Cooling structure of screw vacuum pump

Abstract

The utility model relates to a cooling structure of a screw vacuum pump, and relates to the technical field of screw vacuum pumps. Comprising a shell, a first cavity and a second cavity are formed in the shell, the first cavity is formed in the outer side of the second cavity, the first cavity is connected with a heat preservation pipe, the end, away from the first cavity, of the heat preservation pipe is connected with a liquid nitrogen tank, a first electromagnetic valve is arranged on the heat preservation pipe, and a cooling pipeline is arranged in the first cavity; the whole cooling pipeline is spiral, one end of the cooling pipeline is connected with a water pump, the other end of the cooling pipeline is connected with a water pipe, a cooling-water machine is arranged between the water pipe and the water pump, and a screw is arranged in the second cavity. The cooling structure of the screw vacuum pump solves the problems that an existing cooling structure of the screw vacuum pump only adopts a water cooling mode, the cooling mode is single, and the cooling speed is low.

Description

Technical Field

[0001] The utility model provides a cooling structure for a screw vacuum pump, which relates to the technical field of screw vacuum pumps. Background Technique

[0002] A screw vacuum pump is a gas pumping device that uses a pair of screws to rotate synchronously and at high speed in the pump housing to generate suction and exhaust effects. It is a replacement product for oil-sealed vacuum pumps and can pump gases containing a large amount of water vapor and a small amount of dust. It is widely used in domestic enterprises such as pharmaceuticals, chemicals, and semiconductors that have high requirements for clean vacuum. The main structure of a screw vacuum pump is that a drive shaft is connected to the main rotor, and the driven rotor is driven to rotate through a synchronous gear. A cooling water channel is opened on the housing to cool the temperature of the rotor and the exhaust port. The synchronous gear and bearings are lubricated with oil, and the bearings and the inside of the housing are sealed through seals to achieve an oil-free effect. Among them, the cooling structure is essential. By passing cooling water through the machine shell body and outside the bearings, the purpose of cooling the housing and then cooling the rotor can be achieved.

[0003] However, the cooling structures of existing screw vacuum pumps on the market usually only adopt the water-cooling method, and the cooling method is single. Sometimes the working temperature of the screw vacuum pump is too high, and water-cooling cannot quickly reduce the temperature, resulting in deformation of the screw rotor and the machine shell, affecting the pumping effect, and even the screw vacuum pump cannot operate normally. For this reason, we propose a cooling structure for a screw vacuum pump. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is that the cooling structure of the existing screw vacuum pump only adopts the water-cooling method, with a single cooling method and a slow cooling speed.

[0005] To solve the above technical problem, the technical solution provided by the utility model is: a cooling structure for a screw vacuum pump, including a housing, a first cavity and a second cavity are arranged in the housing, the first cavity is arranged outside the second cavity, the first cavity is connected with a heat preservation pipe, one end of the heat preservation pipe far away from the first cavity is connected with a liquid nitrogen tank, a first electromagnetic valve is arranged on the heat preservation pipe, a cooling pipe is arranged in the first cavity, the cooling pipe is integrally spiral and one end is connected with a water pump and the other end is connected with a water pipe, a chiller is arranged between the water pipe and the water pump, and a screw is arranged in the second cavity.

[0006] Preferably, a recovery tank is arranged outside the housing, a recovery pipe is connected and communicated between the recovery tank and the housing, and a second electromagnetic valve is arranged on the recovery pipe.

[0007] Preferably, a temperature sensor is fixedly connected to the top of the housing, a controller is fixedly connected to the outer side wall of the housing, and the controller is electrically connected to the temperature sensor, the water pump, the first electromagnetic valve and the second electromagnetic valve.

[0008] Preferably, the first cavity is a cooling cavity, and the second cavity is a vacuum working cavity.

[0009] Preferably, there are 2 sets of screws, the two ends of the screws are fixedly connected with rotating shafts, one end of the screw is rotatably connected with a gear, and a bearing is arranged between the gear and the screw.

[0010] Preferably, a liquid nitrogen pump is arranged on one side of the heat preservation pipe close to the liquid nitrogen tank, and an air extraction pump is arranged on one side of the recovery pipe close to the recovery tank.

