CN218755048U

CN218755048U - Novel recovery rectification coupling system

Info

Publication number: CN218755048U
Application number: CN202222795799.0U
Authority: CN
Inventors: 贾琳蔚; 陈绍林; 程茂林; 宋垒; 李锋; 林燕峰; 王亚萍; 刘逸枫; 甘居富
Original assignee: Sichuan Yongxiang Energy Technology Co ltd
Current assignee: Sichuan Yongxiang Energy Technology Co ltd
Priority date: 2022-10-24
Filing date: 2022-10-24
Publication date: 2023-03-28
Anticipated expiration: 2032-10-24

Abstract

The utility model discloses a novel recovery rectification coupling system, which belongs to the technical field of polysilicon production and comprises a rectifying tower I, a light component removing tower and a rectifying tower II, wherein the bottom of the rectifying tower II is connected with a heat exchanger I, and the top of the rectifying tower I is provided with a gas phase outlet I; the side is equipped with the side outflow, and gaseous phase export I passes through pipeline I to be connected with heat exchanger I, and heat exchanger I passes through pipeline II to be connected rectifying column I's upper portion, and heat exchanger I passes through pipeline III to be connected and takes off the light tower, and rectifying column I's side outflow passes through pipeline IV to be connected with rectifying column II, and it is big to solve among the prior art steam usage in the rectification workshop section, and energy resource consumption is big, and the problem that tower ware investment cost is high.

Description

Novel recovery rectification coupling system

Technical Field

The utility model belongs to the technical field of polycrystalline silicon production, concretely relates to novel retrieve rectification coupled system.

Background

At present, the mode of multi-tower flow is adopted in the field of polycrystalline silicon recovery and rectification, steam is adopted for heating in a rough separation tower and a product rectification tower, and in the traditional process, in order to achieve the maximum utilization of energy, a rectification tower I is coupled with a rectification tower II, namely, heat generated in a gas phase by the rectification tower I is used for heating the rectification tower II after being processed by a heat exchanger, so that the heat recovery and utilization are realized. In the traditional treatment system, the temperature and the pressure of the rectifying tower II are lower due to more light components (the content of DCS is about 30 percent) generated in the rectifying tower I, so that more cold is needed for condensing the DCS at the top of the rectifying tower, the required cost of the whole production process is higher, the equipment investment cost is higher, and the process control is more difficult.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems of higher production cost and insufficient energy utilization of the recovery and rectification workshop section in the polysilicon production process in the prior art.

In order to achieve the above purpose, the technical solution of the present invention is as follows:

a novel recovery rectification coupling system comprises a rectification tower I, a light component removal tower and a rectification tower II, wherein the bottom of the rectification tower II is connected with a heat exchanger I, and the top of the rectification tower I is provided with a gas phase outlet I; the side is equipped with the side outflow, and gaseous phase export I passes through pipeline I and is connected with heat exchanger I, and heat exchanger I passes through pipeline II and connects rectifying column I's upper portion, and heat exchanger I passes through pipeline III and connects the lightness-removing column, and rectifying column I's side outflow passes through pipeline IV and is connected with rectifying column II.

Further, the rectifying tower I is connected with an inlet of a tube pass of the heat exchanger I through a pipeline I, and an outlet of the tube pass of the heat exchanger I is respectively connected with the rectifying tower I and the light component removal tower through a pipeline II and a pipeline III.

And the lower part of the light component removal tower is externally connected with a heat exchanger II, a gas phase outlet II at the top of the light component removal tower is connected with the heat exchanger II through a pipeline V, and the heat exchanger II is connected with the upper part of the light component removal tower through a pipeline VI.

Further, a gas phase outlet II at the top of the decarbonizing tower is connected with an inlet of a tube pass of a heat exchanger II through a pipeline V, and an outlet of the tube pass of the heat exchanger II is connected with the upper part of the decarbonizing tower through a pipeline VI.

Further, the rectifying tower I is a packed tower and comprises a plurality of packing layers, the height of each packing layer is 5-6m, and the lateral flow outlet is arranged between a first packing layer and a second packing layer from top to bottom.

Furthermore, temperature sensors are arranged on the upper part, the middle part and the lower part of the rectifying tower I, and pressure sensors are also arranged on the rectifying tower I.

Further, the bottom of the light component removal tower is communicated with a pipeline IV through a pipeline VII; the rectifying tower I is connected with a feeding pipeline.

