Gas compressor equipment for extracting small molecule gas

Abstract

The invention discloses a gas compressor device for extracting small molecule gas, the gas compressor device is provided with a shell and a Roots blower device, the Roots blower device is arranged in an inner cavity and comprises an impeller assembly, the impeller assembly comprises a pair of impellers, the pair of impellers are located in an impeller cavity, the impellers are centrosymmetric components and are provided with three blades, and the blades of the pair of impellers are meshed with each other; wherein the outer contour shape of each lobe blade is composed of a left half outer contour shape and a right half outer contour shape which are mutually mirrored; according to the direction from the blade top to the blade root of the blade, the outer contour shape of the left half part is provided with a blade top center point, a blade center point, a first transition point, a second transition point, a third transition point, a fourth transition point and a blade root center point; the outer contour shape of the left half part is composed of a blade top opposite rolling arc section, a transition arc section, an involute section, an arc envelope line section, a point meshing cycloid section and a blade root opposite rolling arc section.

Description

Technical Field

[0001] This application relates to the field of compressor technology, specifically to a compressor device for extracting small molecule gases and containing a Roots blower. Background Technology

[0002] In large-scale equipment equipped with gas monitoring systems, it is often necessary to use a compressor to transport sampled gas to the gas monitoring point so that the monitoring device can complete the monitoring procedure at the monitoring point. For the monitoring of some small molecule gases, such as argon isotope gases and hydrogen isotope gases, it is necessary to avoid gas leakage and other problems during the gas transportation process of the compressor equipment.

[0003] A Roots blower is a rotary positive displacement dual-rotor gas conveying device that can be used as a blower and vacuum pump. It compresses and conveys gas through two or three impeller rotors that rotate within a cylinder chamber. The two rotor impellers of a Roots blower do not contact each other; sealing is achieved through a reasonable clearance tolerance. Thanks to this sealing method, the gas conveyed by the Roots blower will not be contaminated by mixing with oil. The structural characteristics and operating principle of the Roots blower determine that it requires no lubricant. It has advantages such as high energy efficiency, stable and accurate exhaust pressure, and long service life, making it particularly advantageous for conveying conventional gases as well as flammable, explosive, and corrosive gases.

[0004] Roots blowers are susceptible to backflow impact and pressure pulsation during use, which places high demands on the reliability of materials. Currently, Roots blowers on the market are mainly used in applications with large flow rates and unrestricted space, while research on Roots blowers suitable for small-flow gas transport and with a compact size is lacking. Summary of the Invention

[0005] To address the aforementioned technical problems, the purpose of this application is to provide a compressor device capable of transporting small-molecule gases at low flow rates with minimal leakage.

[0006] To achieve the above objectives, this application adopts the following technical solution: a compressor device for extracting small molecule gases, comprising a housing and a Roots blower assembly, wherein the housing defines an inner cavity and an inlet and an outlet fluidly communicating with the inner cavity; the Roots blower assembly is disposed in the inner cavity and includes: an inner shell, defining an impeller cavity and one or more intake ports and one or more exhaust ports fluidly communicating with the impeller cavity, the one or more intake ports fluidly communicating with the inlet port, and the one or more exhaust ports fluidly communicating with the outlet port; and an impeller assembly including a first shaft extending along a first axis, a second shaft extending along a second axis parallel to the first axis, and a pair of impellers respectively mounted on the first shaft and the second shaft, the pair of impellers being located within the impeller cavity and configured to convey the gas to be conveyed from the one or more intake ports to the one or more exhaust ports, the impellers being centrally symmetrical members and having three-lobed blades, the blades of the pair of impellers... The blades mesh with each other; wherein, the outer contour shape of each blade is composed of a left half outer contour shape and a right half outer contour shape that are mirror images of each other; in the direction from the tip of the blade to the root of the blade, the left half outer contour shape has a tip center point, a tip point, a first transition point, a second transition point, a third transition point, a fourth transition point, and a root center point, and the left half outer contour shape is composed of a tip rolling arc segment located between the tip center point and the tip point, a transition arc segment located between the tip point and the first transition point, an involute segment located between the first transition point and the second transition point, an arc envelope segment located between the second transition point and the third transition point and meshing with the transition arc segment, a point-meshing cycloid segment located between the third transition point and the fourth transition point and meshing with the tip point, and a root rolling arc segment located between the fourth transition point and the root center point and meshing with the tip rolling arc segment.

