A chlorinated polyethylene drying tail gas waste heat utilization system

Abstract

The utility model discloses a kind of chlorinated polyethylene drying tail gas waste heat utilization systems, it is related to drying tail gas waste heat utilization system.The system includes air filter, air heat exchanger, flash dryer and fluidized bed dryer;Air filter includes first air filter and second air filter, the first air filter and second air filter are uniformly equipped with air inlet pipeline;The output end of first air filter is connected with flash dryer by first air heat exchanger, and the upper portion of fluidized bed dryer is connected by first cyclone dust collector with the flash dryer;The output of second air filter is connected with the bottom of fluidized bed dryer by second air heat exchanger.The utility model reduces the influence of tail gas emission to environment, by recycling heat energy in tail gas, greenhouse gas and other pollutants discharged by factory can be reduced, to reduce the negative influence to environment, improve the environmental protection image of enterprise.

Description

Technical Field

[0001] This utility model relates to the field of engineering design and production operation technology of acid phase chlorinated polyethylene equipment, and relates to a waste heat utilization system for drying tail gas. Background Technology

[0002] During the production of chlorinated polyethylene, the granules contain a certain amount of moisture. If this moisture is not removed, it will affect the product's performance. Dehydration and drying technology can reduce the moisture content of chlorinated polyethylene granules to a certain level (below 0.4%) to meet product performance requirements.

[0003] Currently, most acid-phase production of chlorinated polyethylene uses fluidized bed drying technology. This technology utilizes steam to heat the air in an air heat exchanger, which then transfers mass and heat with the material inside the fluidized bed dryer, removing moisture from the chlorinated polyethylene. This process typically uses steam as the sole heat source, consuming energy, but the large amount of hot exhaust gas generated during the drying process is not fully utilized and is discharged into the atmosphere. Utility Model Content

[0004] This utility model addresses the aforementioned technical problems by providing a waste heat recovery system for the drying exhaust gas of chlorinated polyethylene.

[0005] The objective of this utility model can be achieved through the following technical solutions:

[0006] A waste heat utilization system for the exhaust gas of chlorinated polyethylene drying includes an air filter, an air heat exchanger, a flash dryer, and a fluidized bed dryer.

[0007] The air filter includes a first air filter and a second air filter, both of which are equipped with air inlet pipes;

[0008] The output end of the first air filter is connected to the flash dryer through the first air heat exchanger, and the flash dryer is connected to the upper part of the fluidized bed dryer through the first cyclone dust collector.

[0009] The output of the second air filter is connected to the bottom of the fluidized bed dryer via the second air heat exchanger.

[0010] In this utility model technical solution, a first fluidized bed blower and a first exhaust gas preheater are also provided between the first air filter and the first air heat exchanger.

[0011] In this utility model, a second fluidized bed blower and a second exhaust gas preheater are also provided between the second air filter and the second air heat exchanger.

[0012] In this utility model's technical solution, the first exhaust gas preheater also has an output end connected to the outside.

[0013] In this utility model's technical solution, the second exhaust gas preheater also has an output end connected to the outside.

[0014] In this utility model, one output end of the fluidized bed dryer is connected to the second exhaust gas preheater via a second cyclone dust collector and a second bag dust collector in sequence.

[0015] In this utility model, the other output end of the fluidized bed dryer is connected to the first exhaust gas preheater in sequence through the first cyclone dust collector, the first bag dust collector, and the first exhaust gas preheater.

[0016] The beneficial effects of this utility model are:

[0017] (1) The exhaust gas is used to preheat the air, which solves the problem of heat loss and has a high heat recovery efficiency.

[0018] (2) Make full use of the waste heat of exhaust gas to reduce the steam consumption required for heating air and save production costs.

[0019] (3) Reduce the impact of exhaust emissions on the environment. By recycling the heat energy in the exhaust gas, the greenhouse gases and other pollutants emitted by the factory can be reduced, thereby reducing the negative impact on the environment and improving the company's environmental image. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the present invention.

