JP5142263B2 - Liquid ring pump - Google Patents

Description

  The present invention relates to a liquid ring pump having a cylindrical casing and an impeller having a plurality of blade numbers, and sucking and compressing gas by a seal ring generated by the rotation of the impeller.

  6A and 6B are diagrams showing an example of a conventional liquid ring pump. This conventional liquid ring pump includes a cylindrical casing 1, an impeller 4 having a large number of blades 4a eccentrically mounted therein, an intake port 8 provided on the side of the impeller 4, and a discharge port. It has a configuration provided with a port 9 (see, for example, Patent Document 1).

  In this liquid ring pump, the liquid (sealed liquid) 13 previously injected into the casing 1 is rotated by the impeller 4 in the direction indicated by the arrow R in FIG. By rotating so as to be pressed against the inner wall, a sealing ring L is formed, and an air chamber G surrounded by the blade 4a of the impeller 4 and the gas-liquid boundary surface 10 of the sealing ring L is formed. . The air chamber G expands and contracts while the impeller 4 makes one rotation because the centers of the casing 1 and the impeller 4 are biased.

An intake port 8 and a discharge port 9 are provided on the partition plate 3 provided on the side of the impeller 4 (on one side in the axial direction or on both sides in the axial direction). The discharge port 9 is in a phase where the air chamber G is contracted, and communicates with the external intake port and the discharge port, respectively. As the air chamber G expands, external gas is sucked from the intake port 8, compressed and pressurized by the reduction of the air chamber G , and then discharged from the discharge port 9 to the outside of the casing 1. By the above series of operations, gas is sucked and compressed, and the function as a pump is exhibited.

JP 2002-332978 A

(1) In the casing of the liquid ring pump, the impeller rotates as the impeller rotates, while moving away from the boss surface of the impeller and again approaching the boss surface and reattaching to the boss surface.
Suction and compression are performed by enlarging and reducing the space surrounded by the blades, the boss surface, and the liquid surface. Here, a loss of power occurs due to friction between the sealing liquid rotating with the impeller and the stationary casing.
(2) Depending on the operating conditions, the tip of the blade is separated from the liquid level on the side opposite to the top (the position where the casing and impeller blades are farthest and in the vicinity thereof), and two (or more) working spaces are connected and sealed. The amount is reduced.

An object of the present invention is to increase the gap between the sealing liquid and the casing on the top side of the liquid ring pump to reduce the friction in this portion and reduce the driving power .
In this specification, “the top of the liquid ring pump” means “the position where the casing and the impeller blades are closest to each other and its vicinity”, and “the top side of the liquid ring pump” means “the casing And “the portion within the range of ± 90 ° centered on the position where the impeller blades are closest to each other” and “the opposite side from the top of the liquid ring pump” are “the casing and the impeller blades are farthest away from each other” A portion within a range of ± 90 ° with respect to the position ”.

(1) In order to achieve the above object, a liquid ring pump according to the present invention is provided in a substantially cylindrical casing, an impeller having a plurality of blades attached eccentrically therein, and provided on the side of the impeller. A gas-liquid boundary surface and a blade of a sealing ring , which are provided by an intake port for sucking gas from the outside and a discharge port for discharging a part of the gas in the casing, and rotating the liquid sealed inside the casing with an impeller In a liquid ring pump that sucks and compresses gas by expanding and reducing the space surrounded by the blades of the car, the tip of the impeller is moved by moving the center of curvature of the casing on the top side of the liquid ring pump toward the impeller center It is characterized by forming a large gap with.
(2) The liquid ring pump of the present invention is characterized in that, in the above (1), there are a plurality of curvature centers of the casing on the top side of the liquid ring pump .

The liquid ring pump of the present invention has the following excellent effects.
By increasing a gap between the casing and the impeller tip at the top side of the liquid seal pump, the friction between the casing of the sealing liquid is reduced, it is possible to reduce the power for driving the liquid ring pump.

  Hereinafter, embodiments of the liquid ring pump of the present invention will be described in detail with reference to the drawings. However, the present invention is not construed as being limited thereto and does not depart from the scope of the present invention. However, various changes, modifications, and improvements can be added based on the knowledge of those skilled in the art.

FIG. 1 is a cross-sectional view of a main part of a comparative example for explaining a liquid ring pump according to an embodiment of the present invention.
In the liquid ring pump, an impeller 21 is eccentrically provided in a cylindrical casing 20, and the impeller 21 rotates in the arrow R direction. In addition, an intake port 22 and a discharge port 23 are provided inside the casing 20.
In FIG. 1, point a indicates the center position of the substantially cylindrical casing 20, and the outer broken line 26 is a circle having a diameter D centered on the point a, and is at the top where the impeller and the casing reappear. The casing in the case where the impeller contacts the casing is shown. A point b indicates the center position of the impeller 21, and an inner broken line 27 is a circle having a diameter d with the point b as the center.

  In this liquid ring pump, the liquid (sealed liquid) 24 previously injected into the casing 20 is rotated in the direction indicated by the arrow R by the impeller 21 and is pressed against the inner wall of the casing 20 by centrifugal force. By rotating, a sealing ring is formed, and an air chamber G surrounded by the blade 21a of the impeller 21 and the gas-liquid boundary surface 25 of the sealing ring is formed. And since the center of the casing 20 and the impeller 21 is biased, the air chamber G expands and contracts while the impeller 21 rotates once.

The intake port 22 disposed on the side of the impeller 21 (one axial side or both axial sides) has a phase in which the air chamber G expands, and the discharge port 23 has a phase in which the air chamber G contracts. It communicates with the external intake and discharge ports. As the air chamber G expands, external gas is sucked from the intake port 23, compressed and pressurized by the reduction of the air chamber G , and then discharged from the discharge port 23 to the outside of the casing 20. Through the above series of operations, fluid is sucked and discharged, and the function as a pump is exhibited.

The gap between the casing 20 and the tip of the impeller 21 at the top of the liquid ring pump is considerably small in the original casing indicated by the outer broken line 26. For this reason, the friction between the sealing liquid 24 and the casing 20 increases, and the power consumption for driving the liquid sealing pump increases.
Therefore, as shown in FIG. 1, if the diameter of the casing 20 is increased, the gap dl between the casing 20 and the tip of the impeller 21 at the top is increased, and the friction between the sealing liquid 24 and the casing 20 can be reduced. it can.
However, as shown in FIG. 1, when the diameter of the casing 20 is simply increased, the amount of the sealing liquid 24 increases correspondingly, and the power for driving the liquid sealing pump increases.

Therefore, as shown in FIG. 2, the present invention moves the center of curvature c of the casing 20a at the apex where the casing 20 and the impeller 21 are closest to each other by moving δ in the direction of the impeller 21 center b by the tip of the impeller 21. The gap dl is formed large. In this case, the radius R of the casing 20a at the top and the casing 20b at the opposite side of the top are the same, and the crossing portion is smoothly connected. The range of the casing 20a centering on the center of curvature c is influenced by the size of δ, but is centered on the minimum range of the top of the liquid ring pump and the maximum position where the casing 20 and the impeller 21 are closest. As a range of ± 90 °.
2, the same reference numerals as those in FIG. 1 denote the same members, and the outer broken line 26 indicates the position of the casing when the impeller and the casing are in contact with each other at the top where the impeller and the casing re-approach.
Although the friction between the sealing liquid 24 and the inner surface of the casing 20 is particularly large in the vicinity of the top, the friction can be reduced by forming a large gap dl between the inner surface of the casing 20 and the tip of the impeller 21 at the top.

  In the example illustrated in FIG. 2, the casing 20 a has a single center of curvature c at the top, and is formed by a single radius R curve centered on the point c. A continuous curve may be formed by appropriately moving between the points b and setting a plurality, and changing the radius of curvature in accordance with the centers of curvature.

In FIG. 3, the distance from the tip of the impeller 21 is narrowed by moving the curvature center c of the casing 20 b on the opposite side of the top where the casing 20 and the impeller 21 are closest to each other by δ in the direction of the impeller 21 center b. Indicates the state. In this case, the radius R of the casing 20 at the top and the casing 20b on the side opposite to the top are the same, and the crossing portion is smoothly connected. The range of the casing 20b centered on the center of curvature c is affected by the magnitude of δ, but is a portion within a range of ± 90 ° centered on the position where the casing and the impeller blades are farthest apart (ie, “liquid” For example, a range of ± 60 ° to 90 ° centered on a position where the casing and the impeller blade are farthest apart is desirable.
3, the same reference numerals as those in FIG. 1 denote the same members, and the outer broken line 26 indicates the position of the conventional casing.
By forming the distance between the casing 20b and the tip of the impeller 21 on the side opposite to the top where the casing 20 and the impeller 21 of the liquid ring pump are closest to each other, the tip of the blade 21a is separated from the liquid level 25. Can be prevented.

  In the example shown in FIG. 3, the center of curvature c of the casing 20b on the side opposite to the top is one and formed by a curve of one radius R centered on the point c. A continuous curve may be formed by appropriately moving between the points a and b to set a plurality of points and changing the radius of curvature in accordance with the centers of curvature.

FIG. 4 shows an example in which the short blades 21s in the radial direction are alternately provided with the long blades 21a in the liquid ring pump shown in FIGS.
4, the same reference numerals as those in FIG. 1 mean the same members.

As shown in FIG. 6, the liquid ring pump is provided with a partition plate 3 on the side (one axial side or both axial sides) of the impeller 4, and an intake port 8 and a discharge port 9 are arranged on the partition plate 3. Established.
Also in the present invention, the liquid (sealing liquid) 24 previously injected into the casing 20 is rotated by the impeller 21 and rotated so as to be pressed against the inner wall of the casing 20 by centrifugal force, thereby forming a sealing ring. Is done. At this time, a force that adheres to the partition plate wall surface acts on the sealing liquid that contacts the partition plates on both sides in the axial direction. For this reason, the shape of the gas-liquid boundary surface 25 in the axial direction has a large diameter at the central portion in the axial direction and a small diameter on both sides in the axial direction.
FIG. 5 shows a state in which the diameter of the inner surface of the casing 20 is formed smaller than both end portions in the central portion in the axial direction, and the upper portion shows the top of the liquid ring pump. In this example, the liner 30 is fixed to the inner surface of the casing 20 so as to minimize the diameter of the central portion in the axial direction as in the shape shown in FIG. In addition, it is applied in a crescent shape on the opposite side of the top of the liquid ring pump. Instead of applying the liner 30, the shape of the casing 20 itself may be formed in this way. By adopting such a shape, the gas-liquid boundary surface 25 is formed so that the blade tip does not leave the sealing ring.

  The present invention relates to food, chemical / petroleum, pulp industry (vacuum evacuation, concentration, distillation, drying, compression / air supply of flammable substances) and other industries such as electric / electronic, civil engineering / architecture, steel / metallurgy, pharmaceutical / medical, etc. Available in the field.

It is principal part sectional drawing of a comparative example. It is principal part sectional drawing for demonstrating an example of the liquid ring type pump which concerns on embodiment of this invention. It is principal part sectional drawing for demonstrating the example of the liquid ring type pump which concerns on the related form of this invention. It is principal part sectional drawing for demonstrating the other example of the liquid ring type pump which concerns on the related form of this invention. It is principal part sectional drawing for demonstrating the other example of the liquid ring type pump which concerns on the related form of this invention. It is a figure which shows an example of the conventional liquid ring pump.

Explanation of symbols

20 Casing 21 Impeller 21a Blade 21s Short blade 22 Intake port 23 Discharge port 24 Liquid (sealed liquid)
25 Gas-liquid interface 26 Outer broken line 27 Inner broken line 28 Boss part 30 Liner G Air chamber

Claims (2)

A substantially cylindrical casing, an impeller having a plurality of blades eccentrically attached therein, an intake port provided on the side of the impeller, and a part of the gas in the casing Intake and compression of gas by expanding and reducing the space surrounded by the gas-liquid boundary surface of the seal ring and the impeller blades, which is generated by rotating the liquid sealed inside the casing with the impeller, with a discharge port for discharging In the liquid ring pump, the liquid ring pump is characterized in that the gap between the tip of the casing on the top side of the liquid ring pump and the tip of the impeller is increased by moving the center of curvature of the casing toward the center of the impeller.   The liquid ring pump according to claim 1, wherein there are a plurality of curvature centers of the casing on the top side of the liquid ring pump.

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