[0007] In the above technical solution, preferably, all impellers are cast iron impellers, the blades of the pair of impellers have a first meshing gap, the pair of impellers define an outer peripheral boundary, the inner shell has an inner peripheral boundary that defines the inner diameter of the impeller cavity, the outer peripheral boundary and the inner peripheral boundary have a second gap, and the first meshing gap is less than or equal to twice the second gap.

[0008] In the above technical solution, preferably, the inner shell includes a cylindrical body, a front wall plate that is sealed to the front end face of the body, and a rear wall plate that is sealed to the rear end face of the body. The front and rear ends of the first shaft pass through the front wall plate and the rear wall plate, respectively, and the front end of the second shaft passes through the front wall plate.

[0009] In the above technical solution, preferably, the pair of impellers defines a front end base surface perpendicular to the first axis and a rear end base surface perpendicular to the first axis, the front end base surface has a third gap with the front wall plate, the rear end base surface has a fourth gap with the rear wall plate, and the third gap, the fourth gap and the first meshing gap are equal.

[0010] In the above technical solution, preferably, the one or more air intake ports are located on the cylinder.

[0011] In the above technical solution, preferably, the number of air intake ports is multiple.

[0012] In the above technical solution, preferably, the one or more exhaust ports are located on the rear wall panel.

[0013] In the above technical solution, preferably, the Roots blower device further includes: a gearbox, the gearbox being disposed in the inner cavity and including a housing and a first gear and a second gear located within the housing, the rear end of the housing being sealed to the front wall plate, the first gear and the second gear meshing with each other, the front end of the first shaft extending into the housing, the first gear being mounted on the first shaft, the front end of the second shaft extending into the housing, and the second gear being mounted on the second shaft; wherein, a second meshing clearance exists between the first gear and the second gear, the second meshing clearance being less than or equal to 1 / 3 of the first meshing clearance.

[0014] The Roots blower device further includes a motor assembly, which is placed in the inner cavity and includes a stator, a rotor, and a motor shaft. The motor shaft is coupled to the rear end of the first shaft via a coupling.

[0015] In the above technical solution, preferably, the air inlet and the air outlet are located at the front end and rear end of the outer casing, respectively.

[0016] Compared with the prior art, this application achieves the following beneficial effects: by designing the outer contour shape of the impeller blades, while ensuring that a pair of impellers rotate and mesh with each other, the amount of gas leakage from the meshing gap of a pair of impellers is significantly reduced, thereby ensuring the gas transport capacity of the compressor equipment. Furthermore, the compressor equipment has a small gas transport flow rate, low pressure, no oil stains, corrosion resistance, good stability, small size, and long service life, making it particularly suitable for transporting small molecule gases. Attached Figure Description

[0017] Figure 1A schematic diagram of the structure of a compressor device for extracting small molecule gases provided in an embodiment of this application;

[0018] Figure 2 for Figure 1 A side view of the compressor equipment;

[0019] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0020] Figure 4 for Figure 3 A cross-sectional view along the BB direction;

[0021] Figures 5a-5e This is a schematic diagram of the intake, compression, and exhaust processes of the Roots blower device provided in the embodiments of this application;

[0022] Figure 6 This is a schematic diagram of the outer contour shape of the first impeller provided in an embodiment of this application;

[0023] Figure 7 A schematic diagram of the gap between the first impeller and the second impeller provided in an embodiment of this application. Detailed Implementation

[0024] To illustrate the technical content, structural features, achieved objectives, and effects of this application in detail, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. In the following description, for illustrative purposes, numerous specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of this application. However, various exemplary embodiments may also be implemented without these specific details or in one or more equivalent arrangements. Furthermore, the various exemplary embodiments may differ, but are not necessarily exclusive. For example, without departing from the concept of this application, the specific shape, structure, and characteristics of the exemplary embodiments may be used or implemented in another exemplary embodiment.

