Vacuumizing system

Abstract

The utility model discloses a vacuumizing system, and belongs to the field of vacuumizing equipment. The vacuum pumping device comprises a ventilation opening, a vacuum tank and at least one sucking pump set, each sucking pump set comprises a first vacuum pump and a second vacuum pump which are connected in series, each sucking pump set is connected to the vacuum tank in parallel, the ventilation opening is communicated with the vacuum tank to conduct vacuumizing work, the first vacuum pump comprises a roots pump, and the second vacuum pump comprises a screw pump or a water ring pump. According to the utility model, a high vacuum degree can be obtained, and a high air exhaust rate can be achieved.

Description

Technical Field

[0001] The utility model belongs to the field of vacuum pumping equipment, and particularly relates to a vacuum pumping system. Background Technique

[0002] Vacuum pumping systems are widely used in various fields and usually perform vacuum pumping through vacuum pumps. Common vacuum pumps include dry screw vacuum pumps, water ring pumps, reciprocating pumps, sliding vane pumps, rotary vane pumps, Roots pumps, diffusion pumps, etc. These pumps are essential main pump types in the application of vacuum processes in various industries. The pumping speed of a vacuum pump is inversely proportional to the vacuum degree. As the vacuum degree increases, the pumping speed decreases accordingly. At this time, when a high vacuum degree is required, how to ensure a certain pumping speed is restricted by traditional vacuum pumps and even cannot be achieved. To solve this problem, the traditional approach is to use a higher-grade vacuum pump to obtain a high pumping speed at a high vacuum degree, but the traditional approach has problems such as high cost and serious energy waste. In recent years, for the convenience of use and the needs of various vacuum processes, in the prior art, various vacuum pumps are combined according to their performance requirements and applied in the form of units.

[0003] After retrieval, a Roots water ring vacuum pump unit appears in the prior art. That is, the patent application document with the Chinese patent application number 202211609032.2 and the application date of December 14, 2022 discloses a Roots water ring vacuum pump unit. This patent includes a Roots vacuum pump, a water ring vacuum pump, an inter-stage heat exchanger, a plate heat exchanger, and a steam-water separator. One of the pipe orifices of the Roots vacuum pump is connected to an air inlet pipeline, and the other pipe orifice of the Roots vacuum pump is fixed with an inter-stage heat exchanger. One side of the inter-stage heat exchanger away from the Roots vacuum pump is fixed with an air inlet pipe, and one side of the air inlet pipe away from the inter-stage heat exchanger is connected to one of the pipe orifices of the water ring vacuum pump. The other pipe orifice of the water ring vacuum pump is fixed with an exhaust pipeline, and one end of the exhaust pipeline away from the water ring vacuum pump is fixed with a steam-water separator, and a circulation pipeline is provided on the steam-water separator. For this Roots water ring vacuum pump unit, a bypass pipeline is added at the air inlet of the Roots water ring vacuum unit, and a pneumatic butterfly valve is installed and connected to the inlet of the inter-stage heat exchanger. The unit automatically switches the device according to the operating conditions, thus well solving the problem of tripping due to the two-machine logic interlock. However, it does not mention whether the vacuum degree is increased while the pumping speed is increased.

[0004] The patent application document with the Chinese patent application number 202321498057.X and the application date of June 13, 2023 discloses a Roots screw vacuum pump unit. This patent vacuum pump unit includes: a Roots pump, a frame, a sound insulation system, a power distribution cabinet, and a screw pump; the screw pump is connected in series at the front end of the Roots pump as a front-stage pump, and the Roots pump is used as the main pumping pump. It can operate at high speed, so the pumping speed of the air inlet can be increased several times, and the ultimate vacuum degree of the screw pump can be improved. However, its pumping speed and vacuum degree still need to be further improved.

[0005] Therefore, based on the existing vacuum pumping system, how to further improve the pumping speed and vacuum degree is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] 1. Problems to be Solved

[0007] The utility model provides a vacuum pumping system, aiming to have a high pumping rate when obtaining a high vacuum degree.

[0008] 2. Technical Solutions

[0009] To solve the above problems, the utility model adopts the following technical solutions.

