Patent Application
20170306982
The present disclosure concerns fluid pumps and cavitation generators.
Typical rotational fluid devices, such as pumping, mixing, and cavitation devices, operate on fluids by mechanically rotating a rotor or impeller in a reaction chamber with a stator, while a flow of fluid passes from an inlet, across the rotor or impeller, and to an outlet. Typical fluid devices comprise a one-piece reaction chamber housing with an end-cap sealing the housing or a two-piece housing split laterally to enable longitudinal separation of from piece from the other. These conventional designs enable the fluid device to be constructed or serviced by removing an end of the reaction chamber housing to access the rotor or stator in a longitudinal direction.
The concepts herein encompass using a fluid device having a reaction chamber constructed from casings split longitudinally. The present invention can also relate to pumping devices, cavitation generators, and mixers. The present invention further relates to fluid devices having a reaction chamber housing formed of multiple casings removeably coupled at longitudinal mating regions deposed along the length of the reaction chamber housing with respect to the axis of rotation. Embodiments disclosed herein provide an ability to quickly and easily service or alter the casing and impellers/rotors without the need to completely disassemble the unit. Typical multi-stage fluid device designs require the removal of the entire shaft and internals whereas the present design enables maintenance and replacement of rotor and casing parts to be conducted without disconnecting or modifying the input shaft. One skilled in the art will appreciate a substantial reduction in maintenance complexity using the present design.
In an example, a split casing fluid device includes a reaction chamber housing including a first casing having a first portion of a stator and a second casing having a second portion of the stator. The first and second casings define the reaction chamber housing. A rotor is rotatably mounted inside the stator and the rotor defines a length along a longitudinal axis of rotation. The rotor comprises an exterior surface having a plurality of fluid-interacting features, and the rotor exterior surface and the stator define a fluid passageway there between. The split casing fluid device includes a fluid inlet into the reaction chamber housing, the fluid inlet being in fluid communication with the fluid passageway, and a fluid outlet from the reaction chamber housing, the fluid outlet being in fluid communication with the fluid passageway. Removal of one or more of the casings creates an opening in the reaction chamber housing sized and shaped to allow passing the rotor through the opening.
In some examples, the rotor defines a minimum diameter, and each casing of the reaction chamber housing spans at least the length of the rotor, and at least one of the first and second casing comprises an inner surface defining a width respect to a plane normal to the longitudinal axis of the rotor greater than the minimum diameter of the rotor.
In some examples, the first and second casings defining opposing halves of the reaction chamber housing.
In some examples, the rotor comprises first and second rotor segments removeably coupled together, the first and second rotor segments each spanning the length of the rotor.
In some examples, the first and second rotor segments define opposing halves of the rotor.
In some examples, the rotor includes first and second ends each defining a cone shaped surface varying the width of the fluid passageway along the flow cone.
In some examples, the first portion of the stator is formed on an interior surface of the first casing and the second portion of the stator is formed on an interior surface of the second casing.
In some examples, the first portion of the stator is a first stator sleeve and wherein the second portion of the stator is a second stator sleeve, the first and second stator sleeves removeably nest within an inner surface of the respective first and second casings.
In some examples, the rotor defines an interior rotor volume in fluid communication with the fluid inlet, and wherein the fluid-interacting features are thru-holes between the interior rotor volume and the fluid passageway
In some examples, split casing fluid device further includes an input shaft having first and second ends, and the rotor is coupled to the input shaft and the input shaft adapted to enable rotation of the rotor in the reaction chamber housing and transfer torque to the rotor. The split casing fluid device further includes an inlet assembly including a first bearing coupled with the first end of the input shaft and an outlet assembly comprising a second bearing coupled with the second end of the input shaft.
In some examples, the first and second casings each comprise opposing first and second ends, and wherein the first ends of the first and second casings are removeably coupled to the inlet assembly, and wherein the second ends of the first and second casing are removeably coupled to the outlet assembly.
In some examples, the inlet assembly defines a first inner passageway in fluid communication with the fluid passageway and the outlet assembly defines a second inner passageway in fluid communication with the fluid passageway, the input shaft passing through the first and inner passageways. In some examples, the rotor comprises first and second rotor segments removeably coupled together, the first and second rotor segments each spanning the length of the rotor and wherein the input shaft includes an axial lock key adapted to maintain an axial location of the rotor segments on the input shaft. In some examples, the inlet assembly comprises a first external bearing assembly having the first bearing, and wherein the outlet assembly comprises a second external bearing assembly having the second bearing, and wherein the first and second external bearing assemblies position the first and second bearing outside of the first and second inner passageways.
In some examples, the split casing fluid device is a split casing cavitation generator, and wherein the plurality of fluid-interacting features comprises a plurality of cavitation-inducing features, and wherein the fluid outlet is a heated fluid outlet. In some examples, the stator comprises an inner surface defining a first plurality of apertures and wherein the plurality of cavitation-inducing features comprises a second plurality of apertures.
In some examples, the split casing fluid device is a split casing multi-stage pump, and the plurality of fluid-interacting features comprises a plurality of pumping features.
Another example is a method of servicing a split casing fluid device. The method includes, given a reaction chamber housing comprising a first casing and a second casing and a rotor rotatably mounted inside the reaction chamber housing, releasing the first casing from the second casings, and removing one of the first and second casings from the reaction chamber housing. The removing one of the first and second casings creating an opening in the reaction chamber housing sized and shaped to enable the rotor to pass though the opening. In some examples, the method further comprises passing the rotor though the opening.
