A device and method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke

Abstract

The invention discloses a device and method for purifying high-temperature dusty oil and gas and recovering semi-coke from pyrolysis of pulverized coal, which solves the problems of low oil and gas purification and separation efficiency, easy blockage of long-distance transportation equipment of high-temperature semi-coke, difficulty in recovering heat of high-temperature semi-coke and high transportation equipment cost in existing high-temperature dusty oil and gas. The device includes a high-temperature electrostatic precipitator, which is used for gas-solid separation and fine dust removal of pyrolysis oil and gas to obtain clean pyrolysis oil and gas, and the separated pyrolysis semi-coke is transported to a water-cooled screw conveyor through an embedded scraper conveyor; the water-cooled screw conveyor is used to cool the pyrolysis semi-coke to reduce the temperature of the pyrolysis semi-coke to 380-420°C; the sending tank is used to receive the pyrolysis semi-coke from the water-cooled screw conveyor and transport the pyrolysis semi-coke to a combustion boiler for secondary utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature dust removal, and more specifically to a device and method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke. Background Art

[0002] Coal pyrolysis is the process of heating and evaporating coal in an anaerobic environment. It is a technology that utilizes coal in a graded manner according to its own characteristics to extract high value-added products such as coal gas, tar, and semi-coke, truly realizing the comprehensive resource utilization of coal.

[0003] The high-temperature dusty oil and gas produced by pyrolysis of pulverized coal does not undergo efficient purification of the high-temperature oil and gas (450℃~600℃). The tar product obtained by condensing and washing the tar is dark brown. It is a mixture of liquid tar, semi-coke, and combustion fly ash. Due to its insufficient purity, the tar can only be used as a fuel for secondary utilization at present, with low added value, and the pyrolysis process of pulverized coal is immature.

[0004] The method of purifying and separating dusty tar to obtain clean tar is difficult and costly, and is not suitable for industrial application. Only by performing gas-solid separation before tar condensation at the front end of the process can clean coal gas and clean tar gas be obtained more economically.

[0005] Efficient dust purification (450℃~600℃) of high-temperature dusty oil and gas from pulverized coal pyrolysis is a common technical problem in the pyrolysis process. Conventional dust removal technology cannot meet the process requirements of coal pyrolysis production, resulting in excessively high ash content in tar products, which cannot be efficiently utilized, and to a certain extent restricts the development of coal pyrolysis technology. At the same time, the dust captured by the dust collector in the pulverized coal pyrolysis process contains a large proportion of semi-coke. The hot semi-coke carrying a large amount of energy needs to be efficiently recycled to improve the overall energy efficiency of the process. The existing technology uses a cyclone separator to remove dust from high-temperature dusty oil and gas. The collected dust is cooled to below 100℃ by water cooling equipment and then sent to the boiler for combustion by a pneumatic conveying system.

[0006] In the existing technology, the efficiency of oil, gas and dust separation is not high, resulting in excessive dust content in the recovered tar and coal gas, which cannot be used efficiently; the efficiency of oil, gas and dust separation is not high, which easily causes blockage of subsequent equipment in the pyrolysis system; dust cooling and transportation are adopted, and the separated dust is cooled to below 100°C and then transported to the boiler furnace through the gas ash conveying system. Because the dust will inevitably be mixed with a small amount of pyrolysis gas during the transportation process from the separation equipment into the gas ash conveying system, the cooling of the pyrolysis gas will cause tar precipitation, which will block the water cooling and pneumatic conveying equipment. The low pneumatic conveying temperature will increase the investment in water cooling equipment and increase the consumption of water resources. The pyrolysis dust is cooled to below 100°C by water cooling equipment and then returned to the furnace for combustion, which wastes a large amount of sensible heat carried by the high-temperature dust and reduces the overall energy efficiency of the entire process; Summary of the invention

[0007] The embodiment of the present invention provides a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device and method, which solves the problems of low oil and gas purification and separation efficiency, easy clogging of transportation equipment, difficulty in recovering heat of high-temperature semi-coke and high transportation equipment cost in the existing long-distance transportation of high-temperature semi-coke.

[0008] The embodiment of the present invention provides a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device, comprising:

[0009] A high-temperature electrostatic precipitator is connected to the heat exchanger and is used to perform gas-solid separation and fine dust removal on the pyrolysis oil and gas to obtain clean pyrolysis oil and gas. The separated pyrolysis semi-coke is transported to a water-cooled screw conveyor through an embedded scraper conveyor;

[0010] A water-cooling screw conveyor is arranged below the scraper conveyor and is used to cool the pyrolysis semi-coke to reduce the temperature of the pyrolysis semi-coke to 380-420°C;

[0011] The sending tank is connected to the water-cooled screw machine and is used to receive the cooled pyrolysis semi-coke and transport the pyrolysis semi-coke to the combustion boiler for secondary utilization under pressure.

[0012] Preferably, it also includes a high-temperature cyclone dust collector, a spiral conveyor return machine, a buffer ash tank and a heat exchanger;

[0013] The high-temperature cyclone dust collector is connected to the pyrolysis furnace to perform the first dust removal on the pyrolysis oil and gas;

[0014] The spiral conveyor return machine is arranged below the high-temperature cyclone dust collector and connected to the first outlet and the second outlet of the high-temperature cyclone dust collector, and is used to convey the semi-coke from the high-temperature cyclone dust collector to the combustion boiler for secondary utilization;

[0015] The heat exchanger is connected to the first outlet of the high-temperature cyclone dust collector and is used to exchange heat and cool the pyrolysis oil and gas so that the temperature of the pyrolysis oil and gas drops to 450-600°C;

[0016] The inlet of the buffer ash tank is connected to a water-cooling screw machine for buffering the pyrolysis semi-coke after cooling; the outlet of the buffer ash tank is connected to a sending tank.

[0017] Preferably, it also includes a controller, a first outlet of a nitrogen buffer tank, a second outlet valve of a nitrogen buffer tank, a bag filter, a first exhaust valve and a second exhaust valve;

[0018] The top of the buffer ash tank is closed and provided with a first exhaust valve, the top of the sending tank is closed and provided with a second exhaust valve, the bag filter is arranged above the buffer ash tank, and its inlet is connected to the first exhaust valve and the second exhaust valve respectively;

[0019] The nitrogen buffer tank is provided with a first outlet of the nitrogen buffer tank and a second outlet of the nitrogen buffer tank. The first outlet of the nitrogen buffer tank is connected to the bottom of the buffer ash tank, and is used to blow nitrogen to the pyrolytic semi-coke at the bottom of the buffer ash tank; the second outlet valve of the nitrogen buffer tank is connected to the bottom of the sending tank, and is used to blow nitrogen to the pyrolytic semi-coke at the bottom of the sending tank;

[0020] The controller is electrically connected to the first outlet of the nitrogen buffer tank, the second outlet of the nitrogen buffer tank, the first exhaust valve and the second exhaust valve respectively.

[0021] Preferably, it also includes an induced draft fan, a first ash discharge valve and a second ash discharge valve;

[0022] The induced draft fan is used to guide the pyrolysis oil gas from the pyrolysis furnace to the high-temperature cyclone dust collector, guide the pyrolysis oil gas from the high-temperature cyclone dust collector for the first dust removal to the heat exchanger, and guide the pyrolysis oil gas cooled by the heat exchanger to the high-temperature electrostatic precipitator;

[0023] The first ash discharge valve is arranged between the outlet of the buffer tank and the inlet of the sending tank, and is used to control the opening or closing state of the ash conveying pipeline between the outlet of the buffer tank and the inlet of the sending tank;

[0024] The second ash discharge valve is arranged between the outlet of the water-cooling screw machine and the inlet of the buffer ash tank, and is used to control the opening or closing state of the ash conveying pipeline between the outlet of the water-cooling screw machine and the inlet of the buffer ash tank;

[0025] The first ash discharge valve and the second ash discharge valve are electrically connected to the controller respectively.

[0026] Preferably, it also includes a thermocouple, a cold fluid regulating valve, a timer, a first material level meter and a second material level meter;

[0027] The timer is connected to the first ash discharge valve and is used to determine the opening time of the first ash discharge valve;

[0028] The first material level meter and the second material level meter are sequentially arranged in the buffer ash tank from bottom to top, and are used to determine the amount of pyrolysis semi-coke stored in the buffer ash tank;

[0029] The thermocouple is arranged at the inlet of the high-temperature electrostatic precipitator to determine the temperature of the pyrolysis oil gas entering the high-temperature electrostatic precipitator;

[0030] The cold fluid regulating valve is arranged on the heat exchanger and is used to control the flow rate of the cold fluid entering the heat exchanger;

[0031] The cold fluid regulating valve, the thermocouple, the timer, the first material level meter and the second material level meter are electrically connected to the controller respectively.

