Vacuum pumping assembly of vacuum tower

Abstract

The vacuum-pumping assembly comprises an exhaust pipe connected to a vacuum-pumping opening of the vacuum-pumping tower, the exhaust pipe comprises a flow dividing assembly, the flow dividing assembly comprises a first exhaust pipe and a second exhaust pipe which are connected in parallel, and the two ends of the first exhaust pipe and the two ends of the second exhaust pipe are converged through a three-way pipe and connected with the vacuum-pumping opening and a vacuum pump respectively. A condensing device is arranged on the first exhaust pipe, an electromagnetic reversing valve is arranged between the first exhaust pipe and the second exhaust pipe, a hygristor is arranged in the exhaust pipe close to the vacuumizing opening, the electromagnetic reversing valve is electrically connected with the hygristor, and when the resistance of the hygristor is reduced when encountering water vapor, the electromagnetic reversing valve is switched to the vacuumizing opening to be communicated with the first exhaust pipe; when the hygristor does not meet water vapor, the resistance value is increased, and the electromagnetic reversing valve is switched to the vacuumizing opening to be communicated with the second exhaust pipe. According to the vacuum pumping assembly of the vacuum tower, air in the vacuum tower can be rapidly pumped out at the beginning of vacuum pumping, the vacuum pumping efficiency is effectively improved, and the energy consumption is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of vacuum towers, in particular to a vacuum tower vacuum pumping component. Background Art

[0002] In petroleum refining, after the crude oil is distilled at atmospheric pressure, there are still some high-boiling-point components, such as lubricating oil and wax oil, which are difficult to separate at atmospheric pressure. The function of the vacuum tower is to reduce the pressure in the system so that these high-boiling-point fractions boil and vaporize at a temperature lower than their atmospheric boiling point, so that they can be separated.

[0003] The vacuum tower uses this principle to avoid decomposition and coking of high-boiling point fractions at excessively high temperatures, which helps to improve product quality and yield. It can also obtain fractions in different boiling point ranges for the production of lubricants, asphalt and many other petroleum products.

[0004] The vacuum pumping components in the vacuum tower are mainly used to reduce the pressure in the tower. In the oil refining process, the operating principle of the vacuum tower is to distill crude oil under low pressure. The vacuum pumping components reduce the pressure in the tower to the required vacuum degree by extracting the gas in the tower (including non-condensable gas and some light components).

[0005] In the prior art, the vacuum pumping assembly of the vacuum tower generally reduces the pressure in the tower by sucking the gas in the vacuum tower through a vacuum pump. However, directly sucking the gas in the vacuum tower by the vacuum pump often requires a large amount of suction due to the steam generated by the materials and water inside, and the suction lasts for a long time, consuming a lot of energy, and may cause waste and environmental pollution caused by the discharge of material steam. For example, CN209286693U discloses a vacuum tower vacuum energy-saving auxiliary device, which is provided with a drying condensing device on the air outlet pipe connected to the vacuum pump. The dry condensing device cools the extracted gas so that the internal material steam and water vapor in the gas are liquefied and discharged. On the one hand, this vacuum energy-saving auxiliary device avoids the liquefaction of material steam and water vapor in the vacuum pump to damage the vacuum pump, and on the other hand, it reduces the duration of suction, effectively improves the suction efficiency, and achieves energy-saving effect. However, this type of vacuum energy-saving auxiliary device often has low circulation efficiency and large resistance due to the condensing device. In addition, during long-term use, the internal material vapor will adhere to the inner wall of the pipe after liquefaction, resulting in further reduction of gas circulation efficiency, thereby increasing the power loss of the vacuum pump. In the initial stage of vacuuming, the pressure in the pressure reducing tower is still relatively high, the internal material has not yet evaporated, and the gas generally does not contain material vapor. Directly passing the initially sucked gas through the pipe with the condensing device will undoubtedly consume more energy. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a vacuum tower vacuum pumping component, which can automatically switch pipelines according to the humidity of the extracted gas, and only passes through the pipeline with a condensing device when the humidity is higher than a set value, thereby effectively improving the vacuum pumping efficiency and reducing energy consumption.

