Nitrogen purification device

Abstract

The utility model provides a nitrogen purification device and relates to the technical field of polycrystalline silicon. The device comprises a dehydrogenation device, a cooling condenser, a gas-water separator, a drying assembly and a nitrogen storage tank which are sequentially communicated, a purification assembly is communicated with the nitrogen storage tank, a nitrogen inlet pipe and an oxygen inlet pipe are arranged on the dehydrogenation device, a dehydrogenation catalyst is arranged in the dehydrogenation device, and the purification assembly comprises a main heat exchanger and a rectifying tower which are communicated. The nitrogen storage tank communicates with the main heat exchanger. According to the device, a small amount of hydrogen in the nitrogen is removed, so that the nitrogen is purified to the purity capable of being directly used.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon, in particular to a nitrogen purification device. Background Art

[0002] Polycrystalline silicon is a form of elemental silicon. When molten elemental silicon solidifies under supercooling conditions, silicon atoms are arranged into many crystal nuclei in the form of diamond lattices. If these crystal nuclei grow into grains with different crystal plane orientations, these grains will combine and crystallize into polycrystalline silicon.

[0003] In the prior art, the exhaust gas from the entire plant includes dust-containing exhaust gas and dust-free exhaust gas. The dust-containing exhaust gas contains solid silicon powder. The exhaust gas from the entire plant is discharged after treatment. The components of the discharged air are hydrogen and nitrogen. After separating the nitrogen and hydrogen in the discharged air, the nitrogen still contains a small amount of hydrogen, which does not reach the purity that can be used directly. Utility Model Content

[0004] The utility model aims to develop a nitrogen purification device which can remove a small amount of hydrogen in nitrogen and purify the nitrogen to a purity that can be used directly.

[0005] The utility model is achieved through the following technical solutions:

[0006] A nitrogen purification device, comprising:

[0007] Dehydrogenator, cooling condenser, gas-water separator, drying assembly, and nitrogen storage tank connected in sequence;

[0008] A purification component connected to a nitrogen storage tank;

[0009] The dehydrogenator is provided with a nitrogen inlet pipe and an oxygen inlet pipe, a dehydrogenation catalyst is arranged in the dehydrogenator, the purification component comprises a main heat exchanger and a distillation tower which are connected to each other, and the nitrogen storage tank is connected to the main heat exchanger.

[0010] Optionally, the drying assembly includes two nitrogen dryers connected in parallel.

[0011] Optionally, the purification component also includes a condenser evaporator and a liquid nitrogen storage tank, the condenser evaporator is arranged at the top of the distillation tower, the top of the distillation tower is connected to the condenser evaporator inlet pipeline, and the condenser evaporator outlet is connected to the liquid nitrogen storage tank pipeline.

[0012] Optionally, a branch pipe connected to the top of the distillation tower is provided on the pipeline between the outlet of the condenser evaporator and the liquid nitrogen storage tank.

[0013] Optionally, the purification component also includes a buffer tank and an expander, the buffer tank is connected to the nitrogen use end, and the pipeline between the top of the distillation tower and the inlet of the condenser evaporator is also provided with a pipeline connected to the buffer tank after passing through the main heat exchanger and the expander.

[0014] Optionally, the liquid nitrogen storage tank is connected to a buffer tank pipeline and a vaporizer is provided on the pipeline.

[0015] Optionally, the purification component also includes a subcooler, and a pipeline is provided at the bottom of the distillation tower, which is connected to the condenser evaporator after passing through the subcooler. The condenser evaporator is provided with a pipeline that is connected to two nitrogen dryers after passing through the subcooler, the expander, the subcooler, and the main heat exchanger.

[0016] Optionally, the device further comprises a filter assembly, wherein the filter assembly is arranged between the drying assembly and the nitrogen storage tank.

[0017] Optionally, the filter assembly includes two nitrogen filters connected in parallel.

[0018] The beneficial effects of the utility model are:

[0019] The utility model purifies the nitrogen separated from the vented air to make the nitrogen reach a purity that can be directly used. The nitrogen can be directly supplemented into the generation system, reducing the amount of nitrogen purchased from outside or the amount of nitrogen produced by the public auxiliary air separation nitrogen production device, and improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of the utility model.