[0032] Preferably, the water-cooled screw conveyor is an inner and outer double-layer structure, and a gap is left between the inner shell and the outer shell for passing cooling water to cool the high-temperature pyrolysis semi-coke from the buried scraper conveyor;

[0033] A hollow shaft with a reamer is arranged inside the inner shell body, and cooling water is introduced into the hollow shaft with the reamer to cool it down.

[0034] Preferably, the outer layer of the buffer ash tank is provided with a heat-insulating material or a heat-insulating shell;

[0035] The outer layer of the sending tank is provided with a heat-insulating material or a heat-insulating shell;

[0036] A heat-insulating layer is arranged inside the high-temperature electrostatic precipitator and the buried scraper conveyor.

[0037] The embodiment of the present invention provides a method for purifying high-temperature dusty oil and gas and recovering semi-coke by pyrolysis of pulverized coal, which is characterized by being applied to the above-mentioned high-temperature dusty oil and gas purification and semi-coke recovery device for pyrolysis of pulverized coal, comprising:

[0038] When it is determined that the opening time of the first ash discharge valve reaches the first set time value, the first ash discharge valve and the second exhaust valve are closed, and the sending tank is pressurized so that the pressure inside the sending tank reaches the first set pressure value;

[0039] The discharge valve of the sending tank is opened to allow the pyrolysis semi-coke with a temperature between 380 and 420°C from the high-temperature cyclone dust collector, heat exchange in the heat exchanger, gas-solid separation in the high-temperature electrostatic precipitator, cooling in the water-cooled screw machine, and storage in the buffer ash tank to be transferred from the sending tank to the combustion boiler for secondary utilization under pressure; wherein, the high-temperature electrostatic precipitator obtains pyrolysis tar gas and the pyrolysis semi-coke through gas-solid separation; the first ash discharge valve is arranged between the outlet of the buffer tank and the inlet of the sending tank, and the second exhaust valve is arranged on the top of the sending tank.

[0040] Preferably, after the transmission from the sending tank to the combustion boiler for secondary utilization, the method further comprises:

[0041] When it is determined that the pressure of the ash conveying pipeline between the sending tank and the combustion boiler drops to a second set pressure value, closing the discharge valve of the sending tank;

[0042] If it is determined that the storage height of the pyrolytic semi-coke stored in the buffer ash tank is between the first material level meter and the second material level meter, and the opening time of the first ash discharge valve reaches the second set time value, the first ash discharge valve and the first exhaust valve are opened to allow the pyrolytic semi-coke stored in the buffer ash tank to slide to the sending tank through the buffer ash tank outlet and the sending tank inlet under the action of gravity; wherein the first exhaust valve is arranged on the top of the buffer ash tank, and the first exhaust valve is connected to the bag filter;

[0043] Opening a second outlet of a nitrogen buffer tank connected to the sending tank so that nitrogen from the nitrogen buffer tank is blown toward the pyrolytic semi-coke at the bottom of the sending tank;

[0044] The second exhaust valve is opened to balance the pressure in the sending tank, and the second exhaust valve is connected to the bag filter.

[0045] Close the second ash discharge valve provided between the outlet of the water-cooling screw machine and the inlet of the buffer ash tank;

[0046] Turn off the external motor of the buried scraper conveyor to stop the buried scraper conveyor from working.

[0047] Preferably, it also includes:

[0048] The inlet temperature of the high-temperature electrostatic precipitator is between 450 and 600°C. When it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds A+B°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to A°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than AB°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to A°C;

[0049] Among them, 2 <B<31,450<A-B<A<A+B<600。

[0050] The embodiment of the present invention provides a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device and method, the device includes: a high-temperature electrostatic precipitator, which is connected to the heat exchanger, and is used to perform gas-solid separation and fine dust removal on the pyrolysis oil and gas to obtain clean pyrolysis oil and gas, and the separated pyrolysis semi-coke is conveyed to a water-cooled screw conveyor through an embedded scraper conveyor; the water-cooled screw conveyor is arranged below the embedded scraper conveyor, and is used to cool the pyrolysis semi-coke to reduce the temperature of the pyrolysis semi-coke to 380-420°C; a sending tank, which is connected to the water-cooled screw conveyor, and is used to receive the cooled pyrolysis semi-coke, and under the action of pressure, convey the pyrolysis semi-coke to a combustion boiler for secondary utilization. The device uses a high-temperature cyclone dust collector to roughly remove dust from the pyrolysis oil and gas from the pyrolysis furnace. The semi-coke collected for the first time can be reused in the combustion boiler; the roughly dusted pyrolysis oil and gas are used for the first waste heat through a heat exchanger, and the pyrolysis oil and gas after the first cooling are separated into gas and solid in a high-temperature electrostatic precipitator. The purified clean hot coal gas and tar gas are subsequently subjected to processes such as gas graded condensation and electrostatic coke capture to obtain clean coal gas and high-value-added liquid tar that meets chemical needs; the pyrolysis semi-coke is transported to the water-cooled screw machine by an buried scraper conveyor, and the temperature of the pyrolysis semi-coke of the water-cooled screw machine is It is reduced to 380-420℃, at which temperature the tar in the pyrolytic semi-coke is still in a gaseous state, which can ensure the fluidity of the pyrolytic semi-coke and reduce the risk of clogging of the conveying equipment; furthermore, when the pyrolytic semi-coke is cooled to 380-420℃, its heat loss is relatively small and the available heat is relatively high; and the pyrolytic semi-coke at about 380-420℃ has relatively low requirements for heat resistance and wear resistance of the conveying equipment during transportation, which can reduce the requirements of the conveying equipment for the preparation of materials, reduce the design and operation difficulty of direct high-temperature ash conveying, improve the reliability of the equipment, and reduce a lot of costs. It solves the problems of low oil and gas purification and separation efficiency of existing high-temperature dusty oil and gas, easy clogging of long-distance conveying equipment of high-temperature semi-coke, difficulty in recovering heat of high-temperature semi-coke, and high cost of conveying equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] 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.

[0052] Figure 1 A schematic diagram of the structure of a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device provided in an embodiment of the present invention;

[0053] Figure 2 A schematic diagram of the structure of a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device provided in an embodiment of the present invention;

[0054] Figure 3 A schematic diagram of the structure of a water-cooled spiral machine provided in an embodiment of the present invention;

[0055] Figure 4 A schematic diagram of the structure of a buffer ash tank provided in an embodiment of the present invention;

[0056] Figure 5 A schematic diagram of the structure of a sending tank provided in an embodiment of the present invention;

[0057] Figure 6 A schematic flow chart of a method for purifying high-temperature dusty oil and gas and recovering semi-coke by pyrolysis of pulverized coal provided in an embodiment of the present invention.

[0058] Among them, pyrolysis furnace ~101, high temperature cyclone dust collector ~102, heat exchanger ~103, high temperature electric precipitator ~104, buried scraper conveyor ~105, water-cooled screw machine ~106, buffer ash tank ~107, bag dust collector ~108, sending tank ~109, nitrogen buffer tank ~110, combustion boiler ~111, screw conveyor return machine ~112, high temperature first-stage cyclone dust collector ~1021-1, high temperature second-stage cyclone dust collector ~1021-2, second ash discharge valve ~107-1, first exhaust valve ~107-2, first ash discharge valve ~109-1, second exhaust valve ~109-2. DETAILED DESCRIPTION

[0059] 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.

[0060] Figure 1 A schematic diagram of the structure of a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a water-cooled spiral machine provided in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a buffer ash tank provided in an embodiment of the present invention; Figure 5 A schematic diagram of the structure of a sending tank provided in an embodiment of the present invention; Figure 1 to Figure 5 , a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device provided by an embodiment of the present invention is introduced in detail.

[0061] The system mainly includes a high-temperature electrostatic precipitator 104 , a water-cooled screw machine 106 and a sending tank 109 .

[0062] In the embodiment of the present invention, the high-temperature electrostatic precipitator is designed to be resistant to high temperature and pressure, and adopts a horizontal cylindrical structure. The high-temperature deformation is small, and the equipment can withstand a certain pressure. If a local explosion occurs during the electrostatic precipitator, the explosion relief pressure can be discharged through the high-temperature explosion relief valve without damaging the pressure-bearing structure of the equipment. The overall thermal insulation design of the high-temperature electrostatic precipitator 104 can isolate the influence of high temperature on the equipment shell and ring beam, thereby ensuring the stable operation of the equipment. After the pyrolysis oil and gas enter the high-temperature electrostatic precipitator 104, the gas and solid are separated to obtain clean pyrolysis oil and gas. The high-temperature electrostatic precipitator 104 has low equipment resistance, small pressure loss of the pyrolysis oil and gas, uniform airflow distribution, and high efficiency in collecting fine particles for gas-solid separation. The high-temperature electrostatic precipitator adopts the technology of built-in ash hopper for clearing ash accumulation, decoking and thermal insulation transportation. The equipment has high high-temperature stability, low failure rate, and small temperature loss of pyrolysis semi-coke ash. The equipment has low resistance and is easy to couple into the original pyrolysis process system without adversely affecting the subsequent clean pyrolysis oil and gas processing equipment. At the same time, the clean oil and gas after secondary dust removal can reduce the resistance and blockage risk of subsequent systems in subsequent processing, reduce the wear of subsequent equipment, and the obtained clean coal gas is of higher quality. The obtained liquefied tar products can meet the needs of chemical industry and significantly improve the system efficiency.