The utility model has the advantages that:

1. the utility model discloses in, adopt this novel recovery rectification coupled system, with the fractional distillation in the rectifying column I partly dichloro dihydro silicon direct delivery to rectifying column II in further processing, the gaseous phase that rectifying column I handled and obtains carries out the heat exchange with the material of rectifying column II, namely rectifying column I is as rectifying column II's heat source tower, recycle heat source, because dichloro dihydro silicon in rectifying column I is mostly directly delivered to rectifying column II in, can obviously reduce the treatment pressure of lightness-removing column, namely lightness-removing column can be designed more smallly a bit, reduce the input of equipment, and the smaller equipment is more convenient for control; on the other hand, because the material input of the light component removal tower is reduced, the heat required for heating the light component removal tower is correspondingly reduced.

2. In the utility model, the heat exchanger I is a tube type heat exchanger, which can realize the heat exchange of two materials and can realize the expected heating effect on the rectifying tower II; and the heat exchanger II adopts a tube type heat exchanger, so that heat exchange of two materials can be realized, and the expected heating effect on the rectifying tower II can be realized.

3. The utility model discloses in, still including the decarbonization tower, the decarbonization tower lower part is external to have heat exchanger II, and the high temperature gaseous phase of decarbonization tower top gaseous phase export II output passes through during pipeline V back gets into heat exchanger II, carries out the heat transfer with the material in the decarbonization tower, utilizes the gaseous heat of high temperature that produces in the decarbonization tower to heat the decarbonization tower promptly, can no longer adopt steam to heat the decarbonization tower, reduces the use of steam, and the gaseous phase after heat exchanger II cools off is sent to the decarbonization tower.

4. The utility model discloses in, rectifying column I is the packed column, including a plurality of packing layers, every layer of packing layer height is 5-6m, the side stream export sets up between first layer packing layer and the second floor packing layer from last extremely down, guarantees not higher than 10% through the dichlorosilane's in the rectifying column I treatment back from the material that the side stream export was extracted content, can directly carry to rectifying column II, carries out further rectification treatment, reaches the technological requirement.

5. The utility model discloses in, rectifying column I's upper and middle, lower part all is equipped with temperature sensor for the temperature of each section in the monitoring rectifying column I guarantees from gas phase export I combustion gas and from the composition in the lateral flow export exhaust material stable, guarantees to reach the technological requirement, guarantees the steady operation of production line simultaneously, still is equipped with pressure sensor on the rectifying column I for pressure in the monitoring rectifying column I guarantees production normal operating.

6. In the utility model, the bottom of the light component removing tower is communicated with a pipeline IV through a pipeline VII; and the rectifying tower I is connected with a feeding pipeline, and the feeding pipeline is used for connecting a recovery working section and receiving a chlorosilane by-product stream generated by the recovery working section.

Drawings

FIG. 1 is a schematic structural view of example 1.

FIG. 2 is a schematic view of the structure of embodiment 2.

Fig. 3 is a schematic structural diagram of another embodiment.

Fig. 4 is a schematic view of a rectifying column I.

Fig. 5 is a schematic structural diagram of yet another embodiment.

Wherein, 1, a rectifying tower I; 2. a light component removal tower; 3. a rectifying tower II; 4. a heat exchanger I; 5. a pipeline I; 6. line II; 7. line III; 8. a line IV; 9. a decarbonizing tower; 10. a heat exchanger II; 11. a line V; 12. line VI; 13. line VII; 14. a feed line; 15. a temperature sensor I; 16. a temperature sensor II; 17. a temperature sensor III; 18. a pressure sensor I;1.1, a gas phase outlet I;1.2, a side stream outlet; 1.3, a first filler layer; 1.4, a second packing layer; 4.1, an inlet I;4.2, an outlet I;9.1, a gas phase outlet II;10.1, inlet II;10.2 and an outlet II.

Detailed Description

The present invention will be described in further detail with reference to examples, but the present invention is not limited thereto.

Example 1

The embodiment is the most basic implementation manner, and a novel recovery rectification coupling system belongs to the technical field of polycrystalline silicon production, and refers to fig. 1, and comprises a rectification tower I1, a light component removal tower 2 and a rectification tower II3, wherein the bottom of the rectification tower II3 is connected with a heat exchanger I4, and the top of the rectification tower I1 is provided with a gas phase outlet I1.1; the side is equipped with side stream outlet 1.2, and gaseous phase outlet I1.1 passes through pipeline I5 and is connected with heat exchanger I4, and heat exchanger I4 passes through pipeline II6 and connects the upper portion of rectifying column I1, and heat exchanger I4 passes through pipeline III7 and connects lightness-removing column 2, and rectifying column I1's side stream outlet 1.2 passes through pipeline IV8 and is connected with rectifying column II 3.

