CN106593899A - VPSA large-capacity centrifugal vacuum pump - Google Patents

Abstract

The invention relates to a VPSA large-capacity centrifugal vacuum pump. Each stage adopts a backward-curved ternary impeller and a vaneless diffuser. A cooler is arranged in the middle of every two sections, and a cooler is arranged at the outlet of the last section. There are three coolers in total. Each section is provided with an air intake chamber and an exhaust volute, a total of three air intake chambers and three exhaust volute chambers. The intake chamber is a double-supported radial suction chamber, and the exhaust volute is a circular symmetrical volute; when working, the gas is sucked from the suction chamber and rotates at a high speed with the first-stage impeller. Under the action of centrifugal force, its kinetic energy and The static pressure energy rises, and is thrown out along the radial direction through the flow channel between the blades, and enters the first-stage diffuser whose flow channel area gradually increases, and the kinetic energy of the gas is reduced and converted into static pressure energy, which increases the pressure of the gas, and then Enter the second stage to continue compression through the first stage bend and reflux device. Compression is cycled sequentially, and after the last stage of compression is completed, the gas is collected by the volute and discharged from the exhaust pipe. As the pumping process continues, the mass flow rate decreases continuously, the inlet pressure decreases continuously, and the vacuum degree increases continuously. Until the next cycle, the unit is in the process of constantly changing working conditions.

Description

VPSA large capacity centrifugal vacuum pump

technical field

The invention relates to a vacuum pump, in particular to a VPSA large volume centrifugal vacuum pump.

Background technique

The existing VPSA large-scale vacuum pumps involved in the petrochemical industry and coal chemical industry are all water ring vacuum pumps or piston vacuum pumps. Although the water ring vacuum pump has a large pumping capacity, the vacuum degree varies greatly with the suction flow rate, and the actual pumping efficiency is low. Multiple units need to be used in parallel, which consumes a lot of water, and the vacuum degree is low and unstable due to the influence of water quality. The phenomenon of backflow of water causes the failure of expensive adsorbents, especially the water pollution caused by the contact of water with the medium, which requires manpower and material resources for sewage treatment, which is very inconsistent with the current national concept of energy conservation and environmental protection. Although the piston vacuum pump has the advantages of no oil lubrication and no water pollution, due to structural limitations, the largest piston vacuum pump in China can only reach 17280 m3/h. The suction flow rate will decrease with the increase of the vacuum degree. The efficiency is low, and it often requires multiple parallel connections to meet the requirements, which is far from meeting the needs of the rapid development of the petrochemical industry and the coal chemical industry in recent years.

Contents of the invention

In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a pump with high rotating speed, large flow rate, compact structure, basically constant vacuum degree with the suction flow rate, high pumping efficiency, reliable operation, low noise and low maintenance workload. Small, non-polluting centrifugal vacuum pump.

For achieving above object, the technical scheme that the present invention takes is:

VPSA large-capacity centrifugal vacuum pump includes multi-stage vacuum pump units connected in series. Each vacuum pump unit includes a housing, a rotating shaft and an impeller. The housing includes two-stage chambers, and impellers are installed in each chamber. L-shaped air passage for axial air intake and radial air outlet, each impeller is fixedly connected in series with the rotating shaft; the front section of the first-stage chamber is an air intake chamber, and the air inlet of the impeller in the first-stage chamber is connected to the air intake chamber A pair of first-stage diffusers are symmetrically arranged on the outside of the air outlet of the impeller in the first-stage chamber, and the first-stage diffusers are connected to the inlet of the symmetrically arranged reflux device through a U-shaped bend, and the outlet of the reflux device is connected to the second A pair of circular volute chambers are arranged symmetrically outside the air inlet of the first-stage chamber impeller and the air outlet of the second-stage chamber impeller, and the circular volute chambers communicate with the inlet chamber of the lower-stage vacuum pump unit.

Further, a three-stage vacuum pump unit is included, and the scroll chamber of the third-stage vacuum pump unit is provided with an exhaust port.

Still further, coolers are installed between the vacuum pump units of each stage.

