US20180180056A1

US20180180056A1 - Vertical suspended centrifugal pump

Info

Publication number: US20180180056A1
Application number: US15/646,923
Authority: US
Inventors: Mikhail Aleksandrovich Zolotukhin; Aleksandr Nikolaevich Zolotukhin; Ivan Svyatoslavovich Kruglov
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-12-28
Filing date: 2017-07-11
Publication date: 2018-06-28
Also published as: WO2018122596A1

Abstract

The present invention comprises a vertical suspended centrifugal pump. It is particularly useful to pump process liquids having high purity requirements or for outdoor applications in cold environments. The invention comprises a column that is an outer housing, an internal column that is an inner housing, and a shaft assembly that is partially located inside the inner housing. The outer housing encloses some part of the shaft assembly and at least partially encloses the inner housing. A wet end assembly is positioned to receive liquid through an inlet and to discharge liquid through an outlet. The present invention may be configured to include an internal barrier or buffer liquid reservoir without expensive external piping and reservoirs for pumps having two seals.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application Ser. 62/439,678 filed Dec. 28, 2016.

STATEMENT REGARDING FEDERALLY FUNDED RESEARCH

Not Applicable

FIELD OF INVENTION

The present invention relates to vertical suspended centrifugal pumps. More particularly, the invention relates to vertical suspended pumps that have seals and reservoirs.

BACKGROUND

Vertical suspended pumps are used in multiple industries to transfer liquid medium for collection, raw material extraction, to generate power, and for industrial processes. For example, vertical suspended pumps, described in the prior art, have been used in hydraulic applications in which fluid medium must be pumped from underground tanks, pits, sumps or similar repositories. Such pumps have housings or columns that create an internal space to control hydraulic forces. Rotors in such pumps are vertically oriented having shafts that transfer axial and torsional forces and loads during the pumping process. Torsional loads are often produced from a motor that drives the shaft radially to move or spin impellers that create a force differential to pull the liquid medium upwards, vertically, from the repository. Axial loads are produced from the hydraulic forces of the moving liquid medium. Bearings are used to reduce friction and facilitate smooth radial movement of the shaft and impeller components. Tensile loads are generated through the movement of the liquid medium upwards through the shaft and columns or casings that maintain the vacuum and flow of the liquid medium. Various seals may be employed to contain the liquid medium in the column in which the liquid medium is transferred against opposing hydraulic forces generated during the pumping process. The bearings also impart stability of movement of the shaft components. Tensile loads are also generated between the impeller and the bearings.
In a common set up, the vertical suspended pump is comprised of a motor assembly that is fixedly attached to a mounting plate, the shaft assembly is located inside the column also known as a housing or casing. The casing may be a single casing, axial-flow with discharge through the column, single casing, volute, line-shaft driven or cantilever, double-casing, or diffuser.
Axial or mechanical seals may be used in a single seal system that employs grease or lubricant on the seals or bearings. In addition, there are applications where a dual wet pumping seal is used to contain process fluid or liquid medium. For example, axial seals are used in industrial settings to prevent internal pump component deterioration from pumped corrosive, abrasive, or toxic liquid medium. There is a need in the art to prevent or contain contamination of the pumped process fluid, with bearing material or lubricant or from contact with seal buffer liquid or barrier liquid, when there is failure of the wet end seals.
An example in which minute contamination can destroy the product to be pumped is Diesel Exhaust Fluid (further referred to as DEF). DEF is a standardized product that is also known as AUS32. DEF is an aqueous urea solution that is used for selective catalytic reduction (SCR) of diesel exhaust from diesel burning engines to reduce nitrogen oxide emissions. The DEF is normally pumped from underground reservoirs into containers or dispensing machines for use in diesel engines. The International Organization for Standards (ISO) quality standards for DEF are tightly specified. In order to meet ISO standards for DEF, any surfaces in direct contact with DEF must be free from foreign matter such as fuel, oil, greases, and any other chemicals or natural products. A minute amount of oil from a single or double seal pumping system can completely contaminate an entire DEF reservoir.
Two widely used pumps that are used to pump DEF in commercial retail settings are a submersible turbine pump and a vertical suspended pump. Neither the submersible turbine pump nor the vertical suspended pump readily meet ISO requirements and are not well suited for the application.
Submersible pumps normally are equipped with a motor that is air filled or oil filled and is sealed from the pump wet end by double seals with an oil chamber between the seals. Currently available submersible pumps, that can detect seal failure, utilize a seal leak conductivity probe located in the sealed oil chamber. However, because the seal leak conductivity probe is located in the sealed oil chamber, it will not detect the presence of leaking pumped process fluid optimally. Detection of seal breach will not occur until the pumped process fluid has entered the sealed chamber and both the oil in the sealed chamber and the pumped process liquid are cross-contaminated. Therefore, there is a need in the art to obtain the earliest possible leak detection to prevent significant contamination of the seal buffer liquid or the pumped process fluid.
Submersible pumps that use oil lubricated and oil prefilled motors also can cause contamination of DEF or other pumping fluids if there is failure of the double seals in the pump.
In vertical suspended pumps with axial flow discharge through the column, an enclosed shaft line column with bearings and lubricant is used. The shaft line column is sealed from the pumping fluid by a mechanical seal and positioned inside the column. The drawback of this design is the total absence of, or the complexity of, a leak detection system. If the mechanical seal fails, the pump will continue to pump the process fluid without detecting the seal failure. This will allow the pumped process fluid to enter the shaft column. The pumped process fluid can therefore react or corrode the lubricant, bearings and pump components. Inversely, the bearings and their lubricant can contaminate the pumped process fluid if there is seal failure.
Also, there are different vertical suspended pumps with shaft sealing system that requires using an external reservoir for seal buffer or barrier fluid. For example, vertical suspended pumps may employ piping systems with reservoirs with two liquid seals. The proper operation is only achieved with exclusion of all gas and air bubbles from the piping. Venting of such piping systems during use is critical. In addition, often the price of such piping systems doubles the purchase price and maintenance of the pump. In areas with extremely low winter temperatures, maintaining shaft sealing systems with the external reservoir also requires additional efforts and expenditures.
Suspended centrifugal pumps that are used in chemical, oil and gas industries include configurations where the discharge pipe is separated from the shaft line and shaft guided by the bearings with various lubrication options, for example, by the pumped fluid, external flush, grease, or oil. The line shaft column is sealed from the wet end by the single or double seals. In all of the above configurations, there exists the potential for pumping fluid contamination, because the pumping fluid is either in direct contact with the shaft bearings or in contact with seal buffer or barrier liquid if there is seal failure.
Therefore, a need exists in the suspended pump field to address the issues of pumping fluid contamination and detection of seal failure before the contamination of the pumping fluid occurs. This is achieved in the present invention. In addition, a need also exists to easily and inexpensively maintain the internal conditions and temperature of the pump and the pumped buffer liquid in harsh environments. The present invention also provides improvements in the means to control internal pump conditions by incorporating an internal reservoir.

