Cold hydrogenation dry method and double-tower washing dust removal system
By introducing a filter and a double tower leaching system between the cold hydrogenation reactor and the scrubber, the problem of high boiling substances and silicon powder blockage in polycrystalline silicon production is solved, and efficient filtration and stable operation are achieved, and equipment life is extended.
Patent Information
- Application Number
- CN202422046434.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-08-22
AI Technical Summary
In the prior art, in the cold hydrogenation reaction of polycrystalline silicon, high boiling substances and fine silicon powder are easily adhered to the system equipment and pipelines, resulting in clogging and wear. The existing scrubber towers are prone to clogging, and the circulation pumps frequently fail, so it is impossible to effectively deal with high boiling substances containing silicon.
A set of filters and double tower leaching systems are added between the cold hydrogenation reactor and the scrubbing tower, including filters, silicon powder collection tanks, primary leaching towers and secondary leaching towers. The combination of dry dust removal and leaching towers is adopted. The filter has a 1μm accuracy, the backblowing system is self-cleaned, and the leaching tower is a combination of plate-type and filler towers to ensure efficient filtration and washing of silicon powder.
It realizes efficient filtering of silicon powder, reduces equipment blockage, extends the service cycle, reduces the probability of failure, and improves the stability and efficiency of the system.
Smart Images
Figure CN223170614U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cold hydrogenation, in particular to a cold hydrogenation dry process plus double-tower washing and dust removal system. Background Art
[0002] In the cold hydrogenation reaction of polysilicon production, in addition to trichlorosilane, other byproducts, such as polysilicon atom compounds and metal chlorides, are produced, generally referred to as high-boiling products. Furthermore, unreacted fine silicon powder is carried along with the reaction syngas. High-boiling products have high boiling points and high viscosities, and when they are entrained with fine silicon powder, they tend to accumulate in system equipment and pipelines, reducing heating equipment efficiency and causing pipeline blockages. Furthermore, the presence of high-hardness silicon powder can erode pipe walls, accelerating wear and causing leaks.
[0003] Currently, the commonly used method for treating high-boiling silicon products is a Venturi-based scrubber dust removal system. However, this method suffers from the following drawbacks: as the high-boiling gases rise within the quench tower, the metal chlorides within them desublimate, forming extremely fine particles. These particles, along with the silicon powder, deposit on the scrubber trays, causing tray blockage. Clogged trays and level gauges cause excessively high liquid levels within the scrubber, flooding the Venturi and rendering it ineffective. The high solids content of the silicon powder within the scrubber exceeds the capacity of current slurry-type shielded pumps, leading to frequent malfunctions in the circulating pump elution system and further increasing the probability of scrubber failure. Utility Model Content
[0004] The purpose of the utility model is to solve the shortcomings of the prior art and propose a cold hydrogenation dry process plus double-tower washing and dust removal system, which adds a set of silicon-containing high-boiling-point online filter dry dust removal system between the cold hydrogenation reactor and the washing tower.
[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0006] A cold hydrogenation dry process plus double-tower scrubbing and dust removal system, comprising a filter, a silicon powder collection tank, a primary elution tower, and a secondary elution tower, wherein the filter front end is connected to the silicon powder collection tank, the filter rear end is connected to the primary elution tower, the primary elution tower is connected to the secondary elution tower, the filter is connected to the secondary elution tower via a bypass pipe, and the secondary elution tower is connected to a multi-stage condenser;
[0007] Under normal circumstances, the primary elution tower and the secondary elution tower are used in series; when an abnormality occurs in the primary elution tower, the secondary elution tower can be directly switched to operate alone.
[0008] The filters include two filters A and B connected in parallel, and the filters filter the reaction synthesis gas generated by the cold hydrogenation reactor.
[0009] The multi-stage condenser is connected to a condensate storage tank, and the condensate storage tank is connected to a secondary scrubbing tower through a secondary scrubbing pump, and the secondary scrubbing tower is connected to a primary scrubbing tower through a primary scrubbing pump;
[0010] The condensate produced by the multi-stage condenser is stored in the condensate storage tank. The condensate storage tank is connected to the secondary scrubbing tower through a secondary scrubbing pump to provide spray liquid for the secondary scrubbing tower. The spray liquid after spraying at the bottom of the secondary scrubbing tower is sent to the primary scrubbing tower through the primary scrubbing pump as the spray liquid for the primary scrubbing tower after gas-phase condensation.
[0011] The primary scrubbing tower is a plate tower; the secondary scrubbing tower is a packed tower.
[0012] Slag discharge pipelines are provided at the bottoms of both the primary scrubbing tower and the secondary scrubbing tower.
[0013] The primary scrubbing pump adopts a slurry-type canned motor pump; the secondary scrubbing pump adopts a canned motor pump.
[0014] The filtration accuracy of the filter is 1 μm.
[0015] The filter is equipped with a backwashing system and can filter and self-clean.
