CN114432826A - Small-particle oil shale dry distillation flue gas treatment method and device adopted by same - Google Patents

Abstract

The invention belongs to the technical field of flue gas treatment, and in particular relates to a small particle oil shale dry distillation flue gas treatment method and a device used therefor. The method includes the following steps: introducing the flue gas into the flue gas cyclone separator (1), separating the shale fine powder from the flue gas, and falling to the flue gas cyclone separator fine powder screw conveyor (3); the separated flue gas Passing through the flue gas cooler (5), the flue gas and air complete heat exchange in the flue gas cooler (5); the cooled flue gas enters the flue gas bag filter (6), and the filtered dust falls to the bag filter The fine powder screw conveyor (7) is then transported to the fine powder screw conveyor (3) of the flue gas cyclone separator; the flue gas exhauster (8) discharges the flue gas to the flue gas washing tower (9); The exhaust gases from the preheat burner are mixed together and discharged to the atmosphere through the stack (10). The invention can effectively recover the shale fine powder in the flue gas for recycling, recover the waste heat of the high-temperature flue gas, and remove the ammonia component in the flue gas.

Description

Small particle oil shale dry distillation flue gas treatment method and device therefor

technical field

The invention belongs to the technical field of flue gas treatment, and in particular relates to a small particle oil shale dry distillation flue gas treatment method and a device used therefor.

Background technique

Oil shale belongs to unconventional oil and gas resources, and is listed as a very important replacement energy in the 21st century due to its abundance and feasibility of development and utilization. my country's proven oil shale-converted shale oil reserves are about 440 billion tons, ranking fourth in the world. The application potential of oil shale development and utilization in my country is huge. Oil shale can be heated to obtain products such as shale oil, shale semi-coke and pyrolysis gas using dry distillation technology. The rotary type horizontal oil shale dry distillation device uses small particles of oil shale as raw material. The oil shale becomes semi-coke after high-temperature dry distillation, and the semi-coke contains about 5% fixed carbon. The semi-coke and the circulating shale ash enter the combustion section of the rotary horizontal oil shale retort device. In the combustion section, the fixed carbon in the semi-coke burns with the preheated air to generate heat, and the high-temperature flue gas generated by the combustion returns in reverse. To the preheating section of the rotary horizontal oil shale retort device, and finally exchange heat with the oil shale in the preheating section. The high-temperature flue gas after heat exchange needs to be discharged into the atmosphere, and the composition of the high-temperature flue gas is analyzed. The solid contains three parts, shale, coke and desulfurizer CaO. It is estimated that 1/3 of the total amount of raw shale enters the In the high-temperature flue gas, this part of shale can still be used as circulating shale ash after recovery, so it needs to be recovered before it is discharged into the atmosphere. The gas part includes steam, hydrogen sulfide, sulfur dioxide, ammonia, nitrogen oxides, oxygen, nitrogen, carbon dioxide, carbon monoxide, hydrogen and C1-C3 and other carbon compounds. The content of each part of the gas is measured from the perspective of emission and environmental protection, and ammonia is determined as the main treatment object. It can be seen that from the perspective of economy and environmental protection, the shale ash in the dry distillation flue gas of small particles of oil shale can be recycled, the high temperature flue gas can be used for waste heat recovery, and the ammonia-containing waste gas needs to be treated.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a small particle oil shale dry distillation flue gas treatment method and a device used therefor. According to the characteristics of the flue gas generated by the rotary horizontal oil shale retorting device, targeted recovery and treatment are carried out to ensure high utilization rate of oil shale raw materials, and flue gas emissions meet environmental protection requirements, reduce costs and improve efficiency.

