A flue gas dust removal and mist removal heat recovery system

Abstract

The present invention provides a flue gas dust removal and mist elimination heat recovery system, including a flue gas mist elimination heat recovery box, a water storage tank connected to three heat exchangers through water pipes, a spray circulation pump is also provided between the water storage tank and the heat exchanger, the heat exchanger is also connected to a spray pipe, a spray head is provided at the upper end of the spray pipe, and the upper ends of the three spray pipes are respectively located in the primary operation area, the secondary operation area and the desulfurization tower; the outlet pipe of the heat exchanger is also connected to a high-temperature water tank, a preheating water tank, and a coal washing water pipeline, and the high-temperature water tank provides heating water to the outside through a hot water frequency conversion supply pump. Its beneficial effect is that the multi-stage water film spraying in the system can greatly reduce the temperature of the discharged high-temperature flue gas, and the condensed water and the spray water are stored at the bottom of the box body. After heat exchange by the heat exchanger, hot water resources can be provided for various heat-demanding units in the mining area, such as bathing water, heating water, and preheating of gas or water for equipment.

Description

Technical Field

[0001] The invention relates to the field of flue gas treatment, and in particular to a flue gas dust removal, mist elimination and heat recovery system. Background Art

[0002] Due to the increasingly severe environmental situation, in order to ensure a good production and living environment for urban residents, high-pollution enterprises in Pingdingshan City are restricted from production for a long time every year due to failure to meet environmental protection standards.

[0003] At present, the traditional coal washing plant adopts the rotary kiln type coal slime drying system in the production process. After the boiler is heated to generate a large amount of high-temperature dry hot air, it will fully contact with the wet coal slime inside the rotary kiln and take away the moisture in the coal slime. This method can efficiently dry a large amount of coal slime, but during the drying process, a large amount of fine coal slime dust will be discharged from the drying kiln along with the hot air, causing serious environmental pollution.

[0004] In view of the serious environmental problems caused by the above drying system, as the environmental protection situation becomes increasingly severe, most coal washing plants have taken certain measures to solve the above problems, such as installing cyclone dust collectors, wet high-voltage electrostatic dust collectors, etc. Although the emission of coal dust particles has been greatly reduced, the problem of large-scale emission of white mist cannot be solved.

[0005] The existing improvement methods have alleviated the pollutant emission problem to a certain extent, but a large amount of pollutants are still discharged with the high-temperature flue gas, and the heat discharged in the flue gas is not fully utilized, which not only causes environmental pollution but also wastes resources. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a flue gas dust removal and mist elimination heat recovery system.

[0007] The technical solution of the present invention is achieved in this way:

[0008] A flue gas dust removal and mist elimination heat recovery system, comprising a flue gas mist elimination heat recovery box, wherein the flue gas mist elimination heat recovery box is divided into a primary operation area and a secondary operation area, wherein the lower part of the primary operation area is connected to an air inlet pipe, and the lower part of the secondary operation area is connected to an air outlet pipe, and the air outlet pipe is connected to a tertiary operation area of ​​dust removal and mist elimination;

[0009] A water storage tank is provided at the bottom of the primary operation area, the secondary operation area and the tertiary operation area. The water storage tank is connected to three heat exchangers through water pipes. A spray circulation pump is provided between the water storage tank and the heat exchanger. The heat exchanger is also connected to a spray pipe. A spray head is provided at the upper end of the spray pipe. The upper ends of the three spray pipes are respectively located in the primary operation area, the secondary operation area and the desulfurization tower;

[0010] The outlet pipes of the three heat exchangers are also respectively connected to the high-temperature water tank, the preheating water tank, and the coal washing water pipeline. The water inlet pipe between the high-temperature water tank, the preheating water tank and the heat exchanger is also provided with a hot water circulation pump. The preheating water tank is also connected to a tap water pipe. A water supply pipe is also provided between the high-temperature water tank and the preheating water tank. A water valve is provided on the water supply pipe. The high-temperature water tank provides heating water to the outside through a hot water variable frequency supply pump. The water inlet pipe of the heat exchanger connected to the coal washing water pipeline is a coal slime selection and washing preheating water pipe.

[0011] Furthermore, the three water storage tanks are also connected to the coal preparation water return pipeline through pipelines.

[0012] The beneficial effects of the present invention are:

[0013] 1. By adding multiple two-stage smoke mist elimination and heat recovery boxes to the drying system according to its exhaust-related indicators, it can fully contact with the exhaust gas of the system to achieve the purpose of dust reduction;

[0014] 2. The multi-stage water film spraying in the system can significantly cool down the discharged high-temperature flue gas. The condensed water and spraying water are stored at the bottom of the box. After heat exchange by the heat exchanger, they can provide hot water resources for various heat-demanding units in the mining area, such as bathing water, heating water, wellhead insulation, preheating of gas or water for equipment, etc.

