CN107198923A - A purification treatment process for wet coke quenching steam - Google Patents

Abstract

The invention relates to a purification treatment process of wet quenching steam, wherein steam subjected to primary purification in a wet quenching tower enters a steam absorption tower, is in full contact with industrial circulating water in a primary coil water cooler and a secondary coil water cooler for heat exchange, and condensate is discharged to a coke breeze sedimentation tank; the tail gas after heat exchange enters a cyclone separator through a tail gas pipeline for secondary purification, and the separated dust, water drops and other pollutants enter a coke breeze sedimentation tank; and (3) enabling the tail gas after secondary purification to enter a tail gas processor, heating water vapor and air which are not absorbed in the tail gas to be in an unsaturated state by utilizing the heat of high-temperature steam, enabling the separated dust, water drops and other pollutants to enter a coke breeze sedimentation tank, and enabling the heated tail gas to be discharged through a chimney up to the standard without generating white fog during discharge. The invention has simple and direct process route and low investment cost, can fully purify a large amount of high-temperature steam generated in the wet quenching process, and realizes the standard-reaching emission, particularly the emission without white fog, of tail gas in the wet quenching process.

Description

A purification treatment process for wet coke quenching steam

technical field

The invention relates to the technical field of purification treatment of industrial waste gas, in particular to a purification treatment process for steam at the top of a wet quenching tower in the coking industry.

Background technique

At present, wet coke quenching technology has been widely used in the coking industry. Even in coking plants that mainly use dry coke quenching technology, wet coke quenching is also used as a backup technology for maintenance. Wet coke quenching has the advantages of simple facilities, low investment, and low cost. However, during the wet coke quenching process, a large amount of high-temperature steam containing phenols, cyanides, sulfides and dust will be generated. If it is directly discharged into the atmosphere, it will cause serious pollution. environment. In the newly promulgated "Emission Standards of Pollutants for Coking Chemical Industry" (GB16171-2012), higher requirements are put forward for the exhaust gas emission of coking plants. So far, there is no mature technology applied to wet coke quenching steam purification treatment.

Contents of the invention

The invention provides a purification treatment process for wet coke quenching steam, which has a simple process route and low investment cost, can fully purify a large amount of high-temperature steam generated in the process of wet coke quenching, and realize the discharge of exhaust gas in the wet coke quenching process up to the standard, especially without "White mist" emission.

In order to achieve the above object, the present invention adopts the following technical solutions to realize:

A purification treatment process for wet coke quenching steam. Before the wet coke quenching system starts to work, the washing and cooling device is started to form a water mist layer above the coke quenching tank in the wet coke quenching tower, and a large amount of coke quenching fumes generated during coke quenching The loose matter rises sharply under the action of thermal buoyancy, and is cooled when passing through the water mist layer, forming condensed droplets with dust particles as the core, which continue to rise with the steam; that is, part of the dust particles in the steam are washed down during this process ; After washing and cooling, the rising speed of the steam in the wet quenching tower has decreased. When passing through the baffle dust removal device, the condensed liquid droplets with dust particles as the core are absorbed and deposited in the baffle dust removal device through mechanical collision. Above; the preliminarily purified steam in the wet quenching tower is collected by the suction hood at the top of the wet quenching tower and then discharged; the coke powder particles attached to the baffle dust removal device are regularly and automatically cleaned by the spray cleaning device on the top of the wet quenching tower ; also includes the following steps:

1) The high-temperature steam collected by the suction hood at the top of the wet quenching tower enters the steam absorption tower after passing through the high-temperature steam pipeline and the exhaust gas processor. In the steam absorption tower, the high-temperature steam is cooled with the primary coil water cooler and the secondary coil water cooler The industrial circulating water in the tank is fully contacted for heat exchange, and the condensate flows to the bottom of the steam absorption tower by itself, and is discharged to the powder coke sedimentation tank through the drain at the bottom;

2) After heat exchange in the steam absorption tower, the tail gas enters the cyclone separator through the tail gas pipeline for secondary purification, and the separated dust, water droplets and other pollutants enter the powder coke sedimentation tank;

3) The tail gas after the secondary purification by the cyclone processor enters the tail gas processor through the fan, and uses the heat of high-temperature steam in the tail gas processor to heat the unabsorbed water vapor and air in the tail gas to an unsaturated state, and the separated Dust, water droplets and other pollutants enter the powder coke sedimentation tank, and the heated tail gas is discharged through the chimney up to the standard, and there is no "white mist" during discharge.