In order to solve the above-mentioned technical problems, the present invention is achieved in this way:

The method for treating small particle oil shale dry distillation flue gas includes the following steps:

Step 1: Flue gas separation

The flue gas from the rotary horizontal oil shale retorting device is introduced into the flue gas cyclone separator, and the shale fine powder is separated from the flue gas, and the fine powder passes through the flue gas cyclone wing set under the flue gas cyclone separator. The valve falls under the action of gravity to the fine powder screw conveyor of the flue gas cyclone separator under the flue gas cyclone separator, and the fine powder is transported to the shale humidifier;

Step 2: Flue gas heat exchange

The separated flue gas flows out from the top of the flue gas cyclone separator, and passes through the flue gas cooler vertically downward. The air provided by the blower enters from the lower part of the flue gas cooler, and the flue gas and air complete the heat exchange in the flue gas cooler;

Step 3: Flue Gas Filtration

The cooled flue gas enters the flue gas bag filter to remove the remaining dust particles, and the filtered dust falls to the bag filter fine powder screw conveyor under the flue gas bag filter, and is transported to the flue gas by the bag filter fine powder screw conveyor The fine powder screw conveyor of the cyclone separator is combined with the fine powder separated from the flue gas in step 1 and transported to the shale humidifier;

Step 4: Flue gas scrubbing

The flue gas exhauster discharges the flue gas to the flue gas scrubbing tower, and the water circulates around the flue gas scrubbing tower, mainly absorbing ammonia in the flue gas stream, and the ammonia-containing wastewater is sent to the acid water stripping device for treatment;

Step 5: Flue Gas Emissions

The scrubbed flue gas leaves the flue gas scrubber and is mixed with the exhaust gas from the preheating incinerator, and flows together to the bottom of the flue gas chimney, where it is discharged into the atmosphere through the chimney.

Further, in step 4 of the present invention, when the main drive motor for driving the flue gas exhaust machine is powered off, the emergency motor in the emergency drive module can be activated to drive the flue gas exhaust machine to operate at the minimum working condition.

The device used in the dry distillation flue gas treatment method for small particle oil shale includes a flue gas cyclone, a flue gas cooler, a flue gas bag filter, a flue gas exhauster, a flue gas scrubbing tower and a chimney; the flue gas cyclone The flue gas discharged from the separator enters the air inlet of the chimney through the flue gas cooler, the flue gas bag filter, the flue gas exhauster and the flue gas washing tower in sequence;

A flue gas cyclone split-wing valve is arranged at the bottom of the flue gas cyclone separator; a flue gas cyclone separator fine powder screw conveyor is arranged below the flue gas cyclone split-wing valve;

A blower is connected to the ventilation opening of the flue gas cooler to introduce air for heat exchange; a bag filter fine powder screw conveyor is arranged below the flue gas bag filter; the bag filter fine powder screw The conveyor is connected with the fine powder screw conveyor of the flue gas cyclone separator for conveying the separated shale fine powder.

Further, the bag filter of the present invention is provided with a quick-action ambient air exhaust valve as a backup to ensure that the bag filter element is protected from excessive temperature under all operating conditions.

Further, the present invention is also provided with an emergency drive module; the emergency drive module includes an emergency motor, a gear reducer and an overrunning clutch; the output shaft of the emergency motor sequentially passes through the gear reducer, the overrunning clutch and the tail of the smoke exhaust. Shaft connection.

Further, the present invention is also provided with a high voltage frequency conversion speed regulation device; the signal transmission ports of the high voltage frequency conversion speed regulation device are respectively connected with the signal transmission ports of the main drive motor for driving the flue gas exhaust machine and the emergency motor.

The method for treating small particle oil shale dry distillation flue gas disclosed in the invention can separate, heat exchange, filter, wash and discharge the flue gas generated by the rotary horizontal oil shale dry distillation device, and can effectively recover the flue gas. The recycling of fine shale powder, the recovery of waste heat from high-temperature flue gas, and the removal of ammonia in flue gas are of positive significance in terms of production economy and environmental protection.

Description of drawings

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The protection scope of the present invention is not limited to the description of the following contents.

Fig. 1 is the principle block diagram of the method for treating small particle oil shale dry distillation flue gas of the present invention;

FIG. 2 is a partial principle block diagram of the emergency drive module of the present invention.

In the figure: 1, flue gas cyclone separator; 2, flue gas cyclone split-wing valve; 3, flue gas cyclone separator fine powder screw conveyor; 4, blower; 5, flue gas cooler; 6, flue gas bag filter 7. Bag filter fine powder screw conveyor; 8. Flue gas exhaust machine; 9. Flue gas scrubber; 10. Chimney.

