Stable and efficient Roots compressor for MVR (Mechanical Vapor Recompression)

Abstract

The utility model relates to the technical field of Roots MVR compressors, in particular to a stable and efficient Roots compressor for MVR. Comprising a pump body, end covers arranged at the two ends of the pump body, a cavity formed between the end covers and the pump body and a rotor arranged in the cavity, and further comprises a cooling atomization device arranged on the outer side of the pump body and communicated with the cavity and a combined sealing structure arranged between the rotor and the end covers. The cooling and atomizing device comprises a pump cover fixedly connected to the surface of the pump body, a connecting pipe arranged on the pump cover and an atomizing nozzle detachably connected to the tail end of the connecting pipe. The stable and efficient Roots compressor for the MVR has the advantages of being high in working efficiency, good in cooling effect, good in sealing effect, long in service life, low in cost and the like.

Description

Technical Field

[0001] This utility model relates to the field of Roots MVR compressor technology, and in particular to a stable and efficient Roots compressor for MVR. Background Technology

[0002] MVR stands for Mechanical Vapor Recompression. MVR is an energy-saving technology that reuses the energy of the secondary steam generated by the evaporator, thereby reducing the demand for external energy. Its principle is to compress the secondary steam generated in the evaporator through a compressor, increasing its pressure and temperature, and consequently its enthalpy. This increased enthalpy steam is then sent to the heating chamber of the evaporator as heating steam, maintaining the liquid feed at a boiling state. The heating steam itself condenses into water, thus fully utilizing the latent heat in the secondary steam and achieving energy savings. In this technology, the Roots blower offers the following advantages as both a power and heat source: by using relatively little energy—specifically, the mechanical energy of the compressor impeller under compression heat pump operation—it is converted and added to the process heating medium for continuous circulation. In this case, fresh steam is not required as the heating medium, resulting in significant energy savings. Energy consumption is approximately 1 / 3 to 1 / 5 of that of a traditional evaporator, greatly reducing operating costs. Currently, existing blowers on the market suffer from short lifespans, high vibration, seal failures, and component corrosion. To address these practical needs, this project primarily focuses on developing a stable and efficient Roots compressor for MVR.

[0003] Chinese patent CN213298269U discloses a Roots compressor for MVR (Mechanical Vapor Reduction) processes. A motor transmits power to one rotor via a coupling. This rotor drives a pair of synchronous gears in a gearbox, which in turn drive another rotor, achieving simultaneous, counter-rotating rotation of the two rotors within the pump body. This enables the compressor to perform intake and exhaust functions respectively. Because the rotor employs a three-lobe structure, one rotation results in three intake and three exhaust cycles, achieving an intake-to-exhaust compression ratio of over 10:1. This ensures a secondary steam temperature rise of 20-25°C or higher in the MVR process, maximizing the steam temperature increase. This application utilizes a mechanical seal structure, which is not only simple in structure but also provides excellent sealing performance. It can be widely applied to various complex and special process conditions, including those involving strong corrosion, flammability, explosiveness, high temperature, and high pressure.

[0004] However, this technical solution lacks cooling. Under high-temperature conditions, it may cause the sealing components to age or be damaged due to excessive temperature. High temperature may also cause thermal expansion of the pump body and rotor, thereby changing the gap between the rotors and affecting the compression efficiency. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a stable and efficient Roots compressor for MVR. By using a cooling atomizing device to cool the pump body, the internal temperature of the compressor can be effectively controlled, extending the service life of the equipment. Combined with a combined sealing structure installed between the rotor and the end cover, it can prevent gas leakage inside the compressor and prevent external impurities from entering, ensuring the sealing performance of the compressor and improving working efficiency.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A smooth and efficient Roots compressor for MVR includes: a pump body, end covers disposed at both ends of the pump body, a cavity disposed between the end covers and the pump body, and a rotor disposed inside the cavity. It also includes: a cooling atomizing device disposed outside the pump body and communicating with the cavity, and a combined sealing structure disposed between the rotor and the end covers.

[0008] Preferably, the cooling atomizing device includes: a pump cover fixedly connected to the surface of the pump body, a connecting pipe disposed on the pump cover, and an atomizing nozzle detachably connected to the end of the connecting pipe.

