Roots vacuum pump with water-cooled exhaust end

Abstract

The utility model relates to an exhaust end water-cooled Roots vacuum pump which comprises a pump body, a machine base is arranged below the pump body, a gas-water separation silencer is arranged in the machine base, the gas-water separation silencer comprises a silencer cylinder body, a first-stage cavity, a second-stage cavity and a third-stage cavity are sequentially arranged in the silencer cylinder body, and the first-stage cavity, the second-stage cavity and the third-stage cavity are communicated with each other. A first-stage damping air inlet pipe is arranged in the first-stage cavity, the first-stage damping air inlet pipe is a water-air inlet pipeline, and damping holes which are densely distributed are formed in the lower portion of the first-stage damping air inlet pipe; the second-stage cavity is an expansion cavity, a plurality of baffle plates which are arranged in an up-down staggered mode are arranged in the second-stage cavity, a final-stage damping exhaust pipe is arranged in the third-stage cavity, and the tail end of the final-stage damping exhaust pipe extends out of the silencer barrel. According to the utility model, the functions of gas-water separation and ideal noise reduction are realized, the exhaust resistance is not increased, and the energy consumption of the vacuum pump is not increased.

Description

Technical Field

[0001] The utility model relates to the technical field of Roots vacuum pumps, in particular to an exhaust end water-cooled Roots vacuum pump. Background Art

[0002] Roots vacuum pump is a rotary positive displacement vacuum pump that uses two "8" shaped rotors to rotate in the housing to produce suction and exhaust. When the vacuum pump is running, the gas is compressed by the rotor and then discharged, so that there is a large working pressure difference between the inlet and outlet of the pump body. Due to the high rotor speed (1000r / min~3000r / min), the linear velocity of the rotor surface is close to the thermal motion speed of molecules, and the temperature rise of the Roots pump is directly related to the compression ratio and efficiency. Usually, the heat generated by the compressed gas is dissipated and cooled through the heat sink outside the pump body.

[0003] The internal structure of Roots vacuum pump Figure 1 The two rotors of the pump are supported in rolling bearings on the end covers on both sides of the pump casing. A pair of adjustable synchronous gears are used to keep the two rotors in a certain relative position at high speed. The end surface clearance between the rotor and the end cover is guaranteed by the special structure of the fixed end (close to the motor side). When the pump is working, it can only expand toward one end of the gear box due to heat, resulting in the clearance between the rotors and between the rotor and the pump body being too small and stuck, making the Roots pump unable to work normally.

[0004] At present, the commonly used method is to set heat sinks at the pump body and the front cover to cool the vacuum pump by air cooling, but this cooling method has an unsatisfactory cooling effect, resulting in a short service life of the vacuum pump; some Roots vacuum pumps are cooled by water cooling, but the sealing performance of the cooling cavity is poor, and the existing Roots vacuum pumps have the following main deficiencies:

[0005] (1) When operating under high pressure difference, traditional Roots vacuum pumps may experience temperature rise, rotor overheating, easy jamming, and short-term failure of shaft seal;

[0006] (2) When operating under high pressure difference, the traditional Roots vacuum pump has a large compression ratio between intake and exhaust, which causes serious reflux of the pumped gas and low vacuum pumping efficiency.

[0007] (3) When operating under high pressure difference, the airflow noise is loud, causing noise pollution to the environment.

[0008] (4) When operating under high pressure difference, the temperature rise of traditional Roots vacuum pumps is too high, which seriously shortens the service life of moving parts such as gears and shaft seals, and increases the cost of use and maintenance.

[0009] (5) Traditional mufflers cannot be used on high-efficiency Roots vacuum pumps, and sound-absorbing materials such as sound insulation cotton are not allowed to be used inside the muffler. Summary of the invention

[0010] The purpose of the utility model is to overcome the above-mentioned shortcomings and provide a water-cooled Roots vacuum pump at the exhaust end to solve the drawbacks of overheating, jamming, gas reflux, high failure rate and the like of the Roots vacuum pump at high pressure difference, and to expand the application scope of the Roots vacuum pump; a muffler using physical methods such as damping, deflection and dispersion is used to reduce or consume the noise kinetic energy of the airflow.