Detailed ways

As shown in Figure 1, the small particle oil shale dry distillation flue gas treatment process of the present invention includes the following steps:

Step 1: Introduce the flue gas from the rotary horizontal oil shale dry distillation device into the flue gas cyclone separator 1, use the flue gas cyclone separator 1 to separate the shale fine powder from the flue gas, and separate the flue gas cyclone A flue gas cyclone split-wing valve 2 is arranged under the device 1, and the fine powder passes through the flue gas cyclone split-wing valve 2 and falls under the action of gravity to the flue gas cyclone separator fine powder screw conveyor 3 below the flue gas cyclone separator 1. The fine powder screw conveyor 3 of the flue gas cyclone separator transports the fine powder to the shale humidifier. About 82% of the fines are separated in the flue gas cyclone. The fine powder is transported back to the rotary horizontal oil shale dry distillation device by the fine powder screw conveyor 3 for recycling.

Step 2: the flue gas separated by step 1 flows out from the top of the flue gas cyclone 1. At this moment, the temperature of the flue gas is higher and still has available heat. Therefore, a flue gas cooler is set for waste heat recovery, and the flue gas is vertical. Down through the flue gas cooler 5 . The heat removed from the flue gas can be used to preheat the combustion air required for the combustion section of the rotary horizontal oil shale retort device, improving the overall thermal performance of the system. The air provided by the blower 4 enters from the lower part of the flue gas cooler 5 . The heat exchange between the flue gas and the air is completed in the flue gas cooler 5 . The flue gas cooler 5 is a vertical shell-and-tube heat exchanger, which adopts countercurrent heat exchange. more heat.

Step 3: The cooled flue gas enters the flue gas bag filter 6 to remove the remaining dust particles, and the filtered dust falls to the bag filter fine powder screw conveyor 7 below the flue gas bag filter 6, and the bag filter fine powder The screw conveyor 7 is transported to the fine powder screw conveyor 3 of the flue gas cyclone separator below the flue gas cyclone separator 1, and is transported to the shale humidifier together with the fine powder separated from the flue gas in step 1.

In particular, a quick-action ambient air exhaust valve is provided as a backup in the flue gas filtration system section to ensure that the bag filter element is protected from excessive temperature under all operating conditions. The dedusted flue gas leaves the bag filter and is sucked into the flue gas exhauster. The flue gas exhaust machine is a variable speed device, and the gas flow is controlled by adjusting the speed of the AC variable frequency drive that drives the exhaust machine motor. The flue gas exhauster controls the annular space pressure of the combustion section of the rotary horizontal oil shale dry distillation device by increasing or decreasing the flow of the flue gas. The flue gas extractor is equipped with a slow-speed auxiliary emergency motor that can be driven by emergency power generation. In the event of a power outage, this auxiliary emergency motor will keep the exhauster spinning at low speed, which maintains a small amount of ventilation to the casing of the rotary horizontal oil shale retort unit.

As shown in Figure 2, the working principle of the flue gas exhauster is as follows. The flue gas exhauster is arranged in the open air, and the coaxial arrangement is the main drive motor, the flue gas exhauster, the overrunning clutch, the gear reducer and the emergency motor. The high-voltage frequency conversion speed control device control. Through the high-voltage frequency conversion device, the motor speed can be changed to change the flow of flue gas entering the flue gas exhaust machine, and the inlet guide vane of the flue gas exhaust machine can also be used as an auxiliary adjustment of the flow. The clutch control of the main drive motor and the emergency motor is completed by the overrunning clutch. The emergency motor and the gear reducer are connected to the tail shaft of the flue gas exhaust machine through an overrunning clutch as an auxiliary drive. During normal operation, the main drive motor starts, and the overrunning clutch automatically separates the auxiliary drive to ensure that the auxiliary motor transmission mechanism or motor does not overspeed. When the main drive motor is powered off and the fan rotates freely, the emergency motor starts automatically, the overrunning clutch is combined with the auxiliary drive, and the flue gas exhauster is driven by the emergency motor to run at the minimum working condition. Among them, the model of the fan is SGTYNo34F, the model of the main drive motor is YB710-6W, the model of the emergency motor is YB315-8W, and the model of the high-voltage variable frequency speed control device is BLGBP-2000/6 (PLC control).

