Tail fume control dedusting device explosion-proof upgraded coal dryer

Abstract

The present application relates to the technical field of drying equipment, in particular to a tail gas control dust remover explosion-proof improved coal dryer, which comprises a combustor, a drying cylinder, a material collecting bin, a cyclone and a tail gas treatment unit connected in sequence, the air supply module is arranged at the air inlet end of the combustor, the tail gas detection device is arranged between the cyclone and the tail gas treatment unit, the cooperation of the air supply module and the detection unit is used to control the oxygen content and temperature balance of the flue gas during the drying of the pulverized coal, the oxygen content and temperature of the tail gas during the drying of the pulverized coal are actively controlled to be appropriate, the explosion and deflagration risk of the explosion bag dust remover is far away, the safety production target is achieved, when the temperature sensor 2 detects that the tail gas temperature after the treatment of the bag dust remover exceeds the set value, the high-temperature flue gas can be introduced into the induced draft pipe 2, then the high-temperature flue gas is transported into the flue gas cooling device through the induced draft fan, and then the temperature in the bag dust remover is controlled to be within the safe range, so that the deflagration or explosion is avoided.

Description

Technical Field

[0001] This invention relates to the field of drying equipment technology, specifically to a coal dryer with a non-explosion-proof tail smoke control dust collector. Background Technology

[0002] Upgraded pulverized coal is dried and dehydrated using a dryer on the market, providing a heat source for evaporating water. Fuels include natural gas and pulverized coal. Specifically, the fuel reacts chemically with oxygen in the air to produce a high-temperature flame, which heats the pulverized coal containing water, raising its temperature above the boiling point of water, thus achieving evaporation and dehydration, and increasing the high calorific value of the pulverized coal to meet end-users' demands.

[0003] During the dehydration process of pulverized coal in the dryer for upgrading pulverized coal, the high-temperature heating of the water-containing pulverized coal will also produce chemical gases such as methane, formaldehyde, toluene, and phenol.

[0004] The generation of these chemical gases from pulverized coal takes time, and in many cases, it only occurs when heat from the flame reaches a certain depth into the pulverized coal particles. Therefore, the exhaust gas from drying processes always contains these unburned flammable and explosive gases, which are the fuel conditions for an explosion in an explosion-proof baghouse dust collector.

[0005] Secondly, oxygen is the oxidant in the explosion of explosion-proof baghouse dust collectors: conditions

[0006] To ensure complete combustion and generate light and heat, all burner manufacturers equip the heat source fuel used in dryers with a combustion environment that has a slight surplus of oxygen.

[0007] Although we have strictly adjusted the oxygen ratio used in the burners for upgraded coal, the actual amount of oxygen or air blown into the burner varies depending on local air pressure and temperature. Therefore, it is impossible to perfectly combust all the oxygen.

[0008] Powdered coal has a large exposed surface area, which allows it to adsorb free oxygen, thus contributing to oxygen supply. During production, the content of ultrafine coal powder needs to be controlled within a suitable range based on the user's transportation and intended use requirements for upgraded coal. Excess powder needs to be burned off, which in turn consumes oxygen. Therefore, controlling the oxygen balance during combustion is a challenging problem for all coal powder drying industries during normal production.

[0009] In addition, the dust removal equipment used in the coal drying industry now uses explosion-proof bag dust collectors, which are made of high-temperature resistant, non-combustible dust collector bags with explosion-proof windows.

[0010] Its high-temperature resistant and non-combustible dust collector bags only ensure that the dust collector bags will not burn when combustion occurs inside the dust collector, but cannot guarantee that a fire or explosion will not occur.

[0011] The explosion relief window of a bag filter is only used to release the high-pressure gas from the explosion into the atmosphere in the event of a deflagration inside the dust collector, preventing the entire dust collector from being damaged.