[0063] In the embodiment of the present invention, the buried scraper conveyor 105 is coupled with the high-temperature electrostatic precipitator 104 using an internal insulation structure, which can ensure that the temperature drop in the equipment is less than 50°C, thereby solving the problem of coking and blockage of pyrolysis coke caused by cooling. Furthermore, the collected pyrolysis coke is transported to the water-cooled screw conveyor through the buried scraper conveyor 105.

[0064] Furthermore, the water-cooling screw machine 106 cools down the pyrolysis coke. In practical applications, considering the subsequent secondary utilization of the pyrolysis coke, the temperature of the pyrolysis coke is only reduced to about 380-420° C. through the water-cooling screw machine 106 .

[0065] In the embodiment of the present invention, the pyrolytic semi-coke is cooled to about 380-420°C by the water-cooling screw machine 106. On the one hand, the tar of the pyrolytic semi-coke at the above temperature is still in a gaseous state, which can ensure the fluidity of the pyrolytic semi-coke and avoid the problem of clogging of the conveying equipment caused by the condensation of the tar in the pyrolytic semi-coke. On the other hand, since the pneumatic conveying system includes many valves, the valves are easily damaged after long-term use. Generally, CrMo steel is used for valves, which has a better economic effect. Similarly, CrMo steel has a better wear resistance when the temperature is between 350°C and 450°C. Therefore, the pyrolytic semi-coke is cooled to about 380-4 When the temperature is around 20℃, the service life of the valve can be extended and the system cost can be reduced. On the one hand, the water-cooled screw machine 106 subsequently includes a sending tank 109, which is aimed at pyrolytic semi-coke with a temperature between 380°-420°. Therefore, the sending tank 109 can be made of low-alloy steel and part of boiler steel with slightly lower cost, compared with heat-resistant stainless steel used at high temperatures, which reduces the cost of subsequent equipment in the system. On the other hand, the temperature of the pyrolytic semi-coke after cooling is between 380-420℃, which itself carries a large amount of sensible heat, and the semi-coke is also a very good fuel. After being pneumatically transported to the combustion furnace, it can be effectively reused for a second time, which is more efficient than only using the calorific value of the semi-coke itself after cooling.

[0066] Furthermore, after the pyrolysis semi-coke is cooled by the water-cooling screw machine 106, it can enter the sending tank 109 through the outlet of the water-cooling screw machine. The sending tank 109 is arranged below the water-cooling screw machine 106. Under the action of gravity, the pyrolysis semi-coke in the water-cooling screw machine 106 can flow into the sending tank 109. The pyrolysis semi-coke in the sending tank 109 is transported to the combustion boiler 111 under pressure for secondary utilization.

[0067] The embodiment of the present invention provides a device for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke, which uses a high-temperature cyclone dust collector to roughly remove dust from the pyrolysis oil and gas from the pyrolysis furnace, and the semi-coke collected for the first time can be reused in the combustion boiler; the roughly dusted pyrolysis oil and gas are first utilized for waste heat through a heat exchanger, and the pyrolysis oil and gas after the first temperature reduction are separated into gas and solid in a high-temperature electrostatic precipitator, and the purified clean hot coal gas and tar gas are subsequently subjected to processes such as coal gas graded condensation and electrostatic coke capture to obtain clean coal gas and high-value-added liquid tar that meets chemical industry needs; the pyrolysis semi-coke is transported to a water-cooled screw machine by an buried scraper conveyor The temperature of the pyrolysis semi-coke will be reduced to 380-420℃ by the water-cooled screw machine. At this temperature, the tar in the pyrolysis semi-coke is still in a gaseous state, which can ensure the fluidity of the pyrolysis semi-coke and reduce the risk of clogging of the conveying equipment. Furthermore, the pyrolysis semi-coke is cooled to 380-420℃, and its heat loss is relatively small, and the available heat is relatively high. In addition, the pyrolysis semi-coke at about 380-420℃ has relatively low requirements for heat resistance and wear resistance of the conveying equipment during transportation, which can reduce the requirements of the conveying equipment for the preparation of materials, reduce the design and operation difficulty of direct high-temperature ash conveying, improve the reliability of the equipment, and reduce a lot of costs. The existing problems of long-distance transportation of high-temperature semi-coke, such as easy clogging of the conveying equipment, difficulty in recovering the heat of the high-temperature semi-coke, and high cost of the conveying equipment, are solved.

[0068] For example, the device further includes a pyrolysis furnace 101 , a high-temperature cyclone dust collector 102 , a heat exchanger 103 , an embedded scraper conveyor 105 , a buffer ash tank 107 and a screw conveyor return machine 112 .

[0069] Specifically, the high-temperature cyclone dust collector 102 is connected to the pyrolysis furnace 101, and the pyrolysis oil and gas generated by the pyrolysis furnace 101 with a temperature between 500 and 900°C enters the high-temperature cyclone dust collector 102 for the first dust removal, also known as rough dust removal; the high-temperature cyclone dust collector 102 is small and does not include any moving parts inside, and performs dust removal under high temperature conditions. The equipment is stable and reliable, and the dust removal effect is good; furthermore, after rough dust removal by the high-temperature cyclone dust collector 102, the solid particles in the pyrolysis oil and gas are greatly reduced, which can reduce the wear of the subsequent internal pipelines of the heat exchanger 103.

[0070] Furthermore, the pyrolysis oil gas after rough dust removal flows to the heat exchanger 103 through the first outlet of the high-temperature cyclone dust collector 102; the temperature of the pyrolysis oil gas after passing through the heat exchanger 103 drops to between 450-600°C, and then flows to the high-temperature electrostatic precipitator 104. It should be noted that in actual applications, the heat exchanger 103 can use sensible heat to preheat raw materials or convert them into kinetic energy or electrical energy to reduce process energy consumption.

[0071] Furthermore, after the pyrolysis semi-coke is cooled by the water-cooling screw machine 106, it can enter the buffer ash tank 107 through the outlet of the water-cooling screw machine. In actual application, the inlet of the buffer ash tank is connected to the outlet of the water-cooling screw machine, and the pyrolysis semi-coke after cooling enters the buffer ash tank 107 for buffering. It should be noted that the buffer ash tank 107 uses low-alloy steel and part of boiler steel with slightly lower cost, which reduces the cost of subsequent equipment in the system compared to heat-resistant stainless steel used at high temperatures.

[0072] Furthermore, the sending tank 109 is arranged below the buffer ash tank 107, and the pyrolysis semi-coke in the buffer ash tank 107 can flow into the sending tank 109 under the action of gravity. The pyrolysis semi-coke in the sending tank 109 is transported to the combustion boiler 111 under pressure for secondary utilization.

[0073] Furthermore, a screw conveyor return machine 112 is arranged below the high-temperature cyclone dust collector 102 and connected to the first and second outlets of the high-temperature cyclone dust collector 102, for conveying the semi-coke from the high-temperature cyclone dust collector 102 to the combustion boiler 111 for secondary utilization, wherein the semi-coke is obtained by the first dust removal.

[0074] For example, the device includes a high-temperature cyclone dust collector 102, which can also be divided into a high-temperature primary cyclone dust collector 102-1 and a high-temperature secondary cyclone dust collector 1021-2. Specifically, the inlet of the high-temperature primary cyclone dust collector 102-1 is connected to the outlet of the pyrolysis furnace 101, and is used to perform the first primary dust removal on the pyrolysis oil gas with a temperature between 500-900°C generated by the pyrolysis furnace 101. After the pyrolysis oil gas passes through the high-temperature primary cyclone dust collector 102-1 for the first rough dust removal, the pyrolysis oil gas The solid particles in the gas are greatly reduced. In order to improve the dust removal rate, a high-temperature secondary cyclone dust collector 1021-2 is also connected to the first outlet direction of the high-temperature primary cyclone dust collector 102-1. That is, the pyrolysis oil and gas after the first rough dust removal by the high-temperature primary cyclone dust collector 102-1 enters the high-temperature secondary cyclone dust collector 1021-2 and undergoes the second primary dust removal, thereby greatly reducing the solid particles in the pyrolysis oil and gas and reducing the wear of the subsequent internal pipelines of the heat exchanger 103.

