Coke oven heating gas aeration system

Abstract

A coke oven heating gas aeration system comprises a recycled gas pipeline, an electric butterfly valve is mounted on the recycled gas pipeline, a gas mixing pipeline is connected to the recycled gas pipeline behind the manual butterfly valve through a first manual gate valve, and the gas mixing pipeline adopts the following two paths of gases for mixing: the first path is nitrogen-rich tail gas produced by ethanol, the second path is nitrogen-rich tail gas produced by ethanol, and the third path is nitrogen-rich tail gas produced by ethanol production; the second path is nitrogen; nitrogen-rich tail gas produced by ethanol is connected to an inlet of a first check valve through a second electric butterfly valve, a fan-shaped blind plate valve and a first flow regulating valve in sequence; nitrogen is connected to an inlet of the first check valve through the second manual gate valve, the first pressure regulating valve, the second check valve and the second flow regulating valve in sequence; an outlet of the first check valve is connected to an inlet of a first manual gate valve through a second pressure regulating valve, a safety valve and a quick switching valve in sequence, and an outlet of the first manual gate valve is connected to a remelting gas pipeline. According to the system, the combustion condition of the coke oven is improved.

Description

Technical Field

[0001] The utility model relates to a coke oven, in particular to a coke oven gas heating and gas mixing system, belonging to the technical field of coking. Background Art

[0002] In the production of coke ovens, the quality of heating has an important impact on the uniformity of coke quality, tar quality, and even the tar ash in coal gas, the sulfur foam produced by desulfurization and its acid production process, and the color of ammonium sulfate. The ramming coke oven is large-scale, and the carbonization chamber height reaches 6.25m. It is heated by coke oven gas, and its high-level heating generally performs poorly, which is manifested in the low stability of the furnace top and the large temperature difference between the upper and lower coke cakes, resulting in the height of the coal cakes being limited. The current maximum coal cake height of 6.25 is 5.8 meters, which hinders the increase in production. At the same time, the existing coking is designed with an ethanol production system, which requires nitrogen. In order to meet the needs of the ethanol production system, there will be a surplus of nitrogen, which is basically all discharged, and the tail gas emissions of the ethanol production system contain nitrogen and low calorific value combustible gases. If it can be added to the coke oven gas, at least the gas emission treatment problem in ethanol production can be solved. Summary of the invention

[0003] The utility model aims to provide a coke oven heating gas mixing system.

[0004] To achieve the purpose of the utility model, the following technical scheme is adopted: a coke oven coal heating gas blending system, including a return gas pipeline, an electric butterfly valve is installed on the return gas pipeline, and the mixed gas pipeline is connected to the return gas pipeline behind the manual butterfly valve through a first manual gate valve, and the mixed gas pipeline adopts the following two gas blending: the first path is nitrogen-rich tail gas produced by ethanol; the second path is nitrogen; the nitrogen-rich tail gas produced by ethanol is connected to the inlet of the first check valve through the second electric butterfly valve, the fan-shaped blind plate valve, and the first flow regulating valve in sequence; the nitrogen is connected to the inlet of the first check valve through the second manual gate valve, the first pressure regulating valve, the second check valve, and the second flow regulating valve in sequence; the outlet of the first check valve is connected to the inlet of the first manual gate valve through the second pressure regulating valve, the safety valve, and the quick-cut valve in sequence, and the outlet of the first manual gate valve is connected to the return gas pipeline.

[0005] Furthermore, the diameter of the first pipeline increases after the first flow regulating valve and before the first check valve; the diameter of the second pipeline increases after the first pressure regulating valve.

[0006] Furthermore, pressure gauges, flow meters and thermometers are installed on the first and second routes.

[0007] Furthermore, a calorific value meter is installed on the return gas pipeline after the first manual gate valve.

[0008] The positive and beneficial technical effect of the utility model is that by adding nitrogen and nitrogen-rich tail gas into the recycled coal gas, not only the emission treatment of nitrogen and nitrogen-rich tail gas is omitted, but also the combustion condition of the coke oven is improved, which is explained in detail in conjunction with the specific implementation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of this system. DETAILED DESCRIPTION

[0010] In order to more fully explain the implementation of the utility model, implementation examples of the utility model are provided. These implementation examples are only for the purpose of illustrating the utility model and do not limit the scope of the utility model.

