Chloromethane compression system and compression method

Abstract

According to the technical scheme, the chloromethane compression system is characterized in that an outlet of a washing tower is connected with an inlet of a condenser, an outlet of the condenser is connected with an inlet of a first cooler, an outlet of the first cooler is connected with an air inlet of a screw compressor, and an outlet of the screw compressor is connected with an inlet of a gas-liquid separator; a gas phase outlet of the gas-liquid separator is connected with a chloromethane separation tower, and an outlet of the chloromethane separation tower is connected to a next working section. Meanwhile, the invention further discloses a compression method of the chloromethane compression system. The screw compressor has the beneficial effects that (1) after a traditional reciprocating compressor is replaced by the screw compressor, the screw compressor has the following advantages that the screw compressor is compact in structure, free of quick-wear parts and long in service life; the filler gas leakage rate is low; exhaust is stable, and vibration is small; and (2) after the screw compressor is used, a gas inlet buffer tank does not need to be arranged in front of the compressor to separate a liquid phase, and gas-liquid separation is uniformly performed after compression, so that the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organosilicon monomer production, and in particular relates to a chloromethane compression system and a compression method. Background Art

[0002] In the industrial production process of methylchlorosilane monomer, methyl chloride is one of the key raw materials. Due to its flammable and explosive properties and its sensitivity to oil and water, it needs to be handled with special caution. In traditional processes, in order to ensure safety and meet process requirements, reciprocating compressors are generally used to compress and transport methyl chloride gas. However, this traditional compression method has many problems.

[0003] First, due to its complex mechanical structure, the failure rate of reciprocating compressors is relatively high after long-term operation. Secondly, this type of compressor will generate large vibrations during operation, which not only affects the service life of the equipment itself, but may also have a negative impact on the surrounding environment. Furthermore, gas leakage is prone to occur at the packing of reciprocating compressors, which not only leads to waste of resources, but also may cause safety hazards. In view of the above reasons, maintenance has become a frequent and necessary task: Generally, a medium repair is required every 2,000 to 4,000 hours, including disassembly and cleaning of the gas valve, replacement of valve plates, packing and piston rings; and a comprehensive overhaul is required every 6,000 to 8,000 hours, involving the replacement of all important components such as gas valves and connecting rod bolts. Summary of the invention

[0004] In view of the problems of large vibration, high failure rate and large packing gas leakage of the above-mentioned traditional reciprocating compressors, the present invention provides a chloromethane compression system, and its technical solution is: the outlet of the washing tower is connected to the inlet of the condenser, the outlet of the condenser is connected to the inlet of the first cooler, the outlet of the first cooler is connected to the air inlet of the screw compressor, the outlet of the screw compressor is connected to the inlet of the gas-liquid separator, the gas phase outlet of the gas-liquid separator is connected to the chloromethane separation tower, and the outlet of the chloromethane separation tower is connected to the next work section.

[0005] As a preferred embodiment, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the second cooler, the outlet of the second cooler is connected to the circulation inlet of the coolant storage tank, the circulation outlet of the coolant storage tank is connected to the coolant inlet of the screw compressor through a delivery pump, and a liquid replenishment pipeline is also provided on the coolant storage tank.

[0006] As a preferred solution, the top outlet of the methyl chloride separation tower is connected to the sealing gas inlet of the screw compressor, and a pneumatic valve is provided on the connecting pipeline.

[0007] As a preferred solution, the sealing gas inlet of the screw compressor is connected to the air inlet of the screw compressor through a pipeline.

[0008] The present invention also provides a compression method for a chloromethane compression system, comprising the following steps: Transportation of methyl chloride: The methyl chloride gas passes through the scrubber, condenser, and first cooler in sequence and then enters the air inlet of the screw compressor for compression and transportation. It then enters the gas-liquid separator for gas-liquid separation. The separated gaseous methyl chloride enters the methyl chloride separation tower. After separation in the methyl chloride separation tower, pure methyl chloride is obtained and enters the next stage. Coolant circulation: The coolant in the coolant storage tank is pumped into the screw compressor through a delivery pump. After the coolant cools the yin and yang rotors of the screw compressor, it enters the gas-liquid separator for gas-liquid separation. The liquid phase coolant enters the second cooler for cooling and then returns to the coolant storage tank. Circulation of sealing gas: The chloromethyl gas in the chloromethyl separation tower enters the sealing gas inlet of the screw compressor after being decompressed by the pneumatic valve. The sealing chloromethyl gas returns to the air inlet of the screw compressor for compression and transportation, and then enters the gas-liquid separator for gas-liquid separation. The separated gaseous chloromethyl enters the chloromethyl separation tower.

