gas system of claim 3 wherein the gas preheating mechanism and the air preheating mechanism are both disposed on the body of the bell jar.

6. The bell jar gas system as recited in claim 1 wherein the filter assembly comprises a housing having an inlet end and an outlet end in communication with the gas line;

the box is internal to have the air chamber and set up filter core in the air chamber, the filtration pore of filter core is 80 ~ 200 meshes.

7. The cover furnace heating mantle gas system of claim 6, wherein the filtering means comprises a first filtering section and a second filtering section that are in selective communication with the gas line, the first filtering section and the second filtering section each having a housing.

8. The bell-type furnace heating mantle gas system of any one of claims 1 to 7, wherein a valve on a gas line between the gas preheating mechanism and the bell-type furnace heating mantle is a temperature resistant valve.

9. An operation method of a cover furnace heating cover gas system is characterized by comprising the following steps:

filtering the mixed gas to remove dust in the mixed gas;

and introducing the preheated mixed coal gas into a burner of a heating cover of the bell-type furnace.

10. The method for operating a cover gas system of claim 9, wherein the temperature of the preheated mixed gas is 170 to 250 ℃.