Patent Publication Number: US-2021180833-A1

Title: Segmented cavitation boiler

Description:
FIELD 
     The present disclosure concerns fluid pumps and cavitation boiler. 
     BACKGROUND 
     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. 
     SUMMARY 
     The concepts herein encompass using a fluid device having a reaction chamber constructed from segmented rotors and stators. The concepts herein can also relate to pumping devices, cavitation boiler machines, and mixers. The concepts herein 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 convert a typical multi-stage pump into a cavitation boiler by replacing the pumping segments with a rotor assembly including individual rotor segments that spin inside of corresponding individual stator segments disposed in a stationary outer drum. One skilled in the art will appreciate a substantial reduction in maintenance complexity using the present design. 
     In an example, a cavitation boiler segment is configured to be disposed in a housing. The cavitation boiler segment includes a rotor segment configured to be secured around an inner drum of the housing, where the rotor segment includes: (i) a rotor drum having first and second annular banks of apertures through the rotor drum, the rotor drum defining an outer surface of the rotor segment, (ii) a hub configured to interface with the inner drum, and (iii) an annular web connecting the hub to the rotor drum between the first and second annular banks of apertures. The annular web includes an upstream surface defining a first fluid passageway between an upstream face of the rotor segment and the first bank of apertures, and a downstream surface defining a third fluid passageway between a downstream face of the rotor segment and the second bank of apertures. The cavitation boiler segment also includes a stator segment configured to be inserted into an outer drum of the housing, with the stator segment having a stator drum having third and fourth annular banks of apertures through the stator drum arranged to overlap the first and second banks of apertures through the rotor drum, the stator drum defining an inner surface of the stator segment, and a stator casing configured to interface with an outer drum of the housing, the stator casing enclosing the third and fourth annular banks of apertures in an interior chamber defining a second fluid passageway between the third and fourth annular banks of apertures. In addition, the first, second, and third fluid passageways together define a flowpath through the cavitation boiler segment. 
     In some instances, the outer surface of the rotor segment and the inner surface of the stator segment define a cavitation region therebetween. In some instances, the cavitation region includes a first cavitation region between the first and third banks of apertures, and a second cavitation region between the second and fourth banks of apertures, and wherein, when the rotor segment rotates with respect to the stator segment, the first cavitation region is configured to generate cavitation in a fluid flowing radially outward from to the first bank of apertures to the third bank of apertures, and the second cavitation region is configured to generate cavitation in the fluid flowing radially inward from the fourth bank of apertures to the second bank of apertures. 
     In some instances, the rotor drum extends from the web to an upstream drum lip defining an upstream segment of the rotor drum, and from the web to a downstream drum lip defining a downstream segment of the rotor drum, the upstream segment of the rotor drum having the first bank of apertures and the downstream segment of the rotor drum having the second bank of apertures. 
     In some instances, the rotor segment includes a first ring having the upstream segment of the rotor drum, a first annular web includes the upstream surface of the annular web, and an upstream segment of the hub. In addition, the rotor segment includes a second ring having the downstream segment of the rotor drum, a second annular web including the downstream surface of the annular web, and a downstream segment of the hub. Where the first and second rings are configured to be arranged adjacent to each other on the inner drum of the housing and, when adjacent, form the outer surface of the rotor segment. 
     In some instances, the first and second rings are integrally formed with the rotor segment. 
     In some instances, the first ring includes the first fluid passageway and the first ring is configured to receive an axial flow of a fluid and direct the fluid in a radially outward direction across the first plurality of apertures, and the second ring includes the third fluid passageway and the second ring is configured to receive a radially inward flow of the fluid second annular bank of apertures and direct the fluid in the axial direction. 
     In some instances, wherein the first ring include the upstream surface of the first ring is shaped to direct the axial fluid flow received by the first in a radially outward direction through the first bank of apertures, and the downstream surface of the second ring is shaped to direct the radially inward fluid flow received from the second bank of apertures in the axial direction. 
     In some instances, the upstream face of the first ring defines an inlet opening, and the downstream face of the second ring defines and outlet opening, and wherein the inlet and outlet opening are sized and dimensioned to define opposing halves of an annular chamber. 
     In some instances, the downstream and upstream faces of the rotor segment are each configured to interface with a corresponding face of a second rotor segment arranged adjacent to the rotor segment. 
     In some instances, the first and second fluid passageways are annular channels around the rotor segment. 
     In some instances, the first and second annular banks of apertures are arranged in parallel around the outer drum of the rotor segment, and the third and fourth annular banks of apertures are arranged in parallel around the inner drum of the stator segment. 
     In some instances, the stator casing includes an outer surface configured to secure the stator segment to the outer drum, and an inner surface having formed therein an annular channel defining at least a portion of the interior chamber of the stator segment. 
     In some instances, a gap between the outer surface of the rotor segment and the inner surface of the stator ring is between 0.05 and 0.002 inches along the entire axial length. 
     In some instances, the gap is between and 0.05 and 0.002 inches along the entire axial length. 
     In some instances, when the stator segment is arranged around the rotor segment, the first and third fluid passageways of the rotor segment are only in fluid connection with each other through the second fluid passageway of the stator segment, absent a gap between the outer surface of the rotor drum and the inner surface of the stator drum. 
     In some instances, the third fluid passageway of the stator is configured to direct a radially outward flow from the third bank of apertures into a radially inward flow toward the fourth bank of apertures. 