[0011] Advantages of the present utility model:

[0012] Through the arrangement of the cooling pipeline, when the working temperature of the screw vacuum pump is not high, water cooling can be used for cooling. At the same time, through the arrangement of the liquid nitrogen tank and the heat preservation pipe, when the working temperature of the screw vacuum pump is too high and the water cooling effect is not obvious, the liquid nitrogen evaporation method can be used for rapid cooling to prevent the temperature inside the screw vacuum pump housing from being too high, resulting in deformation of the screw rotor and the housing and affecting the air extraction effect. This solves the problem that the cooling structure of the existing screw vacuum pump only uses the water cooling method, with a single cooling method and a slow cooling speed. Description of the drawings

[0013] Figure 1 It is a schematic diagram of the overall structure of a cooling structure of a screw vacuum pump of the present utility model.

[0014] Figure 2 It is a front view inside the housing of a cooling structure of a screw vacuum pump of the present utility model.

[0015] Figure 3 It is a schematic diagram of the structure of the cooling pipeline and the screw of a cooling structure of a screw vacuum pump of the present utility model.

[0016] (1, chiller; 2, water pump; 3, water pipe; 4, housing; 5, temperature sensor; 6, controller; 7, heat preservation pipe; 8, liquid nitrogen tank; 9, first solenoid valve; 10, second solenoid valve; 11, recovery tank; 12, first cavity; 13, second cavity; 14, gear; 15, cooling pipeline; 16, screw; 17, bearing; 18, rotating shaft) Detailed implementation manners

[0017] Next, the preferred embodiments of the present utility model will be described in detail in conjunction with the drawings.

[0018] Refer to Figures 1 to 3, the present utility model provides a cooling structure for a screw vacuum pump, including a housing 4. A first cavity 12 and a second cavity 13 are arranged inside the housing 4. The first cavity 12 is arranged outside the second cavity 13. The first cavity 12 is a cooling cavity, and the second cavity 13 is a vacuum working cavity. A cooling pipe 15 is arranged inside the first cavity 12. The cooling pipe 15 is integrally spiral and is connected to a water pump 2 at one end and a water pipe 3 at the other end. A chiller 1 is arranged between the water pipe 3 and the water pump 2. A screw 16 is arranged inside the second cavity 13. Specifically, when the vacuum pump operates, the cooling water of the chiller 1 is transported to the cooling pipe 15 through the water pump 2. The cooling pipe 15 cools the first cavity 12. Since the first cavity 12 wraps the second cavity 13, the second cavity 13 is cooled. Then the cooling water is transported to the chiller 1 through the water pipe 3, realizing the recycling of the cooling water. In this application, the chiller 1 adopts the existing technology, so its structure and working principle will not be elaborated. The optional model of the chiller 1 is ICW_3 water-cooled industrial chiller.

[0019] Further, as Figure 1 shown, in the present utility model, the first cavity 12 is connected to a heat preservation pipe 7. One end of the heat preservation pipe 7 far from the first cavity 12 is connected to a liquid nitrogen tank 8. A liquid nitrogen pump is arranged on the side of the heat preservation pipe 7 close to the liquid nitrogen tank 8. A first electromagnetic valve 9 is arranged on the heat preservation pipe 7. A temperature sensor 5 is fixedly connected to the top of the housing 4. A controller 6 is fixedly connected to the outer side wall of the housing 4. The controller 6 is electrically connected to the temperature sensor 5, the water pump 2, the first electromagnetic valve 9, and the liquid nitrogen pump. Specifically, the temperature sensor 5 is used to measure the temperature of the first cavity 12. A temperature threshold can be set through the controller 6. If the temperature does not reach the temperature threshold, the controller 6 starts the water pump 2 to cool by water-cooling. When the temperature inside the second cavity 13 reaches the temperature threshold, the first electromagnetic valve 9 and the liquid nitrogen pump are opened through the controller 6. The liquid nitrogen pump pumps the liquid nitrogen in the liquid nitrogen tank 8 into the heat preservation pipe 7 and transports it to the first cavity 12 through the heat preservation pipe 7. The liquid nitrogen volatilizes in the first cavity 12, realizing the rapid cooling of the second cavity 13.

