CN103388045B - Pneumatic transmission system for dry dedusting of thick ash in converter gas - Google Patents

Abstract

The invention relates to a pneumatic conveying system for converter gas dry dust removal and coarse ash, which includes a high-efficiency waste heat recovery heat exchanger (1), a horizontal chain conveyor (2), an ash unloading main pipe (3), and a pneumatic three-way distributor ( 5), the first ash unloading branch pipe (8), the second ash unloading branch pipe (13), the first warehouse pump (11), the second warehouse pump (16), the pneumatic conveying pipe (24) and the coarse ash bin (25) ; The first warehouse pump (11), the second warehouse pump (16) and the coarse ash warehouse (25) are connected through a pneumatic conveying pipe (24). The invention adopts the high-efficiency waste heat recovery heat exchanger and adopts the indirect heat exchange method without direct spraying of water, which completely solves the problem that the evaporative cooler is easy to harden, and also solves the problem of ash stuck in the built-in chain conveyor caused by water droplets. After using the high-efficiency waste heat recovery heat exchanger, it can not only recover a large amount of waste heat in the raw gas, but also remove dust, which is energy-saving and environmentally friendly.

Description

A Pneumatic Conveying System for Converter Gas Dry Dedusting Coarse Ash

technical field

The invention relates to the field of environmental protection equipment, in particular to a coarse ash pneumatic conveying system for converter gas dry dedusting.

Background technique

With the increasing awareness of environmental protection, most newly built and rebuilt converters use dry dust removal. The existing coarse ash conveying technology for dry dust removal is: spray water in the evaporative cooler to reduce dust, and the collected coarse ash is sent to the main converter under the action of gravity through the built-in chain conveyor, pneumatic flapper valve and pneumatic double flap valve. The coarse ash bin in the factory building is transported by car for comprehensive utilization after humidification.

The main problems of the existing coarse ash conveying technology for dry dust removal are as follows: first, the evaporative cooler is easy to harden, and water droplets will precipitate when the water spray control is not good, which will cause the built-in chain conveyor to get stuck and affect the normal production of the converter; First, the storage and transportation of coarse ash are limited by the site and distance; the third is that the humidification of coarse ash is not uniform, resulting in dust everywhere during ash unloading and polluting the environment.

Contents of the invention

The technical problem to be solved by the present invention is to provide a coarse ash pneumatic conveying system for converter gas dry dust removal in view of the above-mentioned defects of the prior art.

The technical solution adopted by the present invention to solve the technical problem is: construct a converter gas dry dust removal coarse ash pneumatic conveying system, including a high-efficiency waste heat recovery heat exchanger, a horizontal chain conveyor, an ash unloading main pipe, and a pneumatic three-way material distribution system. device, the first ash unloading branch pipe, the second ash unloading branch pipe, the first warehouse pump, the second warehouse pump, the pneumatic conveying pipe and the coarse ash bin;

The side of the high-efficiency waste heat recovery heat exchanger is provided with high-efficiency heat exchange tubes, and the horizontal chain conveyor is horizontally arranged under the high-efficiency waste heat recovery heat exchanger;

The first warehouse pump and the second warehouse pump are installed below the horizontal chain conveyor, the ash discharge port of the horizontal chain conveyor and the inlet of the pneumatic three-way distributor are connected through the ash discharge main pipe, The ash unloading main pipe is provided with a pneumatic slide valve;

The first warehouse pump is connected to the pneumatic three-way distributor through the first ash unloading branch pipe, and the first ash unloading branch pipe is provided with a first manual slide valve and a first pneumatic double gate valve, The first warehouse pump is provided with a first vacuum pressure relief valve;

The second warehouse pump is connected to the pneumatic three-way distributor through the second ash unloading branch pipe, and the second ash unloading branch pipe is provided with a second manual slide valve and a second pneumatic double gate valve , the second warehouse pump is provided with a second vacuum pressure release valve;