[0009] As a preferred embodiment, the coolant is a mixture of methylfluorosilane monomer and methyl chloride, and the mixing ratio is methylfluorosilane:methyl chloride = (50-60): (50-40).

[0010] As a preferred solution, the sealing gas needs to be decompressed to 0.2-0.5Mpa through a pneumatic valve.

[0011] Beneficial effects of the present invention: (1) The present invention replaces the traditional reciprocating compressor with a screw compressor, which has the following advantages: compact structure, no wearing parts, long service life; low gas leakage of the packing; stable exhaust and small vibration; (2) After setting up to use a screw compressor, there is no need to set up an air intake buffer tank before the compressor to separate the liquid phase. Instead, gas-liquid separation is performed uniformly after compression, thereby improving production efficiency; (3) During the entire compression and transportation process, methyl chloride is used as a sealing gas and part of the coolant, which will not introduce new impurities and will not cause leakage pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the system structure in the present invention.

[0013] In the figure: 1. washing tower; 2. condenser; 3. first cooler; 4. screw compressor; 5. gas-liquid separator; 6. methyl chloride separation tower; 7. coolant storage tank; 701, liquid replenishment pipeline; 8. delivery pump; 9. second cooler; 10. pneumatic valve. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below based on the accompanying drawings and specific embodiments.

[0015] Example 1 like Figure 1 A chloromethane compression system is shown, including an outlet of a washing tower 1 connected to an inlet of a condenser 2, an outlet of the condenser 2 connected to an inlet of a first cooler 3, an outlet of the first cooler 3 connected to an air inlet of a screw compressor 4, an outlet of the screw compressor 4 connected to an inlet of a gas-liquid separator 5, a gas phase outlet of the gas-liquid separator 5 connected to a chloromethane separation tower 6, and an outlet of the chloromethane separation tower 6 connected to the next work section.

[0016] Furthermore, the liquid phase outlet of the gas-liquid separator 5 is connected to the inlet of the second cooler 9, the outlet of the second cooler 9 is connected to the circulation inlet of the coolant storage tank 7, the circulation outlet of the coolant storage tank 7 is connected to the coolant inlet of the screw compressor 4 through the delivery pump 8, and a liquid replenishment pipe 701 is also provided on the coolant storage tank 7.

[0017] Furthermore, the top outlet of the methyl chloride separation tower 6 is connected to the sealing gas inlet of the screw compressor 4, and a pneumatic valve 10 is provided on the connecting pipeline. The pneumatic valve 10 controls the pressure of the methyl chloride gas flowing through to always remain within the range of 0.2-0.5Mpa to prevent lubricating oil from entering the medium gas.

[0018] Furthermore, the sealing air inlet of the screw compressor 4 is connected to the air inlet of the screw compressor 4 through a pipeline.

[0019] Example 2 The system in the above-mentioned embodiment 1 is used, and its operation process includes the following steps: Transportation of methyl chloride: the methyl chloride gas passes through the washing tower 1, the condenser 2, and the first cooler 3 in sequence, and then enters the air inlet of the screw compressor 4 for compression and transportation, and then enters the gas-liquid separator 5 for gas-liquid separation. The separated gaseous methyl chloride enters the methyl chloride separation tower 6, and after separation in the methyl chloride separation tower 6, pure methyl chloride is obtained and enters the next stage; Coolant circulation: The coolant in the coolant storage tank 7 is pumped into the screw compressor 4 through the delivery pump 8. After the coolant cools the male and female rotors of the screw compressor 4, it enters the gas-liquid separator 5 for gas-liquid separation. The liquid phase coolant enters the second cooler 9 for cooling and then returns to the coolant storage tank 7. The process medium in the front system is used as the coolant to cool and clean the male and female rotors of the screw compressor, which solves the problems of large vibration, high failure rate and large leakage of methyl chloride compressor; When the coolant in the coolant storage tank 7 is insufficient, the liquid replenishing pipe 701 is opened to replenish the coolant in the coolant storage tank 7; Circulation of sealing gas: the chloromethyl gas in the chloromethyl separation tower 6 enters the sealing gas inlet of the screw compressor 4 after being decompressed by the pneumatic valve 10, the chloromethyl gas used for sealing returns to the air inlet of the screw compressor 4 for compression and transportation, and then enters the gas-liquid separator 5 for gas-liquid separation, and the separated gaseous chloromethyl enters the chloromethyl separation tower 6. The leakage of packing gas in the above whole cycle is almost zero.