[0022] Figure numerals: 1. dehydrogenator; 2. cooling condenser; 3. gas-water separator; 4. nitrogen dryer; 5. nitrogen filter; 6. nitrogen storage tank; 7. main heat exchanger; 8. expander; 9. subcooler; 10. condenser evaporator; 11. distillation tower; 12. liquid nitrogen storage tank; 13. vaporizer; 14. buffer tank. DETAILED DESCRIPTION

[0023] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0024] The embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the utility model discloses a nitrogen purification device, comprising a dehydrogenator 1, a cooling condenser 2, a gas-water separator 3, a drying component, a filtering component, a nitrogen storage tank 6 and a purification component which are connected in sequence.

[0026] The dehydrogenator 1 is provided with a nitrogen inlet pipe and an oxygen inlet pipe. A dehydrogenation catalyst is arranged in the dehydrogenator 1. Hydrogen-containing nitrogen enters the dehydrogenator 1 through the nitrogen inlet pipe, and excess oxygen is introduced into the dehydrogenator 1 through the oxygen inlet pipe. The residual hydrogen in the nitrogen reacts with the excess oxygen in the dehydrogenator 1 to generate gaseous water.

[0027] The dehydrogenator 1 inputs the dehydrogenated nitrogen into the cooling condenser 2, and the gaseous water in the nitrogen is condensed into liquid water. The nitrogen containing liquid water passes through the gas-water separator 3, the drying component and the filtering component in sequence. After the water and impurities in the nitrogen are removed, the nitrogen and the remaining oxygen that has not reacted with the hydrogen are input into the nitrogen storage tank 6. At this time, a small amount of oxygen still remains in the nitrogen in the nitrogen storage tank 6, and the nitrogen is further purified by the purification component.

[0028] The drying component includes two nitrogen dryers 4 connected in parallel, and the two nitrogen dryers 4 realize one in use and one in reserve. The filtering component includes two nitrogen filters 5 connected in parallel, and the two nitrogen filters 5 realize one in use and one in reserve.

[0029] The purification component includes a main heat exchanger 7, an expander 8, a subcooler 9, a distillation tower 11, a liquid nitrogen storage tank 12 and a buffer tank 14. The buffer tank 14 is connected to the nitrogen use end. A condenser evaporator 10 is provided on the top of the distillation tower 11.

[0030] The nitrogen storage tank 6 is connected to the bottom pipeline of the distillation tower 11 and the pipeline passes through the main heat exchanger 7. The top of the distillation tower 11 is connected to the inlet pipeline of the condenser evaporator 10. The outlet of the condenser evaporator 10 is connected to the liquid nitrogen storage tank 12 pipeline. A branch pipe connected to the top of the distillation tower 11 is also provided on the pipeline between the outlet of the condenser evaporator 10 and the liquid nitrogen storage tank 12. A pipeline connected to the top of the distillation tower 11 is also provided on the pipeline between the top of the distillation tower 11 and the inlet of the condenser evaporator 10. The pipeline is connected to the buffer tank 14 after passing through the main heat exchanger 7 and the expander 8. The liquid nitrogen storage tank 12 is connected to the buffer tank 14 pipeline and a vaporizer 13 is provided on the pipeline.

[0031] A pipeline is provided at the bottom of the distillation tower 11 and is connected to the condenser evaporator 10 after passing through the cooler 9. A pipeline is provided on the condenser evaporator 10 and is connected to two nitrogen dryers 4 after passing through the cooler 9, the expander 8, the subcooler 9, and the main heat exchanger 7.

