Energy-saving air-cooled Roots water ring vacuum pump unit

Abstract

The invention provides an energy-saving air-cooled Roots water ring vacuum pump unit, which belongs to the technical field of Roots vacuum pumps, and comprises an air-cooled Roots pump, a water ring vacuum pump, a gas-liquid separator, a cold air return pipe, a control unit, a box body, a separation drainage assembly and a linkage flow control assembly, the separation and drainage assembly realizes automatic drainage of condensate through accumulated liquid gravity of a temporary storage box, and equipment safety, energy conservation and consumption reduction are balanced based on dynamic regulation and control of actual requirements; when the temporary storage box is reset, the separation drainage assembly generates impact force to shake off residual liquid drops on the pipe wall, it is ensured that the heat exchange surface is always in efficient contact with gas, condensation is more sufficient, the action frequency of the separation drainage assembly is affected, and forward circulation is formed; the special step-shaped structure of the flow guide cover comprehensively utilizes inertia, gravity and flow direction control, the gas-liquid separation efficiency is improved, it is ensured that dry gas enters the water ring pump, the operation stability of the whole unit is jointly improved, and the service life of the whole unit is jointly prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Roots vacuum pump, in particular to an energy-saving air-cooled Roots water ring vacuum pump unit. BACKGROUND

[0002] In the industrial fields of electric power, chemical industry, pharmaceutical industry, etc., the Roots water ring vacuum pump unit is the core equipment for obtaining and maintaining process vacuum. The traditional unit is usually composed of a Roots pump as the main pump and a water ring pump as the front-stage pump connected in series. In order to improve energy efficiency, an air-cooled Roots pump is introduced in the prior art, which allows the pump to work stably at a higher pressure difference by returning part of the cooled gas to the pump cavity to take away the compression heat.

[0003] However, the applicant found that the existing air-cooled Roots water ring vacuum pump unit still has several structural defects to be solved in actual operation. Firstly, the inter-stage condenser arranged in the unit is used to cool the high-temperature gas discharged by the Roots pump and condense the condensable steam (mainly water vapor) therein. However, when the load is high or the humid gas is processed, the amount of condensate generated is large. If the condensate cannot be timely and automatically discharged, the liquid accumulation will occupy the flow passage space, increase the air flow resistance, and even be carried into the water ring pump by the high-speed airflow, greatly increasing the load of the water ring pump and causing the power consumption to rise and the vacuum degree to drop. In addition, the cold gas return pipe of the air-cooled Roots pump is usually designed with a fixed opening. This design cannot adaptively adjust the cooling gas flow according to the real-time working load of the unit (mainly reflected in the exhaust temperature and pressure). When the load is low, the excessive cooling gas is not only useless but also increases the pumping load of the front-stage pump, causing energy waste. When the load is high, the fixed cooling gas flow may be insufficient, causing poor cooling of the Roots pump and the risk of overheating. The solution to the above problems often relies on regular manual inspection and operation, such as discharging condensate and manually adjusting the valve, which not only increases the operation and maintenance cost but also cannot achieve timely response, affecting the stable and efficient automatic operation of the unit.

[0004] How to invent an energy-saving air-cooled Roots water ring vacuum pump unit to solve these problems has become a problem to be solved by those skilled in the art. SUMMARY

[0005] In order to make up for the above shortcomings, the present application provides an energy-saving air-cooled Roots water ring vacuum pump unit, which aims to solve the problems mentioned in the above background.

[0006] The present application is implemented as follows:

[0007] The application provides an energy-saving air-cooled Roots water ring vacuum pump unit, which comprises an air-cooled Roots pump, a water ring vacuum pump, a gas-liquid separator, a cold air return pipe, a control unit and a box body, a guide inlet, a guide outlet and a return port are arranged on the air-cooled Roots pump, a connecting pipe is connected to the lower end of the guide outlet, the box body is arranged at the middle part of the connecting pipe, the inner cavity of the connecting pipe below the box body is communicated with the corresponding return port through the cold air return pipe, a plurality of heat exchange coils are arranged in the box body, and the unit further comprises:

[0008] A separation and drainage assembly is arranged in the inside and lower side of the box body.

[0009] A linkage flow control assembly is arranged between the cold air return pipe and the box body.

[0010] Preferably, the lower end of the connecting pipe is connected to the air inlet end of the water ring vacuum pump, the liquid outlet of the gas-liquid separator is communicated with the working liquid inlet of the water ring vacuum pump through a liquid supplement pipe, a heat exchanger is arranged on the liquid supplement pipe, and the outlet of the water ring vacuum pump is directly connected to the air inlet of the gas-liquid separator through a pipeline.

[0011] Preferably, pressure sensors are arranged on the exhaust pipeline of the air-cooled Roots pump and the air inlet pipeline of the water ring vacuum pump, the control unit is electrically connected with the pressure sensors, the driving motor of the air-cooled Roots pump and the driving motor of the water ring vacuum pump, and the control unit is configured to control the start-stop sequence and operation of the air-cooled Roots pump and the water ring vacuum pump according to the pressure signals detected by the pressure sensors.

[0012] Preferably, the cooling medium outlet and inlet of the heat exchange coil are respectively connected with an external cooling medium supply system.

[0013] Preferably, the separation and drainage assembly comprises a temporary storage box, a flow guide cover, a water storage box and a fixing rod, the water storage box is fixed at the bottom of the box body, a drainage pipe is arranged on the bottom wall of the water storage box, the flow guide cover is fixedly arranged on the inner cavity bottom wall of the box body, the temporary storage box is slidably arranged in the inside of the box body and located at the lower side of the heat exchange coil, a connecting part is fixedly connected to the bottom of the temporary storage box, a through hole matched with the connecting part is formed in the bottom wall of the box body, a drainage channel is formed in the upper part of the connecting part, a movable cavity is formed in the lower part of the connecting part, the top end of the drainage channel is communicated with the inner cavity of the temporary storage box, the bottom of the drainage channel is annularly provided with a plurality of drainage grooves, the fixing rod is fixedly arranged on the inner cavity bottom wall of the water storage box, the top end of the fixing rod extends into the movable cavity and is slidably connected with the movable cavity, a contact switch is arranged on the inner cavity top of the movable cavity, the lower end of the connecting part is magnetically arranged, and a magnet is fixedly arranged on the inner cavity bottom wall of the water storage box corresponding to the connecting part.