[0007] In order to solve the above technical problems, the present invention is solved through the following technical solutions: a vacuum tower vacuum assembly, including an exhaust pipe connected to the vacuum tower vacuum port, the exhaust pipe including a diversion assembly, the diversion assembly including a first exhaust pipe and a second exhaust pipe in parallel, the first exhaust pipe and the second exhaust pipe are joined at both ends by a three-way pipe to respectively connect the vacuum port and the vacuum pump, a condensing device is arranged on the first exhaust pipe, an electromagnetic reversing valve is arranged between the first exhaust pipe and the second exhaust pipe, a humidity-sensitive resistor is arranged in the exhaust pipe close to the vacuum port, the electromagnetic reversing valve is electrically connected to the humidity-sensitive resistor, when the humidity-sensitive resistor encounters water vapor and the resistance decreases, the electromagnetic reversing valve switches to the vacuum port and is connected to the first exhaust pipe; when the humidity-sensitive resistor does not encounter water vapor, the resistance increases, and the electromagnetic reversing valve switches to the vacuum port and is connected to the second exhaust pipe. This vacuum tower vacuum assembly senses the humidity of the extracted gas through a humidity-sensitive resistor. When the vacuum pump is just turned on, the space inside the vacuum tower is large, and most of the extracted gas is air, which contains almost no water. At this time, the resistance of the humidity-sensitive resistor is high, and there is almost no current in the electromagnet in the electromagnetic reversing valve. At this time, the elastic force of the first spring connects the vacuum port with the second air extraction pipe, so that the air can be quickly discharged from the second air extraction pipe with smaller resistance. After a period of suction, the material and the water therein evaporate, and the resistance of the humidity-sensitive resistor decreases. The electromagnet in the electromagnetic reversing valve passes current. When the current reaches a certain value, the electromagnetic reversing valve automatically switches to the vacuum port to be connected to the first air extraction pipe. This vacuum tower vacuum assembly can quickly extract the air inside the vacuum tower at the beginning of vacuuming, shorten the vacuuming time, thereby effectively improving the vacuuming efficiency and reducing energy consumption.

[0008] In the above technical solution, preferably, a mounting cavity is extended from the side of the exhaust pipe close to the vacuum port, and a power supply and a humidity-sensitive resistor are arranged in the mounting cavity. This structure is convenient for the installation of the power supply and the humidity-sensitive resistor, and for the electrical connection between the humidity-sensitive resistor and the electromagnetic reversing valve.

[0009] In the above technical scheme, preferably, the electromagnetic reversing valve includes a valve housing, a slideway is arranged in the valve housing, a valve core is slidably arranged in the slideway, a first spring is arranged between one end of the valve core and an end face of the slideway, a first electromagnet is arranged at the other end of the valve core, and a second electromagnet is arranged on the end face of the slideway close to the first electromagnet, the first electromagnet and the second electromagnet repel each other after being energized, the first electromagnet, the second electromagnet, the humidity-sensitive resistor and a power supply are connected in series, a first flow channel and a second flow channel are radially arranged on the valve core, a first connecting port connected to the first exhaust pipe and a second connecting port connected to the second exhaust pipe are arranged on both sides of the valve housing, when the humidity-sensitive resistor encounters water vapor and its resistance decreases, the valve core is driven to the first flow channel by the repulsive force of the first electromagnet and the second electromagnet to connect the two first connecting ports, when the humidity-sensitive resistor does not encounter water vapor and its resistance increases, the valve core is driven to the second flow channel by the pulling force of the first spring to connect the two second connecting ports. The electromagnetic reversing valve has a simple structure and can conveniently control the reversing operation by the resistance value of the humidity sensitive resistor.

