Patent Grant
12135038
Centrifugal pumps have been commonplace for ages and have been used in numerous applications. A relatively recent development has been a powerful firefighting type of pump allowing discharge at opposite ends of the pump, such as that found in Seitz et al. U.S. Pat. No. 7,517,186. Such pumps are useful in many cases, including within a firetruck apparatus, especially for discharging a large volume of water over a short time span. Dispensing from different sides of the apparatus allows for flexibility on where the firetruck may be positioned. Such pumps often displace 1500 to 2500 gallons of water or fluid per minute. While operating at such high volumes, the pumps run efficiently and at minimal or acceptable levels of noise. Such high volume powerful pumps are often used for extinguishing major fires, where large volumes of fluid are displaced quickly and over far distances. In some instances, however, a firetruck apparatus may be called to respond to a scene where a relatively small volume of water or fluid is needed. The apparatus may be called to extinguish a dumpster fire or automobile fire, for instance, which typically require minor amounts of water, such as 50 to 100 gallons per minute (which may also be more than plenty to extinguish the fire). In some of these instances the pump will run loudly. Accordingly, there is room for improvement.
Applicant has recognized that in some instances when a pump runs at a lower flow rate, the pump may run loudly or with noise that is greater than when the pump was performing at a higher flow rate at an equal discharge pressure. Applicant appreciates that on occasion a 1500 GPM or higher rated fire pump may be called to extinguish a minor fire. In such cases a high-capacity single impeller pump may tend to run loudly if the pump is at lower impeller speed and smaller volume output. Applicant has developed a pump casing and pump which provides output to opposite sides of the pump while maintaining low noise throughout various operational ranges of the pump, including from high speed, high volume through high speed, lower volume discharge.
In one aspect the invention includes a single piece pump casing allowing discharge flow from the pump at opposite sides of the pump and associated firefighting vehicle. The pump casing has a first cut-water fluid flow path defined at least in part by a first cut-water wall, a second cut-water fluid flow path defined at least in part by a second cut-water wall, a first joint-water path and a second joint-water path, the first cut-water fluid flow path and the second cut-water fluid flow path communicating with the first joint-water path and the second joint-water path, the first joint-water path communicating with a first discharge nozzle and the second joint-water path communicating with a second discharge nozzle, the second cut-water wall spanning less than 180 degrees from a leading edge of the second cut-water wall to a trailing edge of the second cut-water wall.
In a further aspect the invention includes a single piece pump casing having a first cut-water fluid flow path defined at least in part by a first cut-water wall, a second cut-water fluid flow path defined at least in part by a second cut-water wall, a first joint-water path and a second joint-water path, the first cut-water fluid flow path and the second cut-water fluid flow path communicating with the first joint-water path and the second joint-water path, the first joint-water path communicating with a first discharge nozzle and the second joint-water path communicating with a second discharge nozzle, the first discharge nozzle and the second discharge nozzle situated substantially at opposing ends of the casing, the first discharge nozzle defining a first center output point and the second discharge nozzle defining a second center output point, the first center output point and the second center output point defining a line offset from a center point of a center opening passing through the casing, a leading end of the first cut-water wall positioned in a spaced relation with respect to a horizontal centerline running through the center point. In aspects the cut-water walls define a cutwater diameter passing through a center point of a center opening of the casing, the cutwater diameter is greater than 1.07 times the impeller diameter. In further aspects the cutwater diameter is substantially greater than the impeller diameter, in some instances being 1.16, 1.17 times or even greater as compared to the impeller diameter.
In a further aspect the invention includes a single piece casing having a first cut-water fluid flow path defined at least in part by a first cut-water wall, a second cut-water fluid flow path defined at least in part by a second cut-water wall, a first joint-water path and a second joint-water path, the first cut-water fluid flow path and the second cut-water fluid flow path communicating with the first joint-water path and the second joint-water path, the first joint-water path communicating with a first discharge nozzle and the second joint-water path communicating with a second discharge nozzle, the first cut-water wall and the second cut-water wall defining a cutwater diameter passing through a center point of a center opening of the casing, the cutwater diameter having a constant measure from a lead end of the first cut-water wall toward a trailing end of the first cut-water wall. In aspects, the casing has a lead end of the second cut-water wall, were from the lead end toward a trailing end of the second cut-water wall, the diameter transitions from having a constant measure to having a varying measure.
In a further aspect the invention is a single-piece casing having a single discharge nozzle, a first cut-water fluid flow path defined at least in part by a first cut-water wall, a second cut-water fluid flow path defined at least in part by a second cut-water wall, a first joint-water path leading to the discharge nozzle, the first cut-water wall and the second cut-water wall defining a cutwater diameter passing through a center point of a center opening of the casing, the cutwater diameter having a constant measure from a lead end of the first cut-water wall toward a trailing end of the first cut-water wall. In aspects, the casing is configured to receive an impeller having an impeller diameter, the cutwater diameter being greater than 1.07 times the impeller diameter. In aspects the cutwater diameter is substantially greater than the impeller diameter, including at least 1.16 time the impeller diameter. In aspects, the second cut-water wall spans less than 180 degrees from a leading edge of the second cut-water wall to a trailing edge of the second cut-water wall.
The above partial summary of the present invention is not intended to describe each illustrated embodiment, aspect, or every implementation of the present invention. The figures and detailed description that follow more particularly exemplify these embodiments and further aspects of the invention.
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not necessarily to limit the invention to the particular embodiments or aspects described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention and as defined by the appended claims.
Referring to
With particular reference to
Casing 22 includes second cut-water wall 36 having a second cut-water 34 disposed at a leading end of the second cut-water wall 36 and a cut-water wall trailing end 38 at a trailing end of wall 36. Second cut-water wall 36 in part defines second cut-water fluid flow path 42. As fluid exits spinning impeller 26 the fluid travels along second cut-water fluid flow path 42. Subsequent flow of the fluid within path 42 is described further below.
Referring to
In one aspect nozzles 46, 48 have a terminal flow path radius “r” (i.e., a flow path radius at a terminal end of nozzle 46). In one aspect the radius “r” is 2 inches. In other aspects the radius “r” may be less than or greater than 2 inches. In further aspects, nozzles 46, 48 have a terminal flow path which is not necessarily circular in cross-section, and may have a rectangular, oval or other cross-section configuration. In aspects, line X (and corresponding output points 47, 48 of nozzles 46, 48) is offset from centerline H by a measure of at least “r” length. In one aspect, casing 22 defines a center opening 23 which passes through the casing 22. The center opening 23 has a radius r′ with a center point 23′ of the center opening 23 defining a horizontal center point which lies along centerline H. In one aspect, line X is offset from centerline H by a measure of at least r′ length. In a further aspect, line X is offset from centerline H by about 3 to 4 inches. In aspects line X is offset from centerline H by about 3.5 inches to assure a substantial benefit in space savings while still maintaining clearance from other components of the vehicle. Such offset allows casing 22, 22′, 22″ and pump 20 to be set lower within a vehicle. In one aspect, line X is offset from centerline H by over 3.6 inches, resulting in a corresponding lowering of casing 22, 22′, 22″ as compared to prior applications. Such lowering is a substantial lowering and increase in space utilization for a vehicle into which pump 20 is positioned. In aspect such substantial lowering accommodates more space within a cab portion of the vehicle which is positioned above the pump. Use of the offset and lowering of the profile position of the pump minimizes or eliminates the need to have a projection into the cab area to accommodate for pump clearance. This lessens or eliminates a “bump” which might otherwise be positioned at the floor of the cab.
In a further aspect casing 22, 22′, 22″ includes a foot 55 used to set upon or connect to a flange which in one instance is connected to a rail of the vehicle. Connection of nozzles 4648 to discharge piping and connection of foot 55 to rail provides a secure three-point contact to secure the pump casing 22. In one aspect foot 55 is configured with a planar lower surface such that when the planar lower surface is oriented horizontally, line X is also oriented horizontally or substantially horizontally. Plastic or rubber washers or bushings may be positioned at the respective connections of the casing 20.
In operation, fluid from path 40 continues to circulate through casing 22, 22′, 22″. Particularly, a portion of fluid travels along first cut-water fluid flow path 40a to exit at discharge nozzle 46, and a portion travels, or may travel, along first cut-water fluid flow path 40b to exit at discharge nozzle 48. Likewise, fluid from path 42 continues to circulate through casing 22, 22′, 22″. Particularly, a portion of fluid travels along second cut-water fluid flow path 42a to exit at discharge nozzle 46, and a portion travels, or may travel, along second cut-water fluid flow path 42b to exit at discharge nozzle 48. Joint water path 44a includes both first path 40a and second path 42a, and joint water path 44b includes both first path 40b and second path 42b. It may be appreciated that at least a portion of path 40 and at least a portion of path 42 define path 40b to create joint water path 44b. As such, both the impeller side 33 and casing side 31 of wall 32, 32′, 32″ in part define first cut-water fluid flow path 40. First cut-water wall 32, 32′, 32″ defines in part flow path 40 and defines in part second joint-water path 44b. Having joint-water path 44b allows pump 20 to efficiently deliver fluid to ends 56a, 56b in a low-profile arrangement. While other pump designs may deliver fluid to both ends of a vehicle, joint-water path 44b contained entirely within casing 22, 22′, 22″ achieves an efficient low-profile arrangement. Having outputs 47, 49 of discharge nozzles 46, 48 arranged along a line X which is offset upward from a center point 23′ of the center opening 23 allows for a lower profile configuration. As a single casting, casing 22, 22′, 22″ also accommodates for efficient manufacture and assembly of pump 20 and positioning and connecting within a vehicle. In one aspect pump 20 includes a single impeller 26 (one and only one impeller in such aspect) and thus a single suction for efficient use and plumbing. In aspects, either of nozzles 46, 48 may be closed to allow or force liquid to flow to the other open nozzle to allow a user to select which side (or both sides) of the pump (or fire truck) for discharge of liquid.
Joint-water path 44b allows for efficient operation of pump 20 especially where an operator desires to vary the fluid output through respective discharge nozzles 46, 48. For instance, a user may close off (or partially close) fluid flow through nozzle 46 without disrupting radial balance of impeller 26, since the entire output from flow path 40 and flow path 42 would then be directed through nozzle 48. Likewise, if a user were to close fluid flow through nozzle 48 (or partially close the flow), the output from flow path 40 and flow path 42 would then be directed through nozzle 46. If respective nozzles 46, 48 were to be otherwise fed directly from respective flow paths without the combining of fluid in a joint water path, radial forces could disrupt the balance of impeller 26 impacting performance and pump life. Having water paths 40 and 44b contained within a single casing further allows for a low profile which would otherwise require additional or external plumbing about the pump casing to supply opposite sides of the vehicle. Other outlets or nozzles may also be provided on the casing 22, 22′, 22″, including at discharge arm 60.
In further aspects of operation, impeller 26 spins in a first direction represented by arrow A. While arrow A depicts a counterclockwise direction (when viewed opposite a suction side of the casing 22, 22′, 22″), it may be appreciated that pump 20 may be designed for impeller 26 to spin in a clockwise direction. The first-direction spinning impeller 26 releases fluid (such as water or foam for fighting fires) into paths 40, 42. In aspects, pump 20 includes means for continuing transporting fluid in the first direction. Means for transporting is represented by reference numeral 44b, which may include means such as second joint-water path 44b, first cut-water fluid flow path 40b, and second cut-water fluid flow path 42b. In one aspect, means 44b has a generally arch-like configuration, or lies generally along a radius or modified radius. In one aspect means for transporting includes a joint-water path spanning substantially from a first end 56a to a second end 56b of the pump 20. In one aspect means 44b spans from adjacent trailing edge 38 to first discharge outlet 46 and continues to span to second discharge outlet 48. In one aspect means for continuing transporting is contained entirely within single piece casing 22, 22′, 22″. Providing a simple single, non-split, casing design in which all water paths are located (including means for continuing transportation, such as path 44b which curves to either side of the casing) allows for ease of manufacture, assembly, hook-up, and use. It may be appreciated that connections to the nozzles of the pump may likewise be confined to a modest space to achieve an overall low-profile solution.
For pump 20 to accommodate dual output at discharge nozzles 46, 48, pump 20 in one aspect includes joint-water path 44b which spans at least 45 degrees, and in some aspects at least 135 degrees, and even at least 180 degrees or greater than 180 degrees in further aspects. Having joint-water path 44b span at least 135 degrees accommodates for joint-water path 44b to wrap back or span to a significant degree, and accommodates a lower profile casing (and/or elimination of external conduit to supply fluid to opposite sides of the firetruck) and provides meaningful spacing of respective outputs or nozzles 46, 48. The joint-water path 44b spans in a curving manner along an arch generally defined by an arch line spanning from trailing edge 38 to discharge outlet 48. In one aspect arch line is a curving centerline of joint-water path 44b. Joint-water path 44b may commence adjacent trailing edge 38 of second cut-water wall 36 and follows generally circumferentially in direction A to discharge nozzle 48. In one aspect trailing edge 38 aligns along or substantially along reference line H. In one aspect with respect to
In further aspects with respect to
In one aspect first discharge arm 60 is positioned adjacent trailing edge 38 of second cut-water wall 36, while second discharge arm 62 is position distal the trailing edge 38. In further aspects, fluid travels upward at the exit (adjacent trailing edge 38) from the first cut-water fluid flow path 40.
As shown in
In a further aspects with respect to
Casing 22′, 22″ includes second cut-water wall 36′, 36″ having a second cut-water 34 disposed at a leading end of the second cut-water wall 36′, 36″ and cut-water wall trailing end 38 at a trailing end of wall 36′, 36″. Second cut-water wall 36′, 36″ in part defines second cut-water fluid flow path 42. As fluid exits spinning impeller 26 the fluid travels along second cut-water fluid flow path 42. Subsequent flow of the fluid within path 42 is described above with respect to
First cut-water fluid flow path 40 and second cut-water fluid flow path 42 communicate to join into a first joint water path 44a and a second joint water path 44b. Casing 22′, 22″ further includes a first discharge nozzle 46 and a second discharge nozzle 48. Both first path 40 and second path 42 communicate with first discharge nozzle 46 and second discharge nozzle 48. Both first joint water path 44a and second joint water path 44b communicate with first discharge nozzle 46 and second discharge nozzle 48. First discharge nozzle 46 and second discharge nozzle 48 are situated at or substantially at opposing ends 56a, 56b of casing 22′, 22″. In further aspects discharge nozzles 46, 48 have a center output 47, 49 (particularly, first center output point 47 and second center output point 49) which define a center point of the respective nozzles. A horizontal centerline H aligns with a horizontal center of impeller drive shaft 28. In further aspects horizontal centerline H aligns with a center point 23′ of center opening 23. The center output points 47, 49 define a line “X” which line X is offset from horizontal centerline H. In further aspects, centerline H is not necessarily horizontal, yet line “X” may be parallel to centerline H. In one aspect, centerline H is horizontal when casing 22, 22′, 22″ is positioned with a bottom surface of foot 55 oriented along or resting on a horizontal surface. Alignment of nozzles 46, 48 accommodates for efficient dual outlets to be extended to both sides of an emergency vehicle. An emergency response vehicle may be a fire truck such as, but not limited to, the vehicle 10 shown in
In aspects casing 22′, 22″ includes features noted above with respect to casing 22, and casings 22, 22′ operate similarly or substantially similarly. Pumps 20 made with respective casings 22, 22′ exhibit desired low noise characteristics. Variations in the noise characteristics may be achieved by employing the various features of casings 22, 22′.
In further aspects,
In one non-limiting, representative example, Example 1, impeller 26 of pump 20 has five vanes having an assumed thickness of about 0.59 inches, a 23-degree discharge angle, an outside diameter of about 10.9 inches, and a specific speed of about 1800 rpm using a 4 inch inside diameter water path. A cut-water diameter CD (i.e., CD1) of about 12.75 inches, which is 1.16 times the impeller diameter (i.e., ID) of 10.969 inches, provides a fully functioning and quieter pump as compared to having a much smaller cut-water diameter CD (such as a diameter CD1 of merely or less than 1.07 times the impeller diameter). For instance, Applicant has experienced lower decibel readings with the casings 22′, 22″ as compared to casing 22 (or other casing configurations) at various impeller speeds and pressure settings. In an aspect where the cut-water diameter CD1 is 12.875, the ratio is greater than 1.17 (1.17376) and provides even further noise reduction. Applicant believes larger ratios will provide further noise reduction.
It may be appreciated that to reduce noise, expanding the cut-water diameter CD1 of the casing 22 of
In a further aspect with reference to
A pump casing, such as that shown in
In a further example, Chart 1 (as shown in
Chart 1 presents various measurements of volume (USGPM/LPM), pressures (PSI/BAR), horsepower (HP), impeller speed (RPM), and Noise (dBa). In operation (the operational range of the pump 20), pump 20 runs in the following ranges: 0-250 PSI up to 1000 GPM, 0-200 PSI up to 1400 GPM, and 0-150 PSI up to 2000 GPM. A noise level of 95 dBa in some applications is considered a low noise level or an acceptable noise level. Measurements below 500 GPM and at operating pressure above 150 PSI, for instance, are shown in Chart 1 to greatly exceed 95 dBa. The line representing 95 dBa is shown to pass through a significant portion of the operational range of the pump. In some or many instances, a noise level above 95 decibels is unacceptable or undesired.
In a further example, Chart 2 (as shown in
Chart 2 presents various measurements of volume (USGPM/LPM), pressures (PSI/BAR), horsepower (HP), impeller speed (RPM), and Noise (dBa). In operation (the operational range of the pump 20), pump 20 runs in the following ranges: 0-250 PSI up to 1000 GPM, 0-200 PSI up to 1400 GPM, and 0-150 PSI up to 2000 GPM. Measurements below 500 GPM and at operating pressure above 150 PSI are shown in Chart 2 to exceed 90 or 92.5 dBa, which is a significant noise decrease as compared to the noise levels of Chart 1. Comparison of the charts demonstrates significant noise level decreases are achieved throughout the range of operation. The line representing 95 decibels in Chart 2 is shown at levels at the higher end of the normal operational ranges of the pump. Chart 2 shows the pump still achieves desired outputs for the range of operation.
In a further example, Chart 3 (as shown in
Chart 3 presents various measurements of volume (USGPM/LPM), pressures (PSI/BAR), horsepower (HP), impeller speed (RPM), and Noise (dBa). In operation (the operational range of the pump 20), pump 20 runs in the following ranges: 0-250 PSI up to 1000 GPM, 0-200 PSI up to 1400 GPM, and 0-150 PSI up to 2000 GPM. Measurements below 500 GPM and at operating pressure above 150 PSI are shown in Chart 3 to exceed 90 or 92.5 dBa, which is a significant noise decrease as compared to the noise levels of Chart 1 and Chart 2. Comparison of the charts demonstrates significant noise level decreases are achieved throughout the range of operation. The line representing 95 decibels in Chart 3 is shown at levels at the higher end of the normal operational ranges of the pump. Chart 3 shows the pump still achieves desired outputs for the range of operation.
While the present invention has been described with reference to several particular example embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention, which is set forth in the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2291760 | Rupp | Aug 1942 | A |
| 2341871 | Karrer | Feb 1944 | A |
| 3289598 | Frederic | Dec 1966 | A |
| 5141390 | Haentjens | Aug 1992 | A |
| 7517186 | Seitz | Apr 2009 | B2 |
| 20060165523 | Rozario | Jul 2006 | A1 |
| Entry |
|---|
| Val S. Lobanoff and Robert R. Ross, Centrifugal Pumps Design & Application, Second Edition, cover and pp. IV, 28-37 and 56-63, 1992, Butterworth-Heinemann, An imprint of Elsevier, United Kingdom. |
