Efficient dry type vacuum system easy to maintain

Abstract

The utility model belongs to the technical field of vacuum systems, and particularly relates to an efficient dry-type vacuum system easy to maintain, which is characterized by comprising a multi-stage separation and recovery device, a condensing device and a vacuum buffer device which are sequentially connected, the multi-stage separation and recovery device comprises a separation buffer tank, the separation buffer tank is sequentially connected with a third-stage roots pump, a third-stage heat exchanger, a second-stage roots pump, a second-stage heat exchanger, a first-stage roots pump and a first-stage heat exchanger through pipelines, the bottom of the first-stage roots pump is connected with a first-stage liquid storage tank, the bottom of the second-stage roots pump is connected with a second-stage liquid storage tank, and the bottom of the second-stage roots pump is connected with a second-stage liquid storage tank. The bottom of the third-stage roots pump is connected with a third-stage liquid storage tank; the condensing device is used for condensing the condensable gas into liquid and separating organic waste materials and impurities in the liquid again; the vacuum buffer device is used for recycling vacuum materials. According to the utility model, the problem that the screw and the pump cavity are corroded by accumulated liquid stored in the pump cavity is solved, the problem that the screw and the pump cavity are corroded by residues is solved, and the requirements of actual production can be met.

Description

Technical Field

[0001] The utility model belongs to the technical field of vacuum systems, and in particular relates to a high-efficiency dry vacuum system that is easy to maintain. Background Art

[0002] In the chemical industry, the preparation and inspection of many chemical products need to be carried out under a vacuum system. The function of the vacuum system is to enable the vacuum container to obtain and maintain a vacuum within a specified time and space, thereby ensuring the implementation of a certain process or physical process in the system. When the pressure in the container is lower than the atmospheric pressure, the part below the atmospheric pressure is called vacuum.

[0003] At present, the vacuum pumps used in vacuum systems are divided into wet type and easy-to-maintain high-efficiency dry type vacuum pumps. Among them, water circulation vacuum pumps are noisy and inefficient. They are limited by the saturated vapor pressure of water, have low vacuum degree, and the large amount of circulating water used can easily cause material loss and environmental pollution. In addition, the failure rate of commonly used dry screw vacuum pumps has remained high during operation. The main failures are divided into two categories: First, according to the design of the dry screw vacuum pump, the internal temperature of the pump is between 110°C and 260°C. There is no liquid inside the screw pump to absorb heat, so the maximum inlet temperature of the pump is generally not allowed to exceed 70°C. The inlet gas temperature is too high, resulting in an excessively high internal temperature of the pump, causing the pump to get stuck; second, when the screw vacuum pump extracts condensable gases, condensed liquid will accumulate at the exhaust port of the pump. Once the pump stops, these liquids will return to the pump cavity, making it difficult to restart the pump. The accumulated liquid in the pump cavity increases the vibration and noise during operation. Most of these liquids are corrosive. If they remain in the pump cavity for a long time, they will corrode the screw and pump cavity. Once a failure occurs, frequent cleaning and replacement are required, resulting in increased maintenance costs. Utility Model Content

[0004] In order to reduce the failure rate of screw vacuum pumps, the present application provides an easy-to-maintain, efficient dry vacuum system that can effectively reduce the failure rate of vacuum pumps, improve the problems of pump jamming due to excessive temperature and residual condensable gas corroding the screw and pump chamber.

[0005] This application provides an easy-to-maintain, efficient dry vacuum system using the following technical solutions:

[0006] An easy-to-maintain, high-efficiency dry vacuum system comprises a multi-stage separation and recovery device, a condensing device and a vacuum buffer device connected in sequence through pipelines;

[0007] The multi-stage separation and recovery device includes a separation buffer tank, which is sequentially connected to a three-stage Roots pump, a three-stage heat exchanger, a two-stage Roots pump, a two-stage heat exchanger, a first-stage Roots pump, and a first-stage heat exchanger through pipelines. The bottom of the first-stage Roots pump is connected to a first-stage liquid storage tank, the bottom of the second-stage Roots pump is connected to a second-stage liquid storage tank, and the bottom of the third-stage Roots pump is connected to a third-stage liquid storage tank.

[0008] The condensing device is used to condense the condensable gas into liquid and separate the organic waste and impurities in the liquid again; the vacuum buffer device is used to recover the vacuum material.