[0010] In the above technical solution, preferably, the valve housing is provided with a first air hole and a second air hole at both ends of the slideway, the first air hole is located near the first spring end, the second air hole is located near the second electromagnet end, the first connecting port on the air inlet side is connected to the first air hole through a pipe, and the second connecting port on the air outlet side is connected to the second air hole through a pipe, when the first flow channel connects the two first connecting ports, and the resistance in the first exhaust pipe is too large, the airflow pushes the valve core to move to the second flow channel to connect with the second connecting port. Since a condensing device is provided on the first exhaust pipe, during the long-term vacuuming and condensation process, part of the material will solidify in the pipe inside the condensing device, resulting in a lower and lower flow efficiency in the condensing device, or even blockage. If blockage occurs, on the one hand, the vacuum pump may be burned, and on the other hand, the low pressure state cannot be maintained continuously in the pressure reducing tower, resulting in production stagnation. When this structure is used and there is no blockage in the first exhaust pipe, the first air hole is connected to the second air hole, and the air pressure is basically the same, which will not affect the normal operation control of the valve core. When blockage occurs in the first exhaust pipe, the suction force of the vacuum pump will make the air pressure of the second connecting port on the exhaust side lower than the air pressure of the first connecting port on the intake side, thereby causing the valve core to move toward the second air hole side, so that the second flow channel is connected to the second connecting port, thereby avoiding burning of the vacuum pump and production stagnation.

[0011] In the above technical solution, preferably, a second spring is arranged between the second electromagnet and the end surface of the slideway, a movable rod is axially penetrated on the end surface of the valve housing, the outer end of the movable rod abuts against the touch switch, the touch switch is electrically connected to the alarm, and when the resistance in the first exhaust pipe is too large, the airflow pushes the valve core to move to the second flow channel and connects with the second connection port, the second electromagnet compresses the second spring to move, and the second electromagnet pushes the movable rod to squeeze the touch switch. The second spring does not affect the original movement of the valve core after being arranged, but the second electromagnet will also move at this time. After the second flow channel is connected with the second connection port due to the blockage of the first exhaust pipe, since the first electromagnet and the second electromagnet are still energized and have repulsive force at this time, the second electromagnet moves a greater distance to the second spring side to push the movable rod to squeeze the touch switch to turn on the alarm, prompting the staff that the first exhaust pipe is blocked, and taking necessary measures to treat the exhaust gas or prepare to clean the first exhaust pipe.

[0012] In the above technical solution, preferably, the outer wall of the valve core is sleeved with a plurality of sealing rings. The use of this structure improves the sealing performance between the valve core and the slideway.

[0013] In the above technical solution, preferably, the inner wall of the valve housing is provided with two groups of slots, the valve core is radially provided with a through hole, a third spring is provided in the through hole, and ball head limit blocks are provided at both ends of the third spring. When the first flow channel connects the two first connection ports, the two ends of the ball head limit block are inserted into one group of the slots, and when the second flow channel connects the two second connection ports, the two ends of the ball head limit block are inserted into the other group of the slots. The use of this structure allows the valve core to be limited to a certain extent when the first flow channel connects the two first connection ports or the second flow channel connects the two second connection ports, thereby preventing the valve core from shaking continuously.

[0014] In the above technical solution, preferably, a buffer tank is provided on the exhaust pipe between the diverter assembly and the vacuum pump. The buffer tank is provided to protect the vacuum pump and prevent liquid from entering the vacuum pump, and at the same time, it plays a role in stabilizing and buffering the airflow when switching the electromagnetic reversing valve.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the vacuum tower vacuum assembly senses the humidity of the extracted gas through a humidity-sensitive resistor. When the vacuum pump is just turned on, the space in the vacuum tower is large, and most of the extracted gas is air, which contains almost no water. At this time, the resistance of the humidity-sensitive resistor is high, and there is almost no current in the electromagnet in the electromagnetic reversing valve. At this time, the elastic force of the first spring connects the vacuum port with the second air extraction pipe, so that the air can be quickly discharged from the second air extraction pipe with smaller resistance; after a period of suction, the material and the water therein evaporate, and the resistance of the humidity-sensitive resistor decreases. The electromagnet in the electromagnetic reversing valve passes current. When the current reaches a certain value, the electromagnetic reversing valve automatically switches to the vacuum port to be connected with the first air extraction pipe. The vacuum tower vacuum assembly can quickly extract the air inside the vacuum tower at the beginning of vacuuming, shorten the vacuuming time, thereby effectively improving the vacuuming efficiency and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of Example 1 of the present invention.