[0010] A vacuum pumping system includes a ventilation port, a vacuum tank, and at least one set of air pumping pump groups. Each set of air pumping pump groups includes a first vacuum pump and a second vacuum pump connected in series. Each set of air pumping pump groups is connected in parallel to the vacuum tank. The ventilation port is connected to the vacuum tank for vacuum pumping work. Among them, the vacuum tank is mainly used for buffering to ensure the stability of the system vacuum degree. The first vacuum pump includes a Roots pump, which has the function of improving the pumping rate and vacuum degree of the vacuum pump station system. The second vacuum pump includes a screw pump or a water ring pump. The intake port of the second vacuum pump is connected to the exhaust port of the first vacuum pump through a pipeline. First, the second vacuum pump is started to extract the air inside the vacuum tank to form a certain vacuum degree inside the vacuum tank. When the absolute vacuum degree inside the vacuum tank reaches the optimal operating power point of the first vacuum pump, the first vacuum pump is started under negative pressure, and the absolute vacuum degree inside the vacuum tank is further improved through the buffering effect of the vacuum tank, while significantly increasing the pumping rate.

[0011] As a possible implementation manner of the utility model, there are at least two sets of the air pumping pump groups, and each set of air pumping pump groups is connected in parallel to the vacuum tank.

[0012] As a possible implementation manner of the utility model, the bottom of the vacuum tank is connected to a sewage vacuum tank.

[0013] As a possible implementation manner of the utility model, a vacuum ball valve is provided on the pipeline connecting the vacuum tank and the sewage vacuum tank, which is installed at the inlet of the sewage vacuum tank to control the on-off between the vacuum tank and the sewage vacuum tank.

[0014] As a possible implementation manner of the utility model, an air filter assembly is also connected between the vacuum tank and the first vacuum pump for filtering the gas drawn into the intake end to achieve intake filtration.

[0015] As a possible implementation manner of the utility model, pressure gauges, preferably absolute pressure sensors, are respectively connected to the inlet and outlet of the air filter assembly.

[0016] As a possible implementation of the present utility model, a vacuum check valve is provided on the pipeline connecting the vacuum tank and the air filter assembly, which is arranged at the air inlet of the air filter assembly and is used to control the on-off function of the pipeline between the vacuum tank and the air filter assembly.

[0017] As a possible implementation of the present utility model, an exhaust pipe is provided at the top of the second vacuum pump.

[0018] As a possible implementation of the present utility model, a cooling air conditioner is also provided, which is installed on the top of the vacuum tank and is used for heat dissipation and temperature reduction inside the whole system.

[0019] As a possible implementation of the present utility model, the vacuum pumping system is arranged in a frame with an upper opening: the four sides of the frame are integrally welded with square steel, and the whole is aged to eliminate the welding internal stress. The surface is polished and then painted to achieve beauty, durability and corrosion resistance, and is used to fix the vacuum tank and each pipeline; the vacuum tank is installed at the upper opening of the frame, and the feet are fixed with bolts; the base of the frame is welded by channel steel and steel plates, and the whole is aged to eliminate the welding internal stress. The surface is polished and then painted to achieve beauty, durability and corrosion resistance; the second vacuum pump is installed on the base of the frame, and the feet are fixed with bolts, which is mainly used to improve the air extraction rate and vacuum degree of the system in a cascade form with the first vacuum pump; the sewage vacuum tank is also installed on the base of the frame, and the feet are fixed by bolts, which is used for vacuum drainage and sewage discharge of the vacuum tank.

[0020] As a possible implementation of the present utility model, a plurality of ventilation ports are provided, and the ventilation ports are connected by ISO160 standard flange interfaces. Multiple interfaces can be connected to externally connect multiple user air extraction ends at the same time.

[0021] 3. Beneficial effects

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

[0023] The vacuum pumping system of the present utility model can improve the pumping rate and vacuum degree, and effectively solve the problem of insufficient pumping rate at high vacuum degrees: on the one hand, it enters the vacuum pump station in a cascaded manner, with a simple and practical structure, low cost, and can obtain a high pumping rate at high vacuum degrees; on the other hand, through the buffering effect of the vacuum tank, the absolute vacuum degree in the vacuum tank is further improved, and at the same time, the pumping rate is increased. The specific principle is as follows: Two groups of variable-frequency oil-injected screw vacuum pumps and Roots vacuum pumps are connected in a form of parallel connection between groups and series connection within groups. Its operating principle is to first start the variable-frequency oil-injected screw vacuum pump. When the absolute vacuum degree in the vacuum tank reaches the optimal operating power point of the Roots pump (usually around 100 mbar), the Roots pump is started under negative pressure. Through the buffering effect of the vacuum tank, the absolute vacuum degree in the vacuum tank is further improved, and at the same time, the pumping rate is increased; among them, the variable-frequency oil-injected screw vacuum pump is a reliable, durable, efficient and energy-saving wet screw vacuum pump. Its working principle is to use two meshing and rotating screws to form relative movement in the pump, so as to suck the gas from the inlet, compress and discharge it to the outlet; compared with the traditional dry screw pump, it has higher reliability and is more efficient and energy-saving. Description of the Drawings