[0009] Preferably, a nitrogen purging device is provided on one side of the combined sealing structure.

[0010] Preferably, the nitrogen purging device includes: a nitrogen inlet disposed on one side of the end cap and an air inlet pipe disposed at the end of the nitrogen inlet, the end of the air inlet pipe being disposed directly opposite the combined sealing structure.

[0011] Preferably, a pressure relief hole is provided on the other side of the end cap.

[0012] Preferably, the flow medium inside the pump body is made of 2205 / D-5S material.

[0013] Preferably, an independent oil tank is provided on the outer side of the end cap.

[0014] Preferably, the outer periphery of the oil tank is provided with several cooling coils.

[0015] Preferably, the rotor adopts a three-lobe circular arc rotor hollow design.

[0016] Preferably, the combined sealing structure includes: a packing ring disposed between the bushing on the outer periphery of the rotor and the inner wall of the end cover, a positioning ring disposed on the side adjacent to the packing ring, and a skeleton oil seal disposed on the side adjacent to the positioning ring.

[0017] Preferably, the combined sealing structure includes: a labyrinth seal ring disposed between the bushing on the outer periphery of the rotor and the inner wall of the end cover, and the skeleton oil seal is disposed on the adjacent side of the labyrinth seal ring.

[0018] The beneficial effects of this utility model are as follows:

[0019] (1) This utility model sprays the cooling medium into the cavity through the atomizing nozzle to cool the inside of the compressor, reduce the temperature of the rotor and the cavity, prevent equipment damage and performance degradation caused by high temperature, and the atomizing nozzle is detachable, which is convenient for maintenance and replacement, and reduces maintenance costs; and the combined sealing structure has a good sealing effect, which can effectively reduce leakage and improve the working efficiency and reliability of the compressor.

[0020] (2) By installing a nitrogen purging device on one side of the combined sealing structure, this utility model further prevents gas leakage and impurities from entering, enhances the sealing effect, and further improves the reliability of the compressor; at the same time, nitrogen purging can remove some heat and play an auxiliary role in cooling, further protecting the equipment.

[0021] (3) This utility model uses 2205 / D-5S material as the flow medium inside the pump body. Because it is a duplex stainless steel, it has good corrosion resistance and can effectively resist the corrosion of the pump body by the medium, ensuring the service life of the pump body. It is suitable for working environments with high humidity and corrosion, reducing the maintenance cost and replacement frequency of the equipment. At the same time, this material also has high strength and toughness, and can withstand greater pressure and mechanical stress.

[0022] (4) This utility model provides independent lubricating oil storage and circulation for the compressor's lubrication system by installing an independent oil tank on the outside of the end cover, ensuring the normal operation of the lubrication system and reducing equipment wear; the independent oil tank is completely separated from the cavity, avoiding direct heat transfer from the pump body to the independent oil tank during the pump compression process, resulting in a low oil temperature in the independent oil tank and ensuring its service life. In addition, several cooling coils are provided on the outer periphery of the oil tank. By increasing the contact area with the cooling medium (such as water), the cooling coils can quickly dissipate the heat of the lubricating oil in the oil tank, thereby effectively reducing the temperature of the lubricating oil. This efficient heat exchange method can ensure that the lubricating oil is always within a suitable working temperature range, improve the lubrication effect, and reduce the decline in lubricating oil performance caused by high temperature.

[0023] (5) By adopting a hollowed-out three-lobe circular arc rotor design, this utility model has a high rotor area utilization coefficient, low airflow pulsation, and the gas pressure on the rotor is reduced by 1 / 3 compared with the traditional two-lobe rotor. The pump speed is higher for the same size, the volumetric efficiency is higher, and the bearing life is longer.

[0024] (6) This utility model seals both the rotor and the end cover by different sealing methods to adapt to various working conditions, such as high temperature, high pressure, and high speed, so that the compressor can be used correctly, ensuring working efficiency and improving its service life.