[0016] The beneficial effects of the present utility model are as follows: Dry dust removal by the filter can ensure efficient filtration of silicon powder in the syngas entering the scrubbing tower; the backwashing system backwashes the filtration area to clean the filter element of the filter and extend the service life; the primary scrubbing tower is a plate tower; the secondary scrubbing tower is a packed tower, combining the advantages of both types of towers to fully guarantee the impurity washing and dust removal effect. Description of the Drawings
[0017] Figure 1 It is a system diagram of the washing and dust removal system of the present utility model;
[0018] In the figure: 1. Filter A; 2. Filter B; 3. Silicon powder collection tank; 4. Primary scrubbing tower; 5. Secondary scrubbing tower; 6. Primary scrubbing pump; 7. Secondary scrubbing pump; 8. Multi-stage condenser; 9. Condensate storage tank. Detailed Embodiments
[0019] Such as Figure 1As shown in the figure, the utility model provides a dry cold hydrogenation plus double-tower washing and dust removal system, the structure of which is as follows: it includes a filter, a silicon powder collection tank 3, a primary washing tower 4 and a secondary washing tower 5. The filter is two parallel filters A1 and filters B2. The front end of the filter is connected to the silicon powder collection tank 3, the rear end of the filter is connected to the primary washing tower 4, the primary washing tower 4 is connected to the secondary washing tower 5, the filter is connected to the secondary washing tower 5 through a bypass pipeline, and the secondary washing tower 5 is connected to a multi-stage condenser 8; the multi-stage condenser 8 is connected to a condensate storage tank 9, the condensate storage tank 9 is connected to the secondary washing tower 5 through a secondary washing pump 7, and the secondary washing tower 5 is connected to the primary washing tower 4 through a primary washing pump 6;
[0020] Further, the primary washing tower 4 is a plate tower; the secondary washing tower 5 is a packed tower;
[0021] Further, slag discharge pipelines are provided at the bottoms of both the primary washing tower 4 and the secondary washing tower 5;
[0022] Further, the primary washing pump 6 adopts a slurry-type canned motor pump; the secondary washing pump 7 adopts a canned motor pump;
[0023] Further, the filtration accuracy of the filter is 1μm;
[0024] Further, the filter is equipped with a backwashing system;
[0025] Specifically, the filter filters the reaction synthesis gas generated by the cold hydrogenation reactor. The filtered synthesis gas passes through the primary washing tower 4 and the secondary washing tower 5 for washing, and the washed synthesis gas is condensed by the multi-stage condenser 8; normally, the primary washing tower 4 and the secondary washing tower 5 are used in series; when the primary washing tower 4 malfunctions, it can be directly switched to the secondary washing tower 5 to operate alone; the condensate produced by the multi-stage condenser 8 is stored in the condensate storage tank 9. The condensate storage tank 9 is connected to the secondary washing tower 5 through the secondary washing pump 7 to provide spray liquid for the secondary washing tower 5. The spray liquid after spraying at the bottom of the secondary washing tower 5 passes through gas phase condensation and is sent to the primary washing tower 4 through the primary washing pump 6 as the spray liquid for the primary washing tower 4.
Claims
1. A dry cold hydrogenation plus double-tower washing and dust removal system, characterized in that: It includes a filter, a silicon powder collection tank, a primary washing tower, and a secondary washing tower. The front end of the filter is connected to the silicon powder collection tank, the back end of the filter is connected to the primary washing tower, the primary washing tower is connected to the secondary washing tower, the filter is connected to the secondary washing tower through a bypass pipeline, and the secondary washing tower is connected to a multi-stage condenser.
2. The dry cold hydrogenation double-tower washing and dust removal system according to claim 1, wherein: The filter consists of two parallel filters, Filter A and Filter B.
3. The dry cold hydrogenation double-tower washing and dust removal system according to claim 1, wherein: The multi-stage condenser is connected to a condensate storage tank. The condensate storage tank is connected to the secondary washing tower through a secondary washing pump, and the secondary washing tower is connected to the primary washing tower through a primary washing pump.
4. A dry cold hydrogenation and double-tower washing and dust removal system according to claim 1, characterized in that: The primary washing tower is a plate tower; the secondary washing tower is a packed tower.
5. A dry cold hydrogenation double-tower washing and dust removal system according to claim 1, characterized in that: Discharge pipelines are provided at the bottom of both the primary washing tower and the secondary washing tower.
6. The dry cold-hydrogenation dual-tower washing and dust removal system according to claim 3, characterized in that: The primary washing pump is a slurry-type canned motor pump; the secondary washing pump is a canned motor pump.
7. A dry cold hydrogenation dual-tower washing and dust removal system according to claim 1, characterized in that: The filtration accuracy of the filter is 1 μm.
8. A dry cold hydrogenation double-tower washing and dust removal system according to claim 1, characterized in that: An anti-blowback system is installed in the filter.