The exhaust gas processor is a shell-and-tube heat exchanger. The high-temperature steam collected by the suction hood enters the shell-side inlet of the exhaust gas processor through a high-temperature steam pipe, and the steam after heat exchange with the exhaust gas enters the steam from the shell-side outlet of the exhaust gas processor. Pipeline; the exhaust gas after the secondary purification of the cyclone processor is sent to the tube side inlet of the exhaust gas processor by the fan, and is sent to the chimney by the tube side outlet after heat exchange with high-temperature steam.

The washing and cooling device is a spraying device or an atomizing spraying device.

The baffle and dust removal device is composed of at least 2 layers of baffles, each layer of baffles is composed of a wooden frame and dust removal grids arranged in a broken line, and the dust removal grids of each layer of baffles are arranged in a staggered manner.

On the high-temperature steam pipeline before the exhaust processor, on the steam pipeline before the steam absorption tower, and on the water supply pipeline upstream of the washing and cooling device, electric valves are respectively arranged, and the above electric valves, the driving device of the cyclone separator, and the driving device of the fan are respectively Connect the wet coke quenching control system; the water intake of the washing and cooling device, the flow rate of high temperature steam, the steam flow rate, the intake volume of the cyclone separator and the fan are all related to the coke processing capacity and process of the wet coke quenching system.

Compared with prior art, the beneficial effect of the present invention is:

1) A large amount of high-temperature steam generated during the wet quenching process undergoes steam-water heat exchange and other processes, and achieves the purpose of fully absorbing steam heat energy through evaporation and condensation;

2) The steam condensate, dust and other pollutants separated from the steam absorption tower, cyclone separator and tail gas processor are discharged to the powder coke sedimentation tank, and can be sent to the phenol cyanide wastewater treatment section in the coking plant for treatment without pollutants emission;

3) By setting up the tail gas processor, the heat of high-temperature steam is used to heat the unabsorbed water vapor, air and other gases in the tail gas to an unsaturated state, and the tail gas discharged from the chimney to the atmosphere meets the standard discharge without "white fog";

4) The whole process system is controlled by the automatic control system and linked with the wet coke quenching system. It is easy to operate, reliable in operation, low in investment cost and high in efficiency.

Description of drawings

Fig. 1 is a process route diagram of a purification treatment process for wet coke quenching steam according to the present invention.

In the figure: 1. Wet coke quenching tower 2. Coke quenching tank 3. Washing and cooling device 4. Baffle dust removal device 5. Suction hood 6. High temperature steam pipeline 7. Exhaust gas processor 8. Fan 9. Steam pipeline 10. Steam Absorption tower 101. Primary coil water cooler 102. Secondary coil water cooler 11. Condensate pipeline 12. Powder coke sedimentation tank 13. Exhaust gas pipeline 14. Cyclone separator

detailed description

The specific embodiment of the present invention will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, a purification treatment process for wet coke quenching steam according to the present invention, before the wet coke quenching system starts to work, the washing and cooling device 3 is started first, and the coke cooling device 3 is formed above the coke quenching tank 2 in the wet coke quenching tower 1. In the water mist layer, a large number of coke quenching fugitives produced during coke quenching rise sharply under the action of thermal buoyancy, and are cooled when passing through the water mist layer, forming condensed droplets with dust particles as the core, which continue to rise with the steam; During this process, part of the particle dust in the steam is washed down; the rising speed of the steam after washing and cooling in the wet quenching tower 1 has decreased, and when passing through the baffle dust removal device 4, the condensation with dust particles as the core The liquid droplets are adsorbed and deposited on the baffle dust removal device 4 through mechanical collision; the steam that is initially purified in the wet quenching tower 1 is collected by the suction hood 5 at the top of the wet coke quenching tower 1 and then discharged; the baffle dust removal device The coke powder particles attached to the 4 are regularly and automatically cleaned by the spray cleaning device on the top of the wet coke quenching tower 1; the following steps are also included:

1) The high-temperature steam collected by the suction hood 5 at the top of the wet quenching tower 1 passes through the high-temperature steam pipeline 6 and the tail gas processor 7 and then enters the steam absorption tower 10. In the steam absorption tower 10, the high-temperature steam and the first-stage coil water cooler 101. The industrial circulating water in the secondary coil water cooler 102 is fully exposed to heat exchange, and the condensate flows to the bottom of the steam absorption tower by itself, and is discharged to the powder coke sedimentation tank 12 through the drain at the bottom;

2) The tail gas after heat exchange in the steam absorption tower 10 enters the cyclone separator 14 through the tail gas pipeline 13 for secondary purification, and the separated dust, water droplets and other pollutants enter the powder coke sedimentation tank 12;

3) The tail gas after the secondary purification by the cyclone processor 14 enters the tail gas processor 7 through the fan 8, and in the tail gas processor 7, the heat of the high-temperature steam is used to heat the unabsorbed water vapor and air in the tail gas to an unsaturated state, The separated dust, water droplets and other pollutants enter the powder coke sedimentation tank 12, and the heated tail gas is discharged through the chimney up to the standard, and there is no "white mist" during discharge.

The tail gas processor 7 is a shell-and-tube heat exchanger. The high-temperature steam collected by the suction hood 5 enters the shell-side inlet of the tail gas processor 7 through the high-temperature steam pipeline 6, and the steam after heat exchange with the tail gas comes from the exhaust gas processor 7. The shell-side outlet enters the steam pipe 9; the exhaust gas after secondary purification by the cyclone processor 14 is sent to the tube-side inlet of the exhaust gas processor 7 by the fan 8, and is sent to the chimney by the tube-side outlet after heat exchange with high-temperature steam.

The washing and cooling device 3 is a spraying device or an atomizing spraying device.

The baffle and dust removal device 4 is composed of at least 2 layers of baffles, each layer of baffles is composed of a wooden frame and dust removal grids arranged in a broken line, and the dust removal grids of each layer of baffles are arranged in a staggered manner.

On the high-temperature steam pipeline 6 before the tail gas processor 7, on the steam pipeline 9 before the steam absorption tower 10, on the water delivery pipeline upstream of the washing and cooling device 3, electric valves are respectively set, and the above electric valves and the driving device of the cyclone separator 14 The driving device of fan 8 and fan 8 are respectively connected to the wet coke quenching control system; the water intake of the washing and cooling device 3, the flow rate of high temperature steam, the steam flow rate and the intake volume of cyclone separator 14 and fan 8 are all related to the coke processing capacity of the wet coke quenching system associated with the processing.

As shown in Figure 1, in the wet coke quenching tower 1, above the coke quenching tank 2, coke quenching injection pipe, washing and cooling device 3, baffle dust removal device 4 and suction hood 5 are arranged successively from bottom to top; The processor 7 is a shell-and-tube heat exchanger, and its shell-side inlet is connected to the steam outlet at the top of the wet quenching tower through a high-temperature steam pipeline 6, and the shell-side outlet is connected to the steam inlet of the steam absorption tower 10 through a steam pipeline 9, and the steam absorption tower 10 The exhaust gas outlet is connected to the tube-side inlet of the cyclone separator 14, the fan 8 and the exhaust gas processor 7 in sequence, and the tube-side outlet of the exhaust gas processor 7 is connected to the chimney; the steam absorption tower 10, the cyclone separator 14 and the exhaust gas processor 7 are respectively provided with drains The fine coke sedimentation tank 12 is connected through the condensate pipeline 11 .

