CN204984891U - Two effect liquid rotary pumps of doublestage - Google Patents

Abstract

The utility model provides a (B, ) two effect liquid rotary pumps of doublestage (b). Set up the baffle in the impeller and the pump body, constitute two independent pump bodys. The impeller separates the doublestage impeller that constitutes the vacuum pump by the baffle, and central symmetry is placed in the pump body, every grade of impeller is at the in -process that rotates the round, all to twice effect of the gas medium within the pendular ring. When main part parts size was the same with the rotational speed, theoretical bleed air flow was the twice of existing product. The doublestage impeller all is central symmetrical arrangement in this product, can keep balance the radial force, reduces the vibration and increases the bearing life -span, compares with three present kind liquid rotary pumps, and the gas flow that it had the double -acting pump concurrently is big, the advantage of the compression relative altitude of the balanced and two -stage (two -speed) pump of radial force.

Description

A double-stage double-acting liquid ring pump

technical field

The utility model relates to a liquid ring pump, in particular to a double-stage double-action liquid ring pump.

technical background

Liquid ring pump is a kind of fluid machine that uses the space formed by the high-speed rotating liquid to cooperate with the blades to achieve the purpose of compressing and transporting gas. Its working principle can be illustrated by the schematic diagram of a typical liquid ring pump shown in Figure 6. In the circular pump body there is an impeller with blades. There is a small distance between the impeller and the center of the pump body (this distance is called eccentricity). The inside of the pump body is filled with a certain amount of liquid. When the impeller rotates, it drives the liquid to rotate. Due to the centrifugal force, the liquid will flow against the inner wall of the pump, thus forming a liquid ring. Due to the eccentricity of the pump body, an eccentric cavity is formed between the inner surface of the liquid ring and the hub of the impeller. In this way, a closed space is formed between the two blades and the inner surface of the liquid ring. In the direction of rotation shown in the figure, the volume of the closed space on the right gradually increases, while the volume of the closed space on the left gradually decreases. If the space on the right is communicated with the outside world, the gas will be sucked in through the intake window, and the space on the left side is communicated with the outside world, then the gas can be compressed and discharged through the exhaust window. This working process is similar to vane (vane) pumps in hydraulic and pneumatic engineering. The liquid ring of the liquid ring pump is equivalent to the pump body of the sliding vane pump. However, since the liquid ring itself is non-rigid, its shape and size will change with the change of speed and pressure, so the gas flow will also change, which is very different from the sliding vane pump. In engineering, most of the working liquid is water, so liquid ring pumps are also called water ring pumps. But in fact the liquid is not limited to water. For example, when chlorine gas is transported in chemical engineering, the working liquid is concentrated sulfuric acid.

When the liquid ring pump is working, if the inlet pressure is lower than the atmospheric pressure and the outlet pressure is equal to the atmospheric pressure, it is a vacuum pump. If the inlet pressure is equal to atmospheric pressure and the outlet pressure is higher than atmospheric pressure, it is a compressor. There are also cases where the inlet pressure is lower than atmospheric pressure and the outlet pressure is higher than atmospheric pressure. At this time, the liquid ring pump works as a vacuum pump and a compressor at the same time. Compared to other volumetric machines for conveying gases. The liquid ring pump has the characteristics of simple structure and convenient maintenance. At the same time, since no lubricating oil is needed, the gas conveyed will not be polluted by oil, which is very important for the application of the food industry. Due to these characteristics, liquid ring pumps are widely used in processes with low vacuum or low pressure, such as vacuum filtration (chemical treatment, mineral processing, papermaking, etc.), vacuum distillation (food, papermaking), vacuum disinfection (hospital, Laboratory, etc.), chemical process (transporting flammable, explosive and corrosive gases) and power engineering (vacuum maintenance of steam turbine condenser) and other fields.

Single and double acting pumps. The closed space of the liquid ring pump shown in Figure 6 sucks and exhausts once during the impeller rotation, so it is called a single-acting pump. Figure 7 shows a double-acting pump. The inner surface of the pump body is not a circle, but two semicircles with a certain distance. In this way, the shape of the inner surface of the liquid ring also forms two semicircles, which is different from that of the double-acting vane pump. The inner surface of the stator is similar. The closed working space between the blades has two suction and exhaust processes during the impeller rotation, so it is called double action. Compared with single-acting pumps, under the condition of basically the same size, the gas volume can be doubled, making the pump more compact. At the same time, the radial force acting on the impeller can be balanced, the load on the bearing is reduced, and the service life is improved.