[0014] Preferably, the electromagnet is electrically connected with the contact switch, the electromagnet has the same magnetism as the opposite surface of the connecting part when the electromagnet is electrified, and the electromagnet 86 is coaxially arranged with the connecting part 82.

[0015] Preferably, the flow guide hood is composed of a centrally-located air passage part and a drainage part fixedly connected to the periphery of the air passage part, the flow guide hood is arranged in an umbrella shape, a plurality of air guide holes are formed in the air passage part, a limiting piece is slidably connected to the top of the air passage part, the limiting piece and the air passage part are elastically connected through a spring one, the end of the limiting piece located above the air passage part is fixedly connected with a connecting plate, the bottom of the connecting plate is fixedly connected with a connecting column, and the lower end of the connecting column is fixedly connected with the bottom wall of the inner cavity of the temporary storage box.

[0016] Preferably, the top of the temporary storage box is arranged in an open manner, the middle part of the temporary storage box is provided with a channel matched with the flow guide hood, the cross-sectional height of the air passage part and the drainage part is arranged in a stepped manner, the top of the connecting plate in the initial state of the spring one is in contact with the surface of the heat exchange coil, and at this time, the drainage groove is completely blocked, when the connecting plate is in contact with the top of the air passage part, the contact switch is in contact with the top of the fixed rod, and at this time, the drainage groove is not blocked.

[0017] Preferably, the linkage flow control assembly comprises an L-shaped plate fixedly connected to the outer sidewall of the connecting part, a limiting cylinder, a piston and a limiting rod arranged in the cold air return pipe, wherein the limiting cylinder is fixedly installed in the inner cavity of the cold air return pipe, the piston is slidably connected between the limiting cylinder, the inner cavity of the cold air return pipe and the limiting rod, the piston and the limiting cylinder are elastically connected through a spring two, the middle part of the piston is formed with a gas guide channel, the water storage box and the cold air return pipe are provided with a channel through which the L-shaped plate passes, the sidewall of the L-shaped plate located in the cold air return pipe is fixedly connected with a rack, the limiting rod is rotatably installed in the cold air return pipe, the limiting rod is fixedly connected with a poking piece, the middle part of the limiting rod is fixedly connected with a gear engaged with the rack, the rod part of the piston is annularly formed with a plurality of flow expansion grooves, and the inner side of the limiting cylinder away from the L-shaped plate is formed with a flow-through part.

[0018] Preferably, the end of the poking piece is always in contact with the sidewall of the piston, the flow expansion grooves in the initial state of the spring two are in a blocked state, there is a gap between the flow-through part and the rod part of the piston, and when the contact switch is in contact with the fixed rod, the flow expansion grooves are in the flow-through part.

[0019] The beneficial effects of the present application are:

[0020] The separated drainage assembly takes the accumulated liquid of the temporary storage box as a driving signal by gravity, realizes automatic and intermittent discharge of the condensed liquid, directly avoids the obstruction of the accumulated liquid to the airflow channel and the liquid strike risk to the water ring pump, guarantees continuous and efficient operation of the system, and the drainage action is not an isolated event. The triggering frequency thereof is used as a key control signal by the linkage flow control assembly. The more frequent the drainage is, the higher the system thermal load is, and the linkage flow control assembly responsively increases the cooling air flow. This dynamic regulation based on actual demand fundamentally eliminates energy waste. In high load, the assembly can keep the piston at a maximum opening position, stably maintains large flow cooling, and provides reliable protection for the Roots pump. In low load, the assembly can automatically reset to a minimum flow state, significantly reduces the load and energy consumption of the front-stage pump. This on-demand cooling mode balances the two core requirements of equipment safety and energy saving and consumption reduction.

[0021] When the separated drainage assembly resets, the connecting plate mechanically impacts the heat exchange coil, generates an impact force to shake off the residual liquid drops on the pipe wall, effectively destroys the thermal resistance layer attached to the surface of the heat exchange coil, and ensures that the heat exchange surface is always in efficient contact with the gas. This not only directly improves the heat exchange efficiency of the inter-stage condenser, but also makes the condensation more sufficient, thereby affecting the action frequency of the separated drainage assembly itself, forming a positive cycle that is conducive to improving the overall energy efficiency. The special stepped structure of the flow guide cover comprehensively utilizes inertia, gravity, and flow direction control to achieve a very high gas-liquid separation efficiency, ensures that dry gas enters the water ring pump, and reduces the load of the water ring pump from the source, thereby improving the operation stability and service life of the entire unit. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0023] Figure 1 is a schematic diagram of the overall structure of the present application;

[0024] Figure 2 is a schematic diagram of the front view of the overall structure of the present application;

[0025] Figure 3 is a schematic diagram of the box and air-cooled Roots pump structure of the present application;

[0026] Figure 4 is a schematic diagram of the cross-sectional structure of the box of the present application;

[0027] Figure 5 is a schematic diagram of the Figure 4 enlarged structure at A of the present application

[0028] Figure 6 is the schematic diagram of the amplification structure in the embodiment of the application Figure 4 is the schematic diagram of the amplification structure in the embodiment of the application

[0029] Figure 7 is the schematic diagram of the distribution structure of the limiting cylinder and the piston in the embodiment of the application