[0011] The purpose of the utility model is achieved in this way:

[0012] A water-cooled Roots vacuum pump at the exhaust end, comprising a pump body, wherein the front end of the pump body is provided with a front cover, the rear end is provided with a rear cover, the front end cover is provided with a front cover, and the rear end cover is provided with a rear cover; a pair of three-leaf involute rotors which are parallel, horizontally installed and meshed with each other are provided in the pump body: an active rotor and a driven rotor, the active rotor is arranged on a main shaft, and the driven rotor is arranged on a rotor shaft, the main shaft and the rotor shaft are arranged in the pump body, and the active rotor and the driven rotor are respectively arranged in the front end cover and the rear end cover at both ends of the pump body through bearings; an air inlet is provided at the upper end of the pump body, and an exhaust port is provided at the lower end; a side cover plate is provided on the left and right sides of the pump body, respectively, and a through hole is provided on the side cover plate, the side cover plate is connected to a cooling water nozzle, and the cooling water nozzle is communicated with the pump cavity of the pump body through the through hole of the side cover plate;

[0013] A machine base is provided below the pump body, and a gas-water separation muffler is provided in the machine base. The water separation muffler includes a muffler cylinder, and a first-stage chamber, a second-stage chamber and a third-stage chamber arranged in sequence are provided in the muffler cylinder. A first-stage damping air inlet pipe is provided in the first-stage chamber, and the first-stage damping air inlet pipe is a water gas inlet pipe, and densely arranged damping holes are provided at the lower part of the first-stage damping air inlet pipe; the second-stage chamber is an expansion chamber, and a plurality of baffles arranged in an upper and lower staggered manner are provided in the second-stage chamber, and a final-stage damping exhaust pipe is provided in the third-stage chamber, and the end of the final-stage damping exhaust pipe extends out of the muffler cylinder, and the end of the final-stage damping exhaust pipe is an air outlet;

[0014] The bottom of the first-level chamber is connected to the first drain pipe, the bottom of the second-level chamber is connected to the second drain pipe, the bottom of the third-level chamber is connected to the third drain pipe, and the first drain pipe, the second drain pipe and the third drain pipe are all connected to the main drain pipe.

[0015] Furthermore, the first-stage damping air inlet pipe is vertically arranged, and the top end thereof is connected to the exhaust port at the bottom of the pump body through a connecting flange.

[0016] Furthermore, the baffle is a non-circular metal plate with a notch at one end, and the notches of two adjacent baffles are arranged crosswise at 180 degrees, so that the gas in the second-stage chamber flows back through the notches of the baffles.

[0017] Furthermore, a partition is sleeved on the middle part of the final-stage damping exhaust pipe, and the pipe is divided into two sections by the partition.

[0018] Furthermore, the shaft end of the main shaft extends out of the front cover and is connected to a coupling, and the coupling is connected to the motor.

[0019] Furthermore, the main drain pipe is arranged below the muffler cylinder, and the end of the main drain pipe extends out of the muffler cylinder, and the end of the main drain pipe is a cooling water outlet.

[0020] Furthermore, a gear is arranged in the rear cover, and the gear is sleeved on the end of the main shaft; the driving rotor and the driven rotor are caused to rotate synchronously and at a constant speed in the pump body through a pair of synchronous gears in the oil tank.

[0021] Furthermore, a composite seal is provided at the connection between the front end of the main shaft and the rear end cover.

[0022] Compared with the prior art, the beneficial effects of the utility model are:

[0023] The utility model provides an exhaust-end water-cooled Roots vacuum pump, wherein an air-water separation muffler is arranged below the exhaust port of the Roots vacuum pump, an air-water mixture is separated in the air-water separation muffler through a multi-stage baffle plate, noise is multi-stage returned and reduced through damping holes on a two-end air pipe, cooling water is introduced into a compression chamber in the lower half, cooling effect is good, and the air extraction volume of the pump is not affected and the power consumption of the pump is not increased; the structure is simpler than that of an air-cooled Roots vacuum pump, and the air extraction efficiency of the Roots vacuum pump is higher due to the sealing effect of cooling water on the rotor and the inside of the pump chamber in the pump body.

[0024] The gas-water separation muffler of the utility model is specially designed for a water-cooled Roots vacuum pump, and can effectively separate the gas and water in the gas-water mixed gas discharged by the Roots vacuum pump, and reduce the exhaust noise of the Roots vacuum pump to an environmental protection requirement of below 85 decibels; the gas-water separation muffler of the utility model is a baffle damping muffler, which realizes gas-water separation and ideal noise reduction functions, and does not increase the exhaust resistance and the energy consumption of the vacuum pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the internal structure of an existing Roots vacuum pump.

[0026] Figure 2 It is a structural schematic diagram of the utility model.

[0027] Figure 3 It is a side view of the utility model.