[0011] The utility model is further explained in detail in conjunction with the accompanying drawings, in which the marks are: A: recycled coal gas; B: nitrogen-rich tail gas; C: nitrogen; D: No. 1 coke oven gas main; E: No. 2 coke oven gas main; 1: first electric butterfly valve; 2: first manual gate valve; 3: calorific value meter; 4: second electric butterfly valve; 5: fan-shaped blind plate valve; 6: first flow regulating valve; 7: pressure gauge; 8: flow meter; 9: thermometer; 10: first path reducer; 11: first check valve; 12: second pressure regulating valve; 13: safety valve; 14: safety quick-cut valve; 15: second manual gate valve; 16: first pressure regulating valve; 17: second path reducer; 18: second check valve; 19: second flow regulating valve.

[0012] As shown in the attached figure, a coke oven coal heating gas blending system includes a return gas pipeline, A shows the return gas, a first electric butterfly valve 1 is installed on the return gas pipeline, and the mixed gas pipeline is connected to the return gas pipeline behind the manual butterfly valve through a first manual gate valve 2. The mixed gas pipeline adopts the following two gas blending: the first is the nitrogen-rich tail gas produced by ethanol; B shows the nitrogen-rich tail gas, and the second is nitrogen; C shows nitrogen, and the nitrogen-rich tail gas produced by ethanol is connected in sequence through the second electric butterfly valve 4, the fan-shaped blind plate valve 5, and the first flow regulating valve 6. To the inlet of the first check valve 11; the nitrogen of the second route is connected to the inlet of the first check valve through the second manual gate valve 15, the first pressure regulating valve 16, the second check valve 18, and the second flow regulating valve 19 in sequence; the outlet of the first check valve is connected to the inlet of the first manual gate valve 2 through the second pressure regulating valve 12, the safety quick valve 13, and the quick cut valve 14 in sequence, and the outlet of the first manual gate valve is connected to the return furnace gas pipeline. The diameter of the first route becomes larger after the first flow regulating valve and before the first check valve; 10 shows the diameter reduction point of the first route, where the pipeline is from D159 4.5 becomes D273 7. The diameter of the second line increases after the first pressure regulating valve. 17 shows the diameter change point of the second line, which is from D159 4.5 becomes D219 6. The first and second routes are both equipped with pressure gauges, flow meters, and thermometers; the pressure gauge shown in 7, the flow meter shown in 8, and the thermometer shown in 9 are for the first route, and the second route also has a pressure gauge, a thermometer, and a flow meter.

[0013] In this system, nitrogen and nitrogen-rich tail gas are both produced by the ethanol production system. Nitrogen-rich tail gas comes from the cryogenic part of ethanol production with a pressure of 0.47MPa. Nitrogen (low-pressure nitrogen) comes from the air separation system with a pressure of 0.6-0.8MPa. A second manual gate valve is set for low-pressure nitrogen as a reliable cutoff. At the same time, a pressure reducing valve (first pressure regulating valve) is set with a pressure before the valve of 0.6~0.8MPa and a pressure after the valve of 0.5MPa to ensure that the low-pressure nitrogen can be mixed into the fuel gas pipeline. At the same time, the second check valve, the second regulating valve and the flow meter have a flow rate of 3500Nm 3 / h, the first check valve, pressure reducing valve (second pressure regulating valve), safety valve, and quick-cut valve are installed on the mixing pipeline. The pressure before the second pressure regulating valve is 0.45~0.5MPa, and the pressure reducing pressure is ~12kPa, to ensure that the mixed fuel gas can be mixed into the return gas pipeline (the return gas pressure is about 8-10kPa), mixed into the return coke oven gas main electric butterfly valve, and sent to the coke oven along the coke oven gas pipeline. D and E are coke oven main pipe No. 1 and coke oven main pipe No. 2 respectively. Most of the nitrogen-rich tail gas is nitrogen, with a small amount of combustible gas mixed gas, and the calorific value is lower than that of coke oven gas. The following table shows the test results of nitrogen-rich tail gas sampling for two consecutive weeks (the data is rounded off, and the sum is less than 1, which should be due to other unmeasured trace components):

