阅读说明：本技术 一种电子级多晶硅生产中尾气处理系统及其方法 (Tail gas treatment system and method in electronic grade polycrystalline silicon production ) 是由 徐建均 周同义 于 2021-10-22 设计创作，主要内容包括：本发明公开了一种电子级多晶硅生产中尾气处理系统及其方法,包括集尘装置、吸收塔以及废液回收箱,集尘装置的顶部排气口处设置有反吹气泵,集尘装置的侧壁进气口外部连接有文丘里管,集尘装置的底部排渣口设置有回转阀,集尘装置的顶部排气口与吸收塔下方的进气口连通,吸收塔顶部的排气口处设置有旋转导向风扇,吸收塔底部的集水口与废液回收箱连通,废液回收箱顶部通过多级喷淋装置与吸收塔内部连通。本发明的优点在于通过集尘装置与反吹气泵配合实现集尘的回收,能够有效隔绝生产中尾气内的尘粒,同时回收也更加方便,将未完全反应的废液回收再次喷淋利用,提升利用效率,降低成本,同时改善生产尾气排放质量。(The invention discloses a tail gas treatment system in electronic-grade polycrystalline silicon production and a method thereof, and the tail gas treatment system comprises a dust collecting device, an absorption tower and a waste liquid recovery box, wherein a back-flushing air pump is arranged at an exhaust port at the top of the dust collecting device, a Venturi tube is connected with the outside of an air inlet on the side wall of the dust collecting device, a rotary valve is arranged at a slag discharge port at the bottom of the dust collecting device, an exhaust port at the top of the dust collecting device is communicated with an air inlet below the absorption tower, a rotary guide fan is arranged at the exhaust port at the top of the absorption tower, a water collecting port at the bottom of the absorption tower is communicated with the waste liquid recovery box, and the top of the waste liquid recovery box is communicated with the inside of the absorption tower through a multi-stage spraying device. The invention has the advantages that the recovery of dust collection is realized by matching the dust collection device with the back-blowing air pump, dust particles in tail gas in production can be effectively isolated, the recovery is more convenient, the waste liquid which is not completely reacted is recovered and is sprayed and utilized again, the utilization efficiency is improved, the cost is reduced, and the emission quality of the tail gas in production is improved.)

1. The utility model provides a tail gas processing system in production of electronic grade polycrystalline silicon, a serial communication port, including dust collecting device, absorption tower and waste liquid recovery case, dust collecting device's top exhaust port department is provided with the blowback air pump, dust collecting device's lateral wall air inlet external connection has venturi, dust collecting device's bottom scum outlet is provided with the rotary valve, dust collecting device's top exhaust port and the air inlet intercommunication of absorption tower below, the exhaust port department at absorption tower top is provided with rotatory guide fan, the mouth that catchments and the waste liquid recovery case intercommunication of absorption tower bottom, the waste liquid recovery case top is through multistage spray set and the inside intercommunication of absorption tower.

2. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 1, characterized in that: the dust collecting device is characterized in that a plurality of groups of dust collecting pipes are arranged in the top exhaust port of the dust collecting device, a dust collecting bag is fixedly sleeved outside the dust collecting pipes through flanges, a flow baffle is arranged at the position, close to the side wall air inlet, of the top of the dust collecting device, and a rotary dredging fan is arranged above the rotary valve at the bottom slag discharge port.

3. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 2, characterized in that: the axis of rotation of rotatory dredging the fan sets up for perpendicular, the fixed arc flabellum that is provided with the symmetric distribution in the axis of rotation, two of symmetric distribution the arc flabellum is one end other end down fixed.

4. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 1, characterized in that: a first stop valve is arranged between a top exhaust port of the dust collecting device and the back-blowing air pump, and a second stop valve is arranged between the top exhaust port of the dust collecting device and an air inlet below the absorption tower.

5. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 1, characterized in that: an ultrasonic dust collector is arranged on the inner wall of the dust collecting device, and the output end of the ultrasonic dust collector is fixedly arranged at the bottom of the dust collecting pipe.

6. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 1, characterized in that: the absorption tower is internally provided with a second cyclone plate, a flow collecting conical plate, a first cyclone plate and a packing layer in sequence from bottom to bottom in the rotary guide fan, and the packing layer is arranged above an air inlet below the absorption tower.

7. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 1, characterized in that: the water collecting opening at the bottom of the absorption tower is provided with a third stop valve and a pressure pump between the water collecting opening and the waste liquid recovery tank, and the inside of the waste liquid recovery tank is provided with a PH tester.