[0028] Figure 4It is a schematic structural diagram of the gas-water separation muffler of the utility model.

[0029] Figure 5 It is a schematic structural diagram of the cooling water nozzle of the utility model.

[0030] in:

[0031] Pump body 1, rear end cover 2, composite seal 3, gear 4, active rotor 5, driven rotor 6, exhaust port 7, air inlet 8, front end cover 9, front cover 10, coupling 11, motor 12, air-water separation muffler 13, first stage chamber 13.1, first stage damping air inlet pipe 13.11, damping hole 13.12, first drain pipe 13.13, connecting flange 13.14, second stage chamber 13.2, baffle 13.21, second drain pipe 13.22, third stage chamber 13.3, final stage damping exhaust pipe 13.31, partition 13.32, third drain pipe 13.33, main drain pipe 13.4, muffler cylinder 13.5, coupling protection cover 14, side cover plate 15, cooling water nozzle 16. DETAILED DESCRIPTION

[0032] In order to better understand the technical solution of the present invention, the following will be described in detail in conjunction with the relevant illustrations. It should be understood that the following specific embodiments are not intended to limit the specific implementation of the technical solution of the present invention, and are only implementations that can be adopted by the technical solution of the present invention. It should be noted that the description of the positional relationship of each component in this article, such as component A being located above component B, is based on the description of the relative positions of the components in the illustration, and is not intended to limit the actual positional relationship of the components. Example 1

[0033] See also Figure 1-Figure 5 , Figure 1 The structural schematic diagram of the utility model is drawn. As shown in the figure, an exhaust end water-cooled Roots vacuum pump comprises a pump body 1, the front end of the pump body 1 is provided with a front cover 9, the rear end is provided with a rear cover 2, the front cover 9 is provided with a front cover 10, and the rear cover 2 is provided with a rear cover; the pump body 1 is provided with a pair of parallel horizontally installed and mutually meshing three-leaf involute rotors: a driving rotor 5 and a driven rotor 6, the driving rotor 5 is installed on the main shaft, and the driven rotor 6 is installed on the rotor shaft, the main shaft and the rotor shaft are arranged in the pump body, the driving rotor 5 and the driven rotor 6 are respectively installed in the front cover 2 and the rear cover 4 at both ends of the pump body through bearings; the rear cover 5 is provided with a gear 4, and the gear 4 is sleeved on the end of the main shaft; the driving rotor 5 and the driven rotor 6 are synchronized and rotated at a constant speed in the pump body through a pair of synchronous gears 4 in the oil tank.

[0034] The shaft end of the main shaft extends out of the front cover 10 and is connected to the coupling 11, and the coupling 11 is connected to the motor 12; a coupling protective cover 14 is provided outside the coupling 11; a composite seal 3 is provided at the connection between the front end of the main shaft and the rear end cover 2.

[0035] An air inlet 8 is provided at the upper end of the pump body 1, and an exhaust port 7 is provided at the lower end; a side cover plate 15 is provided on the left and right sides of the pump body 1 respectively, and a through hole is provided on the side cover plate 15. The side cover plate 15 is connected to a cooling water nozzle 16, and the cooling water nozzle 16 is communicated with the pump cavity of the pump body 1 through the through hole of the side cover plate 15. The high-pressure cooling water is converted into fine micro-particle water droplets through the cooling water nozzle 16, and the micro-particle water droplets are introduced into the pump cavity through the through holes of the side cover plates 15 on both sides of the pump body 1, so as to directly cool the internal heat-generating components of the Roots vacuum pump, so that the cooling of the heat-generating components such as the rotor, pump body and end cover of the Roots vacuum pump is more sufficient.

[0036] The cooling water nozzles 16 can be provided with corresponding numbers on the two sides of the pump body according to the size of the Roots vacuum pump, and the cooling water nozzles 16 are provided on the exhaust side below the horizontal center line of the Roots vacuum pump.

[0037] A machine base is provided below the pump body 1, and a gas-water separation muffler 13 is provided in the machine base. The water separation muffler 13 includes a muffler cylinder 13.5, and a first-stage chamber 13.1, a second-stage chamber 13.2 and a third-stage chamber 13.3 arranged in sequence are provided in the muffler cylinder 13.5. A first-stage damping air intake pipe 13.11 is provided in the first-stage chamber 13.1, and the first-stage damping air intake pipe 13.11 is a water gas inlet pipe. The tube 13.11 is vertically arranged, and its top end is connected to the exhaust port 7 at the bottom of the pump body 1 through a connecting flange 13.14. The lower part of the first-stage damping air inlet pipe 13.11 is provided with densely arranged damping holes 13.12. The gas discharged from the pump body 1 is subjected to primary noise reduction by the damping holes 13.12 on the first-stage damping air inlet pipe 13.11. A small amount of water is separated from the gas in this first-stage damping air inlet pipe 13.11 and enters the first-stage chamber 13.1 through the damping holes 13.12.