[0075] It should be noted that the high-temperature first-stage cyclone dust collector 102-1 includes a first outlet, one end of which is connected to the inlet of the high-temperature second-stage cyclone dust collector 1021-2, and the other end is connected to the spiral conveyor return device; the high-temperature first-stage cyclone dust collector 102-1 includes a first outlet, one end of which is connected to the inlet of the heat exchanger 103, and the other end is connected to the spiral conveyor return device; further, the second outlets included in the high-temperature first-stage cyclone dust collector 102-1 and the high-temperature second-stage cyclone dust collector 1021-2 are also connected to the spiral conveyor return device, which is used to transport the semi-coke obtained from the two first-stage dust removals to the combustion boiler 111 for secondary utilization.

[0076] In the embodiment of the present invention, since the top of the buffer ash tank 107 is closed, in order to avoid the problem of unsmooth flow of the pyrolysis coke due to pressure problems when the pyrolysis coke flows from the buffer ash tank 107 into the sending tank 109, preferably, a first exhaust valve 107-2 is provided on the top of the buffer ash tank 107. The pressure in the buffer ash tank 107 can be balanced through the first exhaust valve 107-2, thereby facilitating the pyrolysis coke to flow smoothly from the buffer ash tank 107 into the sending tank 109.

[0077] Furthermore, when the pyrolytic coke flows from the buffer ash tank 107 into the sending tank 109, since the top of the sending tank 109 is closed and its outlet is also closed, in order to avoid excessive pressure in the sending tank 109, which may cause the pyrolytic coke to not flow smoothly into the sending tank 109, preferably, a second exhaust valve 109-2 is provided on the top of the sending tank 109. The pressure in the sending tank 109 can also be balanced through the second exhaust valve 109-2.

[0078] For example, the device also includes a nitrogen buffer tank 110, which includes a first nitrogen buffer tank outlet and a second nitrogen buffer tank outlet, wherein the first nitrogen buffer tank outlet is connected to the bottom of the buffer ash tank 107, and is used to blow nitrogen to the pyrolytic coke at the bottom of the buffer ash tank 107, thereby preventing the pyrolytic coke from accumulating and agglomerating at the bottom of the buffer ash tank 107, thereby causing the problem of clogging the bottom of the buffer ash tank 107; the second nitrogen buffer tank outlet is connected to the bottom of the sending tank 109, and is used to blow nitrogen to the pyrolytic coke at the bottom of the sending tank 109, thereby preventing the pyrolytic coke from accumulating and agglomerating at the bottom of the sending tank 109, thereby causing the problem of clogging the bottom of the sending tank 109.

[0079] It should be noted that, in actual applications, the method of blowing nitrogen from the nitrogen buffer tank 110 to the pyrolysis semi-coke at the bottom of the buffer ash tank 107 and the bottom of the sending tank 109 is called nitrogen fluidization.

[0080] For example, the device also includes a bag dust collector, which is arranged above the buffer ash tank 107, and its inlet is connected to the first exhaust valve 107-2 arranged on the top of the buffer ash tank 107. The first exhaust valve 107-2 can balance the pressure of the buffer ash tank 107 while allowing the air from the buffer tank to enter the bag dust collector. The bag dust collector removes dust from the incoming air and then discharges it, thereby preventing the gas discharged from the first exhaust valve 107-2 from polluting the environment.

[0081] Correspondingly, the second exhaust valve 109-2 arranged on the top of the sending tank 109 is also connected to the above-mentioned bag dust collector. The second exhaust valve 109-2 can balance the pressure of the sending tank 109 while allowing the air from the sending tank 109 to enter the bag dust collector. The bag dust collector removes dust from the incoming air and then discharges it, thereby avoiding the gas discharged from the second exhaust valve 109-2 from polluting the environment.

[0082] For example, the device also includes an induced draft fan, which is used to lead the pyrolysis oil and gas from the pyrolysis furnace 101 to the high-temperature cyclone dust collector 102, lead the pyrolysis oil and gas from the high-temperature cyclone dust collector 102 that has undergone the first dust removal to the heat exchanger 103, and lead the pyrolysis oil and gas from the heat exchanger 103 that has been cooled to the high-temperature electrostatic precipitator 104. In actual applications, an induced draft fan is provided at the end of the entire pyrolysis process, so the main pipeline is under negative pressure, and the gas flows along the direction of the main pipeline to the induced draft fan, so the gas does not enter the spiral conveyor return device along the lower ash conveying pipeline.

[0083] In practical applications, the induced draft fan is electrically connected to the controller, and the controller is used to control the working state of the induced draft fan.

[0084] By way of example, the device also includes a first ash unloading valve 109-1, which is arranged between the buffer tank outlet and the sending tank 109 inlet, and is electrically connected to the controller, and is used to further control the opening or closing state of the ash conveying pipeline between the buffer tank outlet and the sending tank inlet according to the control of the controller; a second ash unloading valve 107-1, which is arranged between the water-cooled screw machine outlet and the buffer ash tank inlet, and is electrically connected to the controller, and is used to further control the opening or closing state of the ash conveying pipeline between the water-cooled screw machine outlet and the buffer ash tank inlet according to the control of the controller.

[0085] For example, the device further includes a thermocouple and a cold fluid regulating valve. In order to determine the temperature of the pyrolysis oil gas entering the high-temperature electrostatic precipitator 104, a thermocouple is arranged at the inlet of the high-temperature electrostatic precipitator, and the temperature of the pyrolysis oil gas from the heat exchanger 103 is determined by the thermocouple; at the same time, in order to control the heat exchange efficiency of the heat exchanger 103 to the pyrolysis oil gas, a cold fluid regulating valve is arranged on the heat exchanger 103, and the flow rate of the cold fluid entering the heat exchanger 103 can be adjusted by the cold fluid regulating valve. The above-mentioned thermocouple and cold fluid regulating valve are both electrically connected to the controller.

[0086] For example, the device further includes a timer, which is electrically connected to the first ash discharge valve 109 - 1 and is used to determine the opening time of the first ash discharge valve 109 - 1 .

[0087] For example, the device further comprises a weighing device for determining the weight of the sending tank 109 .

[0088] For example, the device further includes a first material level meter and a second material level meter, which are sequentially arranged in the buffer ash tank 107 from bottom to top, and are used to determine the storage amount of the pyrolytic coke stored in the buffer ash tank 107 .

[0089] For example, the device further includes a pressure inlet and a pressurizing device. The pressure inlet is arranged on the sending tank 109 and is in communication with the pressurizing device.

[0090] For example, the motor included in the scraper conveyor 105 is electrically connected to the controller, and the controller controls the opening or closing of the motor. When the motor is turned on, the scraper conveyor 105 can convey the high-temperature pyrolytic coke to the water-cooled screw machine 106. When the motor is turned off, the high-temperature pyrolytic coke from the high-temperature electrostatic precipitator can be temporarily buffered in the scraper conveyor 105.

[0091] It should be noted that the device also includes a controller, an electrical connection method, the controller is electrically connected to the timer, and the controller is used to determine the opening or closing of the first ash unloading valve 109-1, the second exhaust valve 109-2, the discharge valve of the sending tank 109, the second ash unloading valve 107-1, the boosting equipment, the nitrogen buffer tank 110, etc. according to the time feedback from the timer.

[0092] An electrical connection method, in which the controller is electrically connected to the weighing device, and the weight fed back by the weighing device and the time fed back by the timer determine the opening or closing of the first ash unloading valve 109-1, the second exhaust valve 109-2, the discharge valve of the sending tank 109, the second ash unloading valve 107-1, the boosting equipment, the nitrogen buffer tank 110, etc.

[0093] An electrical connection method, in which a controller is electrically connected to a thermocouple and a cold fluid regulating valve, and the flow rate of the cold fluid regulating valve is controlled according to the temperature fed back by the thermocouple.

[0094] It should be noted that, in actual applications, the distance between the sending tank 109 and the combustion boiler 111 may be relatively long. In order to avoid the problem of reduced transmission speed due to reduced pressure before the pyrolytic semi-coke is transmitted to the combustion boiler 111, preferably, multiple conveying gases can be added to the pipeline between the sending tank 109 and the combustion boiler 111, so that the pyrolytic semi-coke in transportation can be supplemented with gas to avoid clogging of the pyrolytic semi-coke in the pipeline. In the embodiment of the present invention, there is no limitation on the amount of conveying gas added to the pipeline.

[0095] In actual application, valves are also provided between the combustion boiler 111 and the ash conveying pipeline. When the discharge valve of the sending tank 109 is opened, the valve is also opened. Before the discharge valve of the sending tank is closed, the valves between the combustion boiler 111 and the ash conveying pipeline need to be closed first.