8. The tail gas treatment system in the production of electronic grade polycrystalline silicon according to claim 1, characterized in that: the multistage spraying device comprises at least three groups of spraying pumps, a spraying head and a liquid inlet pipe, the spraying head is communicated with the spraying pumps and a waste liquid recovery box through the liquid inlet pipe, the spraying head is respectively arranged between the rotary guide fan and the second spiral-flow plate, between the flow collecting conical plate and the first spiral-flow plate and between the first spiral-flow plate and the packing layer, a fourth stop valve is arranged at the main end of the liquid inlet pipe, and the output end of the spraying head is upwards arranged.

9. A tail gas treatment method in electronic grade polycrystalline silicon production is characterized by comprising the following steps: the method comprises the following steps:

(1) firstly, closing the first stop valve and the fourth stop valve, opening the other stop valves, introducing the production tail gas into a dust collecting device through a Venturi tube, cutting off and collecting dust particles in the production tail gas through a dust collecting bag, and introducing the dust particles into an absorption tower through a top exhaust port of the dust collecting device;

(2) the production tail gas enters the absorption tower and then passes through the filler layer, the filler layer is contacted with the treatment liquid on the upper part of the absorption tower to form a liquid film, the liquid film is fully contacted with the production tail gas, and the liquid film is discharged by the rotary guide fan after the full reaction is realized by the upper multistage spray pipe and the rotational flow plate to complete dehydration;

(3) liquid at the bottom of the absorption tower after reaction is guided into a waste liquid recovery box through a pressure pump, waste liquid recovery is realized through a spray pump and a spray head, real-time PH detection is realized in the waste liquid recovery box, if the waste liquid in the waste liquid recovery box tends to be neutral, a third stop valve and the pressure pump are closed, and the liquid is guided into a liquid inlet pipe through external liquid soap;

(4) after the dust collecting device works for a certain time, stopping the air intake of the production tail gas, closing the second stop valve, opening the first stop valve and the pressure pump, blowing down the dust particles on the dust collecting bag, shaking off the dust particles through the ultrasonic dust collector, discharging the dust particles from a slag discharge port at the bottom of the dust collecting device, and opening the rotary dredging fan to dredge and discharge dust in time after the dust collecting device is blocked.

Technical Field

The invention relates to the technical field of polycrystalline silicon tail gas treatment, in particular to a tail gas treatment system and method in electronic grade polycrystalline silicon production.

Background

The new silane method is used for producing polycrystalline silicon, and sodium aluminum fluoride and silane are generated after sodium aluminum hydride and silicon tetrafluoride react in toluene and DME solvent. The aluminum fluoride sodium solid-liquid mixture is separated into a solvent and aluminum fluoride sodium powder through a film dryer, and the solvent and the aluminum fluoride sodium powder respectively enter a rectification system and a negative pressure conveying system and enter different production areas. And the organic solvent steam separated by the film dryer enters a rectification system for purification and separation, and then returns to the solvent storage tank.

Organic solvent steam enters a condenser from an outlet pipeline at the upper end of the film dryer, is liquefied under the cooling action and enters a feeding tank, then enters a rectifying tower as a feed through a feeding pump, and toluene and DME separated by the rectifying tower return to a solvent storage tank. Meanwhile, under the action of the rectification system, light components such as non-condensable gas in the solvent are also discharged from the tower top reflux tank and enter an incineration system for incineration treatment, and harmful gases in the waste gas mainly comprise part of incineration dust particles, sulfur oxides, a small amount of halides and phosphorus compounds.

Disclosure of Invention

The invention aims to provide a tail gas treatment system and a tail gas treatment method in electronic grade polycrystalline silicon production, and the tail gas emission quality in production is improved.

The technical purpose of the invention is realized by the following technical scheme:

the utility model provides a tail gas processing system in production of electronic grade polycrystalline silicon, a serial communication port, including dust collecting device, absorption tower and waste liquid recovery case, dust collecting device's top exhaust port department is provided with the blowback air pump, dust collecting device's lateral wall air inlet external connection has venturi, dust collecting device's bottom scum outlet is provided with the rotary valve, dust collecting device's top exhaust port and the air inlet intercommunication of absorption tower below, the exhaust port department at absorption tower top is provided with rotatory guide fan, the mouth that catchments and the waste liquid recovery case intercommunication of absorption tower bottom, the waste liquid recovery case top is through multistage spray set and the inside intercommunication of absorption tower.

Preferably, the dust collecting device is internally provided with a plurality of groups of dust collecting pipes at a top exhaust port, the dust collecting pipes are externally fixedly sleeved with dust collecting bags through flanges, a flow baffle is arranged at the position, close to the side wall air inlet, of the top of the dust collecting device, and a rotary dredging fan is arranged above the rotary valve at a bottom slag discharge port.

Preferably, the rotation axis of the rotary dredging fan is vertically arranged, the arc-shaped fan blades are symmetrically arranged and fixed on the rotation axis, and the two arc-shaped fan blades are symmetrically arranged, wherein one end of each arc-shaped fan blade faces upwards, and the other end of each arc-shaped fan blade faces downwards.