[0012] Therefore, existing explosion-proof baghouse dust collector technology for upgraded coal only provides remedial measures in the event of an explosion and cannot ensure that the baghouse dust collector is far removed from the control of oxygen content in the working gas during an explosion. Summary of the Invention

[0013] To address the aforementioned issues, this invention provides a high-quality coal dryer with explosion-proof tail gas dust collector. By utilizing the cooperation of an air supply module and a detection unit, the oxygen and temperature balance in the flue gas during coal powder drying is controlled. This proactively achieves suitable oxygen content and temperature in the tail gas of coal powder drying, keeping the explosion-proof bag filter away from the risk of explosion and deflagration, thus achieving the goal of safe production.

[0014] To achieve the above objectives, the present invention employs the following technical solution: a non-explosion-proof coal dryer with tail gas control dust collector, comprising a burner, a drying cylinder, a receiving hopper, a hydrocyclone, and a tail gas treatment unit connected in sequence. The burner has an air supply module at its inlet end, and a circulation pipe connects the tail gas treatment unit and the air supply module. A main flue for flue gas transport is provided between the hydrocyclone and the tail gas treatment unit, and a tail gas detection device is installed on the main flue. The air supply module includes an inlet pipe and an inlet pipe, with an inlet valve and an inlet valve respectively installed on the inlet pipe and the inlet pipe. The inlet pipe is connected to the circulation pipe.

[0015] As a further improvement to the above technical solution: The exhaust gas detection device includes a temperature sensor and an oxygen content detection sensor.

[0016] A closed-loop feeder is installed at the connection between the burner and the drying cylinder, and a feeding conveyor belt is installed above the closed-loop feeder.

[0017] The exhaust gas treatment unit includes an induced draft fan. The feed end of the induced draft fan is provided with an induced draft pipe 1 and an induced draft pipe 2, and the discharge end is provided with an air supply pipe connected to the circulation pipeline.

[0018] A dust removal device is installed between the exhaust pipe and the main flue, and a temperature sensor is installed on the exhaust pipe.

[0019] The set temperature of temperature sensor 2 is lower than the set temperature of temperature sensor 1.

[0020] The dust removal device includes a bag filter and a nitrogen generator, and the feed end of the bag filter is provided with a transfer pipe connected to the main flue.

[0021] The transfer pipe is equipped with a control valve one, and the air duct two is equipped with a control valve two.

[0022] A cooling branch pipe is installed on the air supply pipe, and a flue gas cooling device is installed between the output end of the cooling branch pipe and the circulation pipe. A control valve is installed on the cooling branch pipe.

[0023] The flue gas cooling device includes a spray tower and a spray water tank, and a circulating pump is installed between the spray tower and the spray water tank.

[0024] The beneficial effects of this invention are as follows: The explosion-proof upgraded coal dryer with tail gas control dust collector includes a burner, a drying cylinder, a receiving hopper, a cyclone separator, and a tail gas treatment unit connected in sequence. The burner is equipped with an air supply module at its air inlet end. A main flue pipe for flue gas transportation is provided between the cyclone separator and the tail gas treatment unit. A tail gas detection device is provided on the main flue pipe. By cooperating with the air supply module and the detection unit, the oxygen and temperature balance in the flue gas of coal powder drying is controlled, and the oxygen content and temperature of the tail gas of coal powder drying are made suitable, so that the explosion-proof bag dust collector is kept away from the risk of explosion and deflagration, and the goal of safe production is achieved. When temperature sensor 2 detects that the temperature of the exhaust gas after being treated by the bag filter exceeds the set value, it can guide the high-temperature flue gas into the induced draft pipe 2, and then the induced draft fan will transport the high-temperature flue gas to the flue gas cooling device, thereby controlling the temperature in the bag filter to remain within a safe range and preventing deflagration or explosion. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is the front view of the present invention; Figure 4 This is a flowchart of the present invention.