The pneumatic conveying pipe is connected with the gas storage tank, the inlet of the gas storage tank is connected with the first nitrogen pipe, and the inlet of the first nitrogen pipe is connected with the nitrogen main pipe; the first storehouse pump, the second storehouse pump and the The coarse ash bin is connected by a pneumatic conveying pipe;

A first fluidization device is provided at the bottom of the first warehouse pump, a first pneumatic ball valve is provided between the first warehouse pump and the air storage tank, and a first pneumatic ball valve is provided between the first warehouse pump and the pneumatic conveying pipe. There is a third pneumatic double gate valve;

A second fluidization device is provided at the bottom of the second warehouse pump, a second pneumatic ball valve is provided between the second warehouse pump and the air storage tank, and a second pneumatic ball valve is provided between the second warehouse pump and the pneumatic conveying pipe. Equipped with the fourth pneumatic double gate valve;

The nitrogen pipe at the outlet of the gas storage tank is divided into two paths, one path is connected with the first fluidization device and the pneumatic conveying pipe, and the other path is connected with the second fluidization device and the pneumatic conveying pipe;

The top of the coarse ash bin is equipped with a cloth bag dust collector and a third vacuum pressure release valve, and a third fluidization device is installed in the lower cone of the coarse ash bin. The ash port is connected to the inlet of the third manual flapper valve, and the outlet of the third manual flapper valve is connected to the inlet of the star-shaped ash unloading valve;

The nitrogen main pipe is also connected to the inlet of the second nitrogen pipe, and the outlet of the second nitrogen pipe is divided into two paths, one path is connected to the third fluidization device, and the other path is connected to the bag filter on the top of the warehouse;

A pressure regulating valve and an electromagnetic valve are arranged between the second nitrogen pipe and the third fluidization device.

In the converter gas dry dust removal coarse ash pneumatic conveying system according to the present invention, the horizontal chain conveyor is provided with a first accidental ash unloading main pipe, and a fourth manual inserting plate is provided on the first accidental ash unloading main pipe valve.

In the converter gas dry dust removal coarse ash pneumatic conveying system according to the present invention, the second emergency ash discharge main pipe is provided on the lower cone bucket of the coarse ash bin, and the fifth manual ash discharge main pipe is provided on the second accident ash discharge main pipe. flapper valve.

In the converter gas dry dust removal coarse ash pneumatic conveying system according to the present invention, drain pipes are arranged at the bottoms of the first and second chamber pumps.

Implementation of the converter gas dry dedusting coarse ash pneumatic conveying system of the present invention has the following beneficial effects:

1. The high-efficiency waste heat recovery heat exchanger adopts an indirect heat exchange method without direct spraying of water, which completely solves the problem of easy hardening of the evaporative cooler, and also solves the problem of dust stuck on the built-in chain conveyor caused by water droplets.

2. After using the high-efficiency waste heat recovery heat exchanger, it can not only recover a large amount of waste heat in the raw gas, but also remove dust, which is energy-saving and environmentally friendly.

3. The first warehouse pump and the second warehouse pump can work alternately to ensure the stability of the conveying system and improve the conveying capacity of coarse ash.

4. The coarse ash bin can be placed inside or outside the main converter building. Ash storage and transportation are not limited by site and distance.

5. The present invention cancels the dust humidifier, and can adopt the way of vacuum suction and discharge tank truck to unload the ash, without dust spillage, and is more environmentally friendly.

Description of drawings

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

Fig. 1 is a structural schematic diagram of the coarse ash pneumatic conveying system for converter gas dry dedusting of the present invention.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in Fig. 1 , the coarse ash pneumatic conveying system for converter gas dry process dedusting of the present invention includes a high-efficiency waste heat recovery heat exchanger 1, a horizontal chain conveyor 2, an ash unloading main pipe 3, a pneumatic three-way distributor 5, a first Ash unloading branch pipe 8, second ash unloading branch pipe 13, first storehouse pump 11, second storehouse pump 16, pneumatic conveying pipe 24, coarse ash storehouse 25.