The vapor absorption tower 1 is composed of a shell, a first-stage coil water cooler 101 arranged at the upper part of the shell, a second-stage coil water cooler 102 arranged at the lower part of the shell, and a drain outlet arranged at the bottom of the shell. The circulating water inlet and circulating water outlet of the tube water cooler 101 and the secondary coil water cooler 102 are respectively connected with industrial circulating water pipes in the coking plant.

The coils in the first-stage coil water cooler 101 and the second-stage coil water cooler 102 are seamless steel pipes of DN15-DN200, and the distance between the coils is 20-100 mm.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (5)

1. A purification treatment process for wet coke quenching steam. Before the wet coke quenching system starts to work, the washing and cooling device is started first, and a water mist layer is formed above the coke quenching tank in the wet coke quenching tower, and a large amount of quenching gas generated during coke quenching The coke fugitives rise sharply under the action of thermal buoyancy, and are cooled when passing through the water mist layer, forming condensed droplets with dust particles as the core, which continue to rise with the steam; that is, during this process, part of the dust particles in the steam are Washing down; the rising speed of the steam after washing and cooling in the wet coke quenching tower has decreased. When passing through the baffle dust removal device, the condensate droplets with dust particles as the core are absorbed and deposited in the baffle through mechanical collision. On the dust removal device; the steam initially purified in the wet coke quenching tower is collected by the suction hood on the top of the wet coke quenching tower and then discharged; the coke powder particles attached to the baffle dust removal device pass through the spray cleaning device on the top of the wet coke quenching tower regularly Automatic cleaning; it is characterized in that, also comprises the following steps: 1) The high-temperature steam collected by the suction hood at the top of the wet quenching tower enters the steam absorption tower after passing through the high-temperature steam pipeline and the exhaust gas processor. In the steam absorption tower, the high-temperature steam is cooled with the primary coil water cooler and the secondary coil water cooler The industrial circulating water in the tank is fully exposed to heat exchange, and the condensate flows to the bottom of the steam absorption tower by itself, and is discharged to the powder coke sedimentation tank through the drain at the bottom; 2) After heat exchange in the steam absorption tower, the tail gas enters the cyclone separator through the tail gas pipeline for secondary purification, and the separated dust, water droplets and other pollutants enter the powder coke sedimentation tank; 3) The tail gas after the secondary purification by the cyclone processor enters the tail gas processor through the fan, and uses the heat of high-temperature steam in the tail gas processor to heat the unabsorbed water vapor and air in the tail gas to an unsaturated state, and the separated Dust, water droplets and other pollutants enter the powder coke sedimentation tank, and the heated tail gas is discharged through the chimney up to the standard, and there is no "white mist" during discharge. 2. A purification treatment process for wet coke quenching steam according to claim 1, characterized in that the tail gas processor is a shell-and-tube heat exchanger, and the high-temperature steam collected by the suction hood enters the tail gas through a high-temperature steam pipeline The shell-side inlet of the processor, and the steam after heat exchange with the exhaust gas enters the steam pipe from the shell-side outlet of the exhaust gas processor; the exhaust gas after the secondary purification of the cyclone processor is sent to the tube-side inlet of the exhaust gas processor by the fan, and the high temperature After heat exchange, the steam is sent to the chimney from the outlet of the tube side. 3. A purification treatment process for wet coke quenching steam according to claim 1, characterized in that, the washing and cooling device is a spray device or an atomizing spray device. 4. The purification treatment process of a kind of wet quenching steam according to claim 1, characterized in that, the baffle and dedusting device is composed of at least 2 layers of baffles, and each layer of baffles is composed of a wooden frame and a folding line It is composed of dust-removing grid plates arranged in the same pattern, and the dust-removing grid plates of each layer of baffles are arranged in a staggered manner. 5. The purification treatment process of a kind of wet coke quenching steam according to claim 1, characterized in that, on the high-temperature steam pipeline before the tail gas processor, on the steam pipeline before the steam absorption tower, on the upstream of the washing and cooling device Electric valves are installed on the water supply pipeline, and the above electric valves, the driving device of the cyclone separator, and the driving device of the fan are respectively connected to the wet quenching control system; The amount of air intake is related to the coke processing capacity and processing process of the wet coke quenching system.