[0096] For example, the water-cooled screw machine 106 provided in the embodiment of the present invention is a double-layered inner and outer layer, the inner layer is made of 304 material, the outer layer is made of ordinary carbon steel, and the hollow shaft with reamer is made of 310s material, so as to ensure that it can withstand high temperature when in contact with pyrolytic semi-coke; a gap is left between the inner layer and the outer layer for passing cooling water to cool the high-temperature pyrolytic semi-coke from the buried scraper conveyor 105; the hollow shaft with reamer is arranged inside the water-cooled screw machine 106, and the cooling is also carried out by cooling water. In practical applications, since the shell temperature is lower than 50°C after cooling, the shell material requirements can be reduced, and external insulation is not required.

[0097] It should be noted that the embodiment of the present invention provides a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device, which mainly includes a high-temperature cyclone dust collector 102, a heat exchanger 103, a cyclone separator, a screw feeder, a water-cooled screw machine 106, a buffer ash tank 107 and a sending tank 109. Since the temperature of the pyrolysis oil and gas from the pyrolysis furnace 101 is between 500-900°C, the high-temperature cyclone dust collector 102 needs to keep the pyrolysis oil and gas warm when performing the first dust removal on the pyrolysis oil and gas; when the pyrolysis oil and gas after the first dust removal enters the heat exchanger 103 for heat exchange, it also needs to keep the pyrolysis oil and gas warm; the temperature of the pyrolysis oil and gas after heat exchange is reduced to 450-600°C, and the pyrolysis oil and gas after heat exchange enters the high-temperature electrostatic precipitator 104, which also needs to keep the pyrolysis oil and gas warm when performing gas-solid separation on the pyrolysis oil and gas; the pyrolysis semi-coke from the high-temperature electrostatic precipitator 104 When passing through the buried scraper conveyor 105, the buried scraper conveyor 105 also needs to insulate the pyrolysis semi-coke; the water-cooled screw machine 106 is used to cool the pyrolysis semi-coke, and when the cooled pyrolysis semi-coke enters the buffer ash tank 107 and the sending tank 109, the buffer ash tank 107 and the sending tank 109 also need to insulate and transport the pyrolysis semi-coke. Therefore, in the above embodiment, the high-temperature cyclone dust collector 102, the heat exchanger 103, the cyclone separator, the screw feeder, the water-cooled screw machine 106, the buffer ash tank 107 and the sending tank 109 all need to be insulated, and an insulation layer can be built-in, an insulation layer can be set on the outer layer of the shell, or an insulation material can be set on the outer layer of the shell. In the embodiment of the present invention, the specific insulation form of the high-temperature cyclone dust collector 102, the heat exchanger 103, the cyclone separator, the screw feeder, the water-cooled screw machine 106, the buffer ash tank 107 and the sending tank 109 is not limited.

[0098] Furthermore, the ash conveying pipelines between the high-temperature cyclone dust collector 102, the heat exchanger 103, the cyclone separator, the screw feeder, the water-cooled screw machine 106, the buffer ash tank 107 and the sending tank 109, the ash conveying pipelines between the high-temperature cyclone dust collector 102 and the pyrolysis furnace 101, the ash conveying pipelines between the sending tank 109 and the combustion boiler 111, and the ash conveying pipelines between the spiral conveyor return machine 112 and the high-temperature cyclone dust collector 102 and the combustion boiler 111 are all provided with insulation layers or insulation materials on their outer layers.

[0099] In order to more clearly introduce a pulverized coal pyrolysis high temperature dusty oil and gas purification and semi-coke recovery device provided by an embodiment of the present invention, the following is combined with Figure 6 , a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery method based on the above-mentioned pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device is introduced in detail. The method is applied to a pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device.

[0100] like Figure 6 As shown, the method includes the following two steps:

[0101] Step 101, when it is determined that the opening time of the first ash discharge valve reaches a first set time value, the first ash discharge valve and the second exhaust valve are closed, and the sending tank is pressurized so that the pressure inside the sending tank reaches a first set pressure value;

[0102] Step 102, open the discharge valve of the sending tank, so that the pyrolysis semi-coke with a temperature between 380-420°C from the high-temperature cyclone dust collector for dust removal, the heat exchanger for heat exchange, the high-temperature electrostatic precipitator for gas-solid separation, the water-cooled screw machine for cooling, and the buffer ash tank for storage is transferred from the sending tank to the combustion boiler for secondary utilization under pressure; wherein, the high-temperature electrostatic precipitator separates gas and solid to obtain pyrolysis tar gas and the pyrolysis semi-coke; the first ash discharge valve is arranged between the buffer tank outlet and the sending tank inlet, and the second exhaust valve is arranged on the top of the sending tank.

[0103] It should be noted that the executor of the above-mentioned control method is a controller, which is electrically connected to multiple devices included in the pulverized coal pyrolysis high-temperature dust-containing oil and gas purification and semi-coke recovery device, for example, a second ash unloading valve 107-1 arranged between the outlet of the water-cooled screw machine and the inlet of the buffer ash tank; a first ash unloading valve 109-1 arranged between the outlet of the buffer ash tank and the inlet of the sending tank; an outlet of the second exhaust valve 109-2 arranged on the sending tank 109; a timer arranged on the first ash unloading valve 109-1 or a weighing device arranged at the bottom of the sending tank; a pressure sensor arranged on the sending tank 109, a pressure sensor on the ash conveying pipeline between the sending tank 109 and the combustion boiler 111, a thermocouple arranged on the high-temperature electrostatic precipitator 104, and a cold fluid regulating valve arranged on the heat exchanger 103, etc.

[0104] Before step 101, the pyrolysis oil and gas generated by the pyrolysis furnace 101 has a temperature between 500-900°C, and is subjected to the first dust removal by the high-temperature cyclone dust collector 102. The semi-coke collected after the first dust removal enters the combustion furnace through a screw conveyor return device for combustion utilization; the pyrolysis oil and gas after the first dust removal passes through the heat exchanger 103 for waste heat utilization, and the heat exchanger 103 reduces the temperature of the pyrolysis oil and gas to 450-600°C before entering the high-temperature electrostatic precipitator 104; the high-temperature electrostatic precipitator 104 separates the pyrolysis oil and gas into gas and solids, and the semi-coke and dust contained in the pyrolysis oil and gas are collected and fall into the buried scraper conveyor 105. The purified clean pyrolysis coal gas and tar gas are subsequently subjected to processes such as coal gas graded condensation and electric coke capture to obtain clean coal gas and high-value-added liquid tar that meets chemical needs.

[0105] The buried scraper conveyor 105 adopts an internal insulation structure to couple with the high-temperature electrostatic precipitator 104 to ensure that the temperature drop in the equipment is less than 50°C, and the equipment is not blocked by coking due to the temperature drop. The collected pyrolysis semi-coke is transported to the inlet of the water-cooled screw machine, and the water-cooled screw machine 106 cools the pyrolysis semi-coke.

[0106] The controller controls the opening of the second ash discharge valve 107-1 between the outlet of the water-cooling screw machine and the inlet of the buffer ash tank to allow the cooled pyrolysis coke to enter the buffer ash tank 107; at the same time, in order to prevent the pyrolysis coke from accumulating and agglomerating at the bottom of the buffer ash tank 107; the controller controls the opening of the first outlet of the nitrogen buffer tank 110, and the first outlet of the nitrogen buffer tank is connected to the bottom of the buffer ash tank 107. The nitrogen from the nitrogen buffer tank 110 blows nitrogen toward the pyrolysis coke at the bottom of the buffer ash tank, which can prevent the pyrolysis coke from accumulating and agglomerating at the bottom of the buffer ash tank; at the same time, the controller controls the opening of the first exhaust valve 107-2 set at the top of the buffer ash tank 107 to balance the pressure in the buffer ash tank 107.

[0107] It should be noted that, while the first exhaust valve 107-2 balances the pressure of the buffer ash tank 107, it can also allow the air from the buffer ash tank 107 to enter the bag filter. The bag filter removes dust from the incoming air and then discharges it, thereby preventing the gas discharged from the first exhaust valve 107-2 from polluting the environment.

[0108] Further, when the storage amount of the pyrolytic coke stored in the buffer ash tank 107 reaches the discharge requirement according to the feedback from the first level meter and the second level meter, the controller controls to open the first ash discharge valve 109-1 disposed between the outlet of the buffer ash tank and the inlet of the sending tank, so that the pyrolytic coke in the buffer ash tank 107 slides down to the sending tank 109 under the action of gravity. It should be noted that when the first ash discharge valve 109-1 is opened, the timer disposed on the first ash discharge valve 109-1 starts timing.