[0032] Nitrogen flow path in the purification component:

[0033] The nitrogen in the nitrogen storage tank 6 is cooled to the saturation temperature by the main heat exchanger 7 and then enters the distillation tower 11 for distillation. High-purity nitrogen is obtained at the top of the distillation tower 11. In the process of sending the high-purity nitrogen from the top of the distillation tower 11 to the condenser evaporator 10, a part of the high-purity nitrogen is sent to the main heat exchanger 7 to exchange heat with the nitrogen output from the nitrogen storage tank 6 to achieve reheating, and then is pressurized by the expander 8 and sent to the buffer tank 14 and finally reaches the nitrogen use end, and another part of the high-purity nitrogen is sent to the condenser evaporator 10 for condensation and liquefaction to obtain liquid nitrogen, and a part of the liquid nitrogen is sent to the liquid nitrogen storage tank 12 for storage. When needed, the liquid nitrogen is sent to the buffer tank 14 after passing through the vaporizer 13, and the other part of the liquid nitrogen re-enters the distillation tower 11 as reflux liquid.

[0034] Oxygen flow path in the purification component:

[0035] A portion of the liquid oxygen at the bottom of the distillation tower 11 is throttled and sent to the condenser evaporator 10 as a cold source through the cooler 9. After the liquid oxygen evaporates by heat exchange with nitrogen in the condenser evaporator 10, it enters the subcooler 9 for the first time, then enters the expander 8 for expansion, and then enters the subcooler 9 again, and finally enters the main heat exchanger 7 to exchange heat with the nitrogen output from the nitrogen storage tank 6 for reheating, and then is sent to the corresponding nitrogen dryer 4 as regeneration gas.

[0036] The utility model purifies the nitrogen separated from the vented air to make the nitrogen reach a purity that can be directly used. The nitrogen can be directly supplemented into the generation system, reducing the amount of nitrogen purchased from outside or the amount of nitrogen produced by the public auxiliary air separation nitrogen production device, and improving economic benefits.

[0037] The above embodiments are only preferred embodiments of the present utility model and are not limitations on the technical solutions of the present utility model. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present utility model.

Claims

1. A nitrogen purification device, characterized in that: include: Dehydrogenator, cooling condenser, gas-water separator, drying assembly, and nitrogen storage tank connected in sequence; A purification component connected to a nitrogen storage tank; The dehydrogenator is provided with a nitrogen inlet pipe and an oxygen inlet pipe, a dehydrogenation catalyst is arranged in the dehydrogenator, the purification component comprises a main heat exchanger and a distillation tower which are connected to each other, and the nitrogen storage tank is connected to the main heat exchanger.

2. The nitrogen purification device according to claim 1, characterized in that: The drying assembly includes two nitrogen dryers connected in parallel.

3. The nitrogen purification device according to claim 2, characterized in that: The purification component also includes a condenser evaporator and a liquid nitrogen storage tank. The condenser evaporator is arranged at the top of the distillation tower. The top of the distillation tower is connected to the condenser evaporator inlet pipeline, and the condenser evaporator outlet is connected to the liquid nitrogen storage tank pipeline.

4. The nitrogen purification device according to claim 3, characterized in that: A branch pipe connected to the top of the distillation tower is provided on the pipeline between the outlet of the condenser evaporator and the liquid nitrogen storage tank.

5. The nitrogen purification device according to claim 3, characterized in that: The purification component also includes a buffer tank and an expander. The buffer tank is connected to the nitrogen use end. The pipeline between the top of the distillation tower and the inlet of the condenser evaporator is also provided with a pipeline connected to the buffer tank after passing through the main heat exchanger and the expander.

6. The nitrogen purification device according to claim 5, characterized in that: The liquid nitrogen storage tank is connected to a buffer tank pipeline and a vaporizer is arranged on the pipeline.

7. The nitrogen purification device according to claim 6, characterized in that: The purification component also includes a subcooler. The bottom of the distillation tower is provided with a pipeline connected to the condenser evaporator after passing through the cooler. The condenser evaporator is provided with a pipeline connected to two nitrogen dryers after passing through the cooler, the expander, the subcooler, and the main heat exchanger.

8. The nitrogen purification device according to any one of claims 1 to 7, characterized in that: The device also includes a filter component, which is arranged between the drying component and the nitrogen storage tank.

9. The nitrogen purification device according to claim 8, characterized in that: The filter assembly includes two nitrogen filters connected in parallel.

Images