     Another example is a cavitation boiler chamber including a housing having a rotatable inner drum including first and second end caps configured to couple the inner drum to an input shaft, and a stationary outer drum disposed around the rotatable inner drum. The boiler chamber also includes a plurality of cavitation boiler segments, described above, disposed in the housing, the plurality of cavitation boiler segments being arranged in series such that a fluid passageway is defined through the plurality of cavitation boiler segments, wherein the flow path through each cavitation boiler segment defines a sequential portion of the continuous fluid passageway, and wherein each rotor assembly is arranged in the housing and secured to the rotatable inner drum, and each stator assembly is arranged in the housing and secured to the stationary out drum. 
     In some instances, the cavitation boiler chamber includes a pump segment disposed in the housing upstream of the plurality of cavitation boiler segments, the pump segment having an outlet in fluid communication with the upstream face of a first rotor segment of the plurality of cavitation boiler segments, the pump segment being configured to pump the fluid through the continuous fluid passageway of the plurality of cavitation boiler segments. 
     Yet another example of the present disclosure is a cavitation device having the cavitation boiler chamber described with, an inlet housing defining a fluid inlet into the boiler chamber housing, the fluid inlet in fluid communication with the fluid passageway of the cavitation boiler chamber, an outlet housing defining a fluid outlet from the cavitation boiler chamber, the fluid outlet in fluid communication with the fluid passageway, and an input shaft spanning between the inlet housing and the outlet housing and coupled to the rotatable inner drum of the housing of the cavitation boiler, the input shaft configured to be coupled to a motor. 
     Still yet another example of the present disclosure is a cavitation boiler segment configured to be disposed in a housing. The cavitation boiler segment includes a rotor segment configured to be secured around an inner drum of the housing, where the rotor segment includes a rotor drum defining an outer surface of the rotor segment and having a first and a second set of apertures through the outer drum, the rotor drum, and the rotor segment defining an upstream annular fluid passageway and a downstream annular fluid passageway adjacent and separate from the upstream annular fluid passageway, the upstream annular fluid passageway is configured to receive and axial flow of a fluid and direct the fluid in a radially outward direction across the first set of apertures of the rotor drum, and the downstream annular fluid passageway is configured to receive a radially inward flow of the fluid from the second set of apertures and direct the fluid in an axial direction. Where the rotor segment is configured to interface with a second rotor segment disposed adjacent to the rotor segment, such that the downstream annular fluid passageway of the rotor segment is in fluid communication with the upstream annular fluid passageway of the second rotor segment. The cavitation boiler segment also includes a stator segment configured to be inserted into an outer drum of the housing, where the stator segment includes a stator drum defining an inner surface of the stator segment and having a third and a fourth set of apertures through the stator drum located to overlap the first and second sets of apertures when the stator segment is disposed around the rotor segment, and a stator casing configured to interface with an outer drum of the housing, the stator casing enclosing the third and fourth sets of apertures in an interior chamber defining a stator fluid passageway between the third and fourth sets of apertures. 
     Yet another example is a method for generating cavitation with a cavitation boiler segment comprising a rotor segment disposed inside a stator segment. The method includes rotating the rotor segment inside the stator segment such that a first plurality of apertures of the rotor segment transits a first plurality of apertures of the stator segment and a second plurality of apertures of the rotor segment transits a second plurality of apertures of the stator segment. The first plurality of apertures of the rotor and stator segments define a first cavitation region therebetween, and the second pluralities of apertures of the rotor and stator segments define a second cavitation region therebetween. Continuing, the method includes accepting a flow of a fluid at an upstream side of the rotor segment and passing the fluid from the an upstream side of the rotor segment into a fluid passageway in the stator segment through the first cavitation region, whereby the rotation of the rotor segment generates cavitation in the fluid passing through the first cavitation region. Then passing the fluid passageway in the stator segment into a downstream side of the rotor segment through the second cavitation region, whereby the rotation of the rotor segment generates cavitation in the fluid passing through the second cavitation region. 
     Generally, one skilled in the art will appreciate that individual rotor and stator segments enables a cavitation reaction chamber housing to be constructed around an existing multi-stage pumping housing. Additionally, one skilled in the art will appreciate that the segmented cavitation boiler design described herein enables precise tolerances to be maintained in a cavitation region between each set of a rotor and stator segment set without similarly precise tolerances being maintained between adjacent rotor and stator segments. The tolerances discussed include stack up tolerances of a multi-stage pump type pump/cavitator. Because of each stage being completely separate and typically unable to be machined as a complete assembly, stack up tolerances become a larger issue as more and more sections are stacked. Aspects of the present disclosure alleviate those issues by enabling a stack up of the assembly to do a final machine step to ensure there is no stack up between stages. In addition, the segmented cavitation boiler design minimizes unwanted movement of fluid through each segment by focusing the work (e.g., cavitation) to locations farther from the central axis of rotation. The internal design of the rotor and stator segments also reduce the radial length of travel of a fluid and thereby reduce the overall length of the path of travel for fluid through the cavitation boiler. 
     Some, none or all of the aforementioned examples, and examples throughout the following descriptions, can be combined. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a cut-away view of a cavitation boiler installed in a multi-stage pump assembly. 
         FIG. 1B  is a detailed cut-away view of the interior components of the cavitation boiler of  FIG. 1A . 
         FIG. 2  is a cross-section illustration of a cavitation boiler. 
         FIGS. 3A and 3B  are illustrations of a rotor segment. 
         FIG. 4  is a cross-sectional diagram of a rotor assembly. 
         FIG. 5A-5D  are illustrations showing assembly of a rotor assembly from individual rotor segment on an inner drum. 
         FIGS. 6A and 6B  are illustration of a stator segment including a stator and a stator casing. 
         FIGS. 7A-7C  are cross-sectional diagrams of the stator segment. 
         FIGS. 7D and 7E  are cross-sectional diagrams of an alternative stator segment. 
         FIGS. 8A and 8B  are illustrations showing assembly of a stator assembly from individual stator segments inside an outer drum. 