The high-efficiency waste heat recovery heat exchanger 1 is provided with high-efficiency heat exchange tubes on the side, and the horizontal chain conveyor 2 is horizontally arranged under the high-efficiency waste heat recovery heat exchanger 1 . The first warehouse pump 11 and the second warehouse pump 16 are installed below the horizontal chain conveyor 2, and the ash unloading port and the inlet of the pneumatic three-way distributor 5 are connected through the ash unloading main pipe 3, and the ash unloading main pipe 3 is equipped with a pneumatic Gate valve 4.

The first warehouse pump 11 is connected to the pneumatic three-way distributor 5 through the first ash unloading branch pipe 8 , and the first ash unloading branch pipe 8 is provided with a first manual slide valve 9 and a first pneumatic double gate valve 10 . When the first manual slide valve 9 and the first pneumatic double gate valve 10 are opened, the coarse ash in the pneumatic three-way distributor 5 enters the first warehouse pump 11 through the first ash unloading branch pipe 8 . The first chamber pump 11 is provided with a first vacuum pressure release valve 12, which can prevent the internal pressure of the first chamber pump 11 from being too high.

The second warehouse pump 16 is connected to the pneumatic three-way distributor 5 through the second ash discharge branch pipe 13, and the second ash discharge branch pipe 13 is provided with a second manual slide valve 14 and a second pneumatic double gate valve 15. When the second manual slide valve 14 and the second pneumatic double gate valve 15 are opened, the coarse ash in the pneumatic three-way distributor 5 enters the second warehouse pump 16 through the second ash unloading branch pipe 13 . The second chamber pump 16 is provided with a second vacuum pressure relief valve 17, which can prevent the internal pressure of the second chamber pump 16 from being too high.

The pneumatic conveying pipe 24 is connected with the gas tank 19, the inlet of the gas tank 19 is connected with the first nitrogen pipe 18, the inlet of the first nitrogen pipe 18 is connected with the nitrogen main pipe, the first storehouse pump 11, the second storehouse pump 16 and the rough The ash bin 25 is connected through a pneumatic conveying pipe 24 . A first fluidization device is provided at the bottom of the first warehouse pump 11, a first pneumatic ball valve 20 is provided between the first warehouse pump 11 and the air storage tank 19, and a third pneumatic ball valve 20 is provided between the first warehouse pump 11 and the pneumatic conveying pipe 24. Double gate valve 21. A second fluidization device is provided at the bottom of the second warehouse pump 16, a second pneumatic ball valve 22 is provided between the second warehouse pump 16 and the air storage tank 19, and a fourth pneumatic ball valve 22 is provided between the second warehouse pump 16 and the pneumatic conveying pipe 24. Pneumatic double gate valve 23. The nitrogen pipe at the outlet of the gas storage tank 19 is divided into two paths, one path is connected with the first fluidizing device and the pneumatic conveying pipe 24, and the other path is connected with the second fluidizing device and the pneumatic conveying pipe 24.

The top of the coarse ash bin 25 is provided with a bin top bag filter 26 and a third vacuum pressure release valve 27 . The bag filter 26 on the top of the bin is used to collect the dust on the top of the coarse ash bin 25 . The third vacuum pressure relief valve 27 is used to prevent excessive pressure inside the coarse ash bin 25 . A third fluidization device 35 is provided in the lower cone of the coarse ash bin 25, the ash discharge port of the lower cone of the coarse ash bin 25 is connected to the inlet of the third manual flapper valve 28, and the outlet of the third manual flapper valve 28 is connected to the star-shaped Ash unloading valve 29 inlets are connected.

The nitrogen main pipe is also connected with the inlet of the second nitrogen pipe 32, and the outlet of the second nitrogen pipe 32 is divided into two paths, one path is connected with the third fluidization device 35, and the other path is connected with the bag filter 26 on the warehouse top.