[0020] Further, as Figure 1 shown, a recovery tank 11 is arranged outside the housing 4 of the present utility model. A recovery pipe is connected and communicated between the recovery tank 11 and the housing 4. An air extraction pump is arranged on the side of the recovery pipe close to the recovery tank 11. A second electromagnetic valve 10 is arranged on the recovery pipe. Both the second electromagnetic valve 10 and the air extraction pump are electrically connected to the controller 6. Specifically, by opening the second electromagnetic valve 10 and the air extraction pump through the controller 6, the nitrogen in the first cavity 12 can be pumped into the recovery tank 11 to realize the recovery of nitrogen.

[0021] Further, as Figure 3As shown in the figure, there are two sets of screws 16 in the present utility model. Both ends of the screw 16 are fixedly connected with a rotating shaft 18. One end of the screw 16 is rotatably connected with a gear 14, and a bearing 17 is arranged between the gear 14 and the screw 16. Specifically, the drive shaft is rotatably connected with one set of screws 16, and the other set of screws 16 is synchronously driven to rotate by the meshing of the gears 14.

[0022] Working principle: During the working process of the screw vacuum pump, the temperature in the second cavity 13 rises. When the temperature does not reach the set temperature threshold, the controller 6 starts the water pump 2, and the cooling water in the chiller 1 is transported to the cooling pipeline 15 through the water pump 2, and then the cooling water is transported back to the chiller 1 through the water pipe 3, realizing the cooling in the water cooling method; when the temperature reaches the set temperature threshold, the controller 6 opens the first solenoid valve 9 and the liquid nitrogen pump, and the nitrogen gas in the liquid nitrogen tank 8 is transported to the first cavity 12 through the heat preservation pipe 7, and fully volatilizes in the first cavity 12, quickly cooling by the volatilization of liquid nitrogen. At the same time, the controller 6 opens the second solenoid valve 10 and the air extraction pump, and the gas expanded in the first cavity 12 is collected into the recovery tank 11 to realize the recovery of nitrogen.

[0023] The above describes the present utility model and its implementation manners. Such description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present utility model, and the actual structure is not limited thereto. All in all, if those of ordinary skill in the art are inspired by it and design similar structural manners and embodiments without creative efforts without departing from the creative purpose of the present utility model, they shall fall within the protection scope of the present utility model.

Claims

1. A cooling structure for a screw vacuum pump, comprising a housing (4), wherein a first cavity (12) and a second cavity (13) are arranged inside the housing, and the first cavity (12) is arranged outside the second cavity (13), characterized in that: The first cavity (12) is connected with a heat preservation pipe (7). One end of the heat preservation pipe (7) far away from the first cavity (12) is connected with a liquid nitrogen tank (8). A first electromagnetic valve (9) is arranged on the heat preservation pipe (7). A cooling pipeline (15) is arranged in the first cavity (12). The cooling pipeline (15) is integrally spiral. One end of the cooling pipeline (15) is connected with a water pump (2), and the other end is connected with a water pipe (3). A chiller (1) is arranged between the water pipe (3) and the water pump (2). A screw rod (16) is arranged in the second cavity (13). A recovery tank (11) is arranged outside the housing (4). A recovery pipe is connected and communicated between the recovery tank (11) and the housing (4). A second electromagnetic valve (10) is arranged on the recovery pipe. A temperature sensor (5) is fixedly connected to the top of the housing (4). A controller (6) is fixedly connected to the outer side wall of the housing (4). The controller (6) is electrically connected to the temperature sensor (5), the water pump (2), the first electromagnetic valve (9), and the second electromagnetic valve (10).

2. The cooling structure of a screw vacuum pump according to claim 1, characterized in that: The first cavity (12) is a cooling cavity, and the second cavity (13) is a vacuum working cavity.

3. The cooling structure of a screw vacuum pump according to claim 1, characterized in that: There are 2 groups of the screw rods (16). Shafts (18) are fixedly connected to both ends of the screw rods (16). One end of the screw rod (16) is rotatably connected with a gear (14). A bearing (17) is arranged between the gear (14) and the screw rod (16).

4. The cooling structure of a screw vacuum pump according to claim 1, characterized in that: A liquid nitrogen pump is arranged on one side of the heat preservation pipe (7) close to the liquid nitrogen tank (8). An air extraction pump is arranged on one side of the recovery pipe close to the recovery tank (11).

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