[0017] Figure 2 It is a schematic diagram of a partially enlarged structure of Example 1 of the present invention.

[0018] Figure 3 It is a schematic diagram of the cross-sectional structure of the electromagnetic reversing valve in Example 1 of the present invention.

[0019] Figure 4 It is a schematic diagram of the partial cross-sectional structure of the electromagnetic reversing valve in Example 1 of the present invention.

[0020] Figure 5 It is a schematic diagram of a partially enlarged structure of Example 2 of the present invention.

[0021] Figure 6 It is a schematic diagram of the cross-sectional structure of the electromagnetic reversing valve in Example 2 of the present invention.

[0022] Figure 7 for Figure 6 A partial enlarged view of . DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Figures 1 to 4A vacuum tower vacuum assembly comprises an exhaust pipe connected to a vacuum outlet of the vacuum tower, the exhaust pipe comprises a flow dividing assembly 1, the flow dividing assembly 1 comprises a first exhaust pipe 2 and a second exhaust pipe 3 connected in parallel, the first exhaust pipe 2 and the second exhaust pipe 3 are joined at both ends by a three-way pipe 4 and are respectively connected to the vacuum outlet and a vacuum pump (not shown in the figure), a condensing device 5 is arranged on the first exhaust pipe 2, the condensing device 5 is not limited in type, and various condensers 5 can be arranged for different condensation purposes, an electromagnetic reversing valve 6 is arranged between the first exhaust pipe 2 and the second exhaust pipe 3, a humidity-sensitive resistor (not shown in the figure) is arranged in the exhaust pipe close to the vacuum outlet, the electromagnetic reversing valve 6 is electrically connected to the humidity-sensitive resistor, when the humidity-sensitive resistor encounters water vapor, the resistance decreases, the electromagnetic reversing valve 6 switches to the vacuum outlet and is connected to the first exhaust pipe 2; when the humidity-sensitive resistor does not encounter water vapor, the resistance increases, and the electromagnetic reversing valve 6 switches to the vacuum outlet and is connected to the second exhaust pipe 3. The type of the electromagnetic reversing valve 6 is also not limited. The electromagnetic reversing valve 6 in the prior art can also achieve the purpose of the present invention as long as it can switch the path after power is turned on and reset and switch to another path after power is turned off. This vacuum tower vacuuming component senses the humidity of the extracted gas through a hygrometer. When the vacuum pump is just turned on, the space in the vacuum tower is large, and most of the extracted gas is air, which contains almost no water. At this time, the resistance of the hygrometer is high, and there is almost no current in the electromagnet in the electromagnetic reversing valve 6. At this time, the vacuum port is connected to the second air extraction pipe 3 by the elastic force of the first spring, so that the air can be quickly discharged from the second air extraction pipe 3 with less resistance; after a period of suction, the material and the water therein evaporate, and the resistance of the hygrometer is reduced. The electromagnet in the electromagnetic reversing valve 6 passes the current. When the current reaches a certain value, the electromagnetic reversing valve 6 automatically switches to the vacuum port and is connected to the first air extraction pipe 2. This vacuum tower vacuuming component can quickly extract the air inside the vacuum tower at the beginning of vacuuming, shorten the vacuuming time, thereby effectively improving the vacuuming efficiency and reducing energy consumption.