BRIEF SUMMARY OF THE INVENTION

The present invention is a vertical suspended centrifugal pump comprising a column assembly, consisting of at least an outer housing, an outer housing cavity, an inner housing, and an inner housing cavity. The present invention also has a rotatable shaft, where the shaft is enclosed partially within the inner housing. The inner housing is enclosed at least partially within the outer housing, the inner housing cavity, and the outer housing cavity, are isolated from each other. A probe, sensor, or switch may optionally be used to detect a breach of the various isolated cavities by a pumped process liquid or by liquid contamination from the upper sections of the housing or from the inner housing cavity. For example, water or other liquids from the external environment may enter the outer housing cavity.
The present invention may employ a motor assembly located outside of a storage tank from which a liquid medium is contained that is to be pumped. The motor assembly can be mounted in different positions to a base plate by various mounts or other components. The total length of the column assembly can vary depending on the need of the customer or other application requirements. It can also be configured as a single section or as a multi-sectioned column. The present invention also has a wet end assembly that includes a casing assembly, one or more impellers and wet end seal that can be made out of various materials in various shapes. The outer housing cavity may optionally be sealed to maintain the required isolation of internal cavities. The seals are created between the inner housing and outer housing and have a geometry that allows at least a portion of the shaft to be exposed directly to the outer housing cavity. The exposed portion of the shaft is a line shaft assembly that lies below the inner housing assembly and above a wet end. The sensors or switches may optionally be installed in the outer housing cavity. A discharge pipe that is separate from the column assembly runs from the casing assembly and may optionally be connected to or positioned through the base plate. The base plate, optionally, is sealed. It is contemplated that there also will be one or more discharge ports to connect the casing assembly with the external piping or with the other equipment. The discharge ports may be formed in different shapes and configurations such as a threaded connection, flanged connection, or other means to allow connection to the casing assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross sectional view of one example of the vertical suspended centrifugal pump assembly with a dry outer housing cavity according to various embodiments described herein.

FIG. 2 illustrates a cross sectional view of one example of the vertical suspended centrifugal pump assembly with a reduced outer housing length according to various embodiments described herein.

FIG. 3 illustrates a cross sectional view of one example of the vertical suspended centrifugal pump assembly with an outer housing cavity that is prefilled with a liquid according to various embodiments described herein.