[0021] In the figure, 21. First air filter, 22. Second air filter, 23. First fluidized bed blower, 24. Second fluidized bed blower, 25. First exhaust gas preheater, 26. Second exhaust gas preheater, 27. First air heat exchanger, 28. Second air heat exchanger, 29. Flash dryer, 30. Fluidized bed dryer, 31. First cyclone dust collector, 32. Second cyclone dust collector, 33. First bag filter, 34. Second bag filter. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto:

[0023] like Figure 1As shown, a waste heat utilization system for the drying tail gas of chlorinated polyethylene is disclosed. The system comprises: a first air inlet pipe 1, a second air inlet pipe 2, a first air filter outlet pipe 3, a second air filter outlet pipe 4, a first fluidized bed blower outlet pipe 5, a second fluidized bed blower outlet pipe 6, a first tail gas preheater outlet pipe 7, a second tail gas preheater outlet pipe 8, a first tail gas outlet pipe 9, a second tail gas outlet pipe 10, a first steam inlet pipe 11, a second steam inlet pipe 12, a first air heat exchanger outlet pipe 13, a second air heat exchanger outlet pipe 14, a wet material inlet pipe 15, and a flash dryer. 16. Outlet pipe of the first cyclone dust collector; 17. Outlet pipe of the second cyclone dust collector; 18. First hot exhaust gas recovery pipe; 19. Second hot exhaust gas recovery pipe; 20. 21. First air filter; 22. Second air filter; 23. First fluidized bed blower; 24. Second fluidized bed blower; 25. First exhaust gas preheater; 26. Second exhaust gas preheater; 27. First air heat exchanger; 28. Second air heat exchanger; 29. ​​Flash dryer; 30. Fluidized bed dryer; 31. First cyclone dust collector; 32. Second cyclone dust collector; 33. First bag filter; 34. Second bag filter.

[0024] The air filter includes a first air filter 21 and a second air filter 22, both of which are equipped with air inlet pipes;

[0025] The output end of the first air filter 21 is connected to the flash dryer 29 through the first air heat exchanger 27, and the flash dryer 29 is connected to the upper part of the fluidized bed dryer 30 through the first cyclone dust collector 31.

[0026] The output end of the second air filter 22 is connected to the bottom of the fluidized bed dryer 30 through the second air heat exchanger 28.

[0027] A first fluidized bed blower 23 and a first exhaust gas preheater 25 are also provided between the first air filter 21 and the first air heat exchanger 27. A second fluidized bed blower 24 and a second exhaust gas preheater 26 are also provided between the second air filter 22 and the second air heat exchanger 28.

[0028] The first exhaust gas preheater 25 also has an output terminal connected to the outside. The second exhaust gas preheater 26 also has an output terminal connected to the outside.

[0029] One output of the fluidized bed dryer 30 is connected to the second exhaust gas preheater 26 via a second cyclone dust collector 32 and a second bag filter 34 in sequence. The other output of the fluidized bed dryer 30 is connected to the first exhaust gas preheater 25 via a first cyclone dust collector 31 and a first bag filter 33 in sequence.

[0030] Instructions for running the example:

[0031] Air is fed into the first air filter 21 and the second air filter 22 through the first air inlet pipe 1 and the second air inlet pipe 2, respectively, for filtration. Then, it passes through the first fluidized bed blower 23 and the second fluidized bed blower 24, respectively, and enters the first exhaust gas preheater 25 and the second exhaust gas preheater 26. In the first exhaust gas preheater 25 and the second exhaust gas preheater 26, the air is preheated to 65°C by the incoming hot exhaust gas. The other end of the exhaust gas preheater is connected to the exhaust gas pipeline, and the exhaust gas is discharged through the exhaust gas outlet pipes (first exhaust gas outlet pipe 9 and second exhaust gas outlet pipe 10).

[0032] Preheated air enters the first air heat exchanger 27 and the second air heat exchanger 28, where it is heated to 100°C by steam. The air heated in air heat exchanger 27 then enters the flash dryer 29 through the air heat exchanger outlet pipe 13. Wet material enters the flash dryer 29 through the wet material inlet pipe 15 and comes into full contact with the hot air, completing the surface drying of the material. The air heated in air heat exchanger 28 is then sent to the fluidized bed dryer 30 as high-temperature drying air.

