Device for prolonging service life of filter bag of bag-type dust collector

Abstract

A device for prolonging the service life of a filter bag of a bag-type dust collector comprises a waste heat boiler (1), a connecting pipeline (2), a heat exchanger (3) and a dry dust collector (9), the connecting pipeline (2) is communicated with the waste heat boiler (1) and the dry dust collector (9) and comprises a vertical pipeline part, and the heat exchanger (3) is arranged on the vertical pipeline part. According to the device, the flue gas temperature of dry dedusting is reduced from 240 DEG C to below 200 DEG C, and the service life of the filter bag is prolonged from half a year to more than two years; outlet water of the heat exchanger can be further used as inlet water of the waste heat boiler, and follow-up generating capacity is improved.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of steel smelting, and more specifically, to a device for increasing the life of a bag filter of a bag filter. Background Art

[0002] When using smelting reduction technology to produce high-purity pig iron, the injected coal powder cannot be completely oxidized or burned, generating a large amount of high-temperature raw coal gas containing impurities. Low-temperature clean coal gas is obtained through gasification cooling pipelines, gravity dust removal, cyclone dust removal, waste heat boilers and dry dust collectors, and finally used for hot air heating of hot blast furnaces, coal powder drying and power generation. The dry dust collector is the last equipment to purify coal gas, and the filter bag is the core spare part of the dry dust collector, which reduces the dust content of coal gas to 5mg / Nm 3 The following ensures that the emissions of clean coal gas after combustion meet environmental protection requirements.

[0003] However, the life of the filter bag is less than half a year, far from the designed life of two years. When replacing the filter bag, it is often found that the filter bag is severely hardened, and even holes appear on the surface. This damage is caused by the operating temperature of the filter bag exceeding the tolerance range of the filter bag (below 200℃), resulting in excessive heat shrinkage of the filter bag. Therefore, it is necessary to reduce the gas temperature passing through the filter bag to increase the service life of the filter bag. Utility Model Content

[0004] The utility model aims to provide a device for increasing the life of a filter bag of a bag filter, so as to solve the problem that the current life of the filter bag is far lower than the designed life.

[0005] In order to solve the above technical problems, the technical solutions adopted by the utility model are as follows:

[0006] A device for increasing the life of a bag filter comprises a waste heat boiler 1, a connecting pipe 2, a heat exchanger 3 and a dry dust collector 9, wherein the connecting pipe 2 connects the waste heat boiler 1 and the dry dust collector 9, the connecting pipe 2 comprises a vertical pipe portion, and the heat exchanger 3 is arranged in the vertical pipe portion.

[0007] Further, the heat exchanger 3 is installed in the middle of the vertical pipe section of the connecting pipe 2 .

[0008] Furthermore, there are more than one heat exchanger 3 .

[0009] Furthermore, a heat exchanger inlet thermometer 7 is provided at the inlet of the heat exchanger 3 , and a heat exchanger outlet thermometer 8 is provided at the outlet of the heat exchanger 3 .

[0010] Furthermore, 48-96 tube bundles 4 are arranged in the heat exchanger 3, the diameter of the tube bundle is 20-50 mm, and the interval between the tube bundles is 2-10 mm.

[0011] Furthermore, the inner diameter of the connecting pipe 2 is 2800-3200 mm.

[0012] Furthermore, the inner diameter of the heat exchanger 3 is 2800-3200 mm.

[0013] Furthermore, it also includes an inlet pipe 5 and an outlet pipe 6. Cooling water enters the heat exchanger 3 from the inlet pipe 5 of the heat exchanger, is branched into the tube bundle 4 in the heat exchanger 3, and is collected into the outlet pipe 6 after heat exchange with the raw gas discharged from the waste heat boiler.

[0014] Furthermore, the inner diameters of the water inlet pipe 5 and the water outlet pipe 6 are 200-250 mm.