[0009] By adopting the above technical solution, by installing a multi-stage separation and recovery device and a condensation device before the vacuum buffer device, the gas entering the vacuum buffer device is cooled to an appropriate temperature, and the condensable gas is separated and condensed and recovered at multiple stages, greatly reducing the possibility of liquid accumulation in the vacuum buffer device and corrosion. After the steam is cooled by the first-stage heat exchanger, some of the condensable gas condenses into liquid, which is collected by the first-stage liquid storage tank. The gas recovered after the first-stage separation enters the second-stage separation and recovery, where the condensable gas is further condensed and collected. This process is repeated multiple times until as much of the condensable gas as possible is condensed into liquid. The gas then enters the vacuum buffer device, where it is evacuated and the vacuum material is recovered.

[0010] In a specific possible implementation scheme, the condensing device includes a condenser, a one-way valve is provided at the bottom of the condenser, and the one-way valve is connected to a condensate collection tank.

[0011] By adopting the above-mentioned technical solution, a condensing device is arranged before the vacuum buffer device, so that the condensable gas entering the condenser is condensed and recovered into the condensate collection tank through the one-way valve arranged at the bottom, so that the gas entering the vacuum buffer device is cooled to a suitable temperature, and the condensable gas is avoided from condensing and remaining in the pump cavity for a long time, corroding the screw and the pump cavity.

[0012] In a specific possible implementation scheme, the outlet of the first-stage heat exchanger is provided with a three-way pipe fitting, one end of which is connected to the condenser, and the other end is connected to a gate valve, and the gate valve is connected to a steam source.

[0013] By adopting the above technical solution, the steam source is connected to the gate valve through a pipeline, and then the steam enters the primary heat exchanger and condenser respectively through the three-way pipe fitting, thereby improving the steam-liquid separation efficiency and cooling rate, so that the gas entering the vacuum buffer device is cooled to a suitable temperature, and condensation of condensable gas is avoided, thereby making the vacuum buffer device less prone to failure and easy to maintain.

[0014] In a specific possible implementation scheme, the vacuum buffer device includes a screw vacuum pump, the screw vacuum pump is connected to a vacuum buffer tank, and the vacuum buffer tank is also provided with a vent valve.

[0015] By adopting the above technical solution, the multi-stage separation and recovery device and condensation device ensure that the temperature of the gas entering the screw vacuum pump is appropriate, avoiding excessive temperatures that could cause the pump to jam. It also maximizes the recovery of condensable gases and avoids the accumulation of corrosive liquid in the pump chamber, which can cause increased vibration and noise, and corrode the screw and pump chamber, requiring repair and replacement. A vacuum buffer tank and vent valve further recover a very small amount of condensable gas, while non-condensable gases are discharged through the vent valve, improving the vacuum level and vacuuming efficiency.

[0016] In a specific embodiment, the condensate collection tank is sequentially connected to a check valve, a second vacuum gauge and a condensation heat exchanger, and the condensation heat exchanger is connected to the screw vacuum pump.

[0017] By adopting the above technical solution, a check valve and a second vacuum gauge are set between the condensate collection tank and the screw vacuum pump, so that the gas can be fully condensed to a suitable temperature, the vacuum degree can be observed at all times, and the maintenance of the instrument and fault detection are facilitated, making the system safer and more reliable.

[0018] In a specific implementation scheme, the separation buffer tank is connected to a first vacuum gauge through a pipeline, the first vacuum gauge is connected to a hydraulic valve, the hydraulic valve is connected to a vacuum box, and the hydraulic valve is also connected to the screw vacuum pump.

[0019] By adopting the above technical solution, the gas after multi-stage separation, recovery and heat exchange enters the screw vacuum pump through the first vacuum gauge and the hydraulic valve, avoiding excessive temperature and causing the pump to get stuck and cause malfunction.

[0020] In a specific implementation scheme, the first-stage Roots pump, the second-stage Roots pump, and the third-stage Roots pump are all connected to the screw vacuum pump through pipelines.

[0021] By adopting the above technical solution, in each stage of the recovery and separation process, after heat exchange in the heat exchanger, part of the gas that has been cooled and purified enters the screw vacuum pump, thereby improving the efficiency of the dry vacuum system and reducing the energy consumption of continuous operation.