Preferably, a first stop valve is arranged between the top exhaust port of the dust collecting device and the back-blowing air pump, and a second stop valve is arranged between the top exhaust port of the dust collecting device and the air inlet below the absorption tower.

Preferably, an ultrasonic dust collector is arranged on the inner wall of the dust collecting device, and the output end of the ultrasonic dust collector is fixedly arranged at the bottom of the dust collecting pipe.

Preferably, a second cyclone plate, a flow collecting conical plate, a first cyclone plate and a packing layer are sequentially arranged in the absorption tower from bottom to bottom in the rotary guide fan, and the packing layer is arranged above the air inlet below the absorption tower.

Preferably, a third stop valve and a pressure pump are arranged between the water collecting opening at the bottom of the absorption tower and the waste liquid recovery tank, and a PH tester is arranged inside the waste liquid recovery tank.

Preferably, the multistage spraying device comprises at least three groups of spraying pumps, spraying heads and a liquid inlet pipe, the spraying heads are communicated with the spraying pumps and the waste liquid recovery box through the liquid inlet pipe, the spraying heads are respectively arranged between the rotary guide fan and the second spiral-flow plate, between the flow collecting conical plate and the first spiral-flow plate and between the first spiral-flow plate and the packing layer, a fourth stop valve is arranged at the main end of the liquid inlet pipe, and the output end of the spraying heads is upwards arranged.

A tail gas treatment method in electronic grade polycrystalline silicon production is characterized by comprising the following steps: the method comprises the following steps:

(1) firstly, closing the first stop valve and the fourth stop valve, opening the other stop valves, introducing the production tail gas into a dust collecting device through a Venturi tube, cutting off and collecting dust particles in the production tail gas through a dust collecting bag, and introducing the dust particles into an absorption tower through a top exhaust port of the dust collecting device;

(2) the production tail gas enters the absorption tower and then passes through the filler layer, the filler layer is contacted with the treatment liquid on the upper part of the absorption tower to form a liquid film, the liquid film is fully contacted with the production tail gas, and the liquid film is discharged by the rotary guide fan after the full reaction is realized by the upper multistage spray pipe and the rotational flow plate to complete dehydration;

(3) liquid at the bottom of the absorption tower after reaction is guided into a waste liquid recovery box through a pressure pump, waste liquid recovery is realized through a spray pump and a spray head, real-time PH detection is realized in the waste liquid recovery box, if the waste liquid in the waste liquid recovery box tends to be neutral, a third stop valve and the pressure pump are closed, and the liquid is guided into a liquid inlet pipe through external liquid soap;

(4) after the dust collecting device works for a certain time, stopping the air intake of the production tail gas, closing the second stop valve, opening the first stop valve and the pressure pump, blowing down the dust particles on the dust collecting bag, shaking off the dust particles through the ultrasonic dust collector, discharging the dust particles from a slag discharge port at the bottom of the dust collecting device, and opening the rotary dredging fan to dredge and discharge dust in time after the dust collecting device is blocked.

In conclusion, the invention has the following beneficial effects:

1. the invention realizes the recovery of dust collection by matching the dust collection device with the back-blowing air pump, can effectively isolate dust particles in tail gas in production, and is more convenient to recover.

2. The second cyclone plate, the flow collecting conical plate, the first cyclone plate and the filler layer are sequentially arranged in the absorption tower, so that dehydration and discharge are completed through full reaction, a liquid film is formed when liquid is sprayed on the filler, the liquid film increases the contact area of gas phase and liquid phase, the gas phase and the liquid phase are in full contact, and physical dissolution and chemical reaction processes occur between the liquid phase and the gas phase in the contact process, so that harmful ingredients in tail gas are removed, and the emission quality of the tail gas in production is improved.

3. The invention adopts the waste liquid recovery box to recover and spray the incompletely-reacted waste liquid for reuse, thereby improving the utilization efficiency and reducing the cost.

Drawings

FIG. 1 is a schematic view of the structures of the present invention.

Detailed Description

The following further describes the embodiments of the present invention with reference to the drawings, and the present embodiment is not to be construed as limiting the invention.

As shown in fig. 1, a tail gas treatment system in electronic grade polycrystalline silicon production, including dust collector 1, absorption tower 2 and waste liquid recovery case 3, dust collector 1's top exhaust port department is provided with blowback air pump 4, dust collector 1's lateral wall air inlet external connection has venturi 25, dust collector 1's bottom deslagging mouth is provided with rotary valve 5, dust collector 1's top gas vent and the air inlet intercommunication of absorption tower 2 below, the exhaust port department at absorption tower 2 top is provided with rotatory guide fan 6, the water catch bowl and the waste liquid recovery case 3 intercommunication of absorption tower 2 bottom, the inside intercommunication of waste liquid recovery case 3 top through multistage spray set and absorption tower 2.