[0015] 3. After the high-temperature humid flue gas passes through the multi-stage water film dust removal and mist elimination heat recovery system, the humid hot flue gas fully contacts and exchanges heat with the water film, which greatly reduces the final exhaust temperature and greatly reduces the generation of white fog. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 It is a schematic diagram of the structure of the application of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] like Figure 1-Figure 2 The smoke dust removal and mist removal heat recovery system shown in the figure comprises a smoke mist removal heat recovery box 2, the smoke mist removal heat recovery box 2 is divided into a primary operation area 4 and a secondary operation area 5, a desulfurization tower 3 is connected to the secondary operation area 5, and the smoke enters the primary operation area 4 from the air inlet pipe, passes through the secondary operation area 5 and the desulfurization tower 3, and is then discharged;

[0021] A water storage tank 7 is provided at the bottom of the primary operation area 4, the secondary operation area 5 and the desulfurization tower 3. The water storage tank 7 is connected to three heat exchangers 8 through water pipes. A spray circulation pump 9 is provided between the water storage tank 7 and the heat exchanger 8. The heat exchanger 8 is also connected to a spray pipe 10. A spray head is provided at the upper end of the spray pipe 10. The upper ends of the three spray pipes 10 are respectively located in the primary operation area 4, the secondary operation area 5 and the desulfurization tower 3;

[0022] The outlet pipes of the three heat exchangers 8 are also respectively connected to the high-temperature water tank 11, the preheating water tank 12, and the coal washing water pipeline 13. The water inlet pipes between the high-temperature water tank 11 and the preheating water tank 12 and the heat exchanger 8 are also provided with a hot water circulation pump 14. The preheating water tank 12 is also connected to a tap water pipe 15. A water supply pipe 16 is also provided between the high-temperature water tank 11 and the preheating water tank 12. A water valve is provided on the water supply pipe 16. The high-temperature water tank 11 provides heating water to the outside through a hot water variable frequency supply pump 17. The water inlet pipe of the heat exchanger 8 connected to the coal washing water pipeline 13 is a coal slime selection and washing preheating water pipe 18.

[0023] The water storage tank at the lower part of the desulfurization tower 3 is also connected to a tap water pipe 15.

[0024] The three water storage tanks 7 are also connected to the coal preparation water return pipe 19 through pipes. The hot water in the water storage tanks 7 will contain a large amount of dust accumulated at the bottom. This part of the hot water with a large amount of dust is discharged into the coal preparation water pool through the coal preparation water return pipe 19 through the pipe. The hot water can also increase the temperature of the coal preparation water pool.

[0025] The working principle of this system is as follows:

[0026] First, the high-temperature flue gas that has completed the drying operation enters the primary operating area 4 of the two-stage flue gas mist elimination and reheat box 2 from the bottom. During the movement of the flue gas from bottom to top, it will fully contact with the water film spray water. The full contact between the water film and the high-temperature flue gas can effectively condense the water vapor brought by the flue gas while cooling and removing dust. After the flue gas is treated, it comes from the upper part of the box body of the two-stage flue gas mist elimination and reheat box 2 to the secondary operating area 5 and starts to move downward. The structure and flue gas treatment process of the secondary operating area 5 are basically the same as those of the primary operating area 4. The flue gas moving to the bottom of the box body will enter the desulfurization tower 3 from the lower connecting pipe; in the desulfurization tower 3, the flue gas moves from bottom to top, and at this time it will contact with the third-stage spray water film. After sufficient cleaning and cooling, the clean flue gas is finally discharged from the top of the desulfurization tower 3.

[0027] Three water tanks 7 are arranged at the bottom of the two-stage flue gas mist elimination and heat recovery box 2 and the desulfurization tower 3. The dust-containing hot water brought by the spray cleaning is stored in the water tanks 7 at the bottom of the corresponding area as heat source water for the waste heat recovery device; each water tank 7 corresponds to a hot water treatment system, which are the primary treatment system 20, the secondary treatment system 21, and the tertiary treatment system 22. A spray circulation pump 9 and a plate heat exchanger 8 are arranged outside each level of the treatment system. The dust-containing hot water in the water tank 7 will be pumped out by the spray circulation pump 9 according to the system design, and will be sent to the corresponding spray pipe 10 and sprayed out after sufficient heat exchange in the plate heat exchanger 8, and will fall back into the water tank 7 after fully contacting with the high-temperature flue gas to absorb heat to complete the cycle.

[0028] The bottom of the three water storage tanks 7 is provided with a liquid level balance pipeline, and a sewage discharge valve, a water supply valve and a variety of sensors are set, and the sewage discharge and water supply operations are completed through the adjustment of the system host.