DETAILED DESCRIPTION OF THE INVENTION

The descriptions and terminology used herein are intended to be illustrative of the principles of the present invention of a vertical suspended centrifugal pump and are not intended to be limiting. Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the present invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
One of skill in the art will recognize and understand that there are suitable modifications and equivalents that may be used which fall within the scope of the invention described herein. The use of singular forms “a,” “an,” and “the” include plural references unless the context clearly requires otherwise. The embodiments are not limited to those illustrated in the drawings. It should also be understood that the drawings are not necessarily to scale. In certain instances, details may have been omitted that are not necessary for an understanding of the embodiments disclosed herein, for example, conventional fabrication and assembly.
In describing the invention, it will be understood that a number of techniques and steps are disclosed. Each of these has individual benefit and each can also be used in conjunction with one or more, or in some cases all, of the other disclosed techniques. Accordingly, for the sake of clarity, this description will refrain from repeating every possible combination of the individual steps in an unnecessary fashion. Nevertheless, the specification and claims should be read with the understanding that various combinations are entirely within the scope of the invention and the claims.
In one embodiment, the vertical suspended centrifugal pump comprises, an outer housing that defines an outer housing cavity, an inner housing, that defines an inner housing cavity, a rotatable shaft, where the shaft is enclosed partially within the inner housing, the inner housing, being enclosed partially within the outer housing, the inner housing cavity, and the outer housing cavity, being isolated from each other. The term isolated is meant to describe that the inner housing cavity, and the outer housing cavity, are not in fluid or open communication with each other and are intended to have the space defined in each cavity to be separately maintained and isolated from other cavity spaces in the operation of the present invention. In this embodiment, the present invention, also comprises a sensor, the senor is capable of detecting the presence or absence of a liquid within the outer housing cavity.
In one embodiment the vertical suspended centrifugal pump of the present invention comprises an outer housing that defines an outer housing cavity, an inner housing that defines an inner housing cavity, a rotatable shaft, and a wet end seal. The shaft is enclosed partially within the inner housing, the inner housing is enclosed partially within the outer housing, the inner housing cavity and the outer housing cavity are isolated from each other, wherein a portion of the shaft communicates with the outer housing cavity below the inner housing cavity and above the wet end seal. The embodiment herein described contains at least one sensor, the at least one sensor is capable of detecting the presence or absence of a liquid within the outer housing cavity.
Referring to FIG. 1, the pump of the present invention is illustrated and may be driven by at least one motor assembly 10 connected by means such as a direct drive, belt, or coupling means, 148, to a shaft or shaft assembly, 116, which shaft assembly, 116, transfers torque. The shaft assembly 116 can be comprised in one or more sections. The motor assembly, 10, can be mounted firmly on to a base plate, 112, either directly or via other means such as a mount, 44.
It should be noted that the base plate is an optional element and the present invention may be stabilized by the base plate or by other means.
Referring to FIG. 1, the vertical suspended centrifugal pump of the present invention, 100, comprises an outer housing, 118, the outer housing, 118, is a column, wherein the column is formed of at least one section. The outer housing, 118, has an upper end and a lower end. This embodiment further comprises an inner housing, 114, wherein the inner housing, 114, is a column. The column is formed of at least one section that has an upper end and a lower end. The inner housing, 114, further defines an inner housing cavity, 130. The present invention, 100, as shown in the embodiment of FIG. 1, also may have a pump casing assembly, 120, that is formed of at least one section, the pump casing assembly, 120, is positioned at the lower end of the outer housing, 118, wherein the boundary surfaces of the outer housing, 118, the inner housing, 114, the pump casing assembly, 120, and optionally the base plate, 112, are mated and define the boundaries of an outer housing cavity, 128. If there is no base plate incorporated, then the upper end of the outer housing will replace the base plate as one of the boundary surfaces that defines the outer housing cavity. It should also be noted that the outer housing may be connected either directly to the base plate or via an intermediary connecting device or element and will depend on the application. This embodiment comprises the inner housing, 114, being enclosed within the outer housing cavity, 128. The present invention, 100, further comprises a pump lower end cap, 119, which defines a void that is isolated from the outer housing cavity, 128. The pump lower end cap, 119, further defines an inlet, 121, and an outlet, 123. The present invention, 100, further comprises a shaft, 116, that has an upper end, a lower end, and a vertical axis, wherein the shaft, 116, is rotatable about its vertical axis. This embodiment also has at least two bearings, 152, wherein the at least two bearings, 152, radially surrounding the shaft, 116, the at least two bearings, 152, are rotatable with respect to one another, and the bearings, 152, are further positioned within the inner housing, 114. The present invention, 100, also has at least one impeller assembly, 122, alternatively known as an impeller. The impeller, 122, is fixedly attached to the lower end of the shaft, 116, and is also positioned within the void of the pump lower end cap, 119. It is an intention of the present invention that the impeller, 122, is rotatable so that the rotation produces force to drive fluid from the inlet, 121, to the outlet, 123. The embodiment, as illustrated in FIG. 1, also has at least one probe or sensor, 132, capable of detecting the presence or absence of a liquid within the outer housing cavity, 128.
In the embodiment, illustrated in FIG. 1, the vertical suspended centrifugal pump of the present invention, 100, the outer housing, 118, is sealed.
Optionally, the bearings of the present invention are lubricated.
In the present invention, as illustrated in FIG. 1, the vertical suspended centrifugal pump of the present invention, 100, further comprises a top shaft seal, 138, wherein the top shaft seal, 138, is positioned at the upper end of the shaft, 116. The present invention further comprises an outer seal, 136, wherein the outer seal, 136, is positioned at the lower end of the shaft, 116, and a wet end seal, 134, wherein the wet end seal, 134, is positioned at the lower end of the shaft assembly, 116, and vertically below the outer seal, 136, wherein the top shaft seal, 138, and the outer seal, 136, serve to isolate the inner housing cavity, 130, from the outer housing cavity, 128, and from leaks that may occur outside of a reservoir, above the base plate 112. The wet end seal, 134, serves to isolate the void of the pump lower end cap, 119, from the outer housing cavity, 128.
As illustrated in FIG. 1, in order to facilitate optimal detection of contamination, the present invention has at least a portion of the shaft, 116, that lies between the wet end seal, 134, and the outer seal, 136, exposed to the outer housing cavity, 128.
In the embodiment illustrated in FIG. 1, the vertical suspended centrifugal pump further comprises a mount, 144, defining a mount cavity, 145. The mount, 144, has an upper section and a lower section, wherein the mount, 144, is fixedly attached to the base plate, 112, and the base plate, 112, is fixedly attached to the outer housing, 118. The vertical suspended centrifugal pump of the present invention, 100, can further comprise a motor assembly, 10, wherein the motor assembly, 10, is attached to the shaft, 116, by a coupling means, 148, in order to transfer force axially in order to rotate the shaft, 116, about its vertical axis.
In one embodiment, the outer housing, 118, is fixedly attached to the base plate, 112.
Referring again to FIG. 1, the vertical suspended centrifugal pump of the present invention, 100, further comprises a discharge pipe, 124, which has a discharge pipe inlet, 125, the discharge pipe inlet, 125, is connected to the outlet, 123, of the pump lower end cap, 119, and a discharge port, 126, for pumped liquid to exit.
FIG. 2 illustrates an additional embodiment of the present invention of a vertical suspended centrifugal pump, 200, comprising, an outer housing, 218, the outer housing, 218, is a column, wherein the column is formed of at least one section. The outer housing, 218, has an upper end and a lower end. A pump casing assembly, 220, is formed of at least one section, the pump casing assembly, 220, is positioned at the lower end of the outer housing, 218. An inner housing, 214, the inner housing, 214, may be a column, wherein the column is formed of at least one section, the inner housing, 214, defines an inner housing cavity, 230, the inner housing, 214, has an upper end and a lower end. Wherein the outer housing, 218, the inner housing, 214, the pump casing assembly, 220, and optionally, the base plate, 212, are mated and define the boundaries of an outer housing cavity, 228. Wherein the inner housing, 214, is partially enclosed within the outer housing cavity, 228, and the outer housing, 218, is fixedly attached to the inner housing, 214. If there is no base plate incorporated, then the upper end of the outer housing will replace the base plate as one of the boundary surfaces that defines the outer housing cavity. It should also be noted that the outer housing may be connected either directly to the base plate or via an intermediary connecting device or element and will depend on the application. There is also a pump lower end cap, 219, that defines a void which is isolated from the outer housing cavity, 228, the pump lower end cap, 219, further defines an inlet, 221, and outlet, 223. The embodiment also comprises a shaft, 216, having an upper end, a lower end, and a vertical axis, the shaft, 216, is rotatable about its vertical axis, wherein the shaft, 216, is partially enclosed within the inner housing, 214.
The embodiment illustrated in FIG. 2 also comprises at least two bearings, 252, radially surrounding the shaft, 216, the shaft, 216, and the at least two bearings, 252, being rotatable with respect to one another, and the at least two bearings, 252, are located within the inner housing, 214. This embodiment also comprises at least one impeller, 222, wherein the impeller, 222, is fixedly attached to the lower end of the shaft, 216, and positioned within the void of the pump lower end cap, 219. The impeller, 222, is rotatable, and the rotation produces force to drive fluid from the inlet, 221, to the outlet, 223. This embodiment comprises a top shaft seal, alternatively called a top shaft seal assembly, 238, the top shaft seal, 238, is positioned at the upper end of the shaft, 216, an outer seal, 236, the outer seal, 236, is positioned at the lower end of the shaft, 216, and a wet end seal, 234. The wet end seal, 234, is positioned at the lower end of the shaft assembly, 216, and vertically below the outer seal, 236, wherein the top shaft seal, 238, the outer seal, 236, and the wet end seal, 234, serve to isolate the voids of the inner housing cavity, 230, the outer housing cavity, 228, and the void of the pump lower end cap, 219. The embodiment illustrated in FIG. 2 also comprises at least one probe or sensor, 232, wherein the sensor is capable of detecting the presence or absence of a liquid within the outer housing cavity 230. FIG. 2 further illustrates that at least a portion of the shaft, 216, that lies between the wet end seal, 234, and the outer seal, 236, is exposed to the outer housing cavity, 228. This configuration facilitates contamination detection.
In the embodiment, illustrated in FIG. 2, the vertical suspended centrifugal pump of the present invention, 200, further comprises a base plate, 212. The base plate serves to stabilize the present invention. FIG. 2 further illustrates a motor assembly, 10, wherein the motor assembly, 10, is attached to the shaft, 216, by a coupling means, 248, in order to transfer force axially to rotate the shaft, 216, about its vertical axis. FIG. 2 illustrates an embodiment further comprising a mount, 244, that defines a mount cavity, 245, wherein the mount, 244, has an upper section and a lower section and wherein the mount, 244 is attached to the motor assembly, 10. In this embodiment, the mount, 244, is fixedly attached to the base plate, 212, and the inner housing, 214, is fixedly attached to the base plate, 212. FIG. 2 further illustrates the outer housing, 218, fixedly attached to the inner housing 214 and to the casing assembly 220.