[0030] Figure 8 is the schematic diagram of the internal structure of the box in the embodiment of the application

[0031] Figure 9 is the schematic diagram of the structure of the connecting plate and the connecting column in the embodiment of the application

[0032] Figure 10 is the schematic diagram of the structure of the multi-stage Roots pump in the embodiment of the application

[0033] In the figure: 1, air-cooled Roots pump; 2, connecting pipe; 3, water ring vacuum pump; 4, gas-liquid separator; 5, cold air return pipe; 6, box; 7, flow guide cover; 8, water storage box; 9, limiting cylinder; 10, multi-stage Roots pump; 11, inlet; 12, outlet; 13, return port; 61, heat exchange coil; 62, temporary storage box; 71, air passage; 72, drainage guide; 73, connecting plate; 74, limiting member; 75, spring one; 76, connecting column; 80, drain pipe; 81, fixed rod; 82, connecting part; 83, drainage channel; 84, movable cavity; 85, L-shaped plate; 86, electromagnet; 87, limiting rod; 90, through-flow part; 91, piston; 92, spring two; 711, air guide hole; 831, drainage groove; 841, contact switch; 851, rack; 852, gear; 871, actuating member; 911, flow expansion groove; 912, air guide channel. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0035] Example one, with reference to Figures 1-9The utility model provides an energy-saving air-cooled roots water ring vacuum pump unit, which comprises an air-cooled roots pump 1, a water ring vacuum pump 3, a gas-liquid separator 4, a cold gas backflow pipe 5, a control unit and a box body 6, the air-cooled roots pump 1 is provided with a guide inlet 11, a guide outlet 12 and a backflow port 13, which are communicated with the cavity of the air-cooled roots pump 1 respectively, the lower end of the guide outlet 12 is connected with a connecting pipe 2, the box body 6 is arranged at the middle part of the connecting pipe 2, the inner cavity of the connecting pipe 2 below the box body 6 is communicated with the corresponding backflow port 13 through the cold gas backflow pipe 5, a plurality of heat exchange coils 61 are arranged in the box body 6, and the utility model further comprises:

[0036] The separation and drainage assembly is arranged in the inside and the lower side of the box body 6.

[0037] The linkage flow control assembly is arranged between the cold gas backflow pipe 5 and the box body 6.

[0038] Further, the lower end of the connecting pipe 2 is connected with the gas inlet end of the water ring vacuum pump 3, the liquid outlet of the gas-liquid separator 4 is communicated with the working liquid inlet of the water ring vacuum pump 3 through a liquid supplementing pipe, a heat exchanger (not shown in the figure) is arranged on the liquid supplementing pipe, the purpose is to realize the recycling and continuous cooling of the working liquid (usually water), the working performance of the water ring pump is extremely dependent on the temperature and cleanliness of the working liquid, this design can maintain the working liquid in a low-temperature and stable state, and is the key to guaranteeing the high-efficiency and stable operation of the water ring pump, the outlet of the water ring vacuum pump 3 is directly connected to the gas inlet of the gas-liquid separator 4 through a pipeline, and the gas-liquid mixture discharged from the water ring pump can be properly handled, the design ensures that the working liquid can be effectively separated and recovered, and the clean gas can be discharged into the atmosphere, thereby avoiding the waste of the working liquid and the pollution to the environment; the cooling medium outlet and the inlet of the heat exchange coil 61 are connected with an external cooling medium supply system respectively, so as to provide an independent, controllable and efficient cold source for inter-stage cooling, which makes the cooling process of the gas discharged from the roots pump not be disturbed by other factors, the cooling power can be flexibly adjusted according to the requirement, and the best condensation and cooling effect is ensured.

[0039] In the embodiment, the air-cooled roots pump 1 provides a large pumping speed under high vacuum, the water ring vacuum pump 3 provides a front-stage vacuum for the air-cooled roots pump 1 and finally discharges gas, the connecting pipe 2 connects the two, and constitutes the main gas flow channel of the unit, the gas to be pumped enters the air-cooled roots pump 1 from the guide inlet 11, is compressed and discharged from the guide outlet 12, enters the box body 6 through the connecting pipe 2 for cooling, and then enters the water ring vacuum pump 3 for further compression, and finally is discharged into the gas-liquid separator 4 together with the working liquid for gas-liquid separation, the gas is discharged, and the liquid is recycled.

[0040] The pumped medium is first sucked in from the inlet by the air-cooled Roots pump 1, which quickly transfers a large amount of gas at a huge volumetric pumping speed at low pressure, preliminarily compresses the gas, and then the preliminarily compressed gas enters the box 6 through the connecting pipe 2, where the gas exchanges heat with the heat exchange coil 61, the temperature of the gas is significantly reduced, and most of the condensable vapor such as water vapor contained in the gas is condensed into liquid, and then the cooled and dried gas enters the water ring vacuum pump 3, which further compresses the gas by using the water ring formed by the rotating impeller to increase the pressure of the gas to slightly higher than atmospheric pressure, and the gas-liquid mixture discharged from the water ring pump enters the gas-liquid separator 4, where the liquid working fluid and the gas are separated by using the principles of gravity settling, centrifugal separation or impingement, the separated liquid working fluid flows into the bottom of the separator, is transported through the liquid supplement pipeline, and its heat of compression is taken away when flowing through the heat exchanger in the pipeline, and the cooled working fluid is finally pumped into the inlet of the water ring pump 3 to complete a cycle, and the separated gas is discharged from the top of the gas-liquid separator 4 to the atmosphere.