[0025] In summary, this utility model has the advantages of high working efficiency, good cooling effect, good sealing effect, long service life and low cost. Attached Figure Description

[0026] Figure 1 This is a front view of Embodiment 1 of the present utility model;

[0027] Figure 2 This is a side sectional view of Embodiment 1 of the present utility model;

[0028] Figure 3 This is a schematic diagram of the cooling atomizing device according to Embodiment 1 of this utility model;

[0029] Figure 4 This is a schematic diagram of the rotor structure in Embodiment 1 of this utility model;

[0030] Figure 5 This is a partial cross-sectional view of Embodiment 2 of the present invention;

[0031] Figure 6 for Figure 5 Enlarged view of point A;

[0032] Figure 7 This is a schematic diagram of the overall structure of Embodiment 3 of this utility model;

[0033] Figure 8 for Figure 7 Enlarged view of point B. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] Example 1

[0037] like Figures 1-7 As shown, this embodiment provides a stable and efficient Roots compressor for MVR, including: a pump body 1, end caps 2 disposed at both ends of the pump body 1, a cavity 3 disposed between the end caps 2 and the pump body 1, and a rotor 4 disposed inside the cavity 3. It also includes: a cooling atomizing device 5 disposed outside the pump body 1 and connected to the cavity 3, and a combined sealing structure 6 disposed between the rotor 4 and the end caps 2. The cooling atomizing device 5 has a good cooling effect, effectively controlling the internal temperature of the compressor and extending the service life of the equipment. The combined sealing structure 6 prevents internal gas leakage from the compressor and prevents external impurities from entering, ensuring the sealing performance of the compressor and improving working efficiency. Furthermore, the combined sealing structure 6 has a good sealing effect, effectively reducing leakage and improving the working efficiency and reliability of the compressor. The combined design allows for adjustment and optimization according to different operating conditions, making it highly adaptable.

[0038] The cooling atomizing device 5 includes: a pump cover 51 fixedly connected to the surface of the pump body 1, a connecting pipe 52 disposed on the pump cover 51, and an atomizing nozzle 53 detachably connected to the end of the connecting pipe 52. The cooling medium is atomized and sprayed into the cavity 3 through the atomizing nozzle 53 to cool the inside of the compressor, reduce the temperature of the rotor 4 and the cavity 3, prevent equipment damage and performance degradation caused by high temperature, and the atomizing nozzle 53 is detachable, which facilitates maintenance and replacement and reduces maintenance costs.

[0039] In this embodiment, a nitrogen purging device 7 is provided on one side of the combined sealing structure 6. Through the purging action of nitrogen, gas leakage and impurities are further prevented, the sealing effect is enhanced, and the reliability of the compressor is further improved. At the same time, it can remove some heat, play an auxiliary cooling role, and further protect the equipment.

[0040] In this embodiment, the nitrogen purging device 7 includes: a nitrogen inlet 71 disposed on one side of the end cap 2 and an air inlet pipe 72 disposed at the end of the nitrogen inlet 71. The end of the air inlet pipe 72 is disposed directly opposite the combined sealing structure 6, specifically, the end of the air inlet pipe 72 is disposed directly opposite the packing 61. By injecting nitrogen into the combined sealing structure 6, a gas seal is formed, effectively isolating the compressed gas from the external environment and preventing compressed gas leakage. Nitrogen can replace combustible or harmful gases in the sealing structure, reducing the risk of accidents caused by leaked gas. Under high-temperature conditions, the flow of nitrogen can carry away some heat, reducing the operating temperature of the combined sealing structure 6 and extending the service life of each sealing component.

[0041] In this embodiment, a pressure relief hole 21 is provided on the other side of the end cover 2. During the operation of the compressor, the internal pressure of the end cover 2 may increase due to gas leakage or other reasons. The pressure relief hole 21 can release excess pressure in time to prevent equipment damage caused by excessive pressure. When the combined sealing structure 6 fails, the pressure relief hole 21 can safely discharge the leaked gas to avoid gas accumulation inside the equipment, thereby reducing safety risks. By releasing pressure in time, the wear of the combined sealing structure 6 and mechanical parts caused by excessive pressure can be reduced, and the service life of the equipment can be extended.