The embodiment in FIG. 2 further comprises a discharge pipe, 224, that has a discharge pipe inlet, 225, the discharge pipe inlet, 225, is connected to the outlet, 223, of the pump lower end cap, 219, and a discharge port, 226, for pumped liquid to exit.
FIG. 3 illustrates a vertical suspended centrifugal pump of the present invention, 300, comprising: an outer housing, 318, wherein the outer housing, 318, may be a column, the column is formed of at least one section, the outer housing, 318, has an upper end and a lower end, a pump casing assembly, 320, that is formed of at least one section, the pump casing assembly, 320, is positioned at the lower end of the outer housing, 318. An inner housing, 314, the inner housing, 314, is a column, the column being formed of at least one section, the inner housing, 314, defines an inner housing cavity, 330, the inner housing, 314, has an upper end and a lower end. Wherein the outer housing, 318, the inner housing, 314, the pump casing assembly, 320, and optionally the base plate, 312, are mated and define an outer housing cavity, 328, wherein the inner housing, 314, is at least partially enclosed within the outer housing cavity, 328. If there is no base plate incorporated, then the upper end of the outer housing will replace the base plate as one of the boundary surfaces that defines the outer housing cavity. It should also be noted that the outer housing may be connected either directly to the base plate or via an intermediary connecting device or element and will depend on the application.
The embodiment illustrated in FIG. 3 further comprises a pump lower end cap, 319, that defines a void that is isolated from the outer housing cavity, 328, the pump lower end cap, 319, further defines an inlet, 321, and an outlet, 323, a shaft or shaft assembly, 316, having an upper end, a lower end, and a vertical axis, wherein the shaft is rotatable about its vertical axis, at least two bearings, 352, radially surrounding the shaft, 316. The shaft, 316, and the at least two bearings, 352, are rotatable with respect to one another and the at least two bearings, 352, are positioned within the inner housing, 314. The embodiment illustrated in FIG. 3 further comprises at least one impeller or impeller assembly, 322, the impeller, 322, is fixedly attached to the lower end of the shaft, 316, and positioned within the void of the pump lower end cap, 319. The impeller, 322, is rotatable, wherein the rotation produces force to drive fluid from the inlet, 321, to the outlet, 323. A top shaft seal, 338, the top shaft seal, 338, is positioned at the upper end of the shaft, 316, an outer seal, 336, the outer seal, 336, is positioned at the lower end of the shaft, 316, and a wet end seal, 334, the wet end seal, 334, is positioned at the lower end of the shaft assembly, 316, and vertically below the outer seal, 336, wherein the top shaft seal, 338, the outer seal, 336, and the wet end seal, 334, serve to isolate the voids of the inner housing cavity, 330, the outer housing cavity, 328, and the void of the pump lower end cap, 319. Wherein at least a portion of the shaft, 316, that lies between the wet end seal, 334, and the outer seal, 336, is exposed to the outer housing cavity, 328. The embodiment is intended to be operated with a desired liquid, 340, that at least partially fills the outer housing cavity, 328, wherein the outer housing cavity, 328, serves as an internal barrier or buffer in order to provide a barrier or buffer liquid. The barrier liquid provides an alternative means to prevent contamination of the pumped liquid or process fluid. The barrier liquid may be pressurized by air or other means to enhance the barrier effect.
In another embodiment, as illustrated in FIG. 3, the vertical suspended centrifugal pump of the present invention, 300, may be configured, optionally, so that the outer housing cavity, 328, further comprises at least one liquid port, 342, through which a means to add, remove, or circulate the desired liquid, 340 may be employed.
In another embodiment, as illustrated in FIG. 3, the vertical suspended centrifugal pump of the present invention, 300, optionally provides for the desired liquid to be circulated by an internal or external circulation device. Optionally, the present invention, 300, may include the liquid port, 342, a circulation device, 350, or both, to provide a means to circulate liquid within the outer housing cavity, 328.
In another embodiment, as illustrated in FIG. 3, the vertical suspended centrifugal pump of the present invention, 300, further comprises that the outer housing cavity, 328, may be pressurized in order to provide a seal barrier liquid between the wet end seal, 334, and the outer seal, 336.
In another embodiment, the vertical suspended centrifugal pump of the present invention, 300, the outer housing cavity, 328, is not pressurized.
Referring again to FIG. 3, in the embodiment illustrated therein, the vertical suspended centrifugal pump of the present invention, 300, further comprises a base plate, 312, on which the outer housing, 318, is fixedly attached. Optionally, the outer housing, 318, may be attached to the base plate, 312, through an intermediary connector or means which serves as a bridging means between the outer housing, 318, and the base plate, 312.
In another alternative embodiment, as illustrated in FIG. 3, the vertical suspended centrifugal pump of the present invention, 300, further comprises a mount, 344, which defines a mount cavity, 345, the mount, 344, has an upper section and a lower section, wherein the mount, 344, is fixedly attached-to the base plate, 312.
In one embodiment, as illustrated in FIG. 3, the vertical suspended centrifugal pump of the present invention, 300, further comprises a motor assembly, 10, wherein the motor assembly, 10, is attached to the shaft, 316, by a coupling means, 348, in order to transfer force axially in order to rotate the shaft, 316, about its vertical axis.
In another embodiment, as illustrated in FIG. 3, the vertical suspended centrifugal pump of the present invention, 300, further comprises a discharge pipe, 324, having a discharge pipe inlet, 325, the discharge pipe inlet, 325, is connected to the outlet, 323, of the pump lower end cap, 319, and a discharge port, 326, for pumped liquid to exit.
In one embodiment, the motor is connected to the shaft by a connection means that can consists of a coupling made of a rigid or semi-rigid material, a belt, or other type of connection that will allow transfer of axial rotation forces from the motor to the shaft.
In one embodiment, the mount is a flange, brackets, collars, or similar mounting system.
The at least two bearings within the inner housing cavity are intended to mate, facilitate, and stabilize rotational movement of the shaft assembly within the inner housing during operation of the present invention.
In one embodiment, the inner housing cavity is sealed.
In another embodiment, the inner housing cavity is not sealed.
As the application needs require, the outer housing can be configured in different lengths. The outer housing cavity is isolated from the pumped process fluid by the wet end seal. The outer housing alternatively can extend from the pump casing assembly to the base plate, run through the base plate, or can extend from the pump casing assembly and be sealed against the inner housing.
The outer housing cavity, optionally, may be sealed. At least a portion of the outer housing cavity is exposed to the shaft assembly below the inner housing and above the wet end seal. The outer housing cavity alternatively may be dry or prefilled with the seal buffer liquid or barrier liquid.
Single or multiple probes, sensors, or switches may be installed inside the outer housing cavity.
It is intended that one or multiple impellers are employed in the present invention and located inside the pump casing assembly.
The discharge pipe may be attached to the base plate or, alternatively, run through it. The connection between the base plate and the discharge pipe optionally may be sealed. Alternatively, the discharge port may be located on or above the base plate.
Optionally, the inner housing cavity may be sealed between the top shaft seal and the outer seal in order to prevent liquids from uncontrollably entering or exiting the inner housing cavity.
The at least two bearings optionally may be lubricated depending on the choice of the bearings. The outer housing cavity, if left dry, is used as a chamber for detecting and collecting any substances that may leak from the wet end seal or any other leakage into the outer housing cavity. Detection of such leakage may be facilitated by a sensor, probe, float switch or any combination thereof. It is intended that leaked material will be detected by the invention prior to impact of the leaked material to any component inside the inner cavity or the pumping fluid. In this manner, the outer housing cavity in combination with the sensors or probes allows the user to detect leakage and stop pump operation after wet end seal failure or other seal failures and before pumped process fluid or the inner housing cavity are contaminated. This can prevent pumped process fluid contamination by the bearing lubricant or by the other materials inside the inner housing cavity or corrosion of pump internal elements.
In one embodiment, if the outer housing cavity is prefilled with the desired liquid as a seal buffer liquid or barrier liquid reservoir then the present invention is not intended to include liquid ports. In that embodiment, the prefilled outer housing cavity eliminates the need for an external reservoir and piping for the seal buffer liquid or barrier liquid. This solution significantly reduces the cost of the axillary equipment, increases reliability, and simplifies service.
In one embodiment, the at least one liquid port is contemplated to be included in the present invention in order to facilitate liquid filling, venting, a pressure source, draining, cooling, instrumentation, or other means to circulate or monitor the desired liquid that serves as a seal buffer or barrier liquid within the outer housing cavity. The seal buffer liquid or barrier liquid may be circulated in order to flush the outer seal by means of an optional internal circulating device or via the optional external circulation system through the at least one liquid port. The at least one probe or sensor optionally may be installed inside the outer housing cavity. This embodiment is effective in pumps with with a two seal configuration.
Piping losses may be minimized through the correct selection of pipe size, elimination of fittings, use of large radius bends, and reduction in the length of piping runs. All of these requirements often conflict with each other and hard to implement in long vertical suspended pumps. Additionally, proper operation is achieved with exclusion of all gas and air bubbles from the piping. Venting of a system during the commissioning of the pump is critical. Very often the price of such vertical piping systems is close to the price of the pump itself. In outdoor applications, especially in areas with extremely low winter temperatures. There is a high cost to keep such pumps running by using external reservoirs to maintain the internal temperature of the pump. The present invention is intended to minimize those requirements.
Optionally, in one embodiment, the present invention may have two seals. The outer housing cavity may optionally be filled by the seal buffer liquid or barrier liquid.
Optionally an external reservoir and piping may be employed with the present invention for the seal buffer liquid or barrier liquid.
Optionally, the seal buffer liquid or barrier liquid reservoir may include an internal or external circulation device.
While some of the preferred materials for elements have been described, the pump is not limited by these materials. Thermoplastic polymers, rubber, foam, metal alloys, aluminum, and other materials may comprise some or all of the elements of the pump and apparatuses in various embodiments of the present invention. Some of the elements of the present invention may need to be fabricated de novo based on the applications and sizes required for the applications.
Some of the elements for the present invention may be obtained from commercial suppliers. Example suppliers for some elements of the present invention follow. Pump electric motors may be obtained from Baldor Motors, 9810 Industrial Blvd, Lenexa, Kans., 66215. Discharge pipes that are 2 inch diameter 316 stainless steel may be obtained from US METAL, 19102 Gundle Road, Houston Tex., 77073. Discharge ports that are 316 stainless steel may also be obtained from US METAL. Liquid sensors, for example, a stainless steel float level switch with ¼″ NPT stem, model M5600, may be obtained from Madison Company, 27 Business Park Drive, Branford, Conn. 06405. Mechanical seals, for example, a John Crane Type 21 seal, may be obtained from John Crane Inc., 2931 East Apache Street, Tulsa Okla. 74110. Single lip seals may be obtained from Garlock, 628 NW Platte Valley Drive, Riverside, Mo., 64150. Stainless steel 0.5 inch diameter tubing may be obtained from US METAL, 19102 Gundle Road, Houston Tex., 77073. Flexible couplings 1 inch diameter may be obtained from Lovejoy at Bearing Headquarters 3010 South 2th Street, Kansas City, Kans., 66106.
Although the present invention has been illustrated and described herein, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present invention, are contemplated thereby.

Claims

We claim:

1. A vertical suspended centrifugal pump comprising:

an outer housing defining an outer housing cavity,

an inner housing defining an inner housing cavity,

a rotatable shaft,

a wet end seal,

the shaft being enclosed partially within the inner housing, the inner housing being at least partially enclosed within the outer housing, the inner housing cavity and the outer housing cavity being isolated from each other, wherein a portion of the shaft communicates with the outer housing cavity below the inner housing cavity and above the wet end seal, and

at least one sensor, the at least one sensor being capable of detecting the presence or absence of a liquid within the outer housing cavity.

2. A vertical suspended centrifugal pump comprising:

an outer housing, the outer housing being a column, the column being formed of at least one section, the outer housing having an upper end and a lower end,

a pump casing assembly being formed of at least one section, the pump casing assembly being positioned at the lower end of the outer housing,

a pump lower end cap defining a void that is isolated from the outer housing cavity, the pump lower end cap further defining an inlet and an outlet,

a shaft having an upper end, a lower end, and a vertical axis, the shaft being rotatable about its vertical axis,

an inner housing, the inner housing being a column, the column being formed of at least one section, the inner housing defining an inner housing cavity, the inner housing having an upper end and a lower end,

wherein the outer housing, the inner housing, and the pump casing assembly are mated and define the boundaries of an outer housing cavity,

wherein the inner housing is enclosed within the outer housing cavity,

at least two bearings radially surrounding the shaft, the shaft and the at least two bearings being rotatable with respect to one another, the at least two bearings being within the inner housing,

at least one impeller, the impeller being fixedly attached to the lower end of the shaft and positioned within the void of the pump lower end cap, the impeller being rotatable, and wherein the rotation produces force to drive fluid from the inlet and to the outlet, and

3. The vertical suspended centrifugal pump of claim 2 wherein the outer housing is sealed.

4. The vertical suspended centrifugal pump of claim 2 wherein the shaft has a top shaft seal, the top shaft seal being positioned at the upper end of the shaft, an outer seal, the outer seal being positioned at the lower end of the shaft, and a wet end seal, the wet end seal being positioned at the lower end of the shaft assembly and vertically below the outer seal, wherein the top shaft seal, the outer seal, the wet end seal serve to isolate the inner housing cavity, the outer housing cavity, and the void of the pump lower end cap, and wherein at least portion of the shaft that lies between the wet end seal and outer seal, is exposed to the outer housing cavity.

5. The vertical suspended centrifugal pump of claim 2 further comprising a mount, defining a mount cavity, and having an upper section and a lower section, wherein the mount is fixedly attached to a base plate and wherein the base plate is fixedly attached to the outer housing.