[0033] After preliminary drying, the material passes through a cyclone dust collector 31 for dust removal before entering a fluidized bed dryer 30 for further drying. Inside the fluidized bed dryer 30, the material is thoroughly mixed with high-temperature drying air and maintained in a stable fluidized state, completing the heat exchange and drying process within the bed. A discharge port is located on one side of the fluidized bed dryer. The exhaust gas discharged from the top of the fluidized bed dryer 30 is sent to a first cyclone dust collector 31, a second cyclone dust collector 32, a first bag filter 33, and a second bag filter 34 for dust removal and purification. The hot exhaust gas purified by the first bag filter 33 and the second bag filter 34 is sent through a first hot exhaust gas recovery pipe 19 and a second hot exhaust gas recovery pipe 20 to a first exhaust gas preheater 25 and a second exhaust gas preheater 26, where it is recovered and reused as a heat source to preheat the air.

[0034] The exhaust gas from the chlorinated polyethylene drying process is 70℃ with a flow rate of 150,000 Nm³ / h. Its composition is 0.29 wt% H₂O, 99.7 wt% air, and trace amounts of dust. The exhaust gas enters the shell side of the exhaust gas preheater via an exhaust gas pipeline to exchange heat with air. The air temperature is 40℃ with a flow rate of 150,000 Nm³ / h. The preheated air is then passed into an air heat exchanger and heated by steam at a temperature of 200℃, a pressure of 1.0 MPaG, and a flow rate of 2750 kg / h. The air needs to be heated to 100℃. During air preheating, the heat load of the exhaust gas preheater is 193 kW, and the heat exchange area is 33 m².

[0035] Compared to the previous system: The addition of a heat recovery pipeline, using the dried exhaust gas of chlorinated polyethylene as a heat source to preheat the air, reduces steam consumption by 125 kg / h and heat consumption by 324,400 kJ / h, saving production costs and energy. The moisture content of the dried chlorinated polyethylene granules is reduced to 0.39%, meeting production requirements.

Claims

1. A waste heat recovery system for chlorinated polyethylene drying tail gas, characterized in that, The system includes an air filter, an air heat exchanger, a flash dryer, and a fluidized bed dryer; The air filter includes a first air filter (21) and a second air filter (22), both of which are equipped with air inlet pipes; The output end of the first air filter (21) is connected to the flash dryer (29) through the first air heat exchanger (27), and the flash dryer (29) is connected to the upper part of the fluidized bed dryer (30) through the first cyclone dust collector (31); The output end of the second air filter (22) is connected to the bottom of the fluidized bed dryer (30) through the second air heat exchanger (28).

2. The waste heat recovery system for chlorinated polyethylene drying tail gas according to claim 1, characterized in that, A first fluidized bed blower (23) and a first exhaust gas preheater (25) are also provided between the first air filter (21) and the first air heat exchanger (27).

3. The waste heat recovery system for chlorinated polyethylene drying tail gas according to claim 1, characterized in that, A second fluidized bed blower (24) and a second exhaust gas preheater (26) are also provided between the second air filter (22) and the second air heat exchanger (28).

4. The waste heat recovery system for chlorinated polyethylene drying tail gas according to claim 2, characterized in that, The first exhaust gas preheater (25) also has an output end connected to the outside.

5. The waste heat recovery system for chlorinated polyethylene drying tail gas according to claim 3, characterized in that, The second exhaust gas preheater (26) also has an output end connected to the outside.

6. The waste heat recovery system for chlorinated polyethylene drying tail gas according to claim 3, characterized in that, One output end of the fluidized bed dryer (30) is connected to the second exhaust gas preheater (26) in sequence through the second cyclone dust collector (32) and the second bag dust collector (34).

7. The waste heat recovery system for chlorinated polyethylene drying tail gas according to claim 2, characterized in that, The other output end of the fluidized bed dryer (30) is connected to the first exhaust gas preheater (25) in sequence through the first cyclone dust collector (31), the first bag dust collector (33).

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