Technical background:

In the current photovoltaic industry, a large number of high-purity polysilicon materials are required for the manufacturing of crystalline silicon solar cells, which occupy a leading position. The main process of Siemens method is to reduce silicon by reaction of trichlorosilane gas and hydrogen after multistage distillation at 1100 ℃ and continuously deposit on the initial silicon core to grow into silicon rod. After being discharged from the furnace, it is transported to the crushing process, and then crushed into rod and block materials according to different requirements. The whole process requires that the surface of silicon rod shall not be polluted. Therefore, the impact between the silicon rod and the silicon rod and the manual percussion with a tungsten cobalt hammer are generally used for crushing, resulting in different shapes and sizes of silicon blocks. After crushing, the silicon blocks are manually sorted and packaged according to different sizes of silicon blocks. Because the polysilicon block is hard and has sharp shuttle angle, the separation time is long, the efficiency is low, and the labor intensity is large. At the same time, it is directly affected by the emotion of the workers on duty, the sense of responsibility and the management level, etc., which leads to the unsatisfactory effect of silicon block separation. The technical problem to be solved by the utility model is to provide a polysilicon block sorting device with simple structure, automatic sorting process, high efficiency, good effect and low sorting cost.

Advantages of polyurethane:

1. Good appearance, bright color, light weight, high mechanical strength, heat insulation, sound insulation, corrosion resistance, good weather resistance, various colors.

2. High tensile strength and tear resistance, good wear resistance, good resilience, small compression permanent deformation, long service life.

3. It has a strong binding force with the metal matrix and is not easy to peel off and fall off.

4. High surface finish and stable size.

5. Not easy to contaminate polysilicon materials

Advantages of polyurethane vibration screen /polyurethane sieve plate:

1. Long service life and large bearing capacity. Because polyurethane elastic sieve plate uses steel wire rope as the skeleton material, plus polyurethane itself has a very high elastic modulus, high strength absorption impact force, high wear resistance, so it has a very high tensile strength, and its bearing capacity is more than 2.5 times that of rubber sieve plate. Its service life is 8-10 times longer than ordinary metal sieve plate, 3 times longer than stainless steel sieve surface, 3.9 times longer than natural rubber. The material of polyurethane sieve plate is polymer organic elastomer, which has good wear resistance, flexure resistance and large bearing capacity. The raw materials for polyurethane sieve plate production have been specially treated to ensure no delamination under long-term alternating load.

2. High screening efficiency. The screen surface has self-cleaning performance, no plugging and high screening efficiency. Due to its strong water permeability and large sieve cone angle (140 °), polyurethane can effectively prevent the adhesion of wet fine particles, so it is suitable for screening and grading of wet fine materials. The polyurethane sieve plate of our factory is made of imported raw materials. Its elastomer and its own good relaxation performance can effectively avoid hole plugging under dynamic conditions.

3. It can be used in a wide range of fields and is more suitable for any type of vibrating screen machine. Polyurethane sieve plate is used in hydropower station, building materials and other metal separation industry. In the range of 0.1mm-170mm, the screening efficiency of all kinds of materials will not be affected by dry and wet sieves. For the dehydration and demineralization screen in the range of 0.5m-3mm, the superiority of polyurethane screen surface is fully demonstrated. The product is resistant to water, corrosion and aging, and easy to replace and maintain. Polyurethane has low density (1.32kg / M 3), lighter weight than metal screen surface, and can reduce production unit consumption, so it can meet the development requirements of large screen machine.

4. High screening accuracy. The production process of polyurethane sieve plate adopts mold casting forming process, with accurate pore diameter and high screening quality. The particle size of the material under the screen can meet the requirements of users well. The product is suitable for any type of screening machine with light weight. It can be installed on site or replaced for maintenance, greatly reducing the workload.

5. Low working noise, in line with the national environmental noise standards. Compared with metal sieve plate, polyurethane sieve plate can reduce noise by 5-20 decibels, and reduce dust flying greatly, so that the production site has a quiet and clean working environment.

6. Significant economic benefits. Although the price of polyurethane rubber screen surface is higher than that of metal screen plate, if the screening efficiency, maintenance cost, service life and other factors are considered comprehensively, it will be found that the overall benefit of polyurethane screen surface is much better than that of ordinary metal screen surface. According to the survey, 45 tons of steel can be saved for each ton of polyurethane rubber sieve plate. More than RMB 40000 of maintenance cost was saved. Therefore, polyurethane screen replacing steel screen will be the choice of most enterprises in the future.