Axial air distribution and radial air distribution. In the structure shown in Figure 6, the gas enters and leaves the impeller axially from the end face of the impeller, which is called axial gas distribution. In the structure of Figure 7, the gas enters and exits the impeller radially from the center of the impeller, which is called radial gas distribution. Although the axial air distribution in Figure 6 is used for single-acting pumps, and the radial air distribution in Figure 7 is for double-acting pumps, in fact the air distribution mode has nothing to do with the action mode.

Single and dual stage pumps. Since the liquid ring is non-rigid, the pressure used is limited. In order to increase the vacuum (for the vacuum pump) and the discharge pressure (for the compressor), a two-stage liquid ring pump has been developed, that is, two impellers are used in series to increase the pressure or vacuum (in short, to increase the compression ratio). As shown in Figure 2, in engineering practice, the two impellers are often made as a whole, with a partition in the middle to separate the two impellers.

Design method of liquid ring pump. The flow process of liquid and gas in a liquid ring pump is very complicated, and it is difficult to rely on CFD technology for flow calculation at present. Therefore, the design calculation still needs to use traditional calculation methods and carry out sufficient experimental improvements.

For existing liquid ring pumps, to increase the pumping capacity, the diameter of the impeller must be increased or the rotational speed must be increased. Enlarging the diameter of the impeller requires more steel and processing costs, and increasing the rotational speed will reduce the efficiency; at the same time, the impeller is eccentrically arranged, resulting in imbalance The radial force increases the vibration and noise, and the bearing life is also affected.

Contents of the invention

In order to make the structure of the pump more compact, balance the radial force acting on the impeller at the same time, reduce the load on the bearing, and improve the service life of the pump, the utility model integrates two technical measures of double-stage and double-action into one pump body And one impeller, becomes a two-stage double-acting liquid ring pump. The specific idea is:

A two-stage double-acting liquid ring pump, including an impeller, a pump body, a right side cover, a left side cover, a shaft, a bearing part, a sealing part and a working fluid, and is characterized in that the impeller includes a plurality of blades and an integrated Hub body and impeller partition; multiple blades are radially evenly fixed on the hub body, and the impeller partition is located on the hub body to separate each blade into left blade and right blade;

The pump body is a hollow cylindrical body, and its inner cavity is provided with a pump body partition corresponding to the impeller partition. The impeller partition and the pump body partition are in the same plane, perpendicular to the central axis of the pump body, and together The cavity is divided into left and right parts in the axial direction; the gap between the pump body partition and the impeller partition is matched in the radial direction, so that the impeller can rotate freely in the pump body; the pump body partition, impeller partition, left blade, The right vane, the right cover, and the left cover form a left and right two-stage independent double-acting liquid ring pump; the ratio of the axial lengths of the left and right parts is K, and the K value is determined by the distribution of the compression ratio between the two stages. Decide;

The inner cavity of the pump body is filled with working liquid, the impeller is coaxially installed in the pump body, the shaft penetrates into the hub body and is connected with it through a keyway or hot-press fit; the two ends of the shaft are respectively rotatably matched with the left and right side covers through bearing components, And are respectively sealed by the sealing parts; the central axes of the impeller, the pump body and the shaft coincide;

Both the right side cover and the left side cover are provided with an air inlet and an exhaust port;

During work, the air inlets of the right cover and the left cover are connected through the external pipeline, and the exhaust ports of the right cover and the left cover are connected, so that the two-stage working spaces are connected in parallel to form a single-stage double-acting pump ; or the air inlet of the right cover is used as the inlet of the pump, the exhaust port of the right cover is connected with the air inlet of the left cover, and the air outlet of the left cover is used as the outlet of the pump, so that the liquid ring pump works in two stages The space is connected in series to form a two-stage double-acting pump.

Further, in the double-stage double-acting liquid ring pump, a left distributor is installed between the left blade at the left end of the pump body and the sealing member, and a right distributor is installed between the right blade at the right end of the pump body and the sealing member.

Further, in the double-stage double-acting liquid ring pump, the inner cavity surface of the pump body is formed by a smooth transition between the upper and lower cylindrical surfaces and the left and right cylindrical surfaces; the radius of the upper and lower cylindrical surfaces is R, and the eccentric The distance is e, and the radius of the left and right cylindrical surfaces is r; the centers O ₁ and O ₂ of the upper and lower cylindrical surfaces are on the same straight line as the impeller axis center O, and O ₁ and O ₂ are equidistantly symmetrical to O; R, r and e can be calculated and determined according to the existing double-acting pump design method.

Further, in the description of the structure of the double-stage double-acting liquid ring pump, the left-right relationship is relative, and the left-right position reference relationship is interchangeable.

Figure 2 is a simplified diagram of the impeller. The two-stage impeller is made into one integral part, and the middle partition separates the two-stage impeller. Figure 3 shows the structure of the pump body. In fact, two double-acting pump bodies are combined into one part, and the middle is still separated by a partition. Cooperating with the partition of the impeller, the working space of two double-acting pumps is formed, that is, two independent double-acting liquid ring pumps. Although the impeller is rotating and the pump body is stationary, there must be a gap in the radial direction between the pump body diaphragm and the impeller diaphragm, but the gap is small enough. From an engineering point of view, the two spaces can be considered to be independent. of. In this way, if the inlet port of one stage and the other stage of the two-stage impeller are connected, and the exhaust port of one stage is connected with the other stage, that is, the working spaces of the two stages are connected in parallel, a single-stage double-acting pump is formed. If A two-stage double-acting pump is formed by connecting the exhaust port of one stage of the two-stage impellers with the intake port of the other stage. Of course, the angles of the gas distribution windows of the distributor are different under the two connection methods. The geometric dimensions of the two double-acting pumps can be determined by existing design calculation methods. As for distributors and gas distribution methods, connection methods of pipelines, and bearings, seals, transmissions, etc., which constitute the necessary structural components of a complete product, existing general technologies can be used.

Compared with the existing single-acting pump, the double-stage double-acting liquid-ring ring vacuum pump proposed by the utility model can double the air volume under the condition of basically the same size, so that the structure of the pump is more compact. At the same time, the radial force acting on the impeller can be balanced, the load on the bearing is reduced, and the service life is improved.

Description of drawings

Figure 1 is a sectional view of the whole pump;

Fig. 2 is a schematic diagram of the impeller structure;

Fig. 3 is a schematic diagram of the structure of the pump body;

Figures 4a and 4b are sectional views of the impeller and the pump body;

Fig. 5 is a schematic diagram of the side cover;

Fig. 6 is a schematic diagram of a liquid ring pump;

Fig. 7 is a schematic diagram of a double-acting liquid ring pump;

Figures 8a and 8b are structural schematic diagrams of a distributor for radial air intake.

1-impeller, 2-pump body, 3-side cover, 4-side cover, 5-right distributor, 6-left distributor, 7-shaft, 8-bearing parts, 9-sealing parts, 10-left blade , 11-right blade, 12-impeller diaphragm, 13-impeller hub body, 14-pump body diaphragm, 15-air inlet, 16-exhaust port, 17-intake direction, 18-exhaust direction, 19 - pump casing, 20 - gas compression area, 21 - working liquid quality, 22 - suction area, 23 - blades.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

The main difference between the axial air intake and the radial air intake lies in the type of the distributor and the structure of the impeller hub. Here, the radial air intake is taken as an example to illustrate the specific implementation.

As shown in Figures 4a and 4b, it is a two-stage double-acting vacuum pump with radial air intake, left blade 10, right blade 11 and pump body 2; the radius of impeller 1 is r, and the inner surface of the pump body is formed by 4 arcs The cylindrical surface is connected to form, the radius of the upper and lower arcs is R, the radius of the left and right arcs is r, and r is the nominal radius of the impeller. In fact, the radius of these two small arcs on the pump body is slightly larger than the actual impeller. Radius, forming the radial clearance between the pump body and the impeller. The gap value is determined by the structural conditions, and can refer to the existing liquid ring pump gap value method.

In Figure 4a, O is the center of rotation of the impeller and also the axis of the pump. The distance (eccentricity) between the centers O1 and O2 of the _two arcs with _a radius R and the impeller center O is e, and the two ends of the two arcs are connected by a short arc with a radius r. There is a baffle in the middle of the pump body (refer to the baffle 14 in Figure 3), which corresponds to the baffle 12 on the impeller. The direction is divided into two parts, and the ratio of the length of the two parts is K. The dimensions r, R and e of the pump body can be calculated and determined according to the existing double-acting pump design method, while the K value is determined by the distribution of the compression ratio between the two stages.

The shape of the impeller is as shown in Figure 2, 10,11 are two-stage impellers, and 12 is a dividing plate. The impeller is divided into two parts by a partition 12 in the axial direction, and the axial position of the impeller partition is the same as that of the pump body partition 14, which together divide the working space of the whole pump into two independent parts. The size of each part of the impeller can be determined by the existing design calculation method according to the design parameters of the pump. The blade structure is designed according to the existing general liquid ring pump blades, and the inner cavity of the pump body 2 is filled with working liquid quality, and the selection of the working liquid quality is according to the existing general liquid ring pump method.

Fig. 1 is the assembly drawing of the two-stage double-acting liquid ring pump designed according to this utility model.

As shown in Fig. 3 and Fig. 4a, 4b, the core components of the pump are the impeller 1 and the pump body 2, the right side cover 3, the left side cover 4, the right distributor 5 and the left distributor 6, which jointly form a gas inlet and outlet channel. At the same time, the two side covers are also the support of the whole pump. The rest of the structural parts, including shafts, bearings and seals, are the same as conventional products. Fig. 5 is a schematic diagram of a side cover, which is provided with air inlet and outlet ports.

Figures 8a and 8b are structural schematic diagrams of one of the distributors in the radial air intake mode of the double-stage double-acting liquid ring pump designed according to this utility model.

During work, the air inlets of the right cover 3 and the left cover 4 in the two-stage impeller are connected through the external pipeline, and the exhaust ports of the right cover 3 and the left cover 4 are connected, so that the two-stage working spaces are connected in parallel. A single-stage double-acting pump is formed; the air inlet of the right cover 3 in the two-stage impeller is used as the inlet of the pump, the exhaust port of the right cover 3 communicates with the air inlet of the left cover 4, and the left cover 4 The air outlet of the pump is used as the outlet of the pump, so that the two-stage working spaces of the liquid ring pump are connected in series to form a two-stage double-acting pump.

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and modifications made within the spirit and principles of the present utility model Improvements and the like should all be included within the protection scope of the present utility model.

Claims (4)

1. A two-stage double-acting liquid ring pump, comprising an impeller (1), a pump body (2), a right side cover (3), a left side cover (4), a shaft (7), a bearing component (8), a seal Parts (9) and working fluid quality are characterized in that: The impeller (1) includes a plurality of blades and an integrated hub body (13) and impeller partition (12); the plurality of blades are radially and uniformly fixed on the hub body (13), and the impeller partition (12) is located at the hub On the body (13), each blade is divided into a left blade (10) and a right blade (11); The pump body (2) is a hollow cylindrical body, and its inner cavity is provided with a pump body partition (14) corresponding to the impeller partition (12), and the impeller partition (12) and the pump body partition (14) ) are coplanar, perpendicular to the central axis of the pump body (2), and jointly divide the pump body cavity into left and right parts in the axial direction; the pump body diaphragm (14) and the impeller diaphragm (12) have a clearance fit in the radial direction , so that the impeller (1) can rotate freely in the pump body (2); the pump body partition (14), impeller partition (12), left blade (10), right blade (11), right side cover ( 3), the left side cover (4) forms a left and right two-stage independent double-acting liquid ring pump; the ratio of the axial lengths of the left and right parts is K, and the K value is determined by the distribution of the compression ratio between the two stages ; The inner cavity of the pump body (2) is filled with working liquid, the impeller (1) is coaxially installed in the pump body (2), and the shaft (7) penetrates into the hub body (13) and fits it through a keyway or heat press connection; the two ends of the shaft (7) rotate through the bearing parts (8) and the left and right side covers respectively, and are respectively sealed by the sealing parts (9); the center of the impeller (1), the pump body (2) and the shaft (7) Axis coincidence; Both the right side cover (3) and the left side cover (4) are provided with an air inlet and an exhaust port; During work, the air inlets of the right cover and the left cover of the two-stage impeller are connected, and the exhaust ports of the right cover and the left cover are connected through external pipelines, so that the two-stage working spaces are connected in parallel to form a single Two-stage double-acting pump; or the air inlet of the right cover in the two-stage impeller is used as the pump inlet, the exhaust port of the right cover is connected with the air inlet of the left cover, and the air outlet of the left cover is used as the pump outlet , so that the two-stage working space of the liquid ring pump is connected in series to form a two-stage double-acting pump. 2. The double-stage double-acting liquid ring pump as claimed in claim 1, characterized in that: A left distributor (6) is installed between the left end left blade (10) and the left side cover (4) in the pump body (2), and the right end right blade (11) and the right side cover (3) in the pump body (2) ) with the right distributor (5). 3. The double-stage double-acting liquid ring pump according to claim 1 or 2, characterized in that: the surface of the inner cavity of the pump body (2) is smoothly connected by the upper and lower cylindrical surfaces and the left and right cylindrical surfaces. The radius of the upper and lower cylindrical surfaces is R, the eccentricity is e, and the radius of the left and right cylindrical surfaces is r; the centers O ₁ and O ₂ of the upper and lower cylindrical surfaces are on the same line as the center O of the impeller shaft, and O ₁ and O ₂ are equidistantly symmetrical with respect to O; R, r and e can be calculated and determined according to the existing double-acting pump design method. 4. The double-stage double-acting liquid ring pump according to claim 1 or 2, characterized in that the references of the left and right components of the liquid ring pump are interchangeable, and the left and right components are interchangeable.