After adopting the above technical solutions, the beneficial effects of the present invention are: the VPSA large volume centrifugal vacuum pump is a three-stage six-stage type. Each stage adopts backward curved three-way impeller and vaneless diffuser, a cooler is installed in the middle of every two sections, and a cooler is installed at the outlet of the last section, a total of three coolers. Each section is provided with an air intake chamber and an exhaust volute, a total of three air intake chambers and three exhaust volute chambers. The intake chamber is a double-supported radial suction chamber, and the exhaust volute is a circular symmetrical volute; when working, the gas is sucked from the suction chamber and rotates at a high speed with the first-stage impeller. Under the action of centrifugal force, its kinetic energy and The static pressure energy rises, and is thrown out along the radial direction through the flow channel between the blades, and enters the first-stage diffuser whose flow channel area gradually increases, and the kinetic energy of the gas is reduced and converted into static pressure energy, which increases the pressure of the gas, and then Enter the second stage to continue compression through the first stage bend and reflux device. Compression is cycled sequentially, and after the last stage of compression is completed, the gas is collected by the volute and discharged from the exhaust pipe. As the pumping process continues, the mass flow rate decreases continuously, the inlet pressure decreases continuously, and the vacuum degree increases continuously. Until the next cycle, the unit is in the process of constantly changing working conditions.

Description of drawings

Fig. 1 is a schematic structural diagram of a vacuum pump unit.

Fig. 2 is a structural schematic diagram of the present invention.

detailed description

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail:

As shown in the figure, the VPSA large-capacity centrifugal vacuum pump includes three-stage vacuum pump units connected in series. Each vacuum pump unit includes a housing 1, a rotating shaft 2, and impellers 3 and 4. The housing of the three-stage vacuum pump unit is integrally cast. Each housing 1 includes two-stage chambers 5 and 6, and impellers are respectively installed in the chambers of each stage, and the impellers 3 and 4 are provided with L-shaped air passages 7 for axial air intake and radial air outlet, and each impeller is fixed It is connected in series with the rotating shaft 2; the front section of the first-stage chamber 5 is an air intake chamber 8, and the air intake chamber is a double-supported radial air intake mechanism. The air inlet 9 of the impeller 3 communicates with the air inlet chamber, and a pair of first-stage diffusers 11 are arranged symmetrically outside the air outlet 10 of the impeller 3. The diffusers 11 are vaneless diffusers, and the first-stage diffusers 11 pass through The U-shaped bend 12 is connected to the inlet of the reflux 13 arranged symmetrically, and the outlet of the reflux 13 is connected to the air inlet of the impeller 4 of the second chamber 6; both the diffuser 11 and the reflux 13 are changed by changing the ventilation area The pressure of the passing gas. A pair of volute chambers 14 are arranged symmetrically outside the air outlet of the impeller 4 of the second-stage chamber 6, and the volute chambers 14 communicate with the air intake chamber of the lower-stage vacuum pump unit, and the volute chamber of the third-stage vacuum pump unit is provided with an exhaust port 15. A cooler 16 is installed between the above-mentioned vacuum pump units at each stage, and the exhaust port of the last stage volute is connected with a cooler 16, and the cooler 16 can be a tube-and-tube circulating water cooler.

Claims (3)

1.VPSA atm number centrifugal vacuum pump, including the multistage vacuum pump unit being sequentially connected in series, it is characterised in that each vacuum Pump unit includes including two-stage chamber in housing, rotating shaft and impeller, housing that within the chambers at different levels are separately installed with impeller, in impeller Be provided with L shape axial admission radial direction outlets crosses gas passage, and each impeller is fixed and is serially connected with rotating shaft；The leading portion of the first order chamber is Inlet plenum, the air inlet UNICOM inlet plenum of first order within the chamber impeller, is arranged with a pair of first order on the outside of the gas outlet of impeller Diffuser, the entrance of the return channel that first order diffuser Jing U-shaped bend connected symmetrical dendrimer is arranged, the outlet UNICOM second of return channel The air inlet of level chamber impeller, is symmetrically arranged with a pair circular volute casings, the circle on the outside of the air outlet of second level chamber impeller The inlet plenum of subordinate of volute casing UNICOM vacuum pump unit.

2. VPSA atm numbers centrifugal vacuum pump according to claim 1, it is characterised in that including three-level vacuum pump unit, The volute casing of third level vacuum pump unit is provided with air vent.

3. VPSA atm numbers centrifugal vacuum pump according to claim 1, it is characterised in that between the vacuum pump units at different levels Cooler is installed.