In this embodiment, the rectifying tower I1 receives chlorosilane material flow from the recovery section, after steam heating, the obtained materials such as dichlorosilane and trichlorosilane are discharged from the gas phase outlet I1.1, and are sent to the heat exchanger I to exchange heat with the materials in the rectifying tower II3, the materials in the pipeline I5 are sent to the lightness-removing tower 2 to be dehydrogenated after heat exchange and cooling, i.e., dichlorosilane and trichlorosilane are separated, and a part of the materials (mainly trichlorosilane) processed by the rectifying tower I1 is directly conveyed to the rectifying tower II3 through the side stream outlet 1.2, so that the processing amount of the lightness-removing tower 2 can be reduced, on the one hand, a heat source can be saved, on the other hand, the lightness-removing tower 2 can be designed to be smaller, the investment of equipment is reduced, and the small-sized equipment is easy to control.

Example 2

The embodiment is further optimized in embodiment 1, and the difference is that a tube type heat exchanger is used as the heat exchanger I4 in the scheme, referring to fig. 2, the rectifying tower I1 is connected with an inlet I4.1 of a tube side of the heat exchanger I4 through a pipeline I5, and an outlet I4.2 of the tube side of the heat exchanger I4 is connected with the rectifying tower I1 and the light component removal tower 2 through a pipeline II6 and a pipeline III7, respectively.

Example 3

This embodiment is different from embodiment 1-2 in that the system further comprises a decarbonization tower 9, referring to fig. 3, the lower part of the decarbonization tower 2 is externally connected with a heat exchanger II10, a gas phase outlet II9.1 at the top of the decarbonization tower 9 is connected with the heat exchanger II10 through a pipeline V11, and the heat exchanger II10 is connected with the upper part of the decarbonization tower 9 through a pipeline VI 12.

Example 4

This embodiment is further optimized on embodiment 3, except that referring to fig. 3, the heat exchanger II10 in this embodiment is also a shell and tube heat exchanger, the gas phase outlet II9.1 at the top of the decarbonizing tower 9 is connected to the inlet II10.1 of the tube pass of the heat exchanger II10 through a pipeline V11, and the outlet II10.2 of the tube pass of the heat exchanger II10 is connected to the upper part of the decarbonizing tower 9 through a pipeline VI 12.

Example 5

Compared with the embodiment 1-2, the present embodiment is different in that the rectifying tower I1 is a packed tower, and referring to fig. 4, the rectifying tower I comprises a plurality of packing layers, the height of each packing layer is 5-6m, and the side stream outlet 1.2 is arranged between a first packing layer 1.3 and a second packing layer 1.4 from top to bottom.

Preferably, referring to fig. 4, the upper part, the middle part and the lower part of the rectifying tower I1 are respectively provided with a temperature sensor I15, a temperature sensor II16 and a temperature sensor III17, and the top of the rectifying tower I1 is also provided with a pressure sensor I18.

Example 6

This example compares with examples 1-5, with the difference that, with reference to FIG. 5, the bottom of the lightness-removing column 2 communicates with a line IV8 through a line VII 13; the rectifying column I1 is connected to a feed line 14.

Example 7

This embodiment further illustrates the technical solution by taking a recovery and rectification line with a annual throughput of 250 ten thousand tons as an example.

The working section adopts a novel recovery rectification coupling system, belongs to the technical field of polycrystalline silicon production, and particularly comprises a rectifying tower I1, a light component removal tower 2, a rectifying tower II3 and a decarbonization tower 9, referring to a figure 5, wherein the bottom of the rectifying tower II3 is connected with a heat exchanger I4, and the top of the rectifying tower I1 is provided with a gas phase outlet I1.1; the side is equipped with side stream outlet 1.2, and gas phase outlet I1.1 is connected with the import I4.1 of heat exchanger I4 tube side through pipeline I5, heat exchanger I4 is shell and tube heat exchanger, and the export I4.2 of heat exchanger I4 tube side passes through pipeline II6 and connects the upper portion of rectifying column I1, and the export I4.2 of heat exchanger I4 tube side passes through pipeline III7 and connects the lightness-removing column 2, and the side stream outlet 1.2 of rectifying column I1 passes through pipeline IV8 and is connected with rectifying column II 3.

In this embodiment, the lower part of the light component removal tower 2 is externally connected with a heat exchanger II10, the heat exchanger II10 is a tube type heat exchanger, a gas phase outlet II9.1 at the top of the decarbonization tower 9 is connected with an inlet II10.1 of a tube pass of the heat exchanger II10 through a pipeline V11, and an outlet II10.2 of the tube pass of the heat exchanger II10 is connected with the upper part of the decarbonization tower 9 through a pipeline VI 12.

In this embodiment, the rectifying tower I1 is a packed tower, and includes a plurality of packing layers, the height of each packing layer is 6m, and the side flow outlet 1.2 is disposed between a first packing layer 1.3 and a second packing layer 1.4 from top to bottom.

In the embodiment, the bottom of the lightness-removing column 2 is communicated with a pipeline IV8 through a pipeline VII 13; the rectifying column I1 is connected to a feed line 14.