         FIG. 9  is an illustration of a multi-stage pump assembly with the pumping stages removed. 
         FIGS. 10A-10E  are illustrations showing assembly of a rotor assembly and a stator assembly to form a cavitation boiler. 
         FIG. 11  is a cross-sectional diagram of a stator segment arranged around a rotor segment. 
         FIG. 12  is a cross-sectional diagram of a stator assembly arranged around a rotor assembly in a cavitation boiler. 
         FIG. 13  is a cross-section of an example cavitation boiler without an outer drum. 
         FIGS. 14A and 14B  are an exploded view of the example cavitation boiler of  FIG. 13 , showing the stator assembly and of the rotor assembly into the cavitation boiler housing. 
     
    
    
     DETAILED DESCRIPTION 
     One aspect of the present disclosure is a segmented cavitation boiler constructed by removing the pump segments of a multi-stage centrifugal pump, which use a standard impeller designed to move water, and replacing the internals with a new “segmented drum” assembly that include a plurality of individual rotor and stator segments. In some instances, and in contrast to prior art cavitation generators, the segmented cavitation boiler disclosed herein does not increase the pressure of the fluid flowing through cavitation boiler segments. 
       FIG. 1A  is a cut-away view of a cavitation device  10  including cavitation boiler  100  installed in the chassis of a multi-stage pump assembly. The assembly  10  includes an upstream housing  17  with an inlet  12 , a downstream housing  14  with an outlet, and an input  15  shaft passing through the upstream housing  17  and the downstream housing  14 . The upstream housing  17  and the downstream housing  14  each include a motor  16  coupled to the input shaft  15  and an interior volute (not shown) configured to fluidly connect the corresponding inlet  12  and outlet  13  with an outlet port  11  to the cavitation boiler  100 . In operation, fluid is pumped into the inlet  12  and through a fluid passageway of the cavitation boiler  100  (as shown in more detail in  FIG. 1B ), and out the outlet  13 . At a basic level, the cavitation boiler  100  includes a rotating inner drum fixed to the input shaft  15  and a stationary outer drum  150 , which is secured at opposite ends to the upstream housing  17  and the downstream housing  14 , which are themselves fixed in place by tension rods  18 . Rotor segments  120  are fixed to the rotating inner drum  110  and each rotor segment  120  spins inside a stator drum  130  fixed to the outer drum  150  by a stator casing  140 . A torturous fluid passageway is created through each rotating rotor segment  120 , into a corresponding stator drum  130 , and back into a downstream rotor segment  120 , which defines a continuous fluid passageway through the cavitation boiler  100 , as shown in  FIG. 1B . When a fluid passes between the rotating rotor segment  120  and into the stator segment (which includes a stator drum  130  and a stator casing  140 ), it passes through a cavitation region created by two sets of apertures rotating with respect to each other—one set in the rotor segment  120 , and a corresponding set in the stator drum  130 . When the fluid moves between the rotor segment  120  and the stator drum  130 , it does so through the two sets of apertures, which induces cavitation in the fluid in a small region between the rotor segment  120  and the stator drum  130 . 
       FIG. 1B  is a detailed cut-away view of the interior components of the cavitation boiler  100  of  FIG. 1A . As detailed above, the rotating inner drum  110  spins attached rotor segments  120  inside of stationary stator drum  130  that surrounds the rotor segments  130 . Each rotor segment  120  includes an exterior drum surfacing having two annular sets of apertures  121 ,  122  through the drum. Around each rotor segment  120 , is positioned a stator drum  130 , with a two corresponding set of annular apertures  131 ,  132  positioned above (e.g., in the radial direction) the apertures  121 ,  122  of the rotor segment  120 . In this configuration, a fluid passageway is created between each set of the apertures  121 ,  122  of the rotor segment  120  and each corresponding set of the apertures  131 ,  132  of the stator drum  130 . In operation, rotation of the rotor segment  120  inside the stator drum  130  spins the rotor&#39;s apertures  121 ,  122  inside of the stator&#39;s apertures  131 ,  132 . In some instances, a small gap exists between the rotor segment  120  and the stator drum  130 . 
       FIG. 1B  shows a cut-away of the fluid passageway  20  through the cavitation boiler  100 , which includes a rotor fluid passageway  21  and a stator fluid passageway  22 . The rotor fluid passageway  21  is illustrated as an annular interior chamber in the rotor segment  120  that enables fluid in the rotor fluid passageway  21  to pass through the apertures  121 ,  122  of the rotor segment  120 . The stator fluid passageway  22  is illustrated as an annular interior chamber in the stator drum  130  that is created by two grooves in the stator drum  130  (e.g., the location of the stator&#39;s apertures  131 ,  132 ) being enclosed by the stator casing  140  to form the stator fluid passageway  22  that fluidly connects the two sets of the apertures  131 ,  132  of the stator drum  130 . In operation, fluid enters the rotor fluid passageway  21  in an open face of a first rotor segment  120  (e.g., an upstream portion), as shown, as flows into the stator fluid passageway  22  by passing across the apertures of the rotor and then the apertures of the stator. This operation induces cavitation in the fluid in a first cavitation region between a first set of apertures  121  of the rotor segment  120  and a first set of apertures  131  of the stator drum  130  when the rotor segment is rotating with respect to the stator drum  130 , as explained in more detail below. The fluid in the stator fluid passageway  22  is directed from the first set of apertures  131  to the second set of apertures  132 , where the fluid then passes through a second cavitation region between a second set of apertures  132  of the stator drum  130  and a second set of apertures  122  of the rotor segment  120 . The fluid re-enters the rotor segment  120  into a downstream portion of the rotor fluid passageway that is separate from the upstream portion the fluid first entered. In this downstream chamber of the rotor segment  120 , the fluid freely passes to the upstream portion of the rotor fluid passageway  21  in an adjacent (e.g., downstream) rotor segment  120 , and the process repeats until the fluid exists the cavitation boiler  100 , as shown in  FIG. 2 . 