[0041] By connecting the air-cooled Roots pump 1 and the water ring vacuum pump 3 in series, the high pumping speed of the former at high vacuum and the advantage of the latter that can be directly discharged to the atmosphere are combined, so that the entire unit can obtain a higher ultimate vacuum and maintain a large effective pumping speed in a wide pressure range; the closed circulation and cooling design of the working fluid avoid the continuous consumption of fresh water source, and at the same time, the heat exchanger is used to maintain the low temperature of the working fluid, which greatly improves the volumetric efficiency and pumping performance of the water ring pump, thereby reducing the operating power consumption; the inter-stage cooling (the box 6 and the heat exchange coil 61) reduces the gas load and temperature entering the water ring pump, and the gas-liquid separation ensures the cleanliness and circulation of the working fluid, which reduces the risk of cavitation, scaling and overload of the water ring pump, and ensures the stability of long-term operation of the unit.

[0042] A pressure sensor is arranged on the exhaust pipe of the air-cooled Roots pump 1 and the inlet pipe of the water ring vacuum pump 3; the control unit is electrically connected with the pressure sensor, the drive motor of the air-cooled Roots pump 1 and the drive motor of the water ring vacuum pump 3; the control unit is configured to control the start-stop sequence and operation of the air-cooled Roots pump 1 and the water ring vacuum pump 3 according to the pressure signal detected by the pressure sensor.

[0043] In this embodiment, after the control system receives the start instruction, the water ring vacuum pump 3 is first started, and the water ring vacuum pump 3 starts to pump the entire rear pipeline including the connecting pipe 2, the box 6 and the pump cavity of the air-cooled Roots pump 1, the control unit continuously reads the pressure sensor data installed on the inlet pipe of the water ring vacuum pump 3, and when the pressure at this position (i.e. the front stage pressure of the Roots pump) is reduced to a preset safety threshold, the control unit determines that the front stage vacuum has been established and the Roots pump start condition is met; the control unit then sends a start instruction to the drive motor of the air-cooled Roots pump 1, and thus the unit enters a double-pump series full-speed running state.

[0044] During operation, the control unit continuously compares the pressure values at the inlet and outlet of the gas-cooled Roots pump 1, calculates the working pressure difference in real time, and stops the gas-cooled Roots pump 1 as soon as the pressure difference exceeds the maximum allowable value to prevent equipment damage, while the water ring vacuum pump 3 continues to operate to reduce the front-stage pressure. When the system vacuum reaches the required level and enters the maintenance stage, the required pumping capacity is small, and the control unit can determine this working condition based on the pressure signal and execute an energy-saving program: for example, the gas-cooled Roots pump 1 is temporarily stopped, and the vacuum is maintained by the water ring pump 3 alone. If the system pressure rises to a certain set value due to a small leak, the gas-cooled Roots pump 1 is automatically started again, stopped after quickly pumping to the target vacuum, and the cycle is repeated to achieve intermittent operation, thereby achieving significant energy savings.

[0045] Upon receiving a shutdown command, the control unit can be set to first stop the gas-cooled Roots pump 1 and then stop the water ring vacuum pump 3 after a delay to ensure that the gas in the Roots pump is fully evacuated and to allow it to shut down in a state close to the equilibrium pressure, which is beneficial for the next start-up.

[0046] Through mandatory sequential start-up and real-time pressure difference monitoring, the working conditions of the Roots pump starting and running under high back pressure are fundamentally eliminated, effectively avoiding damage to its core components (rotor, bearing, and seal), greatly extending the service life of the equipment, and reducing maintenance costs. Intelligent start-stop and intermittent operation control based on actual vacuum requirements avoid the idling loss of the main pump under low load, and the energy-saving effect is extremely significant, especially in long-term vacuum maintenance processes.

[0047] Further, the separated drainage assembly includes a temporary storage box 62, a flow guide cover 7, a water storage box 8, and a fixing rod 81. The water storage box 8 is fixed at the bottom of the box body 6, the bottom wall of the water storage box 8 is provided with a drainage pipe 80, the flow guide cover 7 is fixedly installed on the inner cavity bottom wall of the box body 6, the temporary storage box 62 is slidably arranged in the inner part of the box body 6 and located at the lower side of the heat exchange coil 61, the bottom of the temporary storage box 62 is fixedly connected with a connecting part 82, the bottom wall of the box body 6 is provided with a through hole matched with the connecting part 82, the upper part of the connecting part 82 is provided with a drainage channel 83, the lower part of the connecting part 82 is provided with a movable cavity 84, the top end of the drainage channel 83 is communicated with the inner cavity of the temporary storage box 62, the bottom part of the drainage channel 83 is annularly provided with a plurality of drainage grooves 831, the fixing rod 81 is fixedly installed on the inner cavity bottom wall of the water storage box 8, the top end of the fixing rod 81 extends to the inside of the movable cavity 84 and is slidably connected therewith, a contact switch 841 is installed on the inner cavity top part of the movable cavity 84, the lower end of the connecting part 82 is magnetically arranged, and a electromagnet 86 is further fixedly installed on the inner cavity bottom wall of the water storage box 8 corresponding to the connecting part 82.

[0048] It should be noted that the electromagnetic iron 86 is electrically connected with the contact switch 841, when the contact switch 841 is triggered, the electromagnetic iron 86 is powered on, the electromagnetic iron 86 is powered on and the magnetic opposite surface of the connecting part 82 is the same, when the electromagnetic iron 86 is powered on, the magnetic repulsion between the electromagnetic iron 86 and the connecting part 82 is generated, so that the temporary storage box 62 is lifted, the electromagnetic iron 86 is coaxially arranged with the connecting part 82, and the magnetic force of the electromagnetic iron 86 when the electromagnetic iron 86 is powered on can act on the corresponding connecting part 82.