[0024] Figure 1 It is the flow chart of the vacuum pumping system in Embodiment 1;

[0025] Figure 2 It is the flow chart of the vacuum pumping system in Embodiment 2;

[0026] Figure 3 It is the front view structural schematic diagram of the vacuum pumping system in Embodiment 2;

[0027] Figure 4 It is the three-dimensional perspective view of the vacuum pumping system in Embodiment 2;

[0028] In the figure:

[0029] 1. Vacuum tank; 11. Drainage vacuum tank; 12. Vacuum ball valve; 2. First vacuum pump; 3. Second vacuum pump; 4. Ventilation port; 5. Air filter assembly; 51. Vacuum check valve; 52. First absolute pressure sensor; 53. Second absolute pressure sensor; 6. Cooling air conditioner; 7. Exhaust pipe; 8. Frame. Detailed Embodiments

[0030] The present utility model will be described in detail below in conjunction with the drawings and specific embodiments.

[0031] Embodiment 1

[0032] A vacuum pumping system according to this embodiment includes a vent port 4, a vacuum tank 1, and a set of air extraction pump sets that are connected in sequence through pipelines: The vent port 4 is connected by an ISO160 standard flange interface and is provided at the air inlet of the vacuum tank 1, or the vent port 4 is connected to the air inlet of the vacuum tank 1 through a pipeline. To increase work efficiency, multiple vent ports can be provided in parallel and externally connected to multiple devices to be evacuated at the same time. The air outlet of the vacuum tank 1 is connected to the air extraction pump set through a pipeline. The air extraction pump set includes a Roots pump and a screw pump. The Roots pump is connected to the air outlet of the vacuum tank 1, and the screw pump is connected to the Roots pump. During the vacuum pumping operation, the device to be evacuated is connected to the vent port 4. If the number of vacuum pumping devices is less than the number of vent ports 4, the vent port 4 not connected to the vacuum pumping device is closed to ensure airtightness. After connecting the device to be evacuated, first start the screw pump to extract the air inside the vacuum tank 1 to form a certain degree of vacuum inside the vacuum tank 1. When the absolute vacuum degree inside the vacuum tank 1 reaches the best operating power point of the Roots pump, usually around 100 mbar, the Roots pump starts under negative pressure, and through the buffering effect of the vacuum tank 1, the absolute vacuum degree inside the vacuum tank 1 is further increased, and at the same time, the air extraction rate is increased.

[0033] In this embodiment, to improve the service life of the vacuum tank 1, a sewage discharge vacuum tank 11 is connected to the bottom of the vacuum tank 1, and the on-off between the two is controlled by a vacuum ball valve 12. When the vacuum ball valve 12 is opened, the sewage such as water vapor inside the vacuum tank 1 is discharged into the sewage discharge vacuum tank 11. After the sewage inside the vacuum tank 1 is discharged, the vacuum ball valve 12 is closed and then the sewage discharge vacuum tank 11 is opened to clean the waste water, maintaining the airtightness inside the vacuum tank 1 during the sewage discharge process.

[0034] Furthermore, an air filter assembly 5 is also connected between the vacuum tank 1 and the first vacuum pump 2. The filter element installed inside the air filter assembly 5 in this embodiment has a model of SCB483236X and a brand of Donaldson. The on-off function of the pipeline between the vacuum tank 1 and the air filter assembly 5 is controlled by setting a vacuum check valve 51; the air filter assembly 5 is used for filtering the gas drawn in at the intake end to achieve intake air filtration. Absolute pressure sensors are respectively connected to the inlet and outlet of the air filter assembly 5, that is, the first absolute pressure sensor 52 and the second absolute pressure sensor 53. Whether the air filter assembly 5 is blocked is judged by testing the difference between the two absolute pressure sensors (usually the pressure difference ≥ 3 bar).