       FIG. 2  is cross-section illustration of the cavitation boiler  100  with the outer drum  150  not shown. In  FIG. 2 , the fluid passageway  20  through the cavitation boiler  100  is illustrated as arrows showing alternating of the rotor fluid passageways  21  and stator fluid passageways  22 , which are connected across cavitation regions, as described above. In contrast to impeller driven cavitation systems, the present cavitation boiler  100  removes unneeded weight and rotational resistance. In general, impellers are designed to move water, but in some instances, the rotor segments  120  and stator segments  130 , and as illustrated, are not configured to pump the fluid through the cavitation boiler  100 . In some instances, a source of pressurized fluid (e.g., a pump upstream of the inlet  12 , or a pump segment upstream of the cavitation boiler  100 ) drives the fluid through the cavitation boiler  100 , which results in less input power supplied to the input shaft  16  to reach an ideal RPM for the rotor segments  120 . In some instances, pumping segments can be interposed between rotor segments  120  to apply pressure to drive the fluid through the cavitation boiler. In some instances, a pumping segment or pumping section is placed as a first segment of the cavitation boiler  100  and eliminates or reduces the pressure necessary on the fluid prior to the inlet  12 . 
     The design of the rotor segment  120  minimizes the amount unwanted movement of fluid in the fluid passageway  20 , which focuses the work applied (e.g., by the input shaft  16  in the form of cavitation) to the area where the maximum amount of energy can be applied. For instances, a shorter overall path of travel for fluid through each rotor segment  120  and stator segment (e.g., the stator drum  130  and the stator casing  140 ) increases a ratio of cavitation region to overall flow path of travel for the fluid through the fluid passageway  20 . Because work is required to pump the fluid through the entirely of the fluid passageway  20  (e.g., in addition to the force required to advance the fluid across the cavitation regions), increasing the ratio of the cavitation region to overall flow path through the fluid passageway  20  increases the efficiency of creating cavitation from a given power input to the input shaft  16 . 
     In some instances, the rotor segment  120  is designed such that it is able to utilize the inlet side of a single chamber and the outlet side while maintaining an axial fluid flow through each adjacent rotor/stator sets. A typical centrifugal pump includes an impeller with a suction side and a discharge side. On the discharge side, the fluid is routed back to the suction of the next impeller inline. Aspects of the present disclosure enable the second stage be where typically only a channel moving water to the second stage is in a conventional set up. In some instances, examples of the present disclosure more than double the amount of cavitation capacity in a given axial distance compared to a centrifugal design. In some instances, an existing chassis of a centrifugal design went from 6 to 20 stages of capacity in the same given space using examples of the present rotor/stator design. In some instances, the present cavitation boiler  100  design allows for subassemblies of rotor segments  120  and stator segments of individually high tolerance assemblies to be manufactured prior to final assembly, unlike typical multi-stage centrifugal designs. As stated previously, given some number of individual rotors/stators that are machined to some tolerance and then “stacked” together in an assembly, a stack up tolerance can put the entire assembly out of tolerance. Aspects of the present design enables all stage to be assembled and then machined as an assembly thereby eliminating any stack up possibility and holding an overall tolerance. This allows the new design to maintain much tighter tolerances (e.g., 0.005″, or 0.1″ to 0.002″, 0.002″ to 0.05″, or as low as 0.002″) over a longer axial distance. Some examples of the present design enable easier maintenance of the internals of the cavitation boiler  100  because the rotor segments  120  are not be “locked” into individual stages like a typical multi-stage centrifugal design. In contrast, and entire rotor segment  120  can be removed from inner drum  110  at a discharge end of the pump without disassembly of the stator/casing assemblies and the stator assembly would remain stationary while the rotor assembly is removed. In a typical ring-section pump, the entire assembly is held together by the tension rods  18  that are used to “squeeze” the midsection together. The tension rod  18  would be removed and rotor segments  120  would be removed by pulling the whole shaft assembly out through an opening in the suction or discharge chambers. In some examples, the cavitation boiler  100  includes a pumping segment (e.g., an impeller section pump), which is much easier to seal than a split case type design or similar. In some instances, the first stage in the cavitator boiler is an actual impeller that acts just as a normal pump impeller would and is sized to provide the exact flow and pressure at the operating rpm that the system would require to operate. In some instances, the inclusion of an initial impeller pump removes the need for a separate circulation pump and drive and makes the overall system smaller and more compact. 