[0109] Furthermore, in order to prevent the pyrolytic coke from accumulating and agglomerating at the bottom of the sending tank 109, the controller controls the nitrogen buffer tank 110 to open the second outlet, and the second outlet of the nitrogen buffer tank is connected to the sending tank 109. The nitrogen from the nitrogen buffer tank 110 blows nitrogen to the pyrolytic coke at the bottom of the sending tank, which can prevent the pyrolytic coke from accumulating and agglomerating at the bottom of the sending tank. At the same time, the controller opens the second exhaust valve 109-2 arranged on the top of the sending tank 109 to balance the pressure in the sending tank 109.

[0110] It should be noted that the second exhaust valve 109-2 can not only balance the pressure of the sending tank 109, but also allow the gas from the sending tank 109 to enter the bag dust collector. The bag dust collector removes dust from the incoming gas and then discharges it, thereby preventing the gas discharged from the first exhaust valve 107-2 from polluting the environment.

[0111] It should be noted that when the controller controls the first ash discharge valve 109 - 1 to open, it will control the sending tank discharge valve provided on the sending tank 109 to close.

[0112] In the embodiment of the present invention, since whether the pyrolytic coke in the sending tank 109 reaches the sending amount can be determined by a timer and a weighing device respectively, the control methods corresponding to the above two determination methods are respectively introduced below.

[0113] One way:

[0114] In step 101, when the controller determines that the opening time of the first ash unloading valve 109-1 reaches the first set time value according to the timer, that is, it is determined that the pyrolysis semi-coke flowing from the buffer ash tank 107 into the sending tank 109 meets the sending requirements, the first ash unloading valve 109-1 and the second exhaust valve 109-2 can be controlled to close.

[0115] Further, when it is determined that the first ash unloading valve 109-1, the second exhaust valve 109-2 and the discharge valve of the sending tank 109 are all in the closed state, the boosting device can be turned on. The boosting device increases the pressure of the sending tank 109 through the pressure inlet on the sending tank 109. The controller determines that the pressure of the sending tank 109 reaches the first pressure setting value based on the pressure sensor provided on the sending tank 109, and then turns off the boosting device.

[0116] In step 102, the controller controls the discharge valve of the sending tank to open, and the pyrolysis semi-coke is rapidly transmitted to the combustion boiler 111 through the ash conveying pipeline under the action of pressure for secondary utilization.

[0117] It should be noted that a pressure sensor is also provided on the ash conveying pipeline between the sending tank 109 and the combustion boiler 111. When the controller determines the second set pressure value of the ash conveying pipeline according to the pressure sensor provided on the ash conveying pipeline, the discharge valve of the sending tank 109 can be closed. It should be noted that the second set pressure value is less than the first set pressure value, and when the second pressure setting value is determined, the first ash discharge valve 109-1 needs to be in a closed state.

[0118] In the embodiment of the present invention, since the volume of the buffer ash tank 107 is relatively large, the first ash discharge valve 109-1 can be opened to input the pyrolytic coke into the sending tank 109 only when the pyrolytic coke stored in the buffer ash tank 107 reaches the requirement. Therefore, it is necessary to determine the opening state of the first ash discharge valve 109-1 according to the storage amount of the pyrolytic coke stored in the buffer ash tank 107.

[0119] Specifically, the controller determines whether the first ash discharge valve 109 - 1 is opened according to the pyrolysis coke storage amount information fed back by the first level meter and the second level meter.

[0120] The first case: when it is determined that the storage height of the pyrolytic semi-coke stored in the buffer ash tank 107 is between the first material level meter and the second material level meter, the controller further needs to determine whether the opening time of the first ash discharge valve 109-1 reaches the second set time value before controlling the opening of the first ash discharge valve 109-1, so that the pyrolytic semi-coke stored in the buffer ash tank 107 slides to the sending tank 109 through the buffer ash tank outlet and the sending tank inlet under the action of gravity;

[0121] At the same time, the first exhaust valve 107-2, the second outlet of the nitrogen buffer tank and the second exhaust valve 109-2 are opened.

[0122] It should be noted that when the controller determines that the storage height of the pyrolytic coke stored in the buffer ash tank 107 is between the first level meter and the second level meter, the second ash unloading valve 107-1 arranged between the inlet of the buffer ash tank 107 and the outlet of the water-cooling screw machine 106 is in an open state, and the pyrolytic coke cooled in the water-cooling screw machine 106 enters the buffer ash tank 107 through the first ash unloading valve 109-1.

[0123] In the second case, when it is determined that the storage height of the pyrolytic coke stored in the buffer ash tank 107 exceeds the second material level meter, since the storage amount of the pyrolytic coke stored in the buffer ash tank 107 exceeds the storage requirement, it is not necessary to determine whether the opening time of the first ash discharge valve 109-1 reaches the second set time value, and the controller directly controls the opening of the first ash discharge valve 109-1, so that the pyrolytic coke stored in the buffer ash tank 107 slides to the sending tank 109 through the buffer ash tank outlet and the sending tank inlet under the action of gravity;

[0124] At the same time, the first exhaust valve 107-2, the second outlet of the nitrogen buffer tank and the second exhaust valve 109-2 are opened.

[0125] It should be noted that, when the controller determines that the storage height of the pyrolytic coke stored in the buffer ash tank 107 exceeds the second material level meter, the controller needs to control the state of the second ash unloading valve 107-1 arranged between the inlet of the buffer ash tank and the outlet of the water-cooling screw machine to be closed, that is, stop the pyrolytic coke cooled in the water-cooling screw machine 106 from entering the buffer ash tank 107 through the first ash unloading valve 109-1.

[0126] In order to prevent the pyrolytic coke entering the water-cooled screw machine 106 from losing temperature due to excessive cooling, preferably, the controller switches the motor of the buried scraper conveyor 105 to an off state. Since the outer shell of the buried scraper conveyor 105 can be insulated, the pyrolytic coke can be temporarily buffered in the buried scraper conveyor 105 for insulation.

[0127] In the third case, when it is determined that the storage height of the pyrolytic coke stored in the buffer ash tank 107 is lower than the first material level meter, since the storage amount of the pyrolytic coke stored in the buffer ash tank 107 does not meet the storage requirements, it is not necessary to determine whether the opening time of the first ash unloading valve 109-1 reaches the second set time value, and the controller does not need to open the first ash unloading valve 109-1 until the storage height of the pyrolytic coke stored in the buffer ash tank 107 is higher than the first material level meter and lower than the second material level meter. The control method of the controller refers to the first case.

[0128] Another way,

[0129] In step 101, when the weight of the sending tank 109 fed back by the weighing device reaches the first set weight, the controller determines that the pyrolysis semi-coke flowing into the sending tank 109 from the buffer ash tank 107 meets the sending requirements, and then the first ash discharge valve 109-1 and the second exhaust valve 109-2 can be controlled to close.

[0130] Further, when it is determined that the first ash unloading valve 109-1, the second exhaust valve 109-2 and the discharge valve of the sending tank 109 are all in the closed state, the boosting device can be turned on. The boosting device increases the pressure of the sending tank 109 through the pressure inlet on the sending tank 109. The controller determines that the pressure of the sending tank 109 reaches the first pressure setting value based on the pressure sensor provided on the sending tank 109, and then turns off the boosting device.

[0131] In step 102, the controller controls the discharge valve of the sending tank 109 to open, and the pyrolysis semi-coke is rapidly transferred to the combustion boiler 111 through the ash conveying pipeline under the action of pressure for secondary utilization.

[0132] It should be noted that when the weight of the sending tank 109 fed back by the weighing device reaches the second set weight, the controller can close the sending tank discharge valve. The second set weight value is less than the first set weight value, and when the second set weight value is determined, the first ash discharge valve 109-1 needs to be closed.

[0133] In the embodiment of the present invention, since the volume of the buffer ash tank 107 is relatively large, the first ash discharge valve 109-1 can be opened to input the pyrolytic coke into the sending tank 109 only when the pyrolytic coke stored in the buffer ash tank 107 reaches the requirement. Therefore, it is necessary to determine the opening state of the first ash discharge valve 109-1 according to the storage amount of the pyrolytic coke stored in the buffer ash tank 107.

[0134] Specifically, the controller determines whether the first ash discharge valve 109 - 1 is opened according to the pyrolysis coke storage amount information fed back by the first level meter and the second level meter.

[0135] The first case: when it is determined that the storage height of the pyrolytic semi-coke stored in the buffer ash tank 107 is between the first material level meter and the second material level meter, the controller further needs to determine that the opening time of the first ash discharge valve 109-1 reaches the second set time value before the first ash discharge valve 109-1 can be controlled to open, so that the pyrolytic semi-coke stored in the buffer ash tank 107 slides to the sending tank 109 through the buffer ash tank outlet and the sending tank inlet under the action of gravity;

[0136] At the same time, the first exhaust valve 107 - 2 , the second outlet of the nitrogen buffer tank 110 , and the second exhaust valve 109 - 2 are opened.