[0049] Further, the flow guide cover 7 is composed of a central ventilation part 71 and a drainage part 72 fixedly connected outside the ventilation part 71, the flow guide cover 7 is arranged in an umbrella shape, a plurality of air guide holes 711 are formed in the ventilation part 71, the top of the ventilation part 71 is slidingly connected with a limiting piece 74, the limiting piece 74 and the ventilation part 71 are elastically connected through a spring one 75, the end of the limiting piece 74 above the ventilation part 71 is fixedly connected with a connecting plate 73, the bottom of the connecting plate 73 is fixedly connected with a connecting column 76, the lower end of the connecting column 76 is fixedly connected with the inner cavity bottom wall of the temporary storage box 62, when the temporary storage box 62 moves, the connecting plate 73 and the limiting piece 74 are driven to move synchronously through the connecting column 76.

[0050] It should be noted that the top of the temporary storage box 62 is arranged in an open manner, which can effectively receive the water falling from the heat exchange coil 61, the middle part of the temporary storage box 62 is provided with a channel matched with the flow guide cover 7, so that the temporary storage box 62 can move normally and ensure sealing, the cross-sectional height of the ventilation part 71 and the drainage part 72 is arranged in a stepped manner, which can guide airflow and realize gas-liquid separation at the same time, the airflow enters below the flow guide cover 7 through the air guide holes 711 on the ventilation part 71, and the liquid slides along the drainage part 72 to the temporary storage box 62, the top of the connecting plate 73 in the initial state of the spring one 75 is in contact with the surface of the heat exchange coil 61, and the drainage groove 831 is completely blocked at this time, the contact switch 841 in contact with the top of the connecting plate 73 and the fixed rod 81 is in contact when the connecting plate 73 is in contact with the top of the ventilation part 71, and the drainage groove 831 is not blocked at this time.

[0051] In this embodiment, the separated drainage assembly of the present application aims to solve a long-standing technical problem in existing air-cooled Roots water ring vacuum pump units: how to automatically, efficiently and reliably drain the condensate generated by the inter-stage condenser while ensuring the sealing of the vacuum system; in traditional designs, if the condensate cannot be drained in time, it will accumulate in the flow passage, occupy the effective flow area, increase the system resistance, reduce the pumping efficiency, and more seriously, the liquid can be entrained by the high-speed airflow, forming liquid impact into the water ring pump, causing the load to increase dramatically, the power consumption to rise, and even the equipment to be damaged, while the present application replaces manual periodic drainage or simple float valve drainage, and through the ingenious combination of mechanics and electrical control, the automatic, intermittent and rapid drainage based on the accumulation of condensate is realized, which improves the automation level and reliability of the unit, and through the unique drainage groove 831 and the electromagnetic auxiliary system, the vacuum system is completely sealed during the non-drainage period to prevent external air from leaking in, and is quickly opened only during the drainage moment, effectively balancing the drainage efficiency and system sealing.

[0052] When the pump set is working, the preliminarily compressed gas enters the box 6 through the connecting pipe 2 and exchanges heat with the heat exchange coil 61, and the temperature is significantly reduced, and most of the condensable vapor such as water vapor is condensed into liquid, and the cooled and dried gas then enters the water ring vacuum pump 3 through the venting part 71.

[0053] The condensate drops from the surface of the heat exchange coil 61 and is effectively collected by the drainage part 72 of the umbrella-shaped flow guide cover 7, and the special stepped structure of the flow guide cover 7 efficiently realizes gas-liquid separation in this process, the gas continues to flow to the water ring vacuum pump 3 through the air guide hole 711 of the venting part 71, and the liquid slides along the drainage part 72 to the temporary storage box 62, and as the condensate continuously accumulates in the temporary storage box 62, its weight gradually increases, and the gravity is transmitted through the connecting column 76 and the connecting plate 73, and under the superposition of the gas flow force, the entire temporary storage box 62 is forced to overcome the pre-tightening force of the spring 75 and slowly move downward, when the liquid in the temporary storage box 62 reaches the preset weight (corresponding to a set liquid level height), the temporary storage box 62 is moved to the critical position, in this process, the drainage groove 831 is quickly moved out of the blocking area and is completely exposed, at this time, the outlet of the drainage channel 83 (i.e. the drainage groove 831) is opened, and the condensate in the temporary storage box 62 is quickly drained into the water storage box 8 below through the drainage channel 83 and the drainage groove 831 under the action of gravity and the pressure difference between the inside and outside of the box 6, and finally is drained out of the system through the drainage pipe 80.

[0054] In this process, the top end of the fixed rod 81 will contact the contact switch 841 at the top of the movable cavity 84, the contact switch 841 is triggered, sending an electrical signal that immediately energizes the electromagnet 86, the electromagnet 86 is energized, generating the same magnetic properties as the lower end of the magnetic connection part 82, according to the principle of same sex repulsion, a momentary upward magnetic repulsion is generated, at the same time, as the condensate is quickly discharged, the liquid level in the temporary storage box 62 rapidly decreases, its total weight significantly decreases, at this time, the restoring force of the compressed spring 75 begins to dominate, this repulsive force and the decreasing liquid weight work together, the restoring force of the compressed spring 75 rapidly pushes the entire temporary storage box 62 upward, accelerating its reset process, and making the drain groove 831 quickly escape from the exposed state, re-sealing the structure of the water storage box 8, the system returns to a sealed state, waiting for the next liquid accumulation cycle.

[0055] At the same time, at the end of the reset stroke of the temporary storage box 62, the top of the moving connecting plate 73 will have a slight mechanical impact with the bottom of the heat exchange coil 61, this design produces an impact force sufficient to shake off the residual droplets and water film attached to the outer wall of the heat exchange coil 61, thereby effectively destroying the thermal resistance layer affecting heat transfer, and removing the water bridge, so that the surface of the heat exchange coil 61 can always be in direct contact with the gas, maintaining high-efficiency condensation heat transfer efficiency.