[0024] In this embodiment, a mounting cavity 7 is extended from the side of the exhaust pipe near the vacuum port, and a power supply and a humidity-sensitive resistor are arranged in the mounting cavity 7. The mounting cavity 7 is sealed after the power supply and the humidity-sensitive resistor are installed. This structure facilitates the installation of the power supply and the humidity-sensitive resistor, and facilitates the electrical connection between the humidity-sensitive resistor and the electromagnetic reversing valve 6.

[0025] In this embodiment, the electromagnetic reversing valve 6 includes a valve housing 8, a slideway is arranged in the valve housing 8, a valve core 9 is slidably arranged in the slideway, a first spring 10 is arranged between one end of the valve core 9 and the end surface of the slideway, a first electromagnet 11 is arranged at the other end of the valve core 9, and a second electromagnet 12 is arranged on the end surface of the slideway close to the first electromagnet 11. The first electromagnet 11 and the second electromagnet 12 repel each other after being energized. The first electromagnet 11, the second electromagnet 12, and the humidity-sensitive resistor are connected in series with the power supply, and the valve core 9 is radially provided with a first The flow channel 13 and the second flow channel 14, the valve housing 8 is provided with a first connection port 15 communicating with the first exhaust pipe 2 and a second connection port 16 communicating with the second exhaust pipe 3 on both sides. When the humidity resistor meets water vapor, the resistance decreases, and the valve core 9 is driven to the first flow channel 13 by the repulsive force of the first electromagnet 11 and the second electromagnet 12 to connect the two first connection ports 15. When the humidity resistor does not meet water vapor, the resistance value increases, and the valve core 9 is driven to the second flow channel 14 by the pulling force of the first spring 10 to connect the two second connection ports 16. This electromagnetic reversing valve 6 has a simple structure and can conveniently realize the reversing operation controlled by the resistance value of the humidity resistor.

[0026] In this embodiment, a plurality of sealing rings 17 are sleeved on the outer wall of the valve core 9. This structure improves the sealing performance between the valve core 9 and the slideway.

[0027] In this embodiment, two groups of slots 18 are provided on the inner wall of the valve housing 8, a through hole is radially provided on the valve core 9, a third spring 19 is provided in the through hole, and ball stop blocks 20 are provided at both ends of the third spring 19. When the first flow channel 13 connects the two first connection ports 15, the two ends of the ball stop block 20 are inserted into one group of slots 18, and when the second flow channel 14 connects the two second connection ports 16, the two ends of the ball stop block 20 are inserted into the other group of slots 18. With this structure, the valve core 9 can be limited to a certain extent when the first flow channel 13 connects the two first connection ports 15 or the second flow channel 14 connects the two second connection ports 16, so as to prevent the valve core 9 from shaking continuously.

[0028] In this embodiment, a buffer tank 21 is provided on the exhaust pipe between the flow dividing assembly 1 and the vacuum pump. The buffer tank 21 is provided to protect the vacuum pump and prevent liquid from entering the vacuum pump, and at the same time, it plays a role in stabilizing and buffering the airflow when switching the electromagnetic reversing valve 6.