[0022] In a specific feasible implementation scheme, the multi-stage separation and recovery device is further provided with a circulating water tank, which is connected to a circulating water supply pump and a circulating water return pump. The circulating water supply pump is respectively connected to the three-stage Roots pump, the two-stage Roots pump, and the first-stage Roots pump through water pipes; the circulating water return pump is respectively connected to the first-stage Roots pump, the two-stage Roots pump, and the three-stage Roots pump.

[0023] By adopting the above technical solution, the circulating water flows into the three-stage Roots pump, the two-stage Roots pump, and the first-stage Roots pump respectively, thereby further cooling the condensable gas entering the Roots pump and improving the cooling efficiency.

[0024] In a specific possible implementation scheme, the condensing device includes a chilled water feed pump, a chilled water return pump and a refrigeration unit. The chilled water feed pump is connected to the refrigeration unit, the chilled water feed pump is connected to the condenser through a water pipe, the condenser is connected to the chilled water return pump through a water pipe, and the chilled water return pump is connected to the refrigeration unit.

[0025] By adopting the above technical solution, the refrigeration unit cools the condenser, thereby improving the condensing efficiency of the condenser.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. By installing a multi-stage separation and recovery device and a condensation device before the vacuum buffer device, the gas entering the vacuum buffer device is cooled to an appropriate temperature. The condensable gas is also separated and condensed and recovered at multiple stages, greatly reducing the possibility of liquid accumulation in the vacuum buffer device and corrosion. After the steam is cooled by the first-stage heat exchanger, some condensable gases condense into liquids, which are collected in the first-stage liquid storage tank. The gas recovered after the first-stage separation and recovery enters the second-stage separation and recovery, where the condensable gases are further condensed and collected. This process is repeated multiple times until as much of the condensable gas as possible is condensed into liquids. The gas then enters the vacuum buffer device, where it is evacuated and the vacuum material is recovered.

[0028] 2. The steam source is connected to the gate valve through a pipeline, and then connected to the three-way pipe fitting so that the steam enters the primary heat exchanger and condenser respectively, thereby improving the vapor-liquid separation efficiency and cooling rate of the steam, so that the gas entering the vacuum buffer device is cooled to a suitable temperature, and condensation of condensable gases is avoided, thereby making the vacuum buffer device less prone to failure and easy to maintain.

[0029] 3. A check valve and a second vacuum gauge are installed between the condensate collection tank and the screw vacuum pump so that the gas can be fully condensed to a suitable temperature and the vacuum degree can be observed at all times, which facilitates instrument maintenance and fault detection, making the system safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of an efficient dry vacuum system that is easy to maintain according to an embodiment of the present application.

[0031] Figure 2 It is a schematic diagram of a multi-stage separation and recovery device according to an embodiment of the present application.

[0032] Figure 3 It is a schematic diagram of the condensing device and the vacuum buffer device of an embodiment of the present application.

[0033] Explanation of reference numerals: 1. multi-stage separation and recovery device; 2. condensing device; 3. vacuum buffer device; 11. separation buffer tank; 12. three-stage Roots pump; 121. three-stage heat exchanger; 122. three-stage liquid storage tank; 13. two-stage Roots pump; 131. two-stage heat exchanger; 132. two-stage liquid storage tank; 14. one-stage Roots pump; 141. one-stage heat exchanger; 142. one-stage liquid storage tank; 15. condenser; 16. one-way valve; 21. condensate collection tank; 22. three-way pipe fitting; 22 1. Gate valve; 23. Steam source; 24. Screw vacuum pump; 25. Vacuum buffer tank; 26. Vent valve; 261. Check valve; 27. Second vacuum gauge; 28. Condensing heat exchanger; 281. First vacuum gauge; 291. Hydraulic valve; 292. Vacuum box; 30. Circulating water tank; 301. Circulating water supply pump; 302. Circulating return water pump; 31. Refrigeration unit; 32. Refrigerated water supply pump; 33. Refrigerated return water pump; 333. Condensate storage tank; 34. Decontaminated water collection tank. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-3 This application is described in further detail.

[0035] The embodiments of the present application disclose a high-efficiency dry vacuum system that is easy to maintain.