A pressure regulating valve 33 and a solenoid valve 34 are provided between the second nitrogen pipe 32 and the third fluidization device 35 .

The technical process of conveying coarse ash by the converter gas dry process dedusting coarse ash pneumatic conveying system of the present invention is as follows:

High-efficiency waste heat recovery heat exchanger 1→horizontal chain conveyor 2→ash unloading port→ash unloading main pipe 3→pneumatic slide valve 4→pneumatic three-way distributor 5→first ash unloading branch pipe 8/second ash unloading branch pipe 13→first warehouse pump 11/second warehouse pump 16→third pneumatic double gate valve 21/fourth pneumatic double gate valve 23→pneumatic conveying pipe 24→coarse ash warehouse 25→third manual gate valve 28→ Star type ash unloading valve 29.

When the dust-laden raw gas passes through the high-efficiency waste heat recovery heat exchanger 1, 25% to 35% (generally 30%) of coarse dust is captured under the action of gravity and centrifugal force and falls into the horizontal chain conveyor (2) The temperature of coarse dust is 200-300°C (generally 250°C); the bulk density of coarse dust is 1.8-2.6t/m ³ ; the moisture content of coarse dust is 0.

The horizontal chain conveyor 2 is interlocked with the converter process and runs periodically during smelting. Coarse ash passes through the horizontal chain conveyor 2 ash discharge port, ash discharge main pipe 3, pneumatic gate valve 4, pneumatic three-way distributor 5, first ash discharge branch pipe 8, first manual gate valve 9 and first pneumatic valve The double gate valve 10 enters the first warehouse pump 11. After the first warehouse pump 11 is full, it is fluidized by the first fluidization device and sent to the coarse ash warehouse 25 through the pneumatic conveying pipe 24. A material level gauge may also be arranged in the first warehouse pump 11, and the amount of coarse ash in the first warehouse pump 11 is detected by the material level gauge. After the first warehouse pump 11 is full, the pneumatic three-way distributor 5 switches to the second ash discharge branch pipe 13, and the coarse ash enters the second warehouse pump through the second manual slide valve 14 and the second pneumatic double gate valve 15 16. The first storehouse pump 11 and the second storehouse pump 16 can work alternately and serve as backups for each other. When one of them is damaged, the whole system can still work normally, ensuring the stability of the conveying system and improving the conveying capacity of coarse ash.

When the electromagnetic valve 34 is opened, the third fluidizing device 35 sprays low-pressure nitrogen gas, which can reduce the temperature of the coarse ash in the coarse ash bin 25, and also fluidize the coarse ash to facilitate ash unloading. The coarse ash collected by the bag filter 26 on the top of the warehouse is transported to the bottom of the coarse ash bin 25 through the second nitrogen pipe 32, so as to ensure that the coarse ash in the coarse ash bin 25 can be quickly and fully unloaded and the residue is reduced. Through the pressure regulating valve 33 can adjust the feeding amount of nitrogen. The ash unloading adopts the method of vacuum suction and discharge of tank trucks, and there is no dust spillage during ash unloading, which is more environmentally friendly.

Further, the horizontal chain conveyor 2 is provided with a first emergency ash unloading supervisor 6 , and a fourth manual slide valve 7 is provided on the first emergency ash unloading supervisor 6 . During maintenance, coarse ash is discharged from the first accident ash unloading supervisor 6.

Further, drain pipes may also be provided at the bottom of the first chamber pump 11 and the second chamber pump 16 for draining accumulated water in the chamber pumps.

Further, a second emergency ash unloading main pipe 30 is provided on the lower cone of the coarse ash bin 25 , and a fifth manual slide valve 31 is provided on the second accidental ash unloading main pipe 30 . When the coarse ash bin 25 is overhauled, the coarse ash is discharged through the cone bucket accident ash discharge port of the coarse ash bin 25, the second accident ash discharge supervisor 30 and the fifth manual slide valve 31.