[0137] It should be noted that when the controller determines that the storage height of the pyrolytic coke stored in the buffer ash tank 107 is between the first level meter and the second level meter, the second ash unloading valve 107-1 arranged between the inlet of the buffer ash tank and the outlet of the water-cooling screw machine is in an open state, and the pyrolytic coke cooled in the water-cooling screw machine 106 enters the buffer ash tank 107 through the first ash unloading valve 109-1.

[0138] In the second case, when it is determined that the storage height of the pyrolytic coke stored in the buffer ash tank 107 exceeds the second material level meter, since the storage amount of the pyrolytic coke stored in the buffer ash tank 107 exceeds the storage requirement, it is not necessary to determine whether the opening time of the first ash discharge valve 109-1 reaches the second set time value, and the controller directly controls the opening of the first ash discharge valve 109-1, so that the pyrolytic coke stored in the buffer ash tank 107 slides to the sending tank 109 through the buffer ash tank outlet and the sending tank inlet under the action of gravity;

[0139] At the same time, the first exhaust valve 107-2, the second outlet of the nitrogen buffer tank and the second exhaust valve 109-2 are opened.

[0140] It should be noted that, when the controller determines that the storage height of the pyrolytic coke stored in the buffer ash tank 107 exceeds the second material level meter, the controller needs to control the state of the second ash unloading valve 107-1 arranged between the inlet of the buffer ash tank and the outlet of the water-cooling screw machine to be closed, that is, stop the pyrolytic coke cooled in the water-cooling screw machine 106 from entering the buffer ash tank 107 through the first ash unloading valve 109-1.

[0141] In order to prevent the pyrolytic coke entering the water-cooled screw machine 106 from losing temperature due to excessive cooling, preferably, the controller switches the motor of the buried scraper conveyor 105 to an off state. Since the outer shell of the buried scraper conveyor 105 can be insulated, the pyrolytic coke can be temporarily buffered in the buried scraper conveyor 105 for insulation.

[0142] In the third case, when it is determined that the storage height of the pyrolytic coke stored in the buffer ash tank 107 is lower than the first material level meter, since the storage amount of the pyrolytic coke stored in the buffer ash tank 107 does not meet the storage requirements, it is not necessary to determine whether the opening time of the first ash unloading valve 109-1 reaches the second set time value, and the controller does not need to open the first ash unloading valve 109-1 until the storage height of the pyrolytic coke stored in the buffer ash tank 107 is higher than the first material level meter and lower than the second material level meter. The control method of the controller refers to the first case.

[0143] It should be noted that, in the above embodiment, the time length of the first set time value only includes the time period when the first ash discharge valve 109-1 is in the open state, that is, the time when the buffer ash tank 107 transfers the pyrolysis semi-coke to the sending tank 109. The time length of the second set time value includes the time period when the first ash discharge valve 109-1 is in the open state, the pressurization time period of the sending tank 109, the opening time period of the discharge valve of the sending tank 109, and the waiting time period, so the time length of the second set time value is greater than the time length of the first set time value.

[0144] It should be noted that in the above embodiment, since the inlet temperature of the high-temperature electrostatic precipitator 104 can be between 450°C and 600°C, in order to accurately control the heat exchange efficiency of the heat exchanger, preferably, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds A+B°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to A°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than AB°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to A°C.

[0145] In the embodiment of the present invention, A is determined as the reference value of the inlet temperature of the high-temperature electrostatic precipitator, and B is determined as the fluctuation value, wherein 2 <B<31,450<A-B<A<A+B<600。

[0146] For example, when the fluctuation value B is determined to be 3, the value range of the reference value A can be determined to be between 454-596 according to 450<AB<A<A+B<600.

[0147] In one way, taking the reference value A as 454 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 457°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 454°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 451°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 454°C;

[0148] In one way, taking the reference value A as 596 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 599°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 596°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 593°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 596°C;

[0149] In one method, taking the reference value A as 480 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 483°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 480°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 477°C, a flow decrease instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 480°C.

[0150] For example, when the fluctuation value B is determined to be 30, the reference value A can be determined to have a value range of 481 to 569 according to 450<AB<A<A+B<600.

[0151] In one way, taking the reference value A as 481 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 511°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 481°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 451°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 481°C;

[0152] In one way, taking the reference value A as 569 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 599°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 569°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 539°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 569°C;

[0153] In one method, taking the reference value A as 500 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 530°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 500°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 470°C, a flow decrease instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 500°C.

[0154] For example, when the fluctuation value B is determined to be 20, the reference value A can be determined to have a value range of 471 to 579 according to 450<AB<A<A+B<600.

[0155] In one way, taking the reference value A as 471 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 451°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 471°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 491°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 471°C;

[0156] In one way, taking the reference value A as 579 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 599°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 579°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 559°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 579°C;

[0157] In one method, taking the reference value A as 500 as an example, when it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds 520°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 500°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than 480°C, a flow decrease instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to 500°C.

[0158] In summary, the embodiment of the present invention provides a device and method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke, the device comprising: a high-temperature cyclone dust collector connected to the pyrolysis furnace for performing a first dust removal on the pyrolysis oil and gas; a heat exchanger connected to the first outlet of the high-temperature cyclone dust collector for performing heat exchange and cooling on the pyrolysis oil and gas to reduce the temperature of the pyrolysis oil and gas to 450-600°C; a high-temperature electrostatic precipitator connected to the heat exchanger for performing gas-solid separation on the pyrolysis oil and gas to obtain a semi-coke recovery device and a semi-coke recovery device. The separated pyrolytic semi-coke is conveyed to the water-cooling screw conveyor through the buried scraper conveyor; the water-cooling screw conveyor is arranged below the buried scraper conveyor and is used to cool the pyrolytic semi-coke so that the temperature of the pyrolytic semi-coke drops to 380-420°C; a buffer ash tank is connected to the water-cooling screw conveyor and is used to buffer the cooled pyrolytic semi-coke; a sending tank is arranged below the buffer ash tank and is used to receive the pyrolytic semi-coke from the buffer ash tank and convey the pyrolytic semi-coke to the combustion boiler under pressure for secondary utilization. The device uses a high-temperature cyclone dust collector to roughly remove dust from the pyrolysis oil and gas from the pyrolysis furnace. The semi-coke collected for the first time can be reused in the combustion boiler; the roughly dusted pyrolysis oil and gas are used for the first waste heat through a heat exchanger, and the pyrolysis oil and gas after the first cooling are separated into gas and solid in a high-temperature electrostatic precipitator. The purified clean hot coal gas and tar gas are subsequently subjected to processes such as gas graded condensation and electrostatic coke capture to obtain clean coal gas and high-value-added liquid tar that meets chemical needs; the pyrolysis semi-coke is transported to the water-cooled screw machine by an buried scraper conveyor, and the temperature of the pyrolysis semi-coke is lowered by the water-cooled screw machine. The temperature is reduced to 380-420℃, at which the tar in the pyrolysis semi-coke is still in a gaseous state, which can ensure the fluidity of the pyrolysis semi-coke and reduce the risk of clogging of the conveying equipment. Furthermore, when the pyrolysis semi-coke is cooled to 380-420℃, the heat loss is relatively small and the available heat is relatively high. In addition, during the transportation process, the pyrolysis semi-coke at about 380-420℃ has relatively low requirements for heat resistance and wear resistance of the conveying equipment, which can reduce the requirements of the conveying equipment for the preparation of materials, reduce the design and operation difficulty of direct high-temperature ash conveying, improve the reliability of the equipment, and reduce a lot of costs. The existing problems of long-distance transportation of high-temperature semi-coke, such as easy clogging of the conveying equipment, difficulty in recovering the heat of the high-temperature semi-coke, and high cost of the conveying equipment, are solved.

[0159] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0160] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device, characterized in that: include: The high-temperature electrostatic precipitator is connected to the heat exchanger and is used to perform gas-solid separation and fine dust removal on the pyrolysis oil and gas to obtain clean pyrolysis oil and gas. The separated pyrolysis semi-coke is transported to the water-cooled screw conveyor through the buried scraper conveyor; the heat exchanger reduces the temperature of the introduced pyrolysis oil and gas to 450-600°C, and the heat exchanger uses sensible heat to preheat the raw materials or convert them into kinetic energy or electrical energy to reduce process energy consumption; A water-cooling screw conveyor is arranged below the buried scraper conveyor and is used to cool the pyrolysis semi-coke to reduce the temperature of the pyrolysis semi-coke to 380-420°C; The sending tank is connected to the water-cooled screw machine and is used to receive the cooled pyrolysis semi-coke and transport the pyrolysis semi-coke to the combustion boiler for secondary utilization under pressure; It also includes a high temperature cyclone dust collector and a spiral conveyor return machine; The high-temperature cyclone dust collector is connected to the pyrolysis furnace and is used to perform the first dust removal on the pyrolysis oil and gas; The spiral conveyor return machine is arranged below the high-temperature cyclone dust collector and connected to the second outlet of the high-temperature cyclone dust collector, and is used to convey the semi-coke from the high-temperature cyclone dust collector to the combustion boiler for secondary utilization; The heat exchanger is connected to the first outlet of the high-temperature cyclone dust collector and is used for heat exchange and cooling of the pyrolysis oil and gas.

2. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as claimed in claim 1, characterized in that: Also includes a buffer ash tank; The inlet of the buffer ash tank is connected to a water-cooling screw machine for buffering the pyrolysis semi-coke after cooling; the outlet of the buffer ash tank is connected to a sending tank.

3. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as claimed in claim 2, characterized in that: It also includes a controller, a first outlet of a nitrogen buffer tank, a second outlet valve of a nitrogen buffer tank, a bag dust collector, a first exhaust valve and a second exhaust valve; The top of the buffer ash tank is closed and provided with a first exhaust valve, the top of the sending tank is closed and provided with a second exhaust valve, the bag filter is arranged above the buffer ash tank, and its inlet is connected to the first exhaust valve and the second exhaust valve respectively; The nitrogen buffer tank is provided with a first outlet of the nitrogen buffer tank and a second outlet of the nitrogen buffer tank. The first outlet of the nitrogen buffer tank is connected to the bottom of the buffer ash tank, and is used to blow nitrogen to the pyrolytic semi-coke at the bottom of the buffer ash tank; the second outlet valve of the nitrogen buffer tank is connected to the bottom of the sending tank, and is used to blow nitrogen to the pyrolytic semi-coke at the bottom of the sending tank; The controller is electrically connected to the first outlet of the nitrogen buffer tank, the second outlet of the nitrogen buffer tank, the first exhaust valve and the second exhaust valve respectively.

4. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as claimed in claim 2, characterized in that: It also includes an induced draft fan, a first ash discharge valve and a second ash discharge valve; The induced draft fan is used to guide the pyrolysis oil gas from the pyrolysis furnace to the high-temperature cyclone dust collector, guide the pyrolysis oil gas from the high-temperature cyclone dust collector for the first dust removal to the heat exchanger, and guide the pyrolysis oil gas cooled by the heat exchanger to the high-temperature electrostatic precipitator; The first ash discharge valve is arranged between the outlet of the buffer tank and the inlet of the sending tank, and is used to control the opening or closing state of the ash conveying pipeline between the outlet of the buffer tank and the inlet of the sending tank; The second ash discharge valve is arranged between the outlet of the water-cooling screw machine and the inlet of the buffer ash tank, and is used to control the opening or closing state of the ash conveying pipeline between the outlet of the water-cooling screw machine and the inlet of the buffer ash tank; The first ash discharge valve and the second ash discharge valve are electrically connected to the controller respectively.

5. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as claimed in claim 2, characterized in that: Also includes a thermocouple, a cold fluid regulating valve, a timer, a first material level meter and a second material level meter; The timer is connected to the first ash discharge valve and is used to determine the opening time of the first ash discharge valve; The first material level meter and the second material level meter are sequentially arranged in the buffer ash tank from bottom to top, and are used to determine the amount of pyrolysis semi-coke stored in the buffer ash tank; The thermocouple is arranged at the inlet of the high-temperature electrostatic precipitator to determine the temperature of the pyrolysis oil gas entering the high-temperature electrostatic precipitator; The cold fluid regulating valve is arranged on the heat exchanger and is used to control the flow rate of the cold fluid entering the heat exchanger; The cold fluid regulating valve, the thermocouple, the timer, the first material level meter and the second material level meter are electrically connected to the controller respectively.

6. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as claimed in claim 1, characterized in that: The water-cooled screw conveyor has an inner and outer double-layer structure, and a gap is left between the inner shell and the outer shell for passing cooling water to cool the high-temperature pyrolysis semi-coke from the buried scraper conveyor; A hollow shaft with a reamer is arranged inside the inner shell body, and cooling water is introduced into the hollow shaft with the reamer to cool it down.

7. A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as claimed in claim 2, characterized in that: The outer layer of the buffer ash tank is provided with a heat-insulating material or a heat-insulating shell; The outer layer of the sending tank is provided with a heat-insulating material or a heat-insulating shell; A heat-insulating layer is arranged inside the high-temperature electrostatic precipitator and the buried scraper conveyor.

8. A method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke, characterized in that: A pulverized coal pyrolysis high-temperature dusty oil and gas purification and semi-coke recovery device as described in any one of claims 1 to 7, comprising: When it is determined that the opening time of the first ash discharge valve reaches the first set time value, the first ash discharge valve and the second exhaust valve are closed, and the sending tank is pressurized so that the pressure inside the sending tank reaches the first set pressure value; The discharge valve of the sending tank is opened to allow the pyrolysis semi-coke with a temperature between 380 and 420°C from the high-temperature cyclone dust collector, heat exchange in the heat exchanger, gas-solid separation in the high-temperature electrostatic precipitator, cooling in the water-cooled screw machine, and storage in the buffer ash tank to be transferred from the sending tank to the combustion boiler for secondary utilization under pressure; wherein, the high-temperature electrostatic precipitator obtains pyrolysis tar gas and the pyrolysis semi-coke through gas-solid separation; the first ash discharge valve is arranged between the outlet of the buffer tank and the inlet of the sending tank, and the second exhaust valve is arranged on the top of the sending tank.

9. A method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke as claimed in claim 8, characterized in that: After the transmission from the sending tank to the combustion boiler for secondary utilization, it also includes: When it is determined that the pressure of the ash conveying pipeline between the sending tank and the combustion boiler drops to a second set pressure value, closing the discharge valve of the sending tank; If it is determined that the storage height of the pyrolytic semi-coke stored in the buffer ash tank is between the first material level meter and the second material level meter, and the opening time of the first ash discharge valve reaches the second set time value, the first ash discharge valve and the first exhaust valve are opened to allow the pyrolytic semi-coke stored in the buffer ash tank to slide to the sending tank through the buffer ash tank outlet and the sending tank inlet under the action of gravity; wherein the first exhaust valve is arranged on the top of the buffer ash tank, and the first exhaust valve is connected to the bag filter; Opening a second outlet of a nitrogen buffer tank connected to the sending tank so that nitrogen from the nitrogen buffer tank is blown toward the pyrolytic semi-coke at the bottom of the sending tank; The second exhaust valve is opened to balance the pressure in the sending tank, and the second exhaust valve is connected to the bag filter.

10. A method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke as claimed in claim 8, characterized in that: After the transmission from the sending tank to the combustion boiler for secondary utilization, it also includes: When it is determined that the pressure of the ash conveying pipeline between the sending tank and the combustion boiler drops to a second set pressure value, closing the discharge valve of the sending tank; If it is determined that the storage height of the pyrolytic semi-coke stored in the buffer ash tank exceeds the second material level timing, the first ash discharge valve and the first exhaust valve are opened to allow the pyrolytic semi-coke stored in the buffer ash tank to slide to the sending tank through the buffer ash tank outlet and the sending tank inlet under the action of gravity; wherein the first exhaust valve is arranged on the top of the buffer ash tank, and the first exhaust valve is connected to the bag filter; Opening a second outlet of a nitrogen buffer tank connected to the sending tank so that nitrogen from the nitrogen buffer tank is blown toward the pyrolytic semi-coke at the bottom of the sending tank; Open the second exhaust valve to balance the pressure in the sending tank, the second exhaust valve is connected to the bag filter; close the second ash discharge valve arranged between the outlet of the water-cooled screw machine and the inlet of the buffer ash tank; Turn off the external motor of the buried scraper conveyor to stop the buried scraper conveyor from working.

11. A method for purifying high-temperature dusty oil and gas from pulverized coal pyrolysis and recovering semi-coke according to any one of claims 9 to 10, characterized in that: Also includes: The inlet temperature of the high-temperature electrostatic precipitator is between 450 and 600°C. When it is determined that the inlet temperature of the high-temperature electrostatic precipitator exceeds A+B°C, a flow increase instruction is sent to the cold fluid regulating valve to reduce the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to A°C; when it is determined that the inlet temperature of the high-temperature electrostatic precipitator is lower than AB°C, a flow reduction instruction is sent to the cold fluid regulating valve to increase the temperature of the pyrolysis oil gas from the heat exchanger so that the inlet temperature of the high-temperature electrostatic precipitator is equal to A°C; Among them, 2<B<31, 450<AB<A<A+B<600.

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