[0036] Reference Figure 1 and Figure 2A high-efficiency dry vacuum system that is easy to maintain comprises a multi-stage separation and recovery device 1, a condensing device 2 and a vacuum buffer device 3 that are sequentially connected through pipelines; the multi-stage separation and recovery device 1 comprises a steam source 23, the steam source 23 is connected to a gate valve 221 through a pipeline, the gate valve 221 is connected to a three-way pipe fitting 22, one end of the three-way pipe fitting 22 is connected to a first-stage heat exchanger 141, the first-stage heat exchanger 141 is connected to a first-stage Roots pump 14, the bottom of the first-stage Roots pump 14 is connected to a first-stage liquid storage tank 142, the first-stage Roots pump 14 is connected to a second-stage heat exchanger 131, the second-stage heat exchanger 131 is connected to a second-stage Roots pump 13, the bottom of the second-stage Roots pump 13 is connected to a second-stage liquid storage tank 132; the second-stage Roots pump 13 is connected to a third-stage heat exchanger 12 1. The three-stage heat exchanger 121 is connected to a three-stage Roots pump 12, and the bottom of the three-stage Roots pump 12 is connected to a three-stage liquid storage tank 122; the three-stage Roots pump 12 is connected to a separation buffer tank 11, and is connected to a first vacuum gauge 281 through a pipeline. The first vacuum gauge 281 is connected to a hydraulic valve 291, and the hydraulic valve 291 is connected to a vacuum box 292; the multi-stage separation and recovery device 1 is also provided with a circulating water tank 30, and the circulating water tank 30 is connected to a circulating water supply pump 301 and a circulating water return pump 302. The circulating water supply pump 301 is respectively connected to the three-stage Roots pump 12, the second-stage Roots pump 13, and the first-stage Roots pump 14 through water pipes; the circulating water return pump 302 is respectively connected to the first-stage Roots pump 14, the second-stage Roots pump 13, and the three-stage Roots pump 12.

[0037] Reference Figure 1 and Figure 3 The vacuum buffer device 3 includes a screw vacuum pump 24, the screw vacuum pump 24 is connected to a vacuum buffer tank 25, and the vacuum buffer tank 25 is also provided with a vent valve 26; Figure 2 The tops of the first-stage Roots pump 14 , the second-stage Roots pump 13 and the third-stage Roots pump 12 are all connected to the screw vacuum pump 24 .

[0038] Reference Figure 1 and Figure 3To effectively save energy and improve the operating efficiency of the dry vacuum system, the other end of the three-way pipe fitting 22 is connected to the condenser 15. A one-way valve 16 is installed at the bottom of the condenser 15, which is connected to the condensate collection tank 21. The top of the condensate collection tank 21 is connected in sequence to a check valve 261, a second vacuum gauge 27, and a condensation heat exchanger 28. The condensation heat exchanger 28 is connected to the screw vacuum pump 24. The condenser 15 is connected to a chilled water supply pump 32 and a chilled water return pump 33 via water pipes. The chilled water supply pump 32 is connected to a refrigeration unit 31, and the chilled water return pump 33 is connected to the refrigeration unit 31. Chilled water is used to cool the condenser 15 to more effectively separate the condensable liquid in the condenser 15 and facilitate timely recovery. The heat exchange area of ​​the condenser 15 is adjusted and designed to ensure that the temperature of the condensed gas phase entering the screw vacuum pump 24 does not exceed 70°C. A valve is installed at the bottom of the condensate collection tank 21, which is connected in sequence to the condensate storage tank 333 and the decontaminated water collection tank. 34 allows the liquid condensed by the condenser 15 to be discharged into the condensate storage tank 333 from time to time. When the vacuum box 292 is not in operation, the liquid in the storage tank can be cleaned and discharged to the sewage collection tank for recycling.

[0039] The implementation principle of the embodiment is as follows: start the vacuum box 292, pass the steam through the three-way pipe fitting 22, so that part of the steam enters the first-stage heat exchanger 141, and performs multi-stage separation and recovery. Through the temperature adjustment of the heat exchanger, the condensable gas raw material of the first-stage Roots pump 14 is partially purified, and one or more liquids are recovered and further purified for other uses to avoid waste. Then, the steam enters the second and third-stage separation and recovery in sequence, so that the liquid is graded and purified, and the problem of residual condensable gas corroding the screw and the pump cavity is improved. In addition, the cooled gas components through the first-stage Roots pump 14, the second-stage Roots pump 13, and the third-stage Roots pump 12 enter the screw vacuum pump 24 to avoid the gas temperature being too high and stuck, causing a malfunction; part of the gas separated in the separation buffer tank 11 enters the screw vacuum pump 24 through the steam hydraulic valve 291; the other end of the three-way pipe fitting 22 is condensed through the condenser 15, the condensed liquid is recovered as much as possible, and the gas phase is cooled to a suitable temperature and enters the screw vacuum pump 24. By cooling and purifying the steam at the same time, the vapor-liquid separation efficiency and cooling rate of the steam are improved, so that the gas entering the vacuum buffer device 3 is cooled to a suitable temperature, and condensation of condensable gas is avoided, thereby making the vacuum buffer device 3 less prone to failure and easier to maintain.