In this embodiment, the chlorosilane material flow recovered from the recovery section enters the rectifying tower I1 of the system through the feed line 14, is heated by a reboiler at the bottom of the rectifying tower I1, that is, heated by steam, the gas phase (mainly including dichlorodisilane and trichlorosilane) treated by the rectifying tower I1 is discharged from a gas phase outlet I1.1, enters the tube pass of the heat exchanger I4 through the line I5, exchanges heat with the material in the rectifying tower II3, the cooled material is discharged from an outlet I4.2 of the tube pass of the heat exchanger I4, and after being returned to the rectifying tower I1 through the line II6, a part of the cooled material is used as reflux of the rectifying tower I1, and the other part of the cooled material is sent to the light component dichlorosilane removal tower 2 through the line III7, and after further treatment, the light component dichlorosilane is separated. 1.2 is collected at the side of the top of the rectifying tower I1 and 13 is collected at the bottom of the lightness-removing tower 2 to be used as the feeding material of the rectifying tower II3, and after being heated by a heat exchanger I4, the silicon trichloride product containing 10-20% dichlorosilane is separated at the top. The decarbonizing tower 9 is a heat source tower for the dehydrogenation tower 2, and the material from the top outlet 9.1 of the decarbonizing tower 9 passes through the tube side inlet 10.1 of the heat exchanger 10 and then enters the decarbonizing tower 9 from the tube side outlet 10.2 through the pipeline 12.

Compared with the traditional multi-tower rectification scheme, the recovery rectification coupling system can save 35-42% of steam, simultaneously reduces the amount of materials entering the lightness-removing tower 2, achieves the purity of dichlorosilane obtained by processing the materials in the rectification tower I1, can be directly input into the rectification tower II3 for processing together, namely the lightness-removing tower 2 can be designed to be smaller, reduces the input amount of equipment, and smaller equipment is more convenient to control.

Claims

1. The utility model provides a novel retrieve rectification coupled system which characterized in that: the device comprises a rectifying tower I (1), a light component removal tower (2) and a rectifying tower II (3), wherein the bottom of the rectifying tower II (3) is connected with a heat exchanger I (4), and the top of the rectifying tower I (1) is provided with a gas phase outlet I (1.1); the side is equipped with side stream outlet (1.2), and gas phase outlet I (1.1) is connected with heat exchanger I (4) through pipeline I (5), and heat exchanger I (4) are connected the upper portion of rectifying column I (1) through pipeline II (6), and light tower (2) is taken off in the connection of heat exchanger I (4) through pipeline III (7), and side stream outlet (1.2) of rectifying column I (1) is connected with rectifying column II (3) through pipeline IV (8).

2. The novel recovery and rectification coupling system as claimed in claim 1, wherein: the rectifying tower I (1) is connected with an inlet of a tube pass of the heat exchanger I (4) through a pipeline I (5), and an outlet of the tube pass of the heat exchanger I (4) is connected with the rectifying tower I (1) and the light component removal tower (2) through a pipeline II (6) and a pipeline III (7) respectively.

3. The novel recovery and rectification coupling system as claimed in claim 1, wherein: the device is characterized by further comprising a decarbonization tower (9), wherein the lower part of the decarbonization tower (2) is externally connected with a heat exchanger II (10), a gas phase outlet II (9.1) at the top of the decarbonization tower (9) is connected with the heat exchanger II (10) through a pipeline V (11), and the heat exchanger II (10) is connected with the upper part of the decarbonization tower (9) through a pipeline VI (12).

4. The novel recovery and rectification coupling system as claimed in claim 3, wherein: and a gas phase outlet II (9.1) at the top of the decarbonizing tower (9) is connected with an inlet of a tube pass of a heat exchanger II (10) through a pipeline V (11), and an outlet of the tube pass of the heat exchanger II (10) is connected with the upper part of the decarbonizing tower (9) through a pipeline VI (12).

5. The novel recovery and rectification coupling system as claimed in claim 1, wherein: the rectifying tower I (1) is a packed tower and comprises a plurality of packing layers, the height of each packing layer is 5-6m, and the lateral flow outlet (1.2) is arranged between a first packing layer (1.3) and a second packing layer (1.4) from top to bottom.

6. The novel recovery and rectification coupling system as claimed in claim 5, wherein: temperature sensors are arranged on the upper part, the middle part and the lower part of the rectifying tower I (1), and pressure sensors are also arranged on the rectifying tower I (1).

7. The novel recovery and rectification coupling system as claimed in claim 1, wherein: the bottom of the light component removal tower (2) is communicated with a pipeline IV (8) through a pipeline VII (13); the rectifying tower I (1) is connected with a feeding pipeline (14).