[0025] See Figure 1 , Figure 2 and Figure 3 As shown, it illustrates a compressor device of this application that can be used to extract small molecule gases for transporting them from one location to another.

[0026] The compressor unit 100 mainly includes a closed housing 10 and a Roots blower assembly 20 disposed within the housing 10. The housing 1 defines an inner cavity 11 and an inlet 12 and an outlet 13 that are in fluid communication with the inner cavity 11. The Roots blower assembly 20 includes an inner shell 2, an impeller assembly 3, a gearbox 4, a bearing assembly 5, and a motor assembly 6. The Roots blower assembly 20 provides the flow power for gas to flow from the inlet 12 to the outlet 13.

[0027] In the embodiments of this application, the air inlet 12 and the air outlet 13 are located at the front and rear ends of the enclosed housing 1, respectively. In some specific embodiments, the enclosed housing 1 may be assembled from multiple housing bodies. In this embodiment, the enclosed housing 1 includes a cap-shaped front housing 101, a cap-shaped rear housing 102, and a connecting housing 103 located in the middle. The air inlet 12 is located at the front of the front housing 101, and the air outlet 13 is located at the rear of the rear housing 102. The rear of the front housing 101 has a flange-shaped flange 1011, and the front of the rear housing 102 has a flange-shaped flange 1021. The flange-shaped flange 1011, the flange-shaped flange 1021, and the connecting housing 103 are fixedly joined together by a plurality of threaded fasteners 104.

[0028] The inner shell 2 is disposed within the inner cavity 11 of the outer shell 1. In this example, the inner shell 2 is placed within the portion of the inner cavity 11 corresponding to the front outer shell 101. In this embodiment, the inner shell 2 includes a cylindrical body 201, a front wall plate 202 that is sealed to the front end face of the cylindrical body 201, and a rear wall plate 203 that is sealed to the rear end face of the cylindrical body 201. Figure 4 As shown, the inner shell 2 defines an impeller cavity 21 and a plurality of intake ports 22 and exhaust ports 23 that are in fluid communication with the impeller cavity 21. The plurality of intake ports 22 are located on the cylinder 201, and the exhaust ports 23 are located on the rear wall plate 203.

[0029] Continue as Figure 3 As shown, an air intake channel 111 is formed inside the inner cavity 11, located outside the inner shell 2; the air intake channel 111 is fluidly connected to the air inlet 12 and multiple air intakes 22. Similarly, an air outlet channel 112 is formed inside the inner cavity 11, located outside the inner shell 2. The air outlet channel 112 is fluidly connected to the air outlet 13 and the exhaust port 23.

[0030] The impeller assembly 3 includes a first shaft 31 extending along a first axis X1, a first impeller 32 mounted on the first shaft 31, a second shaft 33 extending along a second axis X2 parallel to the first axis X1, and a second impeller 34 mounted on the second shaft 33. The first impeller 32 and the second impeller 34 are located within an impeller cavity 21 and are configured to deliver gas from a plurality of intake ports 22 to an exhaust port 23. Referring to Figure 4, the first impeller 32 and the second impeller 34 are uniformly sized, centrally symmetrical members and each has three blades, with the blades of the first impeller 32 meshing with the blades of the second impeller 34.

[0031] See also Figure 3 The gearbox 4 is disposed in the inner cavity 11 and located on the front side of the inner shell 2. The gearbox 4 includes a housing 41 and a first gear 42 and a second gear 43 located within the housing 41. The rear end of the housing 41 is sealed to the front wall plate 202 by a plurality of threaded fasteners 44. The first gear 42 and the second gear 43 mesh with each other.

[0032] The bearing assembly 5 is located in the inner cavity 11 and on the rear side of the inner shell 2. The bearing assembly 5 provides a pair of first bearings 51 arranged front to back and a pair of second bearings 52 arranged front to back. Both the first bearings 51 and the second bearings 52 are supported on the rear wall plate 23. These bearings will help support the first shaft 31 and the second shaft 33.

[0033] The motor assembly 6 is built into the inner cavity 11 and located behind the bearing assembly 5. In this example, the motor assembly 6 is placed in the portion of the inner cavity 11 corresponding to the front housing 101. The motor assembly 6 includes a stator 61, a rotor 62 located inside the stator 61, and a motor shaft 63 fixed to the center of the rotor 62.

[0034] The first shaft 31 is supported on a pair of first bearings 51. The front end of the first shaft 31 passes through the front wall plate 202 and extends into the housing 41. A third bearing 53 is provided between the first shaft 31 and the front wall plate 202, and the third bearing 53 is located inside the housing 41. The rear end of the first shaft 31 is coupled to the front end of the motor shaft 53 via a coupling 7. The front end of the second shaft 32 also passes through the front wall plate 202 and extends into the housing 41. A fourth bearing 54 is provided between the second shaft 31 and the front wall plate 202, and the fourth bearing 53 is located inside the housing 41. The second gear 42 is mounted on the second shaft 32.

[0035] like Figure 5a , Figure 5b , Figure 5c , Figure 5d and Figure 5e As shown, when the compressor equipment is working, it relies on the first impeller 32 and the second impeller 34 of the Roots blower device 20 rotating in opposite directions at the same speed to realize the entire process of intake, compression, and exhaust of the gas 800 to be transported; wherein, Figure 5a This is the inhalation process. Figure 5b , Figure 5c , Figure 5d For the compression process, Figure 5e This refers to the exhaust process. For a three-lobe rotor, six intake and exhaust processes are completed in one working cycle, compared to only four intake and exhaust processes in one working cycle for a two-lobe rotor, making it more efficient.

[0036] See Figure 6The diagram shows a schematic representation of the first impeller 32 according to an embodiment of this application. The first impeller 32 is a centrally symmetrical component and comprises three blades 321, 322, and 323 with identical outer contour shapes. The specific shape of the blade 321 will be described in detail below as an example.

[0037] The outer contour shape of the blade 321 is composed of the left half outer contour shape 3211 and the right half outer contour shape 3212, which are mirror images of each other. Following the direction from the tip of the blade to the root, the outer contour shape 3211 of the left half has a tip center point A, a tip point B, a first transition point C, a second transition point D, a third transition point E, a fourth transition point F, and a root center point G. The outer contour shape of the left half is composed of a tip-rolled arc segment AB located between the tip center point A and the tip point B, a transition arc segment BC located between the tip point B and the first transition point C, an involute segment CD located between the first transition point C and the second transition point D, an arc envelope segment DE located between the second transition point D and the third transition point E and meshing with the transition arc segment, a point-meshing cycloid segment EF located between the third transition point E and the fourth transition point F and meshing with the tip point B, and a root-rolled arc segment FG located between the fourth transition point F and the root center point G and meshing with the tip-rolled arc segment.

[0038] In a specific embodiment, the parameter ranges of each segment of the outer contour shape 3211 of the left half of the blade 321 can be calculated as follows, wherein, among the basic parameters, A is the impeller center distance and D is the theoretical meshing diameter of the impeller; see Figure 6 The pitch circle radius R indicated in the figure p Impeller radius R, pitch circle radius R p =A / 2, impeller radius R = D / 2; in the following formula, α1 can be taken as (2:4)°, z = 3.