[0029] See also Figures 5 to 7, Embodiment 2, Embodiment 2 differs from Embodiment 1 only in the structure of the electromagnetic reversing valve 6. In Embodiment 2, the valve housing 8 is provided with a first air hole 22 and a second air hole 23 at both ends of the slideway, the first air hole 22 is located near the end of the first spring 10, and the second air hole 23 is located near the end of the second electromagnet 12. The first connecting port 15 on the air inlet side is connected to the first air hole 22 through a pipeline, and the second connecting port 16 on the air outlet side is connected to the second air hole 23 through a pipeline. When the first flow channel 13 connects the two first connecting ports 15, and the resistance in the first exhaust pipe 2 is too large, the air flow pushes the valve core 9 to move to the second flow channel 14 and connect with the second connecting port 16. Since the first exhaust pipe 2 is provided with a condensing device 5, and in the long-term vacuuming and condensing process, part of the material will solidify in the pipeline inside the condensing device 5, resulting in a lower and lower circulation efficiency in the condensing device 5, or even a blockage. If a blockage occurs, on the one hand, the vacuum pump may be burned, and on the other hand, the vacuum tower may not be able to maintain a low pressure state continuously, resulting in production stagnation. When this structure is used and there is no blockage in the first exhaust pipe 2, the first air hole 22 is connected to the second air hole 23, and the air pressure is basically the same, which will not affect the normal operation control of the valve core 9. When blockage occurs in the first exhaust pipe 2, the suction force of the vacuum pump will make the air pressure of the second connecting port 16 on the exhaust side lower than the air pressure of the first connecting port 15 on the intake side, so that the valve core 9 moves toward the second air hole 23, and the second flow channel 14 is connected to the second connecting port 16, thereby avoiding the burning of the vacuum pump and production stagnation.

[0030] In this embodiment, a second spring 24 is arranged between the second electromagnet 12 and the end surface of the slideway, and a movable rod 25 is axially penetrated on the end surface of the valve housing 8, and the outer end of the movable rod 25 abuts against the touch switch 26, and the touch switch 26 is electrically connected to the alarm (not shown in the figure). When the resistance in the first exhaust pipe 2 is too large, the airflow pushes the valve core 9 to move to the second flow channel 14 and communicates with the second connecting port 16, and the second electromagnet 12 compresses the second spring 24 to move, and the second electromagnet 12 pushes the movable rod 25 to squeeze the touch switch 26. After the second spring 24 is arranged, it does not affect the original movement of the valve core 9, but the second electromagnet 12 will also move at this time. Specifically, when the first electromagnet 11 and the second electromagnet 12 are energized and mutually repel each other, the first electromagnet 11 and the second electromagnet 12 move in opposite directions, and when the first electromagnet 11 and the second electromagnet 12 are not energized, the first electromagnet 11 and the second electromagnet 12 move toward each other until they are in contact. The only difference is that the equilibrium position of the valve core 9 is different, which does not affect the movement of the valve core 9 to perform basic switching operations.

[0031] If the first exhaust pipe 2 is blocked and the second flow channel 14 is connected to the second connecting port 16, the first electromagnet 11 and the second electromagnet 12 are still energized and have repulsive force, so that the second electromagnet 12 moves a greater distance toward the second spring 24 to push the movable rod 25 to squeeze the touch switch 26 to turn on the alarm, prompting the staff that the first exhaust pipe 2 is blocked, and take necessary measures to treat the exhaust gas or prepare to clean the first exhaust pipe 2.

[0032] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A vacuum tower vacuum pumping assembly, comprising a vacuum pumping pipe connected to a vacuum pumping port of the vacuum tower, characterized in that: The exhaust pipe comprises a flow dividing component (1), the flow dividing component (1) comprises a first exhaust pipe (2) and a second exhaust pipe (3) connected in parallel, the first exhaust pipe (2) and the second exhaust pipe (3) are joined at both ends by a three-way pipe (4) and are respectively connected to the vacuum port and the vacuum pump, the first exhaust pipe (2) is provided with a condensing device (5), an electromagnetic reversing valve (6) is provided between the first exhaust pipe (2) and the second exhaust pipe (3), a humidity sensitive resistor is provided in the exhaust pipe close to the vacuum port, the electromagnetic reversing valve (6) is electrically connected to the humidity sensitive resistor, when the humidity sensitive resistor encounters water vapor and its resistance decreases, the electromagnetic reversing valve (6) switches to the vacuum port and is connected to the first exhaust pipe (2); when the humidity sensitive resistor does not encounter water vapor and its resistance increases, the electromagnetic reversing valve (6) switches to the vacuum port and is connected to the second exhaust pipe (3).