[0042] In this embodiment, the nitrogen purging device 7 can prevent the medium inside the pump body 1 from entering the independent oil tank 8 by isolating it with nitrogen, so as to ensure the service life of the independent oil tank 8.

[0043] In this embodiment, the rotor 4 adopts a synchronous helical gear design, which makes its transmission smoother.

[0044] In this embodiment, the flow medium inside the pump body 1 is made of 2205 / D-5S material. 2205 / D-5S material is a duplex stainless steel with good corrosion resistance, which can effectively resist the corrosion of the pump body 1 by the medium and ensure the service life of the pump body 1. It is suitable for working environments with high humidity and corrosion, reducing the maintenance cost and replacement frequency of the equipment. At the same time, this material also has high strength and toughness and can withstand greater pressure and mechanical stress.

[0045] In this embodiment, an independent oil tank 8 is provided on the outside of the end cover 2 to provide independent storage and circulation of lubricating oil for the compressor's lubrication system, ensuring the normal operation of the lubrication system and reducing equipment wear; the independent oil tank 8 is completely separated from the cavity 3 to prevent the pump body 1 from directly transferring heat to the independent oil tank 8 during the pump compression process, so that the oil temperature in the independent oil tank 8 is low, and the oil cooling device can be eliminated.

[0046] Of course, the outer periphery of the oil tank is equipped with several cooling coils 81. By increasing the contact area with the cooling medium (such as water), the cooling coils 81 can quickly dissipate heat from the lubricating oil in the oil tank, thereby effectively reducing the temperature of the lubricating oil. This efficient heat exchange method ensures that the lubricating oil is always within a suitable operating temperature range, improving lubrication and reducing the decline in lubricating oil performance caused by high temperatures. Furthermore, by effectively controlling the temperature of the lubricating oil, the cooling coils 81 can reduce the rate of oxidation and deterioration of the lubricating oil, extending its service life. At the same time, a stable lubricating oil temperature also helps reduce wear on mechanical parts, thereby extending the overall service life of the compressor.

[0047] In addition, the rotor 4 adopts a hollowed-out three-lobe circular arc rotor 4, which makes the rotor 4 have a high area utilization coefficient, low airflow pulsation, and the gas pressure on the rotor 4 is reduced by 1 / 3 compared with the traditional two-lobe rotor 4. The pump speed is higher for the same size, the volumetric efficiency is higher, and the bearing life is longer.

[0048] Example 2

[0049] like Figure 5 and Figure 6 As shown, components that are the same as or corresponding to those in Embodiment 1 are referred to using the same reference numerals as in Embodiment 1. For simplicity, only the differences from Embodiment 1 are described below. The difference between Embodiment 2 and Embodiment 1 is as follows:

[0050] In this embodiment, the combined sealing structure 6 includes: a packing 61 disposed between the bushing 41 on the outer periphery of the rotor 4 and the inner wall of the end cover 2, a positioning ring 62 disposed on the adjacent side of the packing 61, and a skeleton oil seal 63 disposed on the adjacent side of the positioning ring 62. The packing 61 is a packing sealing material that forms a sealing barrier to prevent liquid or gas leakage. The positioning ring 62 is mainly used to fix the position of the packing 61 and the skeleton oil seal 63, ensuring that the sealing element remains stable during operation, preventing it from shifting due to vibration or axial force, reducing friction between the rotor 4 and the sealing element, improving the reliability and service life of the seal, and achieving multiple sealing effects overall.

[0051] Among them, the packing 61 can be made of different materials, such as graphite and carbon fiber, to meet the sealing requirements of high temperature, high pressure or corrosive media. The packing 61 has a certain degree of elasticity, which can buffer and compensate for the vibration and thermal expansion of the rotor 4 during operation, and reduce the wear of the sealing surface.

[0052] Meanwhile, the positioning ring 62, through its fixing and guiding function, ensures that the sealing element can maintain good sealing performance under complex working conditions such as high temperature, high pressure, and high speed.

[0053] In addition, the skeleton oil seal 63 is a contact sealing element. Its elastic lip makes close contact with the bushing 41 to form a sealing surface, preventing liquid leakage and preventing external dust, impurities and other contaminants from entering the equipment.