Dust collecting device 1 is inside to be provided with several sets of dust collecting tube 7 in the top gas vent, dust collecting tube 7 outside has cup jointed dust bag 8 through the flange, 1 top of dust collecting device is close to lateral wall air inlet department and is provided with fender stream board 9, the bottom slag discharge hole is in the 5 tops of rotary valve and is provided with rotatory dredging fan 10, the axis of rotation of rotatory dredging fan 10 is for setting up perpendicularly, the fixed arc flabellum that is provided with the symmetric distribution in the axis of rotation, two arc flabellums of symmetric distribution are one end other end down fixed, realize preventing stifled mediation to bottom slag discharge hole through rotatory dredging fan 10.

Be provided with first stop valve 11 between dust collecting device 1's the top gas vent and the blowback air pump 4, be provided with second stop valve 12 between dust collecting device 1's the top gas vent and the air inlet of absorption tower 2 below, be provided with ultrasonic cleaner 13 on the dust collecting device 1 inner wall, ultrasonic cleaner 13 output end is fixed to be set up in the dust collecting tube 7 bottom, realizes shaking of dirt particle through ultrasonic cleaner 13 and falls, realizes the clearance to dust collecting device 1 inside more easily.

Inside 2 inside in the rotatory guiding fan 6 of absorption tower down has set gradually second whirl board 14, mass flow awl board 15, first whirl board 16 and packing layer 17, and packing layer 17 sets up in the air inlet top of absorption tower 2 below, realizes fully reacting through top multistage spray set and whirl board and accomplishes the dehydration.

The mouth that catchments of absorption tower 2 bottom is provided with third stop valve 18 and force (forcing) pump 19 between with waste liquid recovery case 3, and waste liquid recovery case 3 is inside to be provided with PH apparatus 20, realizes PH real-time detection in the waste liquid recovery case 3 to judge subsequent waste liquid recovery according to the PH value.

The multi-stage spraying device comprises at least three groups of spraying pumps 21, spraying heads 22 and a liquid inlet pipe 23, the spraying heads 22 are communicated with the spraying pumps 21 through the liquid inlet pipe 23, a waste liquid recycling tank 3 is communicated, the spraying heads 22 are respectively arranged between the rotary guide fan 6 and the second spiral-flow plate 14, between the flow collecting conical plate 15 and the first spiral-flow plate 16 and between the first spiral-flow plate 16 and the packing layer 17, a fourth stop valve 24 is arranged at the general end of the liquid inlet pipe 23, the output end of the spraying heads 22 is upwards arranged, a liquid film is formed when liquid is sprayed on the packing, the liquid film increases the contact area of gas and liquid phases, the liquid and liquid phases are fully contacted, the physical dissolution and chemical reaction processes occur between the liquid phase and the gas phase in the contact process, therefore harmful ingredients in tail gas can be removed, and the emission quality of the produced tail gas is improved.

A tail gas treatment method in electronic grade polycrystalline silicon production comprises the following steps:

(1) the first stop valve 11 and the fourth stop valve 24 are closed, the rest stop valves are opened, the production tail gas is guided into the dust collecting device 1 through the venturi tube 25, dust particles in the production tail gas are cut off and collected through the dust collecting bag 8, and the dust particles enter the absorption tower 2 through the top exhaust port of the dust collecting device 1.

(2) The production tail gas firstly passes through the packing layer 17 after entering the absorption tower 2, the packing layer 17 is contacted with the treatment liquid on the upper part of the absorption tower 2 to form a liquid film, the liquid film is fully contacted with the production tail gas, and the liquid film is discharged through the rotary guide fan 6 after the full reaction is realized through the upper multi-stage spray device and the rotational flow plate to complete the dehydration.

(3) Liquid at the bottom of the absorption tower 2 after reaction is led into the waste liquid recovery box 3 through the pressure pump, waste liquid recovery is realized through the spray pump 21 and the spray header 22, real-time PH detection is realized in the waste liquid recovery box 3, if the waste liquid in the waste liquid recovery box 3 tends to be neutral, the third stop valve 18 and the pressure pump 19 are closed, and the liquid is led into the liquid inlet pipe 23 through the external liquid soap.

(4) After the dust collecting device 1 works for a certain time, stopping the air intake of the production tail gas, closing the second stop valve 12, opening the first stop valve 11 and the pressure pump 19, blowing down the dust particles on the dust collecting bag 8, shaking off the dust particles through the ultrasonic dust collector 13, discharging the dust particles from a slag discharge port at the bottom of the dust collecting device 1, and opening the rotary dredging fan 10 to dredge and discharge dust in time after blockage occurs.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention.