Patent Application
20230287899
The present invention relates to a pump casing and a pump apparatus.
A pump apparatus is known that includes a rotational shaft, an impeller fixed to the rotational shaft, a motor that rotates the impeller together with the rotational shaft, and a pump casing having a suction port and a discharge port and housing the impeller (see for example Patent Document 1).
When the motor is driven, the rotational shaft and impeller rotate. When the impeller rotates, a liquid flows through the suction port into the pump casing and is pressurized as the impeller rotates. The pressurized liquid is discharged from the discharge port.
Depending on the intended use, the pump apparatus is periodically disassembled and cleaned in order to maintain the quality of the liquid to be conveyed. When the pump is removed from a pipe and an inside of the pump casing is cleaned, it is necessary to completely remove a liquid remaining in the pump casing. When the removed pump is moved, there is a concern that the liquid remaining in the pump casing will contaminate the surroundings.
It is therefore an object of the present invention to provide a pump casing and a pump apparatus including the pump casing, which have a simple structure and can be easily cleaned in an internal flow path.
In an embodiment, there is provided a pump casing having a suction port connected to a horizontally extending suction pipe, comprising: a suction nozzle with formed the suction port, and the suction nozzle sloping downward toward the suction port.
In an embodiment, the suction port is a bottom portion in the pump casing.
In an embodiment, the pump casing comprises a volute portion connecting to the suction nozzle, and the suction nozzle has a straight shape extending diagonally downward from the volute portion.
In an embodiment, the suction port is arranged below the volute portion, and a work space for connecting the suction nozzle to the suction pipe is formed between the volute portion and the suction nozzle.
In an embodiment, there is provided a pump casing having a suction port and a discharge port, comprising: a suction nozzle with formed the suction port, and the suction nozzle having a drain port at a bottom portion of the suction nozzle.
In an embodiment, there is provided a pump apparatus comprising: an impeller; a rotational shaft fixing to the impeller; a motor configured to rotate the rotational shaft; and a pump casing according to above described, the pump casing housing the impeller.
In an embodiment, the pump apparatus comprising a leg portion connected to the pump casing.
In an embodiment, the leg portion forms a space below a suction flange portion having the suction port, the space arranging a drain pan configured to catch a liquid discharged from the suction port.
In an embodiment, the pump casing comprises a suction nozzle with formed the suction port, the suction nozzle has a drain port at a bottom portion of the suction nozzle, and the leg portion forms a space below the drain port, the space arranging a drain pan configured to catch the liquid discharged from the suction port.
In an embodiment, the pump casing comprises a suction nozzle with formed the suction port, the suction nozzle has a drain port at a bottom portion of the suction nozzle, and the leg portion forms a space arranging a pipe connectable to the drain port.
In an embodiment, there is provided a pump apparatus comprising: an impeller; a rotational shaft fixing to the impeller; a motor configured to rotate the rotational shaft; and a pump casing housing the impeller, the motor comprises: a bearing configured to rotatably support the rotational shaft; a motor casing having a bearing support portion configured to support the bearing; and a bearing retainer configured to restrict a movement of the bearing in an axial direction of the rotational shaft.
In an embodiment, the bearing retainer is fixed to the bearing support portion.
In an embodiment, the bearing retainer has an annular shape.
In an embodiment, the pump apparatus is a vertical pump apparatus.
In an embodiment, there is provided a vertical pump apparatus comprising: an impeller; a rotational shaft fixing to the impeller; an impeller housing structure configured to house the impeller; and a gap adjustment structure configured to adjust a size of a gap between the impeller and the impeller housing structure.
In an embodiment, the gap adjustment structure comprises: a distance piece attached to a stepped portion of the rotational shaft; and at least one shim arranged between the distance piece and the impeller.
In an embodiment, there is provided a pump casing comprising: a suction nozzle having a suction port; and a volute portion connecting to the suction nozzle, and the suction nozzle slopes downward from a connection portion connected to the volute portion toward the suction port, and has a flow path whose cross-sectional area increases from the suction port to the connection portion.
In an embodiment, the suction nozzle has a wide portion arranged between the suction port and the connection portion.
In an embodiment, the wide portion extends horizontally.
In an embodiment, a cross-sectional area of the flow path increases at a constant rate of change from the suction port toward the connection portion.
In an embodiment, there is provided a pump casing comprising: a suction nozzle having a suction port; and a volute portion connected to a connection portion of the suction nozzle, and the volute portion having a volute chamber, a bottom surface of the volute chamber slopes downward from a peripheral portion of the volute chamber toward the connection portion.
In an embodiment, the suction nozzle slopes downward from the connection portion toward the suction port.
In an embodiment, the suction port is arranged at a position lower than a discharge port of the pump casing.
The pump casing includes a suction nozzle that can discharge an inside liquid at the bottom portion of the flow path of the pump casing. Therefore, the liquid in the pump casing is discharged outside from the suction nozzle by the action of gravity.
Embodiments of the present invention will be described with reference to the drawings.
When the motor 7 is driven, a rotation of the motor 7 is transmitted to the rotational shaft 1, and the rotational shaft 1 and the impeller 3 rotate. When the impeller 3 rotates, the liquid flows into the pump casing 5 through the suction port 12, and is pressurized as the impeller 3 rotates. The pressurized liquid is discharged from the discharge port 13. In the embodiment shown in
The shaft sealing device 30 is a device that seals a gap between the rotational shaft 1 and the intermediate bracket 50. An example of the shaft sealing device 30 includes a double mechanical seal. The shaft sealing device 30 includes a rotary side seal member (not shown) fixed to the rotational shaft 1, and a stationary side seal member (not shown) fixed to the intermediate bracket 50. Therefore, when the rotational shaft 1 rotates, the rotary side seal member comes into sliding contact with the stationary side seal member, and the shaft sealing device 30 generates heat.
Further, in such pump apparatus, the temperature of the liquid to be handled may range from low temperature (e.g., −25° C.) to high temperature (e.g., 140° C.). For example, when the temperature of the liquid to be handled is higher than an allowable temperature of the shaft sealing device 30, if the hot liquid to be handled directly contacts the shaft sealing device 30, the temperature of the shaft sealing device 30 generated by the sliding heat rises further. In this embodiment, the liquid to be handled includes a slurry liquid containing a slurry of about 0.05 mm. In one embodiment, the liquid to be handled may include clean water or dirty water.
In this manner, the shaft sealing device 30 becomes very hot due to the sliding of the rotary side seal member and the stationary side seal member, and contact with the high-temperature liquid to be handled, and the shaft sealing device 30 may fail. As a result, the shaft sealing device 30 cannot fully exhibit its function, and the liquid may leak to the motor 7 side, and the motor 7 may be submerged in water. Therefore, in the pump apparatus, a structure capable of reliably preventing failure of the shaft sealing device 30 is desired.
The pump apparatus includes a normal temperature flow path 60 that keeps the liquid flowing through the shaft sealing device 30 within a predetermined temperature range. In other words, the pump apparatus includes the normal temperature flow path 60 (second flow path) that keeps the liquid to be handled in the flow path 90 within a predetermined temperature range. The opening 50a forms the flow path 90 (first flow path) through which the liquid to be handled flows into the shaft sealing device 30. In the embodiment, the normal temperature flow path 60 is formed in the intermediate bracket 50. More specifically, the intermediate bracket 50 includes a cover portion 51 covering an opening end 5a of the pump casing 5, and a bracket portion 52 connected to the cover portion 51. The normal temperature flow path 60 is formed in at least one of the cover portion 51 and the bracket portion 52.
The normal temperature flow path 60 is formed in both the cover portion 51 and the bracket portion 52, but in one embodiment, the normal temperature flow path 60 may be formed only in the cover portion 51, or may be formed in the bracket portion 52. That is, the opening 50a is formed at an opening 51a in the cover portion 51 through which the rotational shaft 1 passes and/or the opening 52a in the bracket portion 52 through which the rotational shaft 1 passes. The opening 50a forms the flow path 90, and the normal temperature channel 60 is formed adjacent to at least a portion of the opening 50a so that the liquid to be handled in the flow path 90 can be kept within a predetermined temperature range. The shaft sealing device 30 determines an allowable temperature range according to its product specifications. The predetermined temperature range described as “the liquid to be handled in the flow path 90 can be kept within a predetermined temperature range” means that the temperature of the shaft sealing device 30 is within the allowable range even if the shaft sealing device 30 generates heat due to sliding.
The normal temperature flow path 60 is arranged radially outward of the flow path 90 formed by an outer peripheral surface of the rotational shaft 1 and an inner peripheral surface (opening 50a) of the intermediate bracket 50. The liquid to be handled pressurized by the rotation of the impeller 3 contacts the shaft sealing device 30 after being heat-exchanged by the fluid in the normal temperature flow path 60 separated by a side wall 60a when flowing through the flow path 90. In other words, the liquid to be handled in the flow path 90 that has been brought to an appropriate temperature by the fluid in the normal temperature flow path 60 can be used for lubricating the shaft sealing device 30. Therefore, the shaft sealing device 30 can prevent leakage to the motor 7 side even if the liquid to be handled is out of the allowable range.
The normal temperature flow path 60 communicates with a liquid inlet 61 and a liquid outlet 62. The liquid (e.g., tap water) flows from a liquid supply source (not shown) through the liquid inlet 61 into the normal temperature flow path 60. The normal temperature liquid (e.g., clear water of 0° C. to 65° C.) that has flowed into the normal temperature flow path 60 keeps the temperature of the liquid present in the flow path 90 arranged radially inside the normal temperature flow path 60 within a predetermined range (e.g., 0° C. to 65° C.).
For example, when the temperature of the liquid to be handled is higher than the allowable range of the shaft sealing device 30 (e.g., 140° C.), the high-temperature liquid to be handled is cold by the liquid flowing through the normal temperature flow path 60 (e.g., tap water or industrial water of the normal temperature of 0° C. to 35° C.). Conversely, when the temperature of the liquid to be handled is lower than the allowable range of the shaft sealing device 30 (e.g., minus 25° C.), the low-temperature liquid to be handled is heated by the liquid flowing through the normal flow path 60 (e.g., tap water or industrial water of the normal temperature of 0° C. to 35° C.). Thereby, the temperature of the shaft sealing device 30 can be kept within the allowable range. After that, the liquid that has flowed into the normal temperature flow path 60 is discharged from the liquid outlet 62. The liquid flowing through the normal temperature flow path 60 is an example of a fluid, and examples of the fluid may be tap water, factory water, or gas.
In this manner, clean water (tap water, factory pumped water, etc.), which is easy to handle, is used as a fluid for keeping the temperature of the shaft sealing device 30 within the allowable range while avoiding the shaft sealing device 30 from coming into contact with the liquid to be handled whose temperature is outside the allowable range. In the embodiment, the fluid in the normal temperature flow path 60 used for adjusting the temperature of the shaft sealing device 30 does not mix with the liquid to be handled pressurized by the impeller 3. Therefore, the temperature of the shaft sealing device 30 can be kept within the allowable range by using a fluid different from the liquid to be handled. In other words, a user can select the fluid for the normal temperature flow path 60 depending on an equipment and an environment. Therefore, the pump apparatus of this embodiment is particularly effective when the transferred liquid is a special liquid containing slurry or the like.
Further, it is preferable that the intermediate bracket 50 includes a throttle portion 65 that throttles the flow path of the liquid (i.e., the liquid to be handled) flowing through the shaft sealing device 30. The throttle portion 65 shown in
Furthermore, it is preferable that a retaining chamber 66 for liquid flowing to the shaft sealing device 30 is formed between the shaft sealing device 30 and the throttle portion 65. The retaining chamber 66 is an annular chamber formed between an outer peripheral surface of the rotational shaft 1 and the inner peripheral surface of the cover portion 51, and the liquid that has passed through the gap between the throttle portion 65 and the impeller 3 retains in the retaining chamber 66.
During an initial operation of the pump apparatus, the liquid to be handled that has flowed into the pump casing 5 due to the rotation of the impeller 3 passes through the small gap between the impeller 3 and the throttle portion 65, and flows into the retaining chamber 66. The liquid once flowing into the retaining chamber 66 continues to stay in the retaining chamber 66 until the pressure inside the pump casing 5 is sufficiently lowered.
The normal temperature flow path 60 is arranged outside the retaining chamber 66, and the retaining chamber 66 communicates with the shaft sealing device 30. More specifically, the normal temperature flow path 60 is an annular flow path surrounding the retaining chamber 66. Therefore, the liquid existing in the retaining chamber 66 is more actively heat-exchanged with the liquid flowing through the normal temperature flow path 60.
In this manner, the liquid in contact with the shaft sealing device 30 is retained in the retaining chamber 66 for a long time, and heat is exchanged with the liquid flowing through the normal temperature flow path 60. The temperature of the shaft sealing device 30 falls within the allowable range. That is, the liquid to be handled within a predetermined temperature range that allows the temperature of the shaft sealing device 30 to remain in the retaining chamber 66, and the liquid retained in the retaining chamber 66 is used to lubricate the shaft sealing device 30. With such a configuration, the liquid existing in the retaining chamber 66 prevents the contact of the high-temperature or low-temperature liquid outside the predetermined temperature range with the shaft sealing device 30. As a result, the shaft sealing device 30 can be prevented from failing due to contact with the high-temperature or low-temperature liquid.
In this embodiment, the pump apparatus includes the normal temperature flow path 60 that keeps the liquid flowing through the shaft sealing device 30 within a predetermined temperature range, but means for protecting the shaft sealing device 30 is not limited to this embodiment. In one embodiment, the pump apparatus does not need to include at least one of the normal temperature flow path 60, the throttle portion 65, the retaining chamber 66, etc., as long as the shaft sealing device 30 can be protected.
As described above, the pump apparatus is periodically disassembled and cleaned depending on the intended use. During this disassembly and cleaning, it is necessary to completely remove the liquid inside the pump apparatus. However, since an internal flow path of the pump casing 5 has a complicated shape, it is troublesome to remove the remaining liquid.
In particular, in the pump apparatus according to the present embodiment, a slurry liquid is included as the liquid to be handled, and the slurry liquid tends to remain in the pump casing 5 when disassembly and cleaning of the pump apparatus. Therefore, in the embodiment described below, the structure of the pump casing 5, which has a simple structure and can be easily washed, will be described with reference to the drawings.
The pump casing 5 has a suction nozzle 100 with the suction port 12 formed therein. In the pump apparatus, the suction port 12 is flange-connected to a horizontally extending a suction pipe S, and the discharge port 13 is flange-connected to a horizontally extending a discharge pipe D by fasteners (e.g., bolts and nuts). The pump apparatus is operated in that state. The suction nozzle 100 slopes downward toward the suction port 12. More specifically, the pump casing 5 further includes a volute portion 101 to which the suction nozzle 100 is connected, and the suction nozzle 100 slopes downward from the volute portion 101 toward the suction port 12.
The volute portion 101 forms a volute chamber 102 around the impeller 3 housed in the pump casing 5. The transferred liquid pressurized by the impeller 3 in the volute chamber 102 is discharged from the discharge port 13 laterally extending from the volute chamber 102. The suction nozzle 100 is connected to the center of a bottom of the volute portion 101, and extends downward from the volute portion 101.
The suction nozzle 100 includes a connection portion 100a connected to the volute portion 101, a suction flange portion 100b having the suction port 12, and a nozzle portion 100c connected to the connection portion 100a and the suction flange portion 100b. The nozzle portion 100c extends obliquely downward from the connection portion 100a toward the suction flange portion 100b, and the suction port 12 of the suction nozzle 100 is arranged below the connection portion 100a of the suction nozzle 100. That is, the suction port 12 is a bottom portion of the flow path inside the pump casing 5.
Therefore, when the operator stops the pump apparatus, and removes the suction nozzle 100 from the suction pipe S, the liquid in the suction nozzle 100 does not remain in the nozzle portion 100c as indicated by the arrow in
In this manner, the pump apparatus of this embodiment has a simple structure in which the suction nozzle 100 extends obliquely downward. The pump apparatus can cause the liquid to flow out of the pump casing 5 when the suction-side pipe (suction pipe S) is removed. With such a structure, a drain work for removing the liquid from the pump casing 5 can be simplified, and the operator can disassemble and clean the pump apparatus without much trouble.
As shown in the upper drawing of
Therefore, when the suction flange portion 1000b is removed from the suction pipe S, the liquid inside the pump casing 5 may remain on the bottom portion 1000d. In other words, in order to completely remove the liquid in the pump casing 5 at the suction nozzle 1000 shown in the comparative example, it is necessary for the operator to perform the draining work shown in the example below.
(1) Draining work for blowing off the liquid remaining at the bottom 1000d by jetting high-pressure gas.
(2) Draining work by tilting the pump casing 5 and lowering the suction port 12 below the bottom 1000d.
(3) Draining work using another device (e.g., pump apparatus, tool, etc.).
In the embodiment, the nozzle portion 100c has a linear shape extending obliquely downward from the connection portion 1000a, so that the suction port 12 is a lowest bottom portion 100d of the flow path in the pump casing 5. Therefore, when the suction pipe S is removed from the suction flange portion 100b, the liquid in the pump casing 5 is discharged outside through the suction port 12, which is the bottom portion 100d, by the action of gravity, and hardly remains in the nozzle portion 100c. As a result, the above-described draining work can be omitted, and a cleaning work in the pump casing 5 can be simplified.
In the embodiment of lower side of
In the comparative example, the upper portion of the suction flange portion 1000b is arranged side by side with the volute portion 101. Therefore, the suction nozzle 1000 extends outward such that a working space WSa is formed between the volute portion 101 and the suction flange portion 1000b. The work space WSa is a space necessary for a work of a flange-connecting the pump apparatus and the suction pipe S by means of a fastener (e.g., a bolt and nut combination) 110.
Since the suction flange portion 100b of the suction nozzle 100 of the embodiment is arranged at a position lower than the volute portion 101, the work space WSa can be formed between the volute portion 101 and the nozzle portion 100c.
In the suction nozzle 100, the work space WSa can be secured below the volute portion 101 as well. With such a structure, a distance D1 between a center line CL of the pump apparatus and the suction flange portion 100b can be made smaller by a difference DS than a distance D2 between the center line CL of the pump apparatus and the suction flange portion 1000b. In this embodiment, the length of the suction nozzle 100 extending outward from the volute portion 101 can be shortened as compared with the comparative example. Therefore, the pump apparatus including the suction nozzle 100 according to the embodiment can be compact in overall size.
Furthermore, it is preferable that the leg portions 150 and 151 form a space having a height H between the suction flange portion 100b and the floor FL. By forming the space of the height H, a drain pan 155 for collecting waste liquid can be arranged directly below the suction flange portion 100b. As shown in
By removing the suction pipe from the suction nozzle 100, the liquid in the suction nozzle 100 flows from the volute portion 101 toward the suction port 12 and out of the suction port 12 by the action of gravity without remaining in the nozzle portion 100c. The drain pan 155 arranged directly below the suction flange portion 100b can receive the liquid flowing out from the suction port 12.
Since the suction port 12 is the lowest bottom portion 100d of the flow path in the pump casing 5, the bottom portion of the suction flange portion 100b is arranged at the lowest position in the pump apparatus. Therefore, as shown in
The leg portion 160 includes a base portion 166, a wall portion 167 extending vertically from the base portion 166, and a connection portion 168 fixed to the wall portion 167 and connectable to the protrusion 162 of the pump casing 5. The protrusion 162 and the connection portion 168 are connected to each other by fasteners (e.g., bolts) 170.
With such a configuration, the intermediate bracket 50 and the pump casing 5 are connected to each other by the fasteners 165, and the pump casing 5 and the leg portion 160 are connected to each other by fasteners 170. Also in the embodiment shown in
In the embodiment shown in
Furthermore, by providing the leg portions 150 and 151, it is possible to achieve the effect of making the pump apparatus easier to carry and the effect of being able to form the working space WSc below the suction flange portion 100b.
The pump apparatus according to the embodiment described above is a vertical pump apparatus capable of transferring the liquid (i.e., slurry liquid) containing slurry (i.e., light slurry) of about 0.05 mm. The impeller 3 is preferably a semi-open impeller for transferring the slurry liquid. By adopting the semi-open impeller, it is possible to suppress the slurry from being caught between the pump casing 5 and the impeller 3. Furthermore, the pump apparatus includes the impeller 3 having a larger diameter than that of a general impeller in order to obtain a large head relative to the flow rate, and rotates the rotational shaft 1 at a low speed (e.g., 1500 min−1).
With such a structure, the suction pressure of the pump increases, and as a result, a large thrust force that pushes the impeller 3 upward (i.e., toward the cover portion 51) is generated. If the size of the gap between the impeller 3 and the cover portion 51 changes due to this thrust force, there is a risk that the pump apparatus will not be able to exhibit the desired performance, or that the slurry will be trapped to the gap between the impeller 3 and the cover portion 51. Therefore, in the embodiment described below, the pump apparatus has a structure capable of restricting the upward movement of the impeller 3 even if the large thrust force is generated.
The rotational shaft 1 extends through the motor casing 203, and a cooling fan 206 is fixed to an end portion 1a of the rotational shaft 1. The cooling fan 206 is housed in a fan cover 209 connected to the motor casing 203. The second bearing 201B is an anti-load side bearing arranged adjacent to the cooling fan 206. The first bearing 201A is a load side bearing spaced apart from the cooling fan 206.
A rotor 210 and a stator 211 for rotating the rotational shaft 1 are arranged between the first bearing 201A and the second bearing 201B. The rotor 210 is fixed to the rotational shaft 1, and the stator 211 surrounds the rotor 210, and in the stator 211, a winding (coil) 211b receives the electric power to form a rotating magnetic field. The stator 211 includes a stator core 211a, and a plurality of windings 211b wound around the stator core 211a. The rotor 210 is rotated by the rotating magnetic field formed between the rotor 210 and the stator 211, and the rotational shaft 1 to which the rotor 210 is fixed rotates together with the rotor 210.
The first bearing 201A is supported by the first bearing support portion 202A, and the second bearing 201B is supported by the second bearing support portion 202B. As described above, when the thrust force that pushes up the impeller 3 is generated, the thrust force acts on the first bearing 201A and the second bearing 201B through the rotational shaft 1. The thrust force acting on the second bearing 201B is received by the second bearing support portion 202B, while the thrust force acting on the first bearing 201A is not received by the first bearing support portion 202A. Therefore, the motor 7 includes the bearing retainer 205 that receives the thrust force acting on the first bearing 201A.
According to this embodiment, the bearing retainer 205 can reliably receive the thrust force acting on the first bearing 201A. Therefore, the pump apparatus can maintain a desired size of the gap between the impeller 3 and the cover portion 51 even if a large upward thrust force is generated in the impeller 3.
As described above, the pump apparatus is capable of pumping the slurry liquid, including the light slurry. If the slurry liquid is continuously transferred, the components (the impeller 3, the pump casing 5, and the cover portion 51, etc.) of the pump apparatus that come into contact with the slurry liquid may be worn. This wear changes the size of the gap between the impeller 3 and its peripheral members (e.g., the pump casing 5 and the cover portion 51), which may adversely affect the performance of the pump apparatus. Furthermore, the pump apparatus is capable of transferring hot liquids to be handled. In this case, the components of the pump apparatus thermally expand under the influence of the heat of the liquid to be handled, and as a result, there is a risk that the size of the gap between the impeller 3 and its peripheral members will change. Therefore, in the embodiments described below, the pump apparatus includes a gap adjustment structure for adjusting the size of the gap.
Each of the distance piece 306 and the shim 307 has an annular shape, and is arranged concentrically with rotational shaft 1. The shim 307 has a minute thickness (e.g., 0.1 mm). The operator adjusts the size of the gap between the impeller 3 and the impeller housing structure 300 by arranging one or more shims 307 with the distance piece 306 attached.
When transferring a high-temperature liquid to be handled, the operator considers the thermal expansion of the impeller 3 and the impeller housing structure 300, and determines the number of shims 307 to be arranged. According to this embodiment, the size of the gap between the impeller 3 and the impeller housing structure 300 can be freely adjusted by a simple method of adjusting the number of shims 307. In particular, in the embodiment, the pump apparatus has a structure in which the impeller 3 is directly fixed to the rotational shaft 1 extending from the motor 7. Therefore, it is particularly effective to provide the gap adjustment structure 305 that allows the gap to be adjusted without requiring a complex structure.
According to the embodiment, even if the impeller 3 and the impeller housing structure 300 are worn due to transfer the slurry liquid, the operator adds the shim 307 during maintenance of the pump apparatus. Thereby, the size of the gap between the impeller 3 and the impeller housing structure 300 can be adjusted to an appropriate size. Therefore, the cost of the pump apparatus can be reduced.
According to the embodiment, the pump apparatus does not need to have a special structure for transferring the slurry liquid by including the gap adjustment structure 305, and can also transfer the liquid to be handled such as clean water. More specifically, the operator may remove the gap adjustment structure 305 when transferring the liquid to be handled such as clear water, and may attach the gap adjustment structure 305 when transferring the slurry liquid.
In order to make the size of the pump apparatus compact, the size of the suction nozzle 100 in the height direction is reduced, and the width direction (more specifically, a direction from the centerline CL of the pump apparatus to the suction flange 100b) of the suction nozzle 100 is desirable. Also, it is important to minimize the change in the shape of the suction nozzle 100 and increase a cross-sectional area (cross-sectional area in the height direction) of the flow path of the suction nozzle 100 at a constant rate of change. This is because the pump casing 5 generally causes problems such as cavitation when the flow rate on the suction side is largely throttled. Therefore, it is desirable that the suction nozzle 100 has a shape that suppresses pressure loss while ensuring a predetermined cross-sectional area in the flow path.
The wide portion 100d extends horizontally in order to reduce the size of the suction nozzle 100 in the height direction, and realize a compact pump apparatus. The flow rate of the liquid to be handled in the wide portion 100d increases. Therefore, by providing the wide portion 100d, the suction nozzle 100 can increase the cross-sectional area of the flow path 400 at a constant rate of change. As a result, the pump apparatus can ensure the necessary flow rate while preventing cavitation from occurring. Furthermore, the suction nozzle 100 can be tilted at an optimum angle to reduce pressure loss.
By forming the bottom surface 102a, the liquid to be handled that remains in the volute chamber 102 after stopping the operation of the pump apparatus flows down the bottom surface 102a due to the action of gravity, and is smoothly discharged from the volute chamber 102. In the embodiment shown in
As shown in
Although the drain structure applied to the pump casing 5 according to the embodiment shown in
The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope as defined by limitation of the claims.
The present invention is applicable to a pump casing and a pump apparatus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-091475 | May 2020 | JP | national |
| 2021-004159 | Jan 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/016045 | 4/20/2021 | WO |