[0039] (I) Section AB

[0040] Section AB is a blade tip rolling arc of radius R to ensure impeller tip sealing; its parametric equation is:

[0041]

[0042] in, (α2 is described in “(II) BC” below)

[0043] (II) Section BC

[0044] Segment BC is an arc with radius r1 centered on the involute base circle, and its parametric equation is as follows:

[0045]

[0046] Where r2 = r o ; α2=α e -β e r1 = R e sinα e ; (r o α e β e R e See the description of "(III) CD section" below.

[0047] (3) CD segment

[0048] Segment CD is an involute curve, and its parametric equation is as follows:

[0049]

[0050] tanα e ≥t≥tanα b

[0051] Where, r o The radius of the involute base circle is... The base circle correction factor ε1 = 0.9; α p The pressure angle of the pitch circle, The radii of the arcs containing the starting point D and the ending point C of the involute are respectively: The meshing coefficient of the involute segment is ε2 = 0.3; the pressure angles corresponding to the starting point D and ending point C of the involute are respectively: The polar angles corresponding to the starting point D and ending point C of the involute are respectively:

[0052] (iv) Section DE

[0053] Segment DE is the circular envelope that meshes with segment BC, and its parametric equation is as follows:

[0054]

[0055] in,

[0056] (V) Segment EF

[0057] Segment EF is a point-meshing cycloid that meshes with the tip B of the blade, and its parametric equation is as follows:

[0058]

[0059] in, r E The polar radius of point E can be obtained through the parametric equations in "(IV) DE segment".

[0060] (vi) FG section

[0061] Segment FG is the blade root rolling arc segment that meshes with the tip rolling arc segment AB. Its parametric equations are as follows:

[0062]

[0063] In order to prevent collisions and abrasions between the first impeller 32 and the second impeller 34, and to take into account factors such as thermal expansion, deformation under load, clearance of the synchronous gears and bearings, and processing and installation, gaps are provided between the first impeller 32 and the second impeller 34, between the first impeller 32 and the second impeller 34 and the front wall plate 202, between the first impeller 32 and the second impeller 34 and the rear wall plate 203, and between the outer periphery of the first impeller 32 and the second impeller 34 and the impeller cavity 21. Specifically, the gaps are as follows:

[0064] like Figure 7 As shown, the first impeller 32 and the second impeller 34 are both cast iron impellers and have a first meshing clearance d1 between them.

[0065] See also Figure 4 The impeller assembly 3 defines an outer peripheral boundary C1, and the inner shell 2 has an inner peripheral boundary C2 that defines the inner diameter of the impeller cavity 21. There is a second gap d2 between the outer peripheral boundary C1 and the inner peripheral boundary C2. The first meshing gap d1 is less than or equal to twice the second gap d2; preferably, the first meshing gap d1 is twice the second gap d2.

[0066] See also Figure 3 The first impeller 32 and the second impeller 34 define a front base surface F1 perpendicular to the first axis X1 and a rear base surface F2 perpendicular to the first axis X1. The front base surface X1 has a third gap d3 with the front wall plate 202, and the rear base surface F2 has a fourth gap d4 with the rear wall plate 203. The third gap d3, the fourth gap d4 and the first meshing gap d1 are equal.

[0067] In addition, there is a second meshing clearance (not shown in the figure) between the first gear 42 and the second gear 43, which is less than or equal to 1 / 3 of the first meshing clearance d1.

[0068] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made without departing from the spirit and scope of this application. The scope of protection claimed by this application is defined by the appended claims, specification, and their equivalents.