[0020] Furthermore, the coolant is a mixture of methylfluorosilane monomer and methyl chloride, and the mixing ratio is methylfluorosilane:methyl chloride = (50-60): (40-50).

[0021] Furthermore, the sealing gas needs to be decompressed to 0.2-0.5Mpa through the pneumatic valve 10, and the opening of the pneumatic valve 10 is automatically controlled according to the air pressure at both ends of the valve body, so that the pressure of methyl chloride as sealing gas entering the screw compressor 4 is maintained within the range of 0.2-0.5Mpa.

[0022] In the above process, methyl chloride is used as a part of the sealing gas and the coolant, which will not introduce new impurities and will not cause leakage pollution.

Claims

1. A methyl chloride compression system, characterized in that: The invention comprises the following steps: the outlet of the washing tower (1) is connected to the inlet of the condenser (2), the outlet of the condenser (2) is connected to the inlet of the first cooler (3), the outlet of the first cooler (3) is connected to the air inlet of the screw compressor (4), the outlet of the screw compressor (4) is connected to the inlet of the gas-liquid separator (5), the gas phase outlet of the gas-liquid separator (5) is connected to the chloromethane separation tower (6), and the outlet of the chloromethane separation tower (6) is connected to the next working section.

2. A methyl chloride compression system according to claim 1, characterized in that: The liquid phase outlet of the gas-liquid separator (5) is connected to the inlet of the second cooler (9), the outlet of the second cooler (9) is connected to the circulation inlet of the coolant storage tank (7), the circulation outlet of the coolant storage tank (7) is connected to the coolant inlet of the screw compressor (4) via a delivery pump (8), and a liquid replenishing pipeline (701) is also provided on the coolant storage tank (7).

3. A chloromethane compression system according to claim 1, characterized in that: The top outlet of the methyl chloride separation tower (6) is connected to the sealing gas inlet of the screw compressor (4), and a pneumatic valve (10) is provided on the connecting pipeline.

4. A methyl chloride compression system according to claim 3, characterized in that: The sealing gas inlet of the screw compressor (4) is connected to the air inlet of the screw compressor (4) via a pipeline.

5. A compression method for a methyl chloride compression system according to any one of claims 1 to 4, characterized in that The following steps are involved: Transportation of methyl chloride: the methyl chloride gas passes through the scrubbing tower (1), the condenser (2), and the first cooler (3) in sequence, and then enters the air inlet of the screw compressor (4) for compression and transportation, and then enters the gas-liquid separator (5) for gas-liquid separation. The separated gaseous methyl chloride enters the methyl chloride separation tower (6), and after separation in the methyl chloride separation tower (6), pure methyl chloride is obtained and enters the next process stage; Coolant circulation: The coolant in the coolant storage tank (7) is pumped into the screw compressor (4) through the delivery pump (8). After the coolant cools the male and female rotors of the screw compressor (4), it enters the gas-liquid separator (5) for gas-liquid separation. The liquid phase coolant enters the second cooler (9) for cooling and then returns to the coolant storage tank (7). Circulation of sealing gas: The methyl chloride gas in the methyl chloride separation tower (6) is decompressed by the pneumatic valve (10) and then enters the sealing gas inlet of the screw compressor (4). The methyl chloride gas used for sealing returns to the air inlet of the screw compressor (4) for compression and transportation, and then enters the gas-liquid separator (5) for gas-liquid separation. The separated gaseous methyl chloride enters the methyl chloride separation tower (6).

6. The compression method of a chloromethane compression system according to claim 5, characterized in that: The coolant is a mixture of methylfluorosilane monomer and methyl chloride, and the mixing ratio is methylfluorosilane:methyl chloride=(50-60):(40-50).

7. The compression method of a chloromethane compression system according to claim 5, characterized in that: The sealing gas needs to be decompressed to 0.2-0.5Mpa via a pneumatic valve (10).

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