       FIGS. 3A and 3B  are illustrations of a rotor segment  120 . The rotor segment  120  may be constructed from two rings, e.g., an upstream ring  320   a  and a downstream ring  320   b , where each ring  320   a,b  includes a drum portion  323   a,b  that includes one set of the two sets of apertures  121 ,  121 . Splitting the rotor segment  120  into two rings  320   a,b  may significantly reduce the manufacturing costs of the rotor segment  120 . However, in some instances, the rotor segment  120  is constructed from a single piece of material. Each ring  320   a,b  is configured to be secured to the inner drum  110  by a hub portion  324   a,b  that slides over and interfaces with the outer surface of the inner drum  110 . A web portion  325   a,b  connects the drum portion  323   a,b , to the hub portion  324   a,b , and the web portion  325   a,b  defines a surface of an inner chamber of each ring  320   a,b , where each chamber defines a portion of the rotor fluid passageway  21 . Generally, the notion rotor fluid passageway  21  refers to the chamber created by two inner adjacent inner chambers, one in a downstream ring  320   a  and one in an upstream ring  320   b , with the exception that the first and last ring of the cavitation boiler  100  will not have an adjacent rotor segment  120  and the inner chamber without an adjacent rotor segment  120  is an annular open faced chamber of the rotor segment  120  and, in some instances, enables an initial inflow or final outflow of fluid from the cavitation boiler  100 . As illustrated, the web portion  325   a,b  and the drum portion  323   a,b  define an annular chamber in the ring  320   a,b  below the drum portion  323   a,b  that is configured to mate with an adjacent rotor segment  120  to create the rotor fluid passageway  21 . In operation, this enables fluid to flow from the annular chamber in the downstream ring  320   b  the annular chamber in an adjacent upstream ring  320 .  FIG. 3B  illustrates the upstream ring  320   a  and the downstream ring  320   b  in their installed configuration on the inner drum  110  (not shown). In some instances, the rings  320   a,b  include mating features (not shown) to, in one example, secure the upstream ring  320   a  and the downstream ring  320   b  of the same rotor segment  120  to each other, or, in another example, secure a rotor segment  120  to an adjacent rotor segment. 
       FIG. 4  is a cross-sectional diagram of a rotor segment  120 .  FIG. 4  shows a cross section of the upstream ring  320   a  and the downstream ring  320   b , where each ring  320   a,b  includes the drum portion  323   a,b  that includes one set of the two sets of apertures  121 ,  121 , the web portion  325   a,b , and the hub portion  324   a,b . The inner drum  110  is shown as a dotted line and  FIG. 4  illustrates the rotor segment  120  installed around the inner drum  110 . Also shown is the a dotted line  499 , indicating that, in some instances, the rotor segment  120  is comprised of the two separate rings  320   a,b . In other instances, the rotor segment  120  is a single solid ring. 
     In operation, an inflow of fluid (shown as arrows  428 ) enters an upstream portion of the rotor fluid passageway  21  in the upstream run  320   a , and is directed by the surface of the web portion  325   a  in a radially outward direction (as indicated by the bend in the arrows  428 ) against the drum portion  323   a , where it passes through the apertures (e.g., the first set of apertures  121 ) and leave the upstream ring  320   a . Once the flow leaves upstream ring  320   a  of the rotor segment  120 , is returned to the downstream ring  320   b  after passing through the stator  130  a one or cavitation regions between the rotor assembly  130  and the stator  130 , as explained in more detail below. From the stator  130 , an outflow of fluid (represented by arrows  429 ) passes through the apertures (e.g., second set of apertures  122 ) in the drum portion  323   b  and into a downstream portion of the rotor fluid passageway  21 , and is directed by the surface of the web portion  325   b  in a generally axial direction (as indicated by the bend in the arrows  429 ) out of the downstream ring  320   b . From here the fluid may flow to, for example, an adjacent upstream ring  320   b , another component of the cavitation boiler  100 , or to the outlet port  11  of the downstream housing  14  in order to flow out of the assembly  10  through the outlet  13 . In some instances, the rotor segment  120  does not do any work to the fluid flowing into and out of the rotor segment  120 , and merely serves to direct the flow into the first set of apertures  121  from an adjacent upstream component, and direct flow from the second set of apertures  122  into an adjacent downstream component. In some instances, the rotor segment  120  includes fins or impeller portions in one both of the upstream and downstream portions of the rotor fluid passageway  21  in order to assist in the fluid transport described above. 
       FIG. 5A-5D  are illustrations showing assembly of a rotor assembly  520  from individual rotor segments  120  on the inner drum  110 .  FIG. 5A  illustrates a rotor segment  120  (including an upstream ring  320   a  and a downstream ring  320   b  as shown in  FIG. 3 ) being introduced to an end of the inner drum  110 . The opposite end of the inner drum  110  is capped by an end cap  160  which serves to axially secure the rotor segments  120  to the inner drum, as shown in  FIG. 5B .  FIG. 5C  illustrates ten rotor segments  120  installed along the length of the inner drum  110  and the second end cap  160  about to be secure to the inner drum  110  to complete the rotor assembly  520 . As shown, the inner drum  110  is substantially hollow and includes grooves  111  cut into the open end. The end cap  160  includes a cylindrical portion that fits concentrically into the open end of the inner drum  110  and includes ridges  111  that rotationally couple the end cap  160  to the inner drum  110 . The coupling of the end cap  160  to the inner drum  110  enables the end caps  160  to secure the rotor assembly  520  to the input shaft  15 , which delivers a torque to the rotor assembly  520  to spin the completed rotor assembly  520 , as illustrated in  FIG. 5D , in the cavitation boiler  100 . 
       FIGS. 6A and 6B  are illustration of a stator segment  630  including a stator  130  and a stator casing  140 .  FIG. 6A  shows a stator drum  130  prior to insertion in a stator casing  140  to form the stator segment  630 . The stator drum  130  includes a cylindrical drum surface  636  where the two sets of apertures  131 ,  132  are formed. As shown, each set of apertures  131 ,  132  is four parallel annular rows (e.g., banks) of apertures formed through the drum surface  636 . In some instances, the apertures have more or less than four rows of apertures, and the spacing between each row of each set  131 ,  132  may vary. The opposite side of the drum surface  636  includes a raised region  633  defining an inner surface of the stator flow path ( 22  of  FIG. 1B ) between the first set of apertures  131  and the second set of apertures  132  inside the stator segment  630 . The stator drum  130  includes an upstream flange  634  and a downstream flange  635 , each configured to seal the stator drum  130  to the stator casing  140 , as shown in more detail in  FIGS. 7A-7C . Finally,  FIG. 6A  also shows the stator casing  140  includes a curved region  641  configured to be opposite the raised region  633  when assembled, and the curved region defines an outer surface of the of the stator flow path ( 22  of  FIG. 1B ).  FIG. 6B  shows the stator drum  130  inserted into the stator casing  140 , as shown in more detailed in  FIG. 7C . 
       FIGS. 7A-7C  are cross-sectional diagrams of the stator segment  630 .  FIG. 7A  shows the stator drum  130  positioned around a rotor segment  120  (illustrated as a dotted box). This is shown for illustrative purpose only, as the stator drum  130  is, in some examples, assembled with the stator casing  140  prior and then into a stator assembly ( 840  as shown in  FIGS. 8A and 8B ), prior to the stator drum  130  being adjacent to a stator assembly. As shown, the stator drum  130  includes an upstream flange  634  that with a step to seal against a corresponding step ( 744  of  FIG. 7B ) in the stator casing  140  and a downstream flange  635  also with a step to seal against a corresponding step ( 745  of  FIG. 7B ) in the stator casing  140 . The height of the step in the upstream flange  634  is greater than the height of the downstream flange  635  to enable the stator drum  130  to slide into the stator casing without interference, as illustrated in  FIG. 7B .  FIG. 7B  shows the stator drum  130  being inserted axially into the stator casing  140 , as indicated by arrow  799 . Similar to the rotor assembly  120  being shown in  FIG. 7A , the final position of the outer drum  150  is illustrated in  FIG. 7B , but, in some instances, the stator drum  130  and stator casing  140  are assembled together prior to insertion into the outer drum  150 , as detailed below. In operation, the upstream and downstream flanges  634 ,  635  contact the corresponding steps  744 ,  745  annularly around the stator casing  140  and define a portion of the stator fluid passageway  22  in each stator assembly  630 , as shown in  FIG. 7C .  FIG. 7C  is a cross-section of an assembled stator segment  630  showing the stator fluid passageway  22  and the flow of fluid (indicated by arrow  739 ) from the first set of apertures  131  to the second set of apertures  132 . In operation, fluid from a spinning rotor segment  120  (which is illustrated for simplicity as a dotted line) into the stationary stator segment  630  through the first set of apertures  131 . Past the first set of apertures  131 , the fluid is deflected by the curved region  641  of the stator casing  140  to pass through the second set of apertures  132 . The raised region  633  of the stator drum  130  defines a lower portion of the stator fluid passageway  21  and is configured to turn the fluid through the stator fluid passageway  21  to decrease resistance and turbulence prior to entering the next section. 
     Alternatively, as shown in  FIGS. 7D and 7E , each stator segment  630  is not constructed to contain a complete section of the stator fluid passageway  22 , but instead each stator segment defines two separate halves of the stator fluid passageway  22 , similar to the construction of the rotor segment  120 . 
       FIGS. 8A and 8B  are illustrations showing assembly of a stator assembly  840  from individual stator segments  630  inside an outer drum  150 .  FIG. 8A  shows a stator segment  630 , including a stator drum  130  and a stator casing  140 , being inserted (arrow  899 ) into a cylindrical outer drum  150 . Each stator segment  630  defines a cylindrical outer surface that is precisely sized to slide against the inner surface  851  of the outer drum  150  with enough friction to be secured in place while the stator assembly  520  rotates inside of the stator assembly  840 . Because of this, and similar to the rotor segments  120 , each stator segment  630  does not need to be secured to adjacent stator segments  630 , and the tolerances between each stator segment  630  therefore do not need to be as precise as the tolerance between the stator segment  630  and the outer drum  150 .  FIG. 8B  shows a completed stator assembly  840 , which includes ten stator segments  630  inside of the outer drum  850 . 
       FIG. 9  is an illustration of a chassis  90  of a multi-stage pump assembly with the pumping stages removed. In some examples, the cavitation boiler  100  is configured to be secured to the input shaft  15  of an existing multi-stage pump where the pumping components or stages have been removed. As shown in  FIGS. 10A-E , the cavitation boiler  100 , when assembled into the chassis  90 , moves a fluid generally axially along the cavitation boiler  100  in order to take a fluid input to the chassis  90  from the upstream housing  17  to the downstream housing  14 . 
       FIGS. 10A-10E  are illustrations showing assembly of a rotor assembly and a stator assembly to form a cavitation boiler.  FIG. 10A  shows the downstream housing  14  and the input shaft  15  of the chassis  90  with the upstream housing  17  removed to allow the rotor assembly  520  to be installed (indicated by arrow  1098 ) onto the input shaft  15 . The installed position of the rotor assembly  520  is illustrated in  FIG. 10B , where the end cap  16  is securing the rotor assembly  520  to the input shaft. In some instances, the conic shape of the end cap  16  also serves a functional purpose by directing flow to the upstream ring  320   a  of the first rotor segment  120 . In such a configuration, the conical end cap  160  is inserted into the upstream housing  17 , and the opposite end cap is similarly inserted into the downstream housing  14 . As shown in  FIG. 10B , the downstream housing  14  includes an outlet port  11 , which is shown as a closed face, but this is typically an open face into an interior volume of the housing  14  where the end cap  160  is positioned.  FIG. 10C  shows the stator assembly  840  being placed around the rotor assembly  520 . The stator assembly  840  is secured to the chassis  90  to enable the rotor assembly  520  to freely rotate (as indicated by arrow  1099 ) inside of the stator assembly  840 .  FIG. 10D  shows the completed cavitation boiler  100 , and  FIG. 10E  shows the completed assembly  10  with the cavitation boiler  100  secured between the upstream housing  17  and the downstream housing  14  with the tension rods  18  around the outer drum  150 . 