[0054] Example 3

[0055] like Figure 7 and Figure 8 As shown, components that are the same as or corresponding to those in Embodiment 1 are referred to using the same reference numerals as in Embodiment 1. For simplicity, only the differences from Embodiment 1 are described below. The difference between Embodiment 3 and Embodiment 1 is as follows:

[0056] According to different working conditions, in this embodiment, the combined sealing structure 6 includes: a labyrinth seal ring 64 disposed between the bushing 41 on the outer periphery of the rotor 4 and the inner wall of the end cover 2; the skeleton oil seal 63 is disposed on the adjacent side of the labyrinth seal ring 64; the labyrinth seal ring 64 is mainly used to prevent gas or liquid from leaking from the high-pressure area to the low-pressure area, or from the low-pressure area to the high-pressure area; the skeleton oil seal 63 can further enhance the sealing effect, and when used in conjunction with the labyrinth seal ring 64, it forms a double seal, which can effectively balance the pressure difference between the inside and outside of the equipment and improve the reliability of the seal.

[0057] The labyrinth seal 64 has a gap between it and the rotor 4, with no solid contact, making it a non-contact seal. Therefore, it will not wear due to friction and can ensure its service life. The labyrinth seal 64 can effectively reduce leakage through the design of multi-stage throttling and expansion cavities. Since it does not require lubrication and allows thermal expansion, the labyrinth seal 64 is particularly suitable for high temperature, high pressure and high speed applications.

[0058] In addition, the labyrinth seal 64 is connected to the nitrogen inlet 71 and the nitrogen outlet 73 on both sides, respectively, so that nitrogen can form a positive pressure environment on both sides of the labyrinth seal 64, thereby isolating oxygen in the air, further reducing gas or liquid leakage, enhancing the sealing effect, effectively preventing oxidation and corrosion of metal parts inside the equipment; it can also prevent dust, impurities and other contaminants in the external environment from entering the equipment, thereby protecting the equipment.

[0059] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A smooth and efficient Roots compressor for MVR, comprising: The pump body, end caps disposed at both ends of the pump body, a cavity disposed between the end caps and the pump body, and a rotor disposed inside the cavity, characterized in that it further includes: a cooling atomizing device disposed outside the pump body and communicating with the cavity, and a combined sealing structure disposed between the rotor and the end caps.

2. The MVR stable and efficient Roots compressor according to claim 1, characterized in that, The cooling atomizing device includes: a pump cover fixedly connected to the surface of the pump body, a connecting pipe disposed on the pump cover, and an atomizing nozzle detachably connected to the end of the connecting pipe.

3. A stable and efficient Roots compressor for MVR according to claim 1, characterized in that, A nitrogen purging device is provided on one side of the combined sealing structure.

4. A stable and efficient Roots compressor for MVR according to claim 3, characterized in that, The nitrogen purging device includes a nitrogen inlet located on one side of the end cap and an air inlet pipe located at the end of the nitrogen inlet, with the end of the air inlet pipe facing the combined sealing structure.

5. A stable and efficient Roots compressor for MVR according to claim 1, characterized in that, A pressure relief hole is provided on the other side of the end cap.

6. A stable and efficient Roots compressor for MVR according to claim 1, characterized in that, An independent oil tank is provided on the outside of the end cap.

7. A stable and efficient Roots compressor for MVR according to claim 6, characterized in that, The outer periphery of the oil tank is provided with several cooling coils.

8. A stable and efficient Roots compressor for MVR according to claim 1, characterized in that, The rotor adopts a three-bladed, hollowed-out circular arc design.

9. A stable and efficient Roots compressor for MVR according to claim 1, characterized in that, The combined sealing structure includes: a packing ring disposed between the bushing on the outer periphery of the rotor and the inner wall of the end cover, a positioning ring disposed on the side adjacent to the packing ring, and a skeleton oil seal disposed on the side adjacent to the positioning ring.

10. A stable and efficient Roots compressor for MVR according to claim 9, characterized in that, The combined sealing structure includes: a labyrinth seal ring disposed between the bushing on the outer periphery of the rotor and the inner wall of the end cover, and the skeleton oil seal disposed on the adjacent side of the labyrinth seal ring.

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