[0015] Furthermore, it also includes a controller, which is connected to the heat exchanger inlet thermometer 7, the heat exchanger outlet thermometer 8, the water inlet pipe 5 flow meter, the water inlet pipe 5 water pressure gauge, and the water volume control device. The controller monitors the temperature of the heat exchanger inlet thermometer 7 and the heat exchanger outlet thermometer 8, adjusts the water volume control device and then controls the flow and pressure of the cooling water.

[0016] The advantages and effects of the utility model are as follows: (1) The temperature of flue gas in dry dust removal is reduced from 240°C to below 200°C, and the service life of the filter bag is increased from half a year to more than two years; (2) The structure is simple, the heat exchange efficiency is high, and the heat exchange effect is good; (3) The outlet water of the heat exchanger can be further used as the inlet water of the waste heat boiler, thereby improving the subsequent power generation and energy utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a schematic diagram of a device for improving the service life of filter bags of a bag filter.

[0018] Among them: 1. Waste heat boiler 2. Connecting pipes 3. Heat exchanger 4. Tube bundle 5. Water inlet pipe 6. Water outlet pipe 7. Heat exchanger inlet thermometer 8. Heat exchanger outlet thermometer 9. Dry dust collector DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model is clearly and completely described below. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] The technical solution of the utility model is further explained and illustrated below in conjunction with specific embodiments.

[0021] The technical solution of the utility model is further explained and illustrated below in conjunction with specific embodiments.

[0022] A device for increasing the life of a bag filter of a bag filter comprises a waste heat boiler 1, a connecting pipe 2, a heat exchanger 3 and a dry dust collector 9. Raw coal gas is discharged from the waste heat boiler 1, passes through the connecting pipe 2, and is cooled after heat exchange with cooling water in a tube bundle 4 in the heat exchanger 3. The raw coal gas cooled to a certain temperature enters the dry dust collector 9, and is filtered by the filter bag therein to become clean coal gas that meets environmental protection requirements.

[0023] Furthermore, the inlet and outlet of the heat exchanger 3 are provided with a heat exchanger inlet thermometer 7 and a heat exchanger outlet thermometer 8.

[0024] Further, the heat exchanger is installed in the middle of the vertical portion of the connecting pipe 2 .

[0025] Furthermore, the inner diameter of the connecting pipe 2 is 2800-3200 mm.

[0026] Furthermore, 48 to 96 tube bundles 4 are arranged in the heat exchanger 3 .

[0027] Furthermore, cooling water enters the heat exchanger from the heat exchanger water inlet pipe 5 , is divided into the tube bundle 4 in the heat exchanger, and then is gathered into the water outlet pipe 6 .

[0028] Furthermore, in order to increase the life of the tube bundle and reduce the frequency of tube bundle replacement, the tube bundle material is stainless steel.

[0029] Furthermore, the diameter of the tube bundle is 20-50 mm, and the interval between the tube bundles is 2-10 mm, so that the coal gas can fully exchange heat with the cooling water in the tube bundle when bypassing the tube bundle.

[0030] Furthermore, desalted water is used as cooling water, the temperature of cooling water entering the water inlet pipe 5 is controlled at 20-30°C, the temperature of cooling water flowing out of the water outlet pipe 6 is 65-75°C, the cooling water volume is controlled at 100-160 t / h, and the water pressure is controlled at 1.0-1.1 MPa.

[0031] Furthermore, the inner diameters of the water inlet pipe 5 and the water outlet pipe 6 are 200-250 mm.

[0032] Furthermore, the flue gas temperature detected by the heat exchanger inlet thermometer 7 is below 240°C.

[0033] Furthermore, the temperature of the flue gas entering the dry dust collector 9 detected by the heat exchanger outlet thermometer 8 is controlled below 200°C.