Claims

1. A compressor device for extracting small molecule gases, comprising a housing and a Roots blower assembly, said housing defining an inner cavity and an inlet and an outlet in fluid communication with said inner cavity; characterized in that, The Roots blower assembly is disposed within the cavity and includes: An inner casing defines an impeller cavity and one or more intake ports and one or more exhaust ports fluidly communicating with the impeller cavity, the intake ports fluidly communicating with the inlet port and the exhaust ports fluidly communicating with the outlet port; and An impeller assembly includes a first shaft extending along a first axis, a second shaft extending along a second axis parallel to the first axis, and a pair of impellers respectively mounted on the first shaft and the second shaft. The pair of impellers are located within the impeller cavity and are configured to deliver gas to be conveyed from one or more intake ports to one or more exhaust ports. The impellers are centrally symmetrical members and have three-lobed blades. The blades of the pair of impellers mesh with each other. The outer contour shape of each leaf blade is composed of a left half and a right half that are mirror images of each other. Following the direction from the leaf tip to the leaf root, the left half of the outer contour shape has a leaf tip center point (A), a leaf tip point (B), a first transition point (C), a second transition point (D), a third transition point (E), a fourth transition point (F), and a leaf root center point (G). The left half of the outer contour shape consists of a leaf tip rounded arc segment located between the leaf tip center point (A) and the leaf tip point (B), and a segment located from the leaf tip point (B) to the leaf root center point (G). The system comprises a transition arc segment at the first transition point (C), an involute segment between the first transition point (C) and the second transition point (D), an arc envelope segment between the second transition point (D) and the third transition point (E) that meshes with the transition arc segment, a point-meshing cycloid segment between the third transition point (E) and the fourth transition point (F) that meshes with the tip of the blade (B), and a blade root rolling arc segment between the fourth transition point (F) and the center point of the blade root (G) that meshes with the tip rolling arc segment.

2. The compressor equipment according to claim 1, characterized in that, The impeller is a cast iron impeller, and there is a first meshing gap between the blades of the pair of impellers. The pair of impellers defines an outer peripheral boundary. The inner shell has an inner peripheral boundary that defines the inner diameter of the impeller cavity. There is a second gap between the outer peripheral boundary and the inner peripheral boundary. The first meshing gap is less than or equal to twice the second gap.

3. The compressor equipment according to claim 2, characterized in that, The inner shell includes a cylindrical body, a front wall plate that is sealed to the front end face of the body, and a rear wall plate that is sealed to the rear end face of the body. The front and rear ends of the first shaft pass through the front wall plate and the rear wall plate, respectively, and the front end of the second shaft passes through the front wall plate.

4. The compressor equipment according to claim 3, characterized in that, The pair of impellers defines a front base surface perpendicular to the first axis and a rear base surface perpendicular to the first axis. The front base surface has a third gap with the front wall plate, and the rear base surface has a fourth gap with the rear wall plate. The third gap, the fourth gap, and the first meshing gap are equal.

5. The compressor equipment according to claim 3, characterized in that, The one or more air intakes are located on the cylinder.

6. The compressor equipment according to claim 5, characterized in that, The number of air intakes is multiple.

7. The compressor equipment according to claim 3, characterized in that, The one or more exhaust ports are located on the rear wall panel.

8. The compressor equipment according to claim 3, characterized in that, The Roots blower assembly further includes: a gearbox, which is disposed in the inner cavity and includes a housing and a first gear and a second gear located within the housing. The rear end of the housing is sealed to the front wall panel. The first gear and the second gear mesh with each other. The front end of the first shaft extends into the housing and the first gear is mounted on the first shaft. The front end of the second shaft extends into the housing and the second gear is mounted on the second shaft. A second meshing clearance exists between the first gear and the second gear, and the second meshing clearance is less than or equal to 1 / 3 of the first meshing clearance.

9. The compressor equipment according to claim 3, characterized in that, The Roots blower device further includes a motor assembly, which is placed in the inner cavity and includes a stator, a rotor, and a motor shaft. The motor shaft is coupled to the rear end of the first shaft via a coupling.

10. The compressor equipment according to claim 1, characterized in that, The air inlet and the air outlet are located at the front and rear ends of the outer casing, respectively.

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