Step 4: The flue gas exhauster 8 discharges the filtered flue gas to the flue gas washing tower 9 . The water circulates around the flue gas scrubbing tower 9, mainly absorbs the ammonia in the flue gas stream, and the ammonia-containing wastewater is sent to the acid water stripping device for treatment.

Step 5: The washed flue gas leaves the flue gas scrubbing tower 9 and is mixed with the exhaust gas from the preheating incinerator, and flows to the bottom of the flue gas chimney 10 together, and is discharged into the atmosphere through the chimney 10 .

Among them, the flue gas cyclone 1, the flue gas cooler 5, the flue gas bag filter 6, the flue gas exhauster 8, the flue gas washing tower 9 and the chimney 10 are connected in sequence.

Among them, the lower part of the flue gas cyclone separator 1 is provided with a flue gas cyclone split-wing valve 2, and below the flue gas cyclone separator is the flue gas cyclone separator fine powder screw conveyor 3.

Among them, the flue gas cooler 5 is connected with the blower 4 .

Among them, below the bag filter 6 is the bag filter fine powder screw conveyor 7, and the bag filter fine powder screw conveyor 7 is connected with the fine powder screw conveyor 3 of the flue gas cyclone separator.

The device used in the dry distillation flue gas treatment method of small particle oil shale, the main part includes a flue gas cyclone separator 1, a flue gas cooler 5, a flue gas bag filter 6, a flue gas exhauster 8, and a flue gas washing tower 9. and chimney 10; the flue gas discharged from the flue gas cyclone 1 enters the air inlet of the chimney 10 after passing through the flue gas cooler 5, the flue gas bag filter 6, the flue gas exhauster 8 and the flue gas washing tower 9 in turn;

A flue gas cyclone split-wing valve 2 is arranged at the bottom of the flue gas cyclone separator 1; a flue gas cyclone separator fine powder screw conveyor 3 is arranged below the flue gas cyclone split-wing valve 2;

A blower 4 is connected at the ventilation opening of the flue gas cooler 5 to introduce air for heat exchange; a bag filter fine powder screw conveyor 7 is arranged below the flue gas bag filter 6; the bag filter The fine powder screw conveyor 7 is connected with the fine powder screw conveyor 3 of the flue gas cyclone separator to transport the separated shale fine powder.

The bag filter 6 of the present invention is provided with a quick-acting ambient air discharge valve as a backup to ensure that the elements of the bag filter 6 are protected from excessive temperature under all operating conditions.

According to actual design requirements, the present invention is also provided with an emergency drive module and a high-voltage variable frequency speed regulation device; the emergency drive module includes an emergency motor, a gear reducer and an overrunning clutch; the output shaft of the emergency motor sequentially passes through the gear reducer and the overrunning clutch. The clutch is connected with the tail shaft of the flue gas exhaust machine. The signal transmission ports of the high-voltage variable frequency speed regulating device are respectively connected with the signal transmission ports of the main drive motor that drives the flue gas exhaust machine 8 and the emergency motor. The flue gas exhauster 8 is a variable speed device. The gas flow is controlled by adjusting the speed of the AC variable frequency drive that drives the exhauster motor. The flue gas exhauster controls the rotary type horizontal oil by increasing or decreasing the flue gas flow. The pressure in the annular space of the combustion section of the shale dry distillation device, and the exhaust machine is equipped with a slow-speed emergency motor that can be driven by emergency power generation. In the event of a power failure, the emergency motor keeps the exhaust machine rotating at a low speed and maintains the opposite rotary type horizontal oil shale. A small amount of ventilation for the dry distillation unit casing, and the exhaust machine is equipped with a silencer.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated A device or element must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In the present invention, unless otherwise expressly specified and limited, the terms "arrangement", "connection", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integrated It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (6)