     While  FIGS. 10A-10E  have shown the cavitation boiler  100  as including 10 corresponding sets of rotor and stator segments  120 ,  130 , alternatively, cavitation boiler  100  may include as few as one set of rotor and stator segments  120 ,  130  or as many as possible. In other instances, a fluid device may comprise multiple reaction chambers  100  linked together, with each having one or more sets of rotor and stator segments  120 ,  130 . 
       FIG. 11  is a cross-sectional diagram of the stator segment  630  arranged around the rotor segment  120 . The rotor segment  120  is part of a rotor assembly  520 , which is shown by the rotor segment  120  being positioned around the inner drum  110  (shown as dotted line for simplicity). Likewise, the stator segment  630  is part of a stator assembly  840 , which is shown by the stator segment  630  being position inside of the outer drum  150  (also shown as a dotted line for simplicity).  FIG. 11  shows that the inflow of the fluid (shown as arrows  428 ) to the upstream portion of the rotor fluid passageway  21  is directed into the stator fluid passageway  22  of the stator assembly  630 , where it is turn around (as indicated by arrow  739 ) and directed back into the downstream portion of the rotor fluid passageway  21  (shown as arrows  429 ). 
     In operation, the fluid passes between the rotor segment  120  and the stator segment  630  across the apertures  121  in the rotor segment and the apertures  131  in the stator segment  630 , where the apertures  121  of the rotor segment  120  are spinning (e.g., moving in a direction into or out of the page) with respect to the apertures  131  of the stator segment  630 . This movement of the rotor apertures  121  with respect to the stator apertures  131  creates a cavitation zone  1168  where, as the fluid passes between the apertures  121 ,  131 , localized regions of extremely low pressure form in the fluid, which momentarily causes cavitation bubbles to form in the fluid. The subsequent and violent collapse of the cavitation bubbles generates heat within the fluid from the mechanical energy of the spinning rotor segment  120 . Through the act of hydrodynamic cavitation, and/or secondary acoustic cavitation, the fluid is heated/pressurized to a degree that depends on the dimension of the apertures  121 ,  131 , the rotational speed of the rotor segment  120 , and the size of the gap  1190  between the rotor segment  120  and the stator segment  630 . The strength of the cavitation generated in the cavitation region  1168  also depends on the fluid properties, for example, viscosity, specific heat, and heat of vaporization. In some instances the size, position, and number of the apertures  131 ,  132  in the stator segment  630  correspond and match with the apertures  121 ,  122  of the rotor segment  120 . In some instances, an effective size of the overall fluid passageway through the boiler  100  (e.g., an effective cross-sectional area of the rotor fluid passageway  21  and stator fluid passageway  22  between the inlet  12  and the outlet  13 ) is a function of the total size of the apertures  131 ,  132  in the stator segment  630  and the apertures  121 ,  122  of the rotor segment  120  because, together, either one or both of the upstream apertures  121 ,  131  and the downstream apertures  122 ,  132  in each boiler segment, when aligned, defines, in some instances, a minimum effective cross section of the overall fluid passageway though the boiler  100 . As a result, the fluid flow capacity of the boiler  100  can be designed to be sufficient to allow large amounts of flow without excessive pressure drops and without increasing the size of the gap  1190 . In some instances the apertures  121 ,  122 ,  131 ,  132  of each segment of the boiler  100  are identical. In other instances, the size and arrangement of the apertures  121 ,  122 ,  131 ,  132  may vary along the boiler. For example, the apertures  121 ,  122 ,  131 ,  132  may increase in size from the segment closest to the inlet  12  to the segment closest to the outlet  13  in order to adjust for the heating of the fluid. In some instances, the gap  1190  also varies between different stages of the boiler  100 . 
     In an exemplary embodiment, the radial clearance between the exterior surface of the rotor segment  120  and the stator segment  630  (e.g., the gap  1190 ) is less than 0.05 inches, specifically, in some examples, as low as 0.002″. Generally, one skilled in the art will appreciate that different clearances may be necessary depending on fluid viscosity and the presence of impurities (e.g., dissolved salts, dirt, or debris) in the fluid. 
     After passing through the first cavitation zone  1168 , the fluid is directed  739  by the stator segment  630  to a second cavitation region  1169  between the second set of apertures  132  of the stator drum  130  and the second set of apertures of the rotor segment  120 . In this manner, each rotor and stator segment  120 ,  630  combine two create two cavitation regions  1168 ,  1169  per ‘stage’ of the cavitation boiler  100 , where a stage is defined as a combined rotor and stator segment  120 ,  130 . 
       FIG. 12  is a cross-sectional diagram of two adjacent stator assemblies  630  arranged around two adjacent rotor assemblies  120  in a cavitation boiler  100 .  FIG. 12  also shows a non-cavitation segment  1370  as an initial stage in the cavitation boiler  100 . In some instances, this non-cavitation segment  1370  is not present or is not an initial stage, and fluid is directly supplied to the rotor fluid passageway  21  in the first rotor segment from the upstream housing  17 . In other instances, the non-cavitation segment  1370  is a pumping stage configured to be power by rotation of the inner drum  100  and to drive the fluid through the downstream rotor and stator segments  120 ,  630 . In some instances, the cavitation boiler  100  includes multiple pumping or non-cavitation stages  1370 , which may be the first segment. In other instances, the non-cavitation segment  1370  is a collimator configured to create a uniform annular flow of fluid (as indicated by arrow  1299 ) into the first rotor segment  120  or other passive flow-control device or filter. In some instances, the non-cavitation segment  1370  is a standard pump impeller sized to provide the proper flow and pressure at a given rpm. In the configuration shown in  FIG. 12 , a first rotor segment  120  receives a flow  1299  of fluid into the rotor fluid passageway  21  where it is directed  428  into the stationary stator segment  630  across a first cavitation region  1168 , then directed to exit the stator segment  630  and back into rotor segment  120  across a second cavitation region  1169 , where the fluid is then in the downstream portion of the rotor fluid passageway  21 . Here, the fluid is directed  429  out the downstream portion of the first rotor segment  120  and into the adjacent rotor segment, where the process of passing across the two cavitation regions  1168 ,  1169  is repeated. Eventually, at a final rotor segment  120  of the cavitation boiler  120 , the fluid is directed out  429  of the cavitation boiler  100  and into the downstream housing  14  to be delivered out through the outlet  13 . 