[0040] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. An easy-to-maintain, efficient dry vacuum system, characterized in that: The invention comprises a multi-stage separation and recovery device (1), a condensing device (2) and a vacuum buffer device (3) which are sequentially connected through pipelines; the multi-stage separation and recovery device (1) comprises a separation buffer tank (11), the separation buffer tank (11) is sequentially connected through pipelines to a three-stage Roots pump (12), a three-stage heat exchanger (121), a two-stage Roots pump (13), a two-stage heat exchanger (131), a first-stage Roots pump (14), and a first-stage heat exchanger (141); the bottom of the first-stage Roots pump (14) is connected to a first-stage liquid storage tank (142); the bottom of the two-stage Roots pump (13) is connected to a second-stage liquid storage tank (132); and the bottom of the three-stage Roots pump (12) is connected to a third-stage liquid storage tank (122); the condensing device (2) is used to condense condensable gas into liquid and to separate organic waste and impurities in the liquid again; and the vacuum buffer device (3) is used to recover vacuum materials.

2. The easy-to-maintain, high-efficiency dry vacuum system according to claim 1, characterized in that: The condensing device (2) comprises a condenser (15), a one-way valve (16) is provided at the bottom of the condenser (15), and the one-way valve (16) is connected to a condensate collecting tank (21).

3. The easy-to-maintain, high-efficiency dry vacuum system according to claim 2, characterized in that: The outlet of the primary heat exchanger (141) is provided with a three-way pipe fitting (22), one end of which is connected to the condenser (15) and the other end of which is connected to a gate valve (221), and the gate valve (221) is connected to a steam source (23).

4. The easy-to-maintain, high-efficiency dry vacuum system according to claim 1, characterized in that: The vacuum buffer device (3) comprises a screw vacuum pump (24), the screw vacuum pump (24) is connected to a vacuum buffer tank (25), and the vacuum buffer tank (25) is further provided with a vent valve (26).

5. The easy-to-maintain, high-efficiency dry vacuum system according to claim 2, characterized in that: The condensate collecting tank (21) is sequentially connected to a check valve (261), a second vacuum gauge (27) and a condensation heat exchanger (28), and the condensation heat exchanger (28) is connected to a screw vacuum pump (24).

6. The easy-to-maintain, high-efficiency dry vacuum system according to claim 4, characterized in that: The separation buffer tank (11) is connected to a first vacuum gauge (281) via a pipeline, the first vacuum gauge (281) is connected to a hydraulic valve (291), the hydraulic valve (291) is connected to a vacuum box (292), and the hydraulic valve (291) is also connected to the screw vacuum pump (24).

7. The easy-to-maintain, high-efficiency dry vacuum system according to claim 4, characterized in that: The first-stage Roots pump (14), the second-stage Roots pump (13), and the third-stage Roots pump (12) are all connected to the screw vacuum pump (24) through pipelines.

8. The easy-to-maintain, high-efficiency dry vacuum system according to claim 1, characterized in that: The multi-stage separation and recovery device (1) is further provided with a circulating water tank (30), the circulating water tank (30) being connected to a circulating water supply pump (301) and a circulating water return pump (302), the circulating water supply pump (301) being respectively connected to the three-stage Roots pump (12), the two-stage Roots pump (13), and the one-stage Roots pump (14) through water pipes; the circulating water return pump (302) being respectively connected to the one-stage Roots pump (14), the two-stage Roots pump (13), and the three-stage Roots pump (12).

9. The easy-to-maintain, high-efficiency dry vacuum system according to claim 2, characterized in that: The condensing device (2) includes a chilled water supply pump (32), a chilled water return pump (33) and a refrigeration unit (31), wherein the chilled water supply pump (32) is connected to the refrigeration unit (31), the chilled water supply pump (32) is connected to the condenser (15) through a water pipe, the condenser (15) is connected to the chilled water return pump (33) through a water pipe, and the chilled water return pump (33) is connected to the refrigeration unit (31).

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