[0034] Example 1

[0035] A device for increasing the life of a bag filter includes a waste heat boiler 1, a connecting pipe 2, a heat exchanger 3 and a dry dust collector 9. The inner diameter of the connecting pipe 2 is 3000 mm, the inner tube bundle of the heat exchanger 3 has 90 tubes, the tube diameter is 25 mm, and the interval between the tube bundles is 8 mm. The inner diameters of the water inlet pipe 5 and the water outlet pipe 6 are both 200 mm, the cooling water inlet temperature of the water inlet pipe 5 is 25°C, the cooling water volume is 158 t / h, and the water pressure is 1.0 MPa.

[0036] The raw gas is discharged from the waste heat boiler 1, and the temperature detected by the heat exchanger inlet thermometer 7 is 239°C through the connecting pipe 2. After the heat exchanger 3 exchanges heat with the cooling water in the tube bundle 4, the temperature detected by the heat exchanger outlet thermometer 8 is 189°C, and the cooling water outlet temperature of the outlet pipe 6 is 70°C. The raw gas enters the bag filter, and after being filtered by the filter bag, it becomes clean gas that meets environmental protection requirements.

[0037] The device has been running stably for two years, no damage to the filter bags has been found, and the dust removal effect is good.

[0038] Although the implementation methods disclosed in the utility model are as above, the above contents are only implementation methods adopted to facilitate the understanding of the utility model, and are not used to limit the utility model. Any technician in the field to which the utility model belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the utility model, but the scope of patent protection of the utility model shall still be based on the scope defined in the attached claims.

Claims

1. A device for increasing the life of a bag filter, characterized in that: The invention comprises a waste heat boiler (1), a connecting pipe (2), a heat exchanger (3) and a dry dust collector (9), wherein the connecting pipe (2) connects the waste heat boiler (1) and the dry dust collector (9), the connecting pipe (2) comprises a vertical pipe section, and the heat exchanger (3) is arranged in the vertical pipe section.

2. The device for increasing the life of a bag filter according to claim 1, characterized in that: The heat exchanger (3) is installed in the middle of the vertical pipe section of the connecting pipe (2).

3. The device for increasing the life of a bag filter according to claim 1 or 2, characterized in that: The number of the heat exchanger (3) is at least one.

4. The device for increasing the life of a bag filter according to claim 3, characterized in that: The inlet of the heat exchanger (3) is provided with a heat exchanger inlet thermometer (7), and the outlet of the heat exchanger (3) is provided with a heat exchanger outlet thermometer (8).

5. The device for increasing the life of a bag filter according to claim 4, characterized in that: 48-96 tube bundles (4) are arranged in the heat exchanger (3), the diameter of the tube bundle is 20-50 mm, and the interval between the tube bundles is 2-10 mm.

6. The device for increasing the life of a bag filter according to claim 1 or 2, characterized in that: The inner diameter of the connecting pipe (2) is 2800-3200 mm.

7. The device for increasing the life of a bag filter according to claim 4 or 5, characterized in that: The inner diameter of the heat exchanger (3) is 2800-3200 mm.

8. The device for increasing the life of a bag filter according to claim 7, characterized in that: It also includes a water inlet pipe (5) and a water outlet pipe (6). Cooling water enters the heat exchanger (3) from the heat exchanger water inlet pipe (5), is branched in the heat exchanger (3) and enters the tube bundle (4), exchanges heat with the raw gas discharged from the waste heat boiler, and then is collected and enters the water outlet pipe (6).

9. The device for increasing the life of a bag filter according to claim 8, characterized in that: The inner diameters of the water inlet pipe (5) and the water outlet pipe (6) are 200-250 mm.

10. The device for increasing the life of a bag filter according to claim 9, characterized in that: The invention also comprises a controller, which is connected to a heat exchanger inlet thermometer (7), a heat exchanger outlet thermometer (8), a water inlet pipe (5) flow meter, a water inlet pipe (5) water pressure gauge, and a water volume control device. The controller monitors the temperature of the heat exchanger inlet thermometer (7) and the heat exchanger outlet thermometer (8), adjusts the water volume control device, and thus controls the flow and pressure of the cooling water.

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