A split casing fluid device is described herein. The fluid device includes a reaction chamber housing constructed of multiple casings being split longitudinally about the rotational axis of a rotor. The casings may span the length of the rotor to enable the rotor to be installed or removed in a direction perpendicular to the axis of rotation, or, in the alternative, the casings may span a sufficient portion of the length of the rotor to enable to the rotor to be removed or installed by passing through the opening created by removing on or more of the casings. In some examples, each casing may be a casing assembly constructed from multiple segments that can be individually separated as part of the process of removing the casing assembly from the reaction chamber housing. In some aspects, the reaction chamber is constructed from two casings each forming an opposing half of the reaction chamber housing. In some aspects, the reaction chamber housing is constructed from a plurality of casings joined longitudinally with respect to the axis of rotation of the rotor, with the segments having a variety of sizes, lengths, and widths.
Generally, one skilled in the art will appreciate that longitudinally joined casings enables the reaction chamber housing to be constructed around an existing rotor and shaft without modification or disconnection of the input shaft and input/output volutes. Additionally, one skilled in the art will appreciate that the split casing and rotor design described herein enables removal and replacement of the rotor without modification or disconnection of the input shaft and input/output volutes. The ability to avoid modifying the input shaft enables associated shaft features, for example, bearings and packings, to be constructed and installed without concern for routine maintenance work requiring their removal. In some instances, examples reduce complexity and improve reliability over prior art design by employing external bearing assemblies, which may be integrated with the volutes.
Some, none or all of the aforementioned examples, and examples throughout the following descriptions, can be combined.
In operation, the split casing cavitation generator 100 accepts a fluid flow through the inlet 111, into the interior of the reaction chamber housing 20, and to the outlet 131. A rotor (not shown) is disposed in the reaction chamber housing 20 and is driven by the input shaft 150. The rotor is configured to spin in the reaction chamber housing as the fluid flow passes between the rotor and a stator (not shown) on the inner surface of the reaction chamber housing 20. An interaction between the rotor, stator, and fluid flow generates cavitation in the fluid flow. As shown in more detail in
In operation, removal of the top casing 120a enables access to the rotor 240 to allow for servicing and cleaning of, for example, the rotor 240 and the casings 120a,b. As shown, to remove the top casing 120a from the split casing cavitation generator 100, the first and second flanges 122a, 123a of the top casing are disconnected, respectively, from the inlet flange 112 and the outlet flange 133. Additionally, the top casing 120a is decoupled from the bottom casing 120b by removing fasteners (not shown) present in the holes 125 of the longitudinal mating regions 124a,b.
In operation, the split casing rotor 240 enables the rotor segments 340a,b, to be installed on an existing input shaft 150 and with the top casing 120b or bottom casing 120b removed.
In some instances, the stator 560 is formed directly into the surface of the casings 120a,b, or in other instances, is, a removable sleeve nested on the inner surfaces of the casings 120a,b. A removable sleeve stator enables changing the stator 560 without replacing the casing 120a,b, which may be necessary due to wear on the surface or in order to change the radial clearance between the stator 560 and the exterior surface of the rotor 240. In some instances, changing the thickness of the stator 560 allows for different sizes of solids present in the fluid without damaging the surfaces of the stator 560 and rotor 240. Changing the thickness of the stator 560 can also be used to reduce shearing effects or to vary the velocity of the rotor 240 as a function of the fluid's properties. The stator 560 sleeve allows for simple modification of the cavitation parameters without changing the rotor 240 or reaction chamber housing 20.
In operation, the rotor 240 is adapted to spin 699 via the input shaft 150 and a flow of fluid 611, for example, a fluid feedstock, is provided to the inlet 111 of the inlet volute 110 of the split casing cavitation reactor 100. The inlet volute 110 defines an interior volute 610 that directs 612 the flow of fluid 611 to the reaction chamber housing 20. In the reaction chamber housing 20, the fluid 611 passes around the flow cone 341a,b and into the passage 613 between the surface of the rotor 240 and the stator 560. As the fluid between the spinning apertures 245 on the rotor 240 and the stationary aperture 565 on the stator 560, localized regions of extremely low pressure form in the fluid 611, which momentarily causes cavitation bubbles to form in the fluid 611. The subsequent and violent collapse of the cavitation bubbles generates heat within the fluid 611 from the mechanical energy of the spinning rotor 240. The intense heat and pressure of the act of cavitation is able to destroy organics that may be present in the fluid 611 along with other compounds. Through the act of hydrodynamic cavitation, and/or secondary acoustic cavitation, the fluid 611 is heated/pressurized to a degree that depends on, for a given geometry of the rotor 240 and stators 560, the mechanical energy input to the rotor 240, the fluid properties, for example, viscosity, specific heat, and heat of vaporization. Solids present in the flow small enough to pass through the fluid passageway 613 may pass unchanged.
In an exemplary embodiment, the radial clearance between the exterior surface of the rotor 240 and the stator 860a,b is less than one half inch. Generally, one skilled in the art will appreciate that different clearances are necessary depending on fluid viscosity and the presence of impurities (e.g., small rocks, dirt, or debris) in the fluid.
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A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. Accordingly, other implementations are within the scope of the following claims.