1. a small particle oil shale dry distillation flue gas processing method, is characterized in that, comprises the following steps: Step 1: Flue gas separation The flue gas from the rotary horizontal oil shale dry distillation device is introduced into the flue gas cyclone separator (1), the shale fine powder is separated from the flue gas, and the fine powder passes through the flue gas cyclone separator (1). The flue gas cyclone split-wing valve (2) falls under the action of gravity to the flue gas cyclone separator fine powder screw conveyor (3) below the flue gas cyclone separator (1), and the fine powder is transported to the shale humidifier; Step 2: Flue gas heat exchange The separated flue gas flows out from the top of the flue gas cyclone (1), passes through the flue gas cooler (5) vertically downward, and the air provided by the blower (4) enters from the lower part of the flue gas cooler (5), and the flue gas Complete heat exchange with air in the flue gas cooler (5); Step 3: Flue Gas Filtration The cooled flue gas enters the flue gas bag filter (6) to remove the remaining dust particles, and the filtered dust falls to the bag filter fine powder screw conveyor (7) below the flue gas bag filter (6). The fine powder screw conveyor (7) is transported to the fine powder screw conveyor (3) of the flue gas cyclone separator, and is jointly transported to the shale humidifier together with the fine powder separated from the flue gas in step 1; Step 4: Flue gas scrubbing The flue gas exhauster (8) discharges the flue gas to the flue gas washing tower (9), the water circulates around the flue gas washing tower (9), mainly absorbs the ammonia in the flue gas flow, and the ammonia-containing wastewater is sent to the acid water stripping device deal with; Step 5: Flue Gas Emissions The scrubbed flue gas leaves the flue gas scrubbing tower (9) and is mixed with the exhaust gas from the preheating incinerator, and flows together to the bottom of the flue gas chimney (10), and is discharged into the atmosphere through the chimney (10). 2. The method for treating small particle oil shale dry distillation flue gas according to claim 1, characterized in that: in step 4, when the main drive motor for driving the flue gas exhauster (8) is powered off, the emergency drive module is activated by starting the emergency drive module. The emergency motor in the middle drives the flue gas exhauster (8) to operate in the minimum working condition. 3. The device used in the method for treating small particle oil shale dry distillation flue gas according to claim 1, characterized in that, comprising a flue gas cyclone separator (1), a flue gas cooler (5), a flue gas bag filter (6), a flue gas exhauster (8), a flue gas scrubbing tower (9) and a chimney (10); the flue gas discharged from the flue gas cyclone separator (1) passes through the flue gas cooler (5), The flue gas bag filter (6), the flue gas exhauster (8) and the flue gas scrubbing tower (9) enter the air inlet of the chimney (10); A flue gas cyclone split-wing valve (2) is arranged at the bottom of the flue gas cyclone separator (1); a flue gas cyclone fine powder screw conveyor (3) is arranged below the flue gas cyclone split-wing valve (2). ; A blower (4) is connected at the ventilation opening of the flue gas cooler (5) to introduce air for heat exchange; a bag filter fine powder screw conveyor is arranged below the flue gas bag filter (6). (7); the bag filter fine powder screw conveyor (7) is connected with the flue gas cyclone fine powder screw conveyor (3) to transport the separated shale fine powder. 4. The device used in the method for treating small particle oil shale dry distillation flue gas according to claim 3, wherein the bag filter (6) is provided with a quick-acting ambient air discharge valve as a backup to ensure that the bag filter (6) The filter (6) element is protected from excessive temperatures under all operating conditions. 5. The device used in the method for treating small particle oil shale dry distillation flue gas according to claim 4, characterized in that: an emergency drive module is also provided; the emergency drive module comprises an emergency motor, a gear reducer and an overrunning clutch; The output shaft of the emergency motor is connected with the tail shaft of the flue gas exhauster through the gear reducer and the overrunning clutch in sequence. 6. The device used in the method for treating small particle oil shale dry distillation flue gas according to claim 4, characterized in that: a high-voltage variable frequency speed control device is also provided; The main drive motor of the flue gas exhaust machine (8) and the signal transmission port of the emergency motor are connected.

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