     While  FIGS. 1-12  have shown the cavitation boiler  100  and rotor and stator segments  120 ,  130  as having a cylindrical shape, alternatively, the reaction cavitation boiler  100 , in some instances, includes rotor and stator segments  120 ,  130  of different sizes that, in some instances, are sized in response to the expected changes in fluid properties that results from the cavitation of the fluid. 
     While  FIGS. 1-12  have shown the cavitation boiler  100  integrated into the chassis  90  of an existing multi-stage pump, in other stances the cavitation boiler  100  is coupled to a generic input shaft driven by a generic motor and the fluid is supplied to an upstream end of the cavitation boiler  100  in any numbers of ways that one skilled in the art would appreciate. Similarly, in some instances, the downstream end of the cavitation boiler  100  may be coupled to any suitable housing or piping configured to receive the heated fluid of fluid, which may be under extreme pressure. 
     While  FIGS. 1-12  show the input shaft  15  as being contiguous through the cavitation boiler  100 , in some instances the input shaft  15  is a split shaft having two segments each configured to be attached to a respective end cap  160  such that no input shaft passes through the inner drum  100 . In some instances, only one end cap  160  is ‘powered,’ such that the opposite end cap is freely spinning to enable a single motor to drive the rotor assembly  630 . 
     While  FIGS. 1-12  show the cavitation boiler  100  as a cavitation boiler, in some instances the cavitation boiler  100  is also fluid pumping device, configured to draw in fluid and supply the fluid under pressure at the downstream end. In some instances, this is enabled by having a separate fluid pumping segment in the cavitation boiler  100 , and in other instances the rotor segment  120  includes features (e.g., vanes, fines, or impellors) configured to apply a pressure to the fluid in order to advance the fluid through the cavitation boiler  100 . 
     While  FIGS. 1-12  show the inner drum  110  and the outer drum  150  as constructed from a singular cylinder segment, in some instances, the inner drum  110  and the outer drum  150  are segmented as well, where each segment is mated together to form the inner drum  110  and the outer drum  150 . In this manner, the inner drum  110  and the outer drum  150  can be modular to enable rotor and stator segments  120 ,  630  to be added and subtracted from the cavitation boiler  100 . 
     While  FIGS. 1-12  shown the adjacent rotor segments  120  and the stator segments  630  as abutting each other without linking or mating, one skilled in the art will appreciate that both the rotor segments  120  and the stator segments  630  may include mating features configured to restrain the movement of each rotor segment  120  and the stator segment  630  with respect to each other and with respect to the inner drum  110  or the outer drum  150 . In some instances, the inner drum  110  or the outer drum  150  includes grooves or rails configured to align the attached rotor or stator segments  120 ,  630 . In some instances, the upstream and downstream faces of one or both of the rotor segments  120  and the stator segments  630  include interlocking features configures to rotationally align adjacent segments. 
       FIG. 13  is a cross-sections of an example cavitation boiler without an outer drum.  FIG. 13  shows a cavitation boiler  1300  including a stator assembly  840  and a rotor assembly  520 . The stator assembly  840  is made up of axially stacked stator segments  630 , each constructed from a stator casing  140  and a stator drum  130 . The rotor assembly  520  includes axially stacked rotor segments  120  disposed on an inner drum  110 . In this example, the inner drum  110  is attached on opposite sides to end caps  160 , which are integrally formed with input shafts  15  extending outside the cavitation boiler  1300 . The stator assembly  840  is sandwiched between an upstream housing  17  having an input  12  and a downstream housing  14  having an outlet  13 . The upstream and downstream housings  17 ,  14  are open at the axial ends to permit the rotor assembly  520  to be installed axially into the cavitation boiler  1300  without requiring disassembly of the stator assembly  840 . This is a more simple assembly step than shown in  FIGS. 10A-10E , and is due to the open axial ends of the upstream and downstream housings  17 ,  14 , which are subsequently sealed as shown in  FIG. 14B . In operation, and as discussed in detail above, a flow of fluid (shown as arrow  1398 ) enters the upstream housing  17  via the inlet  12  and is directed by the endcap  160  to an upstream face of the first rotor segment  120  of the rotor assembly  520 . After the fluid passes sequentially through each rotor and stator segment, it exists the final rotor segment, enters the downstream housing  14  and exits via outlet  13  (shown as arrow  1399 ). 
     Continuing to refer to  FIG. 13 , the stator assembly  840  does not include an outer drum around the stator segments. As a result, the stator casings  140  include annular interface elements  1341  to seal the cavitation boiler  1300 . In some instances, a gasket or seal is in the interface elements  1341  between each stator casing  140 . In addition, because the stator casings  140  are secured to the stator drums  130  by fasteners  1342 , such that the stator segments form a plurality of separate subassemblies that are held together between the upstream and downstream housings  17 ,  14 , as shown in  FIG. 14A . 
       FIG. 13  shows the fasteners  1342  between each stator casing  140  and stator drum  130 , where fasteners  1342  are placed annularly around the stator segment  630  on both the upstream and downstream sides. In addition, the