[0026] In the diagram: 1. Burner; 2. Drying cylinder; 3. Receiving hopper; 4. Hydrocyclone; 5. Circulation pipe; 6. Inlet pipe 1; 7. Inlet pipe 2; 8. Inlet valve 1; 9. Inlet valve 2; 10. Temperature sensor 1; 11. Oxygen content sensor; 12. Air-closing feeder; 13. Feeding conveyor belt; 14. Exhaust fan; 15. Exhaust pipe 1; 16. Exhaust pipe 2; 17. Air supply pipe; 18. Temperature sensor 2; 19. Baghouse dust collector; 20. Nitrogen generator; 21. Transfer pipe; 22. Control valve 1; 23. Control valve 2; 24. Cooling branch pipe; 25. Control valve 3; 26. Spray tower; 27. Spray water tank; 28. Circulation pump; 29. ​​Main flue. Detailed Implementation

[0027] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0028] like Figure 1-4 As shown in the figure, this embodiment discloses a non-explosion-proof coal dryer with tail gas control dust collector, including a burner 1, a drying cylinder 2, a receiving bin 3, a hydrocyclone 4 and a tail gas treatment unit connected in series. The burner 1 serves as the heat source for drying, and its air inlet is equipped with an air supply module to provide the combustion gas required for the burner 1. At the same time, a circulation pipe 5 is provided between the tail gas treatment unit and the air supply module to realize the recovery and recycling of tail gas.

[0029] A main flue gas pipe 29 for conveying flue gas is provided between the hydrocyclone 4 and the tail gas treatment unit. The dust-laden tail gas generated in the drying cylinder 2 is partially separated by the receiving bin 3 and then enters the hydrocyclone 4 for preliminary dust removal, removing most of the large dust particles in the tail gas. It is then conveyed to the tail gas treatment unit for further treatment through the main flue gas pipe 29. In order to monitor the tail gas status in real time, a tail gas detection device is provided on the main flue gas pipe 29. The tail gas detection device specifically includes a temperature sensor 10 and an oxygen content detection sensor 11. The temperature sensor 10 is used to detect the temperature of the tail gas conveyed in the main flue gas pipe 29, and the oxygen content detection sensor 11 is used to detect the oxygen content in the tail gas to control the amount of air entering and the amount of upgraded coal entering. The gas supply module includes two parallel intake pipes, 6 and 7. Intake pipe 6 is used to introduce fresh air or fuel gas, providing the initial combustion gas source for burner 1. Intake pipe 7 is connected to the circulation pipe 5, used to introduce a portion of the qualified exhaust gas treated by the exhaust gas treatment unit into burner 1, realizing the recycling of exhaust gas. To achieve precise control of the intake air volume, intake pipe 6 and intake pipe 7 are respectively equipped with intake valve 8 and intake valve 9. By adjusting the opening of the two valves, the oxygen content in the combustion gas can be flexibly controlled.

[0030] The specific method is as follows: when the oxygen content in the exhaust gas exceeds the set value of the oxygen content detection sensor 11, the opening of the intake valve 8 is reduced to control the amount of oxygen-containing air entering, and at the same time the conveying capacity of the air-closing feeder 12 is increased to increase the consumption of oxygen. The oxygen content detection sensor 11, the intake valve 8 and the air-closing feeder 12 form an exhaust gas oxygen content detection system to detect the oxygen content in the exhaust gas in real time. When abnormal results occur, adjustments can be made quickly to control the oxygen content in the exhaust gas from the source, thereby reducing the risk of explosion.

[0031] When temperature sensor 10 detects that the temperature exceeds the set value, it indicates that there is excessive heat released from the combustion of chemical gases during coal dry distillation. It is necessary to reduce or close the intake pipe 6 and open the intake pipe 7 to introduce exhaust gas containing no oxygen or only trace amounts of oxygen and water vapor into the burner 1. This cools the combustion zone, reduces the coal dry distillation temperature, and minimizes the emission and combustion of dry distillation gases. Ultimately, this reduces the temperature of the drying exhaust gas, preventing it from becoming too hot and causing deflagration or explosion in the dust collector.

[0032] A closed-loop feeder 12 is installed at the connection between the burner 1 and the drying cylinder 2. The closed-loop feeder 12 has dual functions of locking air and feeding. It can continuously convey the upgraded coal to be dried into the drying cylinder 2, and effectively isolate the drying cylinder 2 from the outside air, ensuring that the drying cylinder 2 can only enter from the air inlet pipe 6, which facilitates precise control of the oxygen content in the drying cylinder 2. A feeding conveyor belt 13 is installed above the closed-loop feeder 12. The discharge end of the feeding conveyor belt 13 corresponds to the inlet of the closed-loop feeder 12, and is used to continuously convey the upgraded coal to be dried to the closed-loop feeder 12.