[0035] The top of the screw pump of this embodiment is also provided with an exhaust pipe 7 for discharging compressed gas. Of course, in order to facilitate the movement of the vacuum system of this embodiment, the vacuum system is arranged in a frame 8 with an upper opening: the four sides of the frame 8 are formed by integral welding of square steel, and the base of the frame 8 is formed by welding of channel steel and steel plate. The whole is subjected to aging treatment to eliminate welding internal stress, and the surface is polished and then painted to achieve beautiful, durable and corrosion-resistant appearance. The vacuum tank 1 is installed at the upper opening of the frame 8, and the base is fixed to the four sides of the frame 8 with bolts; the screw pump and the sewage vacuum tank 11 are installed on the base of the frame 8, and the base is fixed with bolts. In order to facilitate the heat dissipation of the vacuum system of this embodiment, a heat dissipation air conditioner 6 is provided, which is installed on the top of the vacuum tank 1 and is used for heat dissipation and cooling of the entire system. Figure 1 1 is a gas flow chart of the vacuum pumping system of this embodiment.

[0036] Example 2

[0037] The difference between the vacuum pumping system of this embodiment and the embodiment 1 is that two sets of vacuum pumps connected in parallel are used, and the roots pumps in the two vacuum pumps are connected to the vacuum tanks respectively. The other parts are the same as those of the embodiment 1, such as Figure 2 , 3 , as shown in Figure 4.

[0038] Example 3

[0039] The vacuum pumping system of this embodiment is basically the same as that of Embodiment 2, except that the screw pump is replaced by a water ring pump.

[0040] Example 4

[0041] The vacuum pumping system of this embodiment is basically the same as that of embodiment 2, except that: in each vacuum pump group, the screw pump is connected to the air outlet of the vacuum tank 1, and the Roots pump is connected to the screw pump. The connection pipeline of the screw pump and the Roots pump in this embodiment is more complicated, and the screw vacuum pump is started under negative pressure, which reduces the energy efficiency of the screw pump, and is not energy-saving relative to the vacuum pumping system in embodiment 2.

[0042] Comparative Example 1

[0043] Comparative Example 1 is substantially the same as Example 2, except that it does not contain a vacuum tank.

[0044] In the vacuuming systems of the embodiments and comparative examples, when operating on the same equipment to be vacuumed, the vacuuming speed and vacuum degree are shown in the following table:

[0045] Table 1. Pumping speed and vacuum degree of the vacuum pumping system of each embodiment and comparative example

[0046] Example / Comparative Example Vacuum pumping time Pumping speed Vacuum degree Example 1 60min <![CDATA[665.5m 3 / h]]> 0.3mbar Example 2 35min <![CDATA[991.3m 3 / h]]> 0.2mbar Example 3 90min <![CDATA[684.3m 3 / h]]> 0.5mbar Example 4 35min <![CDATA[987.5m 3 / h]]> 0.2mbar Comparative Example 1 60min <![CDATA[659.8m 3 / h]]> 0.3mbar

[0047] The embodiments described above are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

Claims

1. A vacuum pumping system, characterized in that: It includes a vent (4), a vacuum tank (1) and at least one set of air extraction pump groups. Each set of air extraction pump groups includes a first vacuum pump (2) and a second vacuum pump (3) connected in series. Each set of air extraction pump groups is connected in parallel to the vacuum tank (1). The vent (4) is connected to the vacuum tank (1) to perform vacuum pumping work. Among them, the first vacuum pump (2) includes a Roots pump, and the second vacuum pump (3) includes a screw pump or a water ring pump.

2. The vacuum pumping system according to claim 1, wherein: There are at least two sets of the air extraction pump groups, and each set of air extraction pump groups is connected in parallel to the vacuum tank (1).

3. A vacuum pumping system according to claim 1, characterized in that: The bottom of the vacuum tank (1) is connected to a sewage vacuum tank (11).

4. A vacuum pumping system according to claim 3, characterized in that: A vacuum ball valve (12) is provided on the pipeline connecting the vacuum tank (1) and the sewage vacuum tank (11).

5. A vacuum pumping system according to claim 1, characterized in that: An air filter assembly (5) is also connected between the vacuum tank (1) and the first vacuum pump (2).

6. The vacuum pumping system according to claim 5, characterized in that: Pressure gauges are respectively connected to the inlet and outlet of the air filter assembly (5).

7. A vacuum pumping system according to claim 5, characterized in that: A vacuum check valve (51) is provided on the pipeline connecting the vacuum tank (1) and the air filter assembly (5).

8. A vacuum pumping system according to claim 1, wherein: An exhaust pipe (7) is provided at the top of the second vacuum pump (3).

9. The vacuum pumping system according to claim 1, characterized in that: An air-conditioning unit for heat dissipation (6) is also provided.

10. A vacuum pumping system according to any one of claims 1 to 9, characterized in that: Multiple vents (4) are provided.

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