[0038] The second-stage chamber 13.2 is an expansion chamber, and is provided with a plurality of baffles 13.21 which are staggered up and down. The baffles 13.21 are non-circular metal plates with notches at one end, and the notches of two adjacent baffles 13.21 are cross-arranged at 180°. The gas in the second-stage chamber 13.2 flows back through the notches of the baffles 13.21, and the air flow velocity and noise are further released in the second-stage chamber 13.2.

[0039] A final-stage damping exhaust pipe 13.31 is provided in the third-stage chamber 13.3, the end of the final-stage damping exhaust pipe 13.31 extends out of the muffler cylinder 13.5, and the end of the final-stage damping exhaust pipe 13.31 is an air outlet, and a front portion of the final-stage damping exhaust pipe 13.31 is also provided with a plurality of damping holes; a partition plate 13.32 is sleeved on the middle portion of the final-stage damping exhaust pipe 13.31, which is divided into two sections by the partition plate 13.32, and the gas needs to undergo secondary damping and three returns from the expansion chamber to the final-stage exhaust port, so that the airflow energy consumption is released to the maximum extent and the best noise reduction effect is achieved.

[0040] The bottom of the first-stage chamber 13.1 is connected to a first drain pipe 13.13, the bottom of the second-stage chamber 13.2 is connected to a second drain pipe 13.22, and the bottom of the third-stage chamber 13.3 is connected to a third drain pipe 13.33. The first drain pipe 13.13, the second drain pipe 13.22 and the third drain pipe 13.33 are all connected to a main drain pipe 13.4, which is arranged below the muffler cylinder 13.5, and the end of the main drain pipe 13.4 extends out of the muffler cylinder 13.5, and the end of the main drain pipe 13.4 is a cooling water outlet.

[0041] Working principle:

[0042] The utility model discloses an exhaust end water-cooled Roots vacuum pump. A plurality of cooling water atomizing nozzles are arranged on two sides of a Roots vacuum pump body. High-pressure cooling water is transformed into fine water droplets through the nozzles. The water droplets are introduced into a pump cavity through through holes of cover plates on two sides of a Roots vacuum pump head to directly cool the internal heating components of the Roots vacuum pump. The cooling water droplets introduced into the Roots vacuum pump cavity can fill the gap between a pair of mutually meshing rotors in the pump cavity. In this way, the cooling water can prevent the backflow of the pumped gas when the vacuum pump is running at a high pressure difference, and has the purpose of sealing the rotor, thereby improving the air extraction efficiency of the vacuum pump.

[0043] An air-water separation muffler is installed at the exhaust port of the vacuum pump to reduce the exhaust noise of the vacuum pump and automatically separate the gas and cooling water of the air-water mixture discharged from the vacuum pump; the gas and water discharged from the vacuum pump are separated, and the airflow fluctuation noise of the high-pressure difference operation of the vacuum pump is reduced, thereby reducing environmental noise pollution.

[0044] The air-water separation muffler is divided into three chambers; the first chamber is composed of a first-stage damping inlet pipe, the second chamber is an expansion chamber composed of a number of baffles and end plates, and the third chamber is composed of a final damping exhaust pipe. The bottoms of the three chambers are connected to the main drain pipe through three drainage pipes. The exhaust of the Roots vacuum pump enters the air-water separation muffler, first passes through the first-stage damping pipe for primary noise reduction and air-water separation, then enters the second-stage expansion chamber for secondary baffle and dispersion reduction, secondary noise reduction and air-water separation, and finally in the final damping pipe for secondary damping baffle noise reduction and air-water separation.

[0045] The cooling water nozzle is arranged on one side below the horizontal center line of the pump body near the exhaust port in the pump cavity of the Roots vacuum pump, which can help the Roots vacuum pump achieve better cooling effect, lower energy consumption and better sealing effect.