[0033] The exhaust gas treatment unit includes an induced draft fan 14, which provides power for the entire exhaust gas conveying and treatment process. Its inlet end is equipped with an induced draft pipe 15 and an induced draft pipe 16, which are respectively connected to the main flue 29, conveying exhaust gases of different temperatures along different paths. A dust removal device is installed between the induced draft pipe 15 and the main flue 29. The dust removal device includes a bag filter 19 and a nitrogen generator 20. The bag filter 19 is used for deep dust removal of the exhaust gas, removing fine dust particles. The exhaust gas in the main flue 29 is connected to the main flue 29 via the transfer pipe 21. The exhaust gas in the main flue 29 enters the bag filter 19 via the transfer pipe 21. The nitrogen generator 20 is used to introduce nitrogen into the bag filter 19 to reduce the oxygen content in the bag filter 19 and prevent the dust adsorbed on the filter bags from oxidizing and heating up, thus achieving explosion-proof protection for the dust collector. The exhaust end of the induced draft fan 14 is connected to the circulation pipe 5 via the air supply pipe 17. The exhaust gas is sent into the circulation pipe 5 through the air supply pipe 17 and then enters the burner 1.

[0034] Using the induced draft fan 14 and the bag filter 19 to complete the exhaust gas dust removal operation is also the normal operating procedure of this equipment. After the exhaust gas is treated, it is either recycled or discharged uniformly. When the exhaust gas temperature entering the bag filter 19 is too high, it is very easy to cause the bag filter to explode. Therefore, a temperature sensor 2 18 is installed on the induced draft duct 15. When the exhaust gas temperature is detected to be too high, the control valve 1 22 is closed and the control valve 2 23 is opened. The high temperature exhaust gas enters the flue gas cooling device through the induced draft duct 2 16 to ensure that the operating temperature inside the bag filter 19 is within a safe range.

[0035] The high-temperature exhaust gas passing through the second exhaust pipe 16 will enter the cooling branch pipe 24 installed on the exhaust pipe 17 after passing through the exhaust fan. A flue gas cooling device is installed between the output end of the cooling branch pipe 24 and the circulation pipe 5. A control valve 25 is installed on the cooling branch pipe 24. At this time, opening the regulating control valve 25 can control the exhaust gas to enter the flue gas cooling device for cooling before being sent to the circulation pipe 5.

[0036] The flue gas cooling device includes a spray tower 26 and a spray water tank 27. A circulation pump 28 is installed between the spray tower 26 and the spray water tank 27. The spray water tank 27 stores cooling water. The circulation pump 28 transports the cooling water in the spray water tank 27 to the spray tower 26. The cooling water is atomized through the spray head and comes into full contact with the high-temperature exhaust gas transported by the cooling branch pipe 24 to achieve heat exchange and reduce the exhaust gas temperature. The cooled exhaust gas enters the circulation pipe 5 and is then sent to the burner 1 through the second air inlet pipe 7 for recycling. The cooling water after spraying flows back to the spray water tank 27 and can be recycled again after cooling treatment, saving water resources.