[0056] It should be noted that the condensate dripping from the heat exchange coil 61 and the liquid droplets carried by the gas move downward under the action of their own gravity, at the same time, the gas flow carrying a small amount of liquid droplets hits the top conical surface of the flow guide cover 7 or the inclined surface of the flow guide part 72 at a certain speed, the liquid droplets, due to their large mass and inertia, cannot quickly change direction with the gas flow, and will directly hit the surface of the flow guide cover 7, after the impact, the liquid droplets lose kinetic energy and adhere to the cover wall under the action of surface tension and gravity, and gather into a liquid film, the gas, due to its small mass and small inertia, will quickly change direction after hitting the cover wall, and will find a flow channel along the cover wall.

[0057] The liquid film attached to the drainage part 72 flows downward along the inclined cover wall under the action of gravity, while the changed direction gas flows to the vent part 71 in the center of the flow guide cover 7 which is higher in terrain. The cross-sectional height of the vent part 71 and the drainage part 72 is arranged in a stepped manner, which means that the top of the vent part 71 forms a high ground relative to the drainage part 72. This step physically prevents the downward flowing liquid from being carried by the gas flow to the central vent part 71, ensuring that the liquid can only slide along the slope of the drainage part 72 and finally fall into the temporary storage box 62 at the edge. All the gas is forced to flow to the central highest point - the vent part 71, and then gather and pass through the gas guide hole 711 opened in it. The last part of the tiny liquid droplets that the gas may carry will collide and adsorb with the hole wall when passing through the gas guide hole 711, realizing the final fine separation. Then, the dry and clean gas enters the water ring vacuum pump 3, and the liquid gathered in the temporary storage box 62 is periodically discharged according to the above mechanism. The flow guide cover 7 utilizes inertia, gravity and flow control comprehensively, has high separation efficiency, and can effectively protect the water ring pump behind.

[0058] The embodiment realizes automatic discharge based on the load of the condensed liquid completely, without manual intervention, significantly reduces the operation and maintenance cost of the equipment, improves the intelligent level of the unit, and ingeniously uses the mechanical impact of the connecting plate 73 on the heat exchange coil 61 when the temporary storage box 62 is reset to generate impact force to shake off the residual liquid droplets and water film on the pipe wall. This passive design realizes a continuous self-cleaning process, effectively destroys the thermal resistance layer that hinders heat transfer, ensures that the surface of the heat exchange coil 61 is always in direct contact with the gas, and thus maintains a very high condensation heat exchange efficiency for a long time. The special stepped structure of the flow guide cover 7 comprehensively utilizes the three separation mechanisms of inertia collision, gravity sedimentation and flow control, realizes a very high gas-liquid separation efficiency, and the stepped design physically prevents the liquid from being carried by the gas flow, ensuring that the dry gas enters the water ring pump. By timely and automatically discharging the condensed liquid and realizing efficient gas-liquid separation, the occurrence of "liquid impact" phenomenon is fundamentally avoided, the water ring vacuum pump 3 is effectively protected, the load of the water ring vacuum pump 3 is prevented from increasing sharply, the power consumption is prevented from rising, and the equipment is prevented from being damaged, thereby prolonging the service life of the entire unit.

[0059] Embodiment two, refer to Figures 3-9The linkage flow control assembly comprises an L-shaped plate 85 fixedly connected to the outer sidewall of the connecting portion 82, a limiting cylinder 9, a piston 91 and a limiting rod 87 arranged in the cold gas return pipe 5. The limiting cylinder 9 is fixedly installed in the cold gas return pipe 5, the piston 91 is in sliding connection with the limiting cylinder 9 and the inner cavity of the cold gas return pipe 5, the piston 91 is elastically connected to the limiting cylinder 9 through a spring 92, the middle part of the piston 91 is formed with a gas guide channel 912, the water storage box 8 and the cold gas return pipe 5 are provided with passages through which the L-shaped plate 85 passes, the sidewall of the L-shaped plate 85 located in the cold gas return pipe 5 is fixedly connected with a rack 851, the limiting rod 87 is rotatably installed in the cold gas return pipe 5, the limiting rod 87 is fixedly connected with a driving member 871, the middle part of the limiting rod 87 is fixedly connected with a gear 852 engaged with the rack 851, the rod part of the piston 91 is annularly provided with a plurality of flow expansion grooves 911, and the inner side of the limiting cylinder 9 away from the L-shaped plate 85 is provided with a flow-through part 90. When the connecting portion 82 moves, the L-shaped plate 85 and the rack 851 move synchronously, after the rack 851 moves, the gear 852, the limiting rod 87 and the driving member 871 are driven to rotate around the limiting rod 87 through the engagement force, and then the driving member 871 drives the piston 91 to move, so as to change the air flow of the cold gas return pipe 5.

[0060] It should be noted that the end of the driving member 871 is always in contact with the sidewall of the piston 91, so that when the driving member 871 rotates, the piston 91 can be directly pushed to move, the flow expansion grooves 911 in the initial state of the spring 92 are in a blocked state, at this time, the airflow only passes through the gas guide channel 912, there is a gap between the flow-through part 90 and the rod part of the piston 91, and when the contact switch 841 is in contact with the fixed rod 81, the flow expansion grooves 911 are in the flow-through part 90, so that when the flow expansion grooves 911 are in the flow-through part 90, in addition to the gas guide channel 912, the airflow can also pass through the gap between the rod part of the piston 91 and the flow-through part 90.

[0061] In this embodiment, when the system is in a high load working condition, the outlet pressure of the gas-cooled Roots pump 1 increases. This pressure change means two possibilities: the Roots pump is compressing a larger amount of gas, or it is bearing a higher compression ratio. According to the principle of thermodynamics, a large amount of compression heat is generated in the gas compression process, and the increase of the outlet pressure directly leads to the sharp increase of the heat load of the Roots pump.