6. The vertical suspended centrifugal pump of claim 2 wherein the outer housing, the inner housing, the pump casing assembly, and the base plate are mated and define the outer housing cavity.

7. The vertical suspended centrifugal pump of claim 2 further comprising a motor assembly wherein the motor assembly is attached to the shaft by a coupling means in order to transfer force axially in order to rotate the shaft about its vertical axis.

8. The vertical suspended centrifugal pump of claim 2 further comprising a base plate to which the outer housing is fixedly attached.

9. The vertical suspended centrifugal pump of claim 2 further comprising a discharge pipe having a discharge pipe inlet, the discharge pipe inlet being connected to the outlet of the pump lower end cap, and a discharge port for pumped liquid to exit.

10. A vertical suspended centrifugal pump comprising:

an inner housing, the inner housing being a column, the column being formed of at least one section, the inner housing defining an inner housing cavity, the inner housing having an upper end and a lower end, wherein the shaft is at least partially enclosed within the inner housing,

wherein the inner housing is partially enclosed within the outer housing cavity and the outer housing is fixedly attached to the inner housing,

at least one impeller, the impeller being fixedly attached to the lower end of the shaft and positioned within the void of the lower end cap, the impeller being rotatable, and wherein the rotation produces force to drive fluid from the inlet to the outlet,

a top shaft seal, the top shaft seal being positioned at the upper end of the shaft, an outer seal, the outer seal being positioned at the lower end of the shaft, and a wet end seal, the wet end seal being positioned at the lower end of the shaft assembly and vertically below the outer seal, wherein the top shaft seal, the outer seal, and the wet end seal serve to isolate the voids of the inner housing cavity, the outer housing cavity, and the void of the end cap, wherein at least portion of the shaft that lies between the wet end seal and outer seal, is exposed to the outer housing cavity,

and

11. The vertical suspended centrifugal pump of claim 10 further comprising a base plate to which the inner housing is fixedly attached.

12. The vertical suspended centrifugal pump of claim 10 further comprising a mount, defining a mount cavity, and having an upper section and a lower section, wherein the mount is fixedly attached to a base plate and wherein the base plate is fixedly attached-to the inner housing.

13. The vertical suspended centrifugal pump of claim 10 further comprising a motor assembly wherein the motor assembly is attached to the shaft by a coupling means in order to transfer force axially to rotate the shaft about its vertical axis.

14. The vertical suspended centrifugal pump of claim 10 further comprising a discharge pipe having an inlet, the inlet connected to the outlet of the pump lower end cap, and a discharge port for pumped liquid to exit.

15. A vertical suspended centrifugal pump comprising:

wherein the inner housing is at least partially is enclosed within the outer housing cavity,

at least one impeller, the impeller being fixedly attached to the lower end of the shaft and positioned within the void of the pump lower end cap, the impeller being rotatable, and wherein the rotation produces force to drive fluid from the inlet to the outlet,

a top shaft seal, the top shaft seal being positioned at the upper end of the shaft, an outer seal, the outer seal being positioned at the lower end of the shaft, and a wet end seal, the wet end seal being positioned at the lower end of the shaft assembly and vertically below the outer seal, wherein the top shaft seal, the outer seal, and the wet end seal serve to isolate the voids of the inner housing cavity, the outer housing cavity, and the void of the end cap, wherein at least portion of the shaft that lies between the wet end seal and outer seal, is exposed to the outer housing cavity, and

a desired liquid, wherein the desired liquid at least partially fills the outer housing cavity and serves as an internal barrier in order to provide a barrier or buffer liquid, and the outer housing cavity is a liquid reservoir.

16. The vertical suspended centrifugal pump of claim 15 wherein the outer housing cavity further comprises at least one liquid port to facilitate the addition, removal, or circulation of the desired liquid.

17. The vertical suspended centrifugal pump of claim 15 further comprising at least one sensor to monitor the desired liquid.

18. The vertical suspended centrifugal pump of claim 15 wherein the desired liquid is circulated by an internal or external circulation device.

19. The vertical suspended centrifugal pump of claim 15 wherein the outer housing cavity is pressurized in order to provide a seal barrier liquid between the wet end seal and the outer seal.

20. The vertical suspended centrifugal pump of claim 15 wherein the outer housing cavity is not pressurized.

21. The vertical suspended centrifugal pump of claim 15 further comprising a base plate on which the outer housing is fixedly attached.

22. The vertical suspended centrifugal pump of claim 15 further comprising a mount, defining a mount cavity, and having an upper section and a lower section, wherein the mount is fixedly attached to a base plate and wherein the base plate is fixedly attached-to the outer housing.

23. The vertical suspended centrifugal pump of claim 15 further comprising a motor assembly wherein the motor assembly is attached to the shaft by a coupling means in order to transfer force axially in order to rotate the shaft about its vertical axis.

24. The vertical suspended centrifugal pump of claim 15 further comprising a discharge pipe having an inlet, the inlet connected to the outlet of the pump lower end cap and a discharge port for pumped liquid to exit.