[0037] Operating procedure: Burner 1 is circulated with exhaust gas and oxygen-containing air for combustion, and the generated high-temperature gas enters the drying cylinder 2 to dry and heat the upgraded coal. Then, the dried exhaust gas and material are transported to the receiving hopper 3. After passing through the hydrocyclone for preliminary impurity removal, the high-temperature exhaust gas is transported to the main flue 29. An exhaust gas detection device is installed in the main flue 29. The exhaust gas detection device includes a temperature sensor 10 and an oxygen content detection sensor 11 for detecting the oxygen content and temperature of the exhaust gas. When the oxygen content in the exhaust gas exceeds the set value of the oxygen content detection sensor 11, the opening of the intake valve 8 is reduced to control the amount of oxygen-containing air entering. At the same time, the conveying capacity of the air-closing feeder 12 is increased to increase the consumption of oxygen. The oxygen content detection sensor 11, the intake valve 8, and the air-closing feeder 12 form an exhaust gas oxygen content detection system to detect the oxygen content in the exhaust gas in real time. When abnormal results occur, adjustments can be made quickly to control the oxygen content in the exhaust gas from the source and reduce the risk of explosion from the source. When temperature sensor 10 detects that the temperature exceeds the set value, it indicates that there is excessive heat released from the combustion of chemical gases during coal dry distillation. It is necessary to reduce or close the intake pipe 6 and open the intake pipe 7 to introduce exhaust gas containing no oxygen or a small amount of oxygen and water vapor into the burner 1. This cools the combustion zone, reduces the coal dry distillation temperature, reduces the emission of dry distillation gas, and reduces the combustion of dry distillation gas, thereby ultimately reducing the temperature of the drying exhaust gas and preventing the exhaust gas temperature from being too high, which could lead to deflagration or explosion of the dust collector. When the exhaust gas passes the test module, under normal operating conditions, the exhaust gas enters the bag filter for treatment. The treated exhaust gas is then drawn out by the induced draft fan and transported to the circulation pipe 5 as a combustion aid for secondary use. When the temperature sensor 2 detects that the exhaust gas temperature is too high, control valve 1 22 closes and control valve 2 23 opens. The high-temperature exhaust gas enters the flue gas cooling device through the induced draft pipe 2 16 to ensure that the operating temperature inside the bag filter 19 is within a safe range.

[0038] It should be noted that in the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0041] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A non-explosion-proof coal dryer with tail smoke control dust collector, characterized in that, It includes a burner (1), a drying cylinder (2), a receiving bin (3), a hydrocyclone (4) and a tail gas treatment unit connected in sequence. The air inlet end of the burner (1) is provided with an air supply module, and a circulation pipe (5) is provided between the tail gas treatment unit and the air supply module. A main flue pipe (29) for conveying flue gas is provided between the cyclone separator (4) and the exhaust gas treatment unit, and an exhaust gas detection device is provided on the main flue pipe (29); The gas supply module includes an air inlet pipe 1 (6) and an air inlet pipe 2 (7). An air inlet valve 1 (8) and an air inlet valve 2 (9) are respectively provided on the air inlet pipe 1 (6) and the air inlet pipe 2 (7). The air inlet pipe 2 (7) is connected to the circulation pipe (5).

2. The non-explosion-proof coal dryer with tail gas control dust collector according to claim 1, characterized in that, The exhaust gas detection device includes a temperature sensor (10) and an oxygen content detection sensor (11).

3. The non-explosion-proof coal dryer with tail smoke control dust collector according to claim 1, characterized in that, A closed-loop feeder (12) is provided at the connection between the burner (1) and the drying cylinder (2), and a feeding conveyor belt (13) is provided above the closed-loop feeder (12).

4. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 1, characterized in that, The exhaust gas treatment unit includes an induced draft fan (14), the feed end of which is provided with an induced draft pipe one (15) and an induced draft pipe two (16), and the discharge end is provided with an air supply pipe (17) connected to the circulation pipe (5).

5. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 4, characterized in that, A dust removal device is provided between the first exhaust pipe (15) and the main smoke pipe (29), and a second temperature sensor (18) is provided on the first exhaust pipe (15).

6. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 5, characterized in that, The set temperature of the second temperature sensor (18) is lower than the set temperature of the first temperature sensor (10).

7. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 5, characterized in that, The dust removal device includes a bag filter (19) and a nitrogen generator (20). The feed end of the bag filter (19) is provided with a transfer pipe (21) connected to the main flue (29).

8. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 7, characterized in that, The transfer pipe (21) is equipped with a control valve one (22), and the air duct two (16) is equipped with a control valve two (23).

9. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 4, characterized in that, A cooling branch pipe (24) is provided on the air supply pipe (17). A flue gas cooling device is provided between the output end of the cooling branch pipe (24) and the circulation pipe (5). A control valve (25) is provided on the cooling branch pipe (24).

10. The explosion-free upgraded coal dryer with tail gas control dust collector according to claim 9, characterized in that, The flue gas cooling device includes a spray tower (26) and a spray water tank (27), and a circulating pump (28) is provided between the spray tower (26) and the spray water tank (27).

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