[0062] The high-temperature gas discharged from the Roots pump enters the heat exchange coil 61 of the box 6. The increase of the system heat load directly manifests as the increase of the heat exchange load, and the direct result is that more condensable vapor, mainly water vapor, is condensed into liquid. The generation rate and total amount of the condensate are significantly improved. The increased condensate is collected by the flow guide cover 7 and flows into the temporary storage box 62. As the condensate rapidly accumulates in the temporary storage box 62, its total weight rapidly reaches the preset critical value, forcing the temporary storage box 62 to move downward against the pre-tightening force of the spring 75. This movement drives the connecting part 82 and the L-shaped plate 85 and the rack 851 connected thereto to move downward synchronously.

[0063] When the temporary storage box 62 is moved to the critical position, the top end of the fixed rod 81 contacts and triggers the contact switch 841 in the movable cavity 84. The frequency of triggering the contact switch 841 indirectly but truly reflects the generation rate of the condensate, and the generation rate of the condensate is directly proportional to the heat load of the Roots pump, and the fundamental reason is the increase of the outlet pressure; the reciprocating motion of the rack 851 is converted into the rotary motion of the limiting rod 87 through the gear 852 engaged therewith, and the actuator 871 fixed on the limiting rod 87 swings, amplifying the small linear motion of the rack 851 to the effective control stroke of the piston 91.

[0064] Low load state: The condensate is generated slowly, and the temporary storage box 62 is filled and moved down once in a long time, and then quickly resets. The temporary storage box 62 drives the gear 852 and the actuator 871 to swing for a short time through the L-shaped plate 85 and the rack 851, and the actuator 871 pushes the piston 91 slightly, but since the action frequency is low, when the L-shaped plate 85 resets, the piston 91 will be quickly pushed back to the initial position by the elastic force of the spring 92. The piston 91 maintains the state of blocking the flow expansion groove 911 most of the time, and the cooling gas flow is maintained at a minimum.

[0065] High load state: The condensed liquid is generated very quickly, the temporary storage box 62 is frequently, even almost continuously, in the cycle of "down - drainage - reset - again down", the rack 851 makes multiple, continuous reciprocating motion in a very short time window, which makes the dialing member 871 dial the piston 91 to move in stages, when the piston 91 is pushed to a deep enough position, the expansion groove 911 is aligned with the flow-through part 90, and the flow area reaches the maximum, at this time, even if the temporary storage box 62 is in the reset moment, due to the insufficient pushing force of spring two 92 to overcome all mechanical static friction forces at one time to push the piston 91 back completely, the piston 91 will be temporarily kept in this open position, as long as the high load continues, the frequent action of the temporary storage box 62 will "maintain" the piston 91 in this open state, this "maintenance" state is dynamic, as long as the high load condition continues, the frequent action of the temporary storage box 62 will continuously exert a periodic "maintenance force" on the piston 91 through the transmission mechanism, which points to the opening direction, this force not only prevents the piston 91 from retreating under the action of spring two 92, but also may push it to the position again when it is slightly loose, thereby stably maintaining the maximum flow area.

[0066] When the system load decreases, the condensed liquid generation speed slows down, and the action frequency of the temporary storage box 62 also decreases, the maintenance force acting on the piston 91 becomes longer or even disappears, at this time, the continuous pushing force of spring two 92 has enough time to overcome the resistance which has become dynamic friction, slowly and firmly pushes the piston 91 back to the initial blocking position, and the system returns to the energy-saving low-flow state

[0067] The core advantage of the design is to solve the contradiction between sufficient cooling and energy saving: by monitoring the condensed liquid generation frequency, a reliable indicator, intelligently judging the system load state, and accurately adjusting the cooling gas flow, the perfect match of cooling supply and heat dissipation demand is realized, and the cooling gas flow is automatically limited under low load condition, which directly reduces the pumping load of the front stage pump (i.e. water ring vacuum pump 3). The front stage pump consumes electric energy when pumping and compressing cooling gas, the smaller the cooling gas flow, the lower the power consumption of the front stage pump, which is highly consistent with the fundamental goal of "energy saving", and ensures sufficient cooling gas supply under high load condition, effectively prevents the rotor from thermal expansion due to compression heat, avoids the serious failure of rotor and pump cavity friction, dead lock, ensures the safety of core equipment, and prolongs the service life of the pump set; without external power or complex electronic sensors, the structure is solid and has strong anti-interference ability, which is very suitable for long-term and reliable operation in industrial environment.

[0068] Example three, refer to Figure 10The air-cooled Roots pump 1 in the above embodiment can be replaced by a multi-stage Roots pump 10, which adopts a multi-pump cavity in series and can multi-stage compression, so the backflow is small, and the running current is small, the vibration is small, the operation is more stable, the maintenance is low, and is mainly used for energy-saving maintenance of the high vacuum environment of the steam turbine exhaust port, which can significantly improve the power generation efficiency of the unit.

[0069] The control mode of the present application is automatically controlled by the controller, and the control circuit of the controller can be realized by simple programming by those skilled in the art, the power supply also belongs to the common knowledge in the art, and the present application is mainly used for protecting mechanical devices, so the control mode and circuit connection of the present application will not be explained in detail.

[0070] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An energy-saving air-cooled Roots water ring vacuum pump unit, comprising an air-cooled Roots pump (1), a water ring vacuum pump (3), a gas-liquid separator (4), a cold gas return pipe (5), a control unit, and a housing (6), wherein the air-cooled Roots pump (1) is provided with an inlet (11), an outlet (12), and a return port (13), the lower end of the outlet (12) is connected to a connecting pipe (2), the housing (6) is located in the middle of the connecting pipe (2), the inner cavity of the connecting pipe (2) located below the housing (6) is connected to the corresponding return port (13) through the cold gas return pipe (5), and a plurality of heat exchange coils (61) are installed inside the housing (6), characterized in that, Also includes: Separate drainage assembly: The separate drainage assembly is disposed inside and on the lower side of the housing (6); Linkage flow control component: The linkage flow control component is located between the cold air return pipe (5) and the housing (6).

2. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 1, characterized in that, The lower end of the connecting pipe (2) is connected to the air inlet of the water ring vacuum pump (3). The liquid outlet of the gas-liquid separator (4) is connected to the working fluid inlet of the water ring vacuum pump (3) through the replenishment pipe. A heat exchanger is provided on the replenishment pipe. The outlet of the water ring vacuum pump (3) is directly connected to the air inlet of the gas-liquid separator (4) through a pipe.

3. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 1, characterized in that, Pressure sensors are installed on the exhaust pipe of the air-cooled Roots pump (1) and the intake pipe of the water ring vacuum pump (3); the control unit is electrically connected to the pressure sensors, the drive motor of the air-cooled Roots pump (1) and the drive motor of the water ring vacuum pump (3); the control unit is configured to control the start-stop sequence and operation of the air-cooled Roots pump (1) and the water ring vacuum pump (3) according to the pressure signal detected by the pressure sensor.

4. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 1, characterized in that, The cooling medium outlet and inlet of the heat exchange coil (61) are respectively connected to an external cooling medium supply system.

5. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 1, characterized in that, The separation drainage assembly includes a temporary storage box (62), a flow guide (7), a water storage box (8), and a fixing rod (81). The water storage box (8) is fixed to the bottom of the housing (6), and a drain pipe (80) is provided on the bottom wall of the water storage box (8). The flow guide (7) is fixedly installed on the bottom wall of the inner cavity of the housing (6). The temporary storage box (62) is slidably disposed inside the housing (6) and located below the heat exchange coil (61). A connecting part (82) is fixedly connected to the bottom of the temporary storage box (62). A through hole matching the connecting part (82) is opened on the bottom wall of the housing (6). A drainage channel (83) is opened on the upper part of the connecting part (82). The lower part of the connecting part (82) is provided with a movable cavity (84). The top end of the drainage channel (83) is connected to the inner cavity of the temporary storage box (62). The bottom of the drainage channel (83) is provided with a plurality of drainage grooves (831) in a ring shape. The fixing rod (81) is fixedly installed on the bottom wall of the inner cavity of the water storage box (8). The top end of the fixing rod (81) extends into the interior of the movable cavity (84) and is slidably connected thereto. A contact switch (841) is installed on the top of the inner cavity of the movable cavity (84). The lower end of the connecting part (82) is magnetically set. An electromagnet (86) is also fixedly installed on the bottom wall of the inner cavity of the water storage box (8) corresponding to the connecting part (82).

6. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 5, characterized in that, The electromagnet (86) is electrically connected to the contact switch (841). When the electromagnet (86) is energized, the magnetism of the surface opposite to the connecting part (82) is the same. The electromagnet (86) and the connecting part (82) are coaxially arranged.

7. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 5, characterized in that, The flow guide (7) consists of a central ventilation section (71) and a flow guide section (72) fixedly connected to the periphery of the ventilation section (71). The flow guide (7) is umbrella-shaped. The ventilation section (71) has several air guide holes (711). The top of the ventilation section (71) is slidably connected to a limiting member (74). The limiting member (74) and the ventilation section (71) are elastically connected by a spring (75). The end of the limiting member (74) located above the ventilation section (71) is fixedly connected to a connecting plate (73). The bottom of the connecting plate (73) is fixedly connected to a connecting column (76). The lower end of the connecting column (76) is fixedly connected to the inner wall of the temporary storage box (62).

8. The energy-saving air-cooled Roots water ring vacuum pump unit according to claim 7, characterized in that, The top of the temporary storage box (62) is open. The middle of the temporary storage box (62) is provided with a channel that matches the guide shroud (7). The cross-sectional height of the ventilation section (71) and the drainage section (72) is set in a stepped shape. When the spring (75) is in the initial state, the top of the connecting plate (73) is in contact with the surface of the heat exchange coil (61), and the drain groove (831) is completely blocked at this time. When the connecting plate (73) is in contact with the top of the ventilation section (71), the contact switch (841) is in contact with the top of the fixing rod (81), and the drain groove (831) is not blocked at this time.

9. An energy-saving air-cooled Roots water ring vacuum pump unit according to claim 5, characterized in that, The linkage flow control assembly includes an L-shaped plate (85) fixedly connected to the outer wall of the connecting part (82), a limiting cylinder (9), a piston (91), and a limiting rod (87) disposed inside the cold air return pipe (5). The limiting cylinder (9) is fixedly installed inside the cold air return pipe (5). The piston (91) is slidably connected to the limiting cylinder (9) and the inner cavity of the cold air return pipe (5). The piston (91) and the limiting cylinder (9) are elastically connected by a spring (92). An air guide channel (912) is formed in the middle of the piston (91). The water storage box (8) and the cold air return pipe (5) The L-shaped plate (85) is provided with a channel for the L-shaped plate (85) to pass through. The side wall of the L-shaped plate (85) located inside the cold air return pipe (5) is fixedly connected with a rack (851). The limiting rod (87) is rotatably installed inside the cold air return pipe (5). The limiting rod (87) is fixedly connected with a toggle (871). The middle part of the limiting rod (87) is fixedly connected with a gear (852) that meshes with the rack (851). The rod part of the piston (91) is provided with several flow-expanding grooves (911) in an annular shape. The inner side of the limiting cylinder (9) away from the L-shaped plate (85) is provided with a flow passage (90).

10. An energy-saving air-cooled Roots water ring vacuum pump unit according to claim 9, characterized in that, The end of the actuating member (871) is always in contact with the side wall of the piston (91). The expansion groove (911) of the spring (92) in its initial state is in a blocked state. There is a gap between the flow passage (90) and the rod of the piston (91). When the contact switch (841) contacts the fixed rod (81), the expansion groove (911) is in the flow passage (90).

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