[0046] The upper part of the Roots vacuum pump is the suction chamber and the lower part is the compression and exhaust chamber. The heat of the pump is in the compression chamber in the lower part, so there are two advantages to introducing cooling water into the compression chamber in the lower part. One is good cooling effect, the other is that it does not affect the pumping volume of the pump, and the third is that it does not increase the power consumption of the pump. If cooling water is introduced from the suction chamber, it will affect the pumping volume of the pump and increase the running power consumption of the pump.

[0047] The above are only specific application examples of the utility model, and do not constitute any limitation on the protection scope of the utility model. Any technical solution formed by equivalent transformation or equivalent replacement falls within the protection scope of the utility model.

Claims

1. An exhaust end water-cooled Roots vacuum pump, comprising a pump body (1), wherein the front end of the pump body (1) is provided with a front cover (9), and the rear end is provided with a rear cover (2), the front cover (9) is provided with a front cover (10), and the rear cover (2) is provided with a rear cover; the pump body (1) is provided with a pair of parallel horizontally mounted and mutually meshing three-leaf involute rotors: a driving rotor (5) and a driven rotor (6), the driving rotor (5) being mounted on a main shaft, and the driven rotor (6) being mounted on a rotor shaft, the main shaft and the rotor shaft being arranged in the pump body, and the driving rotor (5) and the driven rotor (6) being respectively mounted in the front cover (9) and the rear cover (2) at both ends of the pump body through bearings; characterized in that: The pump body (1) has an air inlet (8) at its upper end and an air outlet (7) at its lower end; a side cover plate (15) is provided on each of the left and right sides of the pump body (1); the side cover plate (15) is provided with a through hole; the side cover plate (15) is connected to a cooling water nozzle (16); and the cooling water nozzle (16) is connected to the pump cavity of the pump body (1) through the through hole of the side cover plate (15); A machine base is provided below the pump body (1), and a gas-water separation muffler (13) is provided in the machine base. The water separation muffler (13) comprises a muffler cylinder (13.5), and a first-stage chamber (13.1), a second-stage chamber (13.2), and a third-stage chamber (13.3) arranged in sequence are provided in the muffler cylinder (13.5). A first-stage damping air intake pipe (13.11) is provided in the first-stage chamber (13.1), and the first-stage damping air intake pipe (13.11) is a water-gas inlet pipe. The lower part of the muffler air inlet pipe (13.11) is provided with densely arranged damping holes (13.12); the second-stage chamber (13.2) is an expansion chamber, the second-stage chamber (13.2) is provided with a plurality of baffles (13.21) arranged in an up-and-down staggered manner, the third-stage chamber (13.3) is provided with a final-stage damping exhaust pipe (13.31), the end of the final-stage damping exhaust pipe (13.31) extends out of the muffler barrel (13.5), and the end of the final-stage damping exhaust pipe (13.31) is an air outlet; The bottom of the first-level chamber (13.1) is connected to a first drain pipe (13.13), the bottom of the second-level chamber (13.2) is connected to a second drain pipe (13.22), the bottom of the third-level chamber (13.3) is connected to a third drain pipe (13.33), and the first drain pipe (13.13), the second drain pipe (13.22) and the third drain pipe (13.33) are all connected to a main drain pipe (13.4).

2. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: The first-stage damping air inlet pipe (13.11) is arranged vertically, and its top end is connected to the exhaust port (7) at the bottom of the pump body (1) via a connecting flange (13.14).

3. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: The baffle (13.21) is a non-circular metal plate with a notch at one end, and the notches of two adjacent baffles (13.21) are arranged crosswise at 180 degrees, so that the gas in the second-stage chamber (13.2) flows back through the notches of the baffles (13.21).

4. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: A partition plate (13.32) is sleeved on the middle part of the final-stage damping exhaust pipe (13.31), and the final-stage damping exhaust pipe (13.31) is divided into two sections by the partition plate (13.32).

5. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: The shaft end of the main shaft extends out of the front cover (10) and is connected to a coupling (11), and the coupling (11) is connected to a motor (12).

6. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: The main drainage pipe (13.4) is arranged below the muffler cylinder (13.5), and the end of the main drainage pipe (13.4) extends out of the muffler cylinder (13.5), and the end of the main drainage pipe (13.4) is a cooling water outlet.

7. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: A gear (4) is provided in the rear cover, and the gear (4) is sleeved on the end of the main shaft; the driving rotor (5) and the driven rotor (6) are caused to rotate synchronously and at a constant speed in the pump body through a pair of gears (4) in the oil tank.

8. The exhaust end water-cooled Roots vacuum pump according to claim 1, characterized in that: A composite seal (3) is provided at the connection between the front end of the main shaft and the rear end cover (2).

Images