Further, the first chamber pump 11 and the second chamber pump 16 are made of 16MnR or Q235B or ductile iron or stainless steel. The capacity of the first warehouse pump 11 and the second warehouse pump 16: 1.0-10m ³ ; the number of the first warehouse pump 11 and the second warehouse pump 16 is ≥1, and multiple combinations can be used. Pneumatic conveying pipe 24 is made of manganese-containing seamless steel pipe, and the elbow and tee are lined with wear-resistant ceramic materials. The bending radius of the pipe is ≥10 times the diameter of the pipe, and the pipe has an anti-blocking function.

The first warehouse pump 11 or the second warehouse pump 16 adopts the mode of discontinuous delivery, and each time the coarse ash is transported, it is a cycle process, and each cycle is divided into steps. Take the first warehouse pump 11 as an example:

1. Feeding: the first manual slide valve 9 is normally open, the first pneumatic double gate valve 10 is open, the first pneumatic ball valve 20 and the third pneumatic double gate valve 21 are closed, and the coarse ash enters under the action of gravity The first warehouse pump 11, when the material level gauge of the first warehouse pump 11 detects that the material is full, sends a signal and is controlled by the PLC program to automatically close the first pneumatic double gate valve 10, and the feeding process ends.

2. Fluidization: the first pneumatic ball valve 20 is opened, nitrogen enters the first fluidization device in the first warehouse pump 11 from the gas storage tank 19, the coarse ash in the first warehouse pump 11 is fully fluidized, and the pressure continues to rise. When the pressure rises to the set working pressure, the third pneumatic double gate valve 21 at the side discharge port of the first warehouse pump 11 is automatically opened through the PLC program control, the fluidization process ends and the conveying process begins.

3. Transportation: After the third pneumatic double gate valve 21 is opened, the uniformly fluidized gas-ash mixture is sent to the coarse ash bin 25 through the pneumatic conveying pipe 24, and the pressure in the first bin pump 11 is kept stable at this time; when the first After the air-ash mixture in the warehouse pump 11 is conveyed, the resistance of the pneumatic conveying pipe 24 drops, and the pressure of the pneumatic conveying pipe 24 begins to drop. At this time, the first pneumatic ball valve 20 and the third pneumatic double gate valve 21 still remain in the open state.

4. Purging: Nitrogen continues to purge the first warehouse pump 11 and the pneumatic conveying pipe 24. At this time, there is no fly ash in the first chamber pump 11, and the gas-ash mixture in the pneumatic conveying pipe 24 gradually decreases, and finally almost all of them are nitrogen. After the system resistance continues to drop and stabilize for a period of time, the purging process ends, close the first pneumatic ball valve 20 and the third pneumatic double gate valve 21, then open the first pneumatic double gate valve 10, and the first warehouse pump 11 resumes feeding state. So far, a conveying cycle including 4 steps ends, and the next cycle starts again.

The converter in the converter gas dry dust removal coarse ash pneumatic conveying system of the present invention is defined as: a decarburization converter or a dephosphorization converter or a lava homogenizing furnace or a stainless steel converter. The pneumatic conveying system of the present invention is suitable for conveying coarse ash of primary flue gas dry dust removal of 80t-300t converters. Its conveying distance is about 300m, and its climbing height is about 30m. The conveying medium adopts low-pressure nitrogen, and the nitrogen pressure is ≥0.6MPa.

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, many forms can also be made without departing from the gist of the present invention and the protection scope of the claims, and these all belong to the protection of the present invention.