2. A vacuum tower vacuum pumping assembly as claimed in claim 1, characterized in that: An installation cavity (7) is extended and arranged on the side surface of the exhaust pipe close to the vacuum outlet, and a power supply and a humidity-sensitive resistor are arranged in the installation cavity (7).

3. A vacuum tower vacuum pumping assembly as claimed in claim 1, characterized in that: The electromagnetic reversing valve (6) comprises a valve housing (8), a slideway is arranged in the valve housing (8), a valve core (9) is slidably arranged in the slideway, a first spring (10) is arranged between one end of the valve core (9) and an end surface of the slideway, a first electromagnet (11) is arranged at the other end of the valve core (9), a second electromagnet (12) is arranged on the end surface of the slideway close to the first electromagnet (11), the first electromagnet (11) and the second electromagnet (12) repel each other when energized, the first electromagnet (11), the second electromagnet (12) and the humidity-sensitive resistor are connected in series with a power source, and a first flow channel (10) is radially arranged on the valve core (9). 3) and a second flow channel (14), a first connection port (15) communicating with the first exhaust pipe (2) and a second connection port (16) communicating with the second exhaust pipe (3) are provided on both sides of the valve housing (8); when the humidity-sensitive resistor encounters water vapor and its resistance decreases, the valve core (9) is driven to the first flow channel (13) by the repulsive force of the first electromagnet (11) and the second electromagnet (12) to connect the two first connection ports (15); when the humidity-sensitive resistor does not encounter water vapor and its resistance increases, the valve core (9) is driven to the second flow channel (14) by the pulling force of the first spring (10) to connect the two second connection ports (16).

4. A vacuum tower vacuum pumping assembly as claimed in claim 3, characterized in that: The valve housing (8) is provided with a first air hole (22) and a second air hole (23) at both ends of the slideway, respectively; the first air hole (22) is located near the end of the first spring (10), and the second air hole (23) is located near the end of the second electromagnet (12); the first connecting port (15) on the air inlet side is connected to the first air hole (22) through a pipeline, and the second connecting port (16) on the air outlet side is connected to the second air hole (23) through a pipeline; when the first flow channel (13) connects the two first connecting ports (15) and the resistance in the first exhaust pipe (2) is too large, the airflow pushes the valve core (9) to move to the second flow channel (14) to connect with the second connecting port (16).

5. A vacuum tower vacuum pumping assembly as claimed in claim 4, characterized in that: A second spring (24) is arranged between the second electromagnet (12) and the end surface of the slideway, and a movable rod (25) is axially penetrated on the end surface of the valve housing (8), and the outer end of the movable rod (25) abuts against a touch switch (26), and the touch switch (26) is electrically connected to an alarm. When the resistance in the first exhaust pipe (2) is too large, the airflow pushes the valve core (9) to move to the second flow channel (14) to communicate with the second connecting port (16), and the second electromagnet (12) compresses the second spring (24) to move, and the second electromagnet (12) pushes the movable rod (25) to squeeze the touch switch (26).

6. A vacuum tower vacuum pumping assembly as claimed in claim 3, characterized in that: The outer wall of the valve core (9) is sleeved with a plurality of sealing rings (17).

7. A vacuum tower vacuum pumping assembly as claimed in claim 3, characterized in that: The inner wall of the valve housing (8) is provided with two groups of slots (18), the valve core (9) is radially provided with a through hole, a third spring (19) is provided in the through hole, and ball head limit blocks (20) are provided at both ends of the third spring (19). When the first flow channel (13) connects the two first connection ports (15), the two ends of the ball head limit block (20) are inserted into one group of the slots (18), and when the second flow channel (14) connects the two second connection ports (16), the two ends of the ball head limit block (20) are inserted into the other group of the slots (18).

8. A vacuum tower vacuum pumping assembly as claimed in claim 1, characterized in that: A buffer tank (21) is provided on the exhaust pipe between the flow diversion component (1) and the vacuum pump.

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