[0029] According to the water film spraying treatment process of high-temperature flue gas, the temperature of the dust-containing hot water in the water tank 7 of the three-stage treatment system decreases in the order of treatment. Therefore, the heat of the dust-containing hot water in the water tank 7 with a relatively high temperature will be used to heat and keep warm the production and living / heating water, and the obtained high-temperature production and living / heating water is stored in the high-temperature water tank 11; the heat of the dust-containing hot water in the third water tank 7 is used to preheat the water for coal slime washing, and to increase the temperature of the water for washing. While being beneficial to the clean coal washing operation, it can also increase the inlet coal slime temperature of the coal slime drying system, further reducing energy consumption.

[0030] All levels of water film dust removal, mist elimination and heat recovery systems work simultaneously. When the production and living water reaches the corresponding use temperature requirements, the operation of the first and second level treatment systems can be suspended according to the actual water vapor and smoke content in the flue gas to save operating costs. After the first and second level treatment systems are suspended, the tertiary treatment system 22 can recover more heat for preheating the selected washing water.

[0031] Embodiment 1:

[0032] When the flue gas mist elimination and heat recovery box is installed in the coal slime drying system used in the mine, the air inlet pipe is connected to the wet high-voltage electrostatic precipitator, and the air outlet pipe is connected to the desulfurization tower, that is, the desulfurization tower is a three-level operation area;

[0033] A flue gas dust removal and mist removal heat recovery system comprises a wet high-voltage electrostatic precipitator 1, a flue gas mist removal heat recovery box 2, and a desulfurization tower 3. The flue gas mist removal heat recovery box 2 is divided into a primary operation area 4 and a secondary operation area 5. The wet high-voltage electrostatic precipitator 1 is connected to the primary operation area 4, and the desulfurization tower 3 is connected to the secondary operation area 5. A sewage pipe 6 is also provided at the lower part of the wet high-voltage electrostatic precipitator 1.

[0034] A water storage tank 7 is provided at the bottom of the primary operation area 4, the secondary operation area 5 and the desulfurization tower 3. The water storage tank 7 is connected to three heat exchangers 8 through water pipes. A spray circulation pump 9 is provided between the water storage tank 7 and the heat exchanger 8. The heat exchanger 8 is also connected to a spray pipe 10. A spray head is provided at the upper end of the spray pipe 10. The upper ends of the three spray pipes 10 are respectively located in the primary operation area 4, the secondary operation area 5 and the desulfurization tower 3;

[0035] The outlet pipes of the three heat exchangers 8 are also respectively connected to the high-temperature water tank 11, the preheating water tank 12, and the coal washing water pipeline 13. The water inlet pipes between the high-temperature water tank 11 and the preheating water tank 12 and the heat exchanger 8 are also provided with a hot water circulation pump 14. The preheating water tank 12 is also connected to a tap water pipe 15. A water supply pipe 16 is also provided between the high-temperature water tank 11 and the preheating water tank 12. A water valve is provided on the water supply pipe 16. The high-temperature water tank 11 provides heating water to the outside through a hot water variable frequency supply pump 17. The water inlet pipe of the heat exchanger 8 connected to the coal washing water pipeline 13 is a coal slime selection and washing preheating water pipe 18.

[0036] The three water storage tanks 7 are also connected to the coal preparation water return pipe 19 through pipes. The hot water in the water storage tanks 7 will contain a large amount of dust accumulated at the bottom. This part of the hot water with a large amount of dust is discharged into the coal preparation water pool through the coal preparation water return pipe 19 through the pipe. The hot water can also increase the temperature of the coal preparation water pool.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flue gas dust removal and mist removal heat recovery system, characterized by: It includes a flue gas mist elimination and heat recovery box, which is divided into a primary operation area and a secondary operation area. The lower part of the primary operation area is connected to an air inlet pipe, and the lower part of the secondary operation area is connected to an air outlet pipe, and the air outlet pipe is connected to a desulfurization tower for dust removal and mist elimination; A water storage tank is provided at the bottom of the primary operation area, the secondary operation area and the desulfurization tower. The water storage tank is connected to three heat exchangers through water pipes. A spray circulation pump is provided between the water storage tank and the heat exchanger. The heat exchanger is also connected to a spray pipe. A spray head is provided at the upper end of the spray pipe. The upper ends of the three spray pipes are respectively located in the primary operation area, the secondary operation area and the desulfurization tower. The outlet pipes of the three heat exchangers are also respectively connected to the high-temperature water tank, the preheating water tank, and the coal washing water pipeline. The water inlet pipe between the high-temperature water tank, the preheating water tank and the heat exchanger is also provided with a hot water circulation pump. The preheating water tank is also connected to a tap water pipe. A water supply pipe is also provided between the high-temperature water tank and the preheating water tank. A water valve is provided on the water supply pipe. The high-temperature water tank provides heating water to the outside through a hot water variable frequency supply pump. The water inlet pipe of the heat exchanger connected to the coal washing water pipeline is a coal slime selection and washing preheating water pipe.

2. The flue gas dust removal and mist elimination heat recovery system according to claim 1 is characterized in that: The three water storage tanks are also connected to the coal preparation water return pipeline through pipelines.

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