Claims (4)

1. A coarse ash pneumatic conveying system for converter gas dry dust removal, characterized in that it includes a high-efficiency waste heat recovery heat exchanger (1), a horizontal chain conveyor (2), an ash unloading main pipe (3), a pneumatic three-way branch Feeder (5), first ash unloading branch pipe (8), second ash unloading branch pipe (13), first warehouse pump (11), second warehouse pump (16), pneumatic conveying pipe (24) and coarse ash bin (25); The side of the high-efficiency waste heat recovery heat exchanger (1) is provided with high-efficiency heat exchange tubes, and the horizontal chain conveyor (2) is horizontally arranged below the high-efficiency waste heat recovery heat exchanger (1); The first warehouse pump (11) and the second warehouse pump (16) are installed below the horizontal chain conveyor (2), and the ash discharge port and the pneumatic tee of the horizontal chain conveyor (2) The inlet of the distributor (5) is connected through the ash unloading main pipe (3), and the ash unloading main pipe (3) is provided with a pneumatic slide valve (4); The first warehouse pump (11) is connected to the pneumatic three-way distributor (5) through the first ash unloading branch pipe (8), and the first ash unloading branch pipe (8) is provided with a first manual A flapper valve (9) and a first pneumatic double gate valve (10), the first vacuum pressure release valve (12) is provided on the first warehouse pump (11); The second warehouse pump (16) is connected to the pneumatic three-way distributor (5) through the second ash unloading branch pipe (13), and the second ash unloading branch pipe (13) is provided with a second hand Moving plate valve (14) and the second pneumatic double gate valve (15), the second storehouse pump (16) is provided with the second vacuum pressure relief valve (17); Described pneumatic conveying pipe (24) is connected with gas storage tank (19), and the inlet of described gas storage tank (19) is connected with first nitrogen pipe (18), and the inlet of described first nitrogen pipe (18) and nitrogen gas The main pipe is connected; the first warehouse pump (11), the second warehouse pump (16) and the coarse ash warehouse (25) are connected through a pneumatic conveying pipe (24); A first fluidization device is provided at the bottom of the first warehouse pump (11), and a first pneumatic ball valve (20) is provided between the first warehouse pump (11) and the air storage tank (19). A third pneumatic double gate valve (21) is provided between the first warehouse pump (11) and the pneumatic conveying pipe (24); A second fluidization device is provided at the bottom of the second warehouse pump (16), and a second pneumatic ball valve (22) is provided between the second warehouse pump (16) and the air storage tank (19). A fourth pneumatic double gate valve (23) is provided between the second warehouse pump (16) and the pneumatic conveying pipe (24); The nitrogen pipe at the outlet of the gas storage tank (19) is divided into two paths, one path is connected with the first fluidization device and the pneumatic conveying pipe (24), and the other path is connected with the second fluidization device and the pneumatic conveying pipe (24). )connect; The top of the coarse ash bin (25) is provided with a bin top bag filter (26) and a third vacuum pressure release valve (27), and the lower cone of the coarse ash bin (25) is provided with a third fluidization device ( 35), the ash discharge port of the lower cone bucket at the bottom of the coarse ash bin (25) is connected to the inlet of the third manual flapper valve (28), and the outlet of the third manual flapper valve (28) is connected to the star-shaped ash discharge port The inlet of valve (29) is connected; The nitrogen main pipe is also connected to the inlet of the second nitrogen pipe (32), and the outlet of the second nitrogen pipe (32) is divided into two paths, one path is connected with the third fluidization device (35), and the other path is connected with the top bag dust collector. Device (26) is connected; A pressure regulating valve (33) and a solenoid valve (34) are arranged between the second nitrogen pipe (32) and the third fluidization device (35). 2. The converter gas dry dedusting coarse ash pneumatic conveying system according to claim 1, characterized in that, the horizontal chain conveyor (2) is provided with a first emergency ash unloading supervisor (6), and the second A fourth manual flapper valve (7) is provided on an accident ash unloading supervisor (6). 3. The converter gas dry process dedusting coarse ash pneumatic conveying system according to claim 1, characterized in that, the second emergency ash unloading supervisor (30) is provided on the lower cone of the coarse ash bin (25), and the The fifth manual flapper valve (31) is provided on the second accident ash unloading supervisor (30). 4. The converter gas dry dust removal coarse ash pneumatic conveying system according to claim 1, characterized in that drain pipes are provided at the bottom of the first warehouse pump (11) and the second warehouse pump (16).