[0014]

[0015] Thermometer measurement uses armored platinum thermal resistor (with integrated temperature transmitter), with integral drilled thermometer sleeve, explosion-proof grade: ExdIICT4, protection grade not less than IP65; pressure gauge uses intelligent pressure transmitter (4-20mA.DC standard signal), the minimum material requirement for measuring elements is 316L, explosion-proof grade: ExdIICT4, protection grade not less than IP65; flow meter nitrogen flow and exhaust flow are realized by standard orifice plate + explosion-proof intelligent transmitter. Calorific value meter uses laser CO analyzer + laser CH 4 Analyzer + Thermal Conductivity H 2 Analyzer or combustion calorific value analyzer.

[0016] The effects of heating the coke oven by aeration using the aeration system and simply using recycled coal gas to heat the coke oven are compared in the following Tables 1 to 4. The aeration ratios of nitrogen and nitrogen-rich tail gas are both about 7%.

[0017]

[0018]

[0019]

[0020]

[0021] The dates involved in the above table are all from the previous year.

[0022] By comparing before and after aeration, it can be seen that the vertical heat removal effect of the coke oven has improved, the tar toluene insolubles have increased, and the acid filter of the filter has been clogged in subsequent use.

[0023] Benefit Analysis:

[0024] A=V×q' / q×24 hours×300 days×coke oven gas price

[0025] A: Annual calculation benefit, 10,000 yuan / year

[0026] V: Nitrogen-rich tail gas flow rate, m 3 / h

[0027] q': calorific value of nitrogen-rich tail gas, Kcal / m 3

[0028] q: Coke oven gas calorific value, Kcal / m 3

[0029] A≈2000×2500÷3900×24×300×0.7

[0030] ≈6.4653 million yuan / year

[0031] Note: Since the nitrogen used in ethanol production utilizes diffused nitrogen, the cost of nitrogen is not included in the calculation.

[0032] Indirect benefits: It is beneficial to improve the high-dimensional uniformity of coke, that is, to improve the strength of metallurgical coke, and to increase the average particle size of coke. It is also beneficial to improve the metallurgical coke rate, and at the same time, it increases the tar toluene insolubles, and alleviates the clogging of subsequent filters.

[0033] After describing the implementation mode of the utility model in detail, people familiar with the technology can clearly understand that various changes and modifications can be made without departing from the scope and spirit of the above-mentioned patent application. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the utility model are within the scope of the technical solution of the utility model, and the utility model is not limited to the implementation mode of the examples given in the specification.

Claims

1. A coke oven heating gas mixing system, comprising a return gas pipeline, on which a first electric butterfly valve is installed, characterized in that: The mixed gas pipeline is connected to the recycled gas pipeline behind the first electric butterfly valve through a first manual gate valve, and the mixed gas pipeline adopts the following two gases for mixing: the first path is the nitrogen-rich tail gas produced by ethanol; the second path is nitrogen; the nitrogen-rich tail gas produced by ethanol is connected to the inlet of the first check valve through the second electric butterfly valve, the fan-shaped blind plate valve, and the first flow regulating valve in sequence; the nitrogen of the second path is connected to the inlet of the first check valve through the manual gate valve, the first pressure regulating valve, the second check valve, and the second flow regulating valve in sequence; the outlet of the first check valve is connected to the inlet of the first manual gate valve through the second pressure regulating valve, the safety valve, and the quick-cut valve in sequence, and the outlet of the first manual gate valve is connected to the recycled gas pipeline.

2. A coke oven heating gas aeration system according to claim 1, characterized in that: The diameter of the pipeline of the first path becomes larger after the first flow regulating valve and before the first check valve; the diameter of the pipeline of the second path becomes larger after the first pressure regulating valve.

3. A coke oven heating gas aeration system according to claim 1, characterized in that: The first and second lines are equipped with pressure gauges, flow meters and thermometers.

4. A coke oven heating gas aeration system according to claim 1, characterized in that: A calorific value meter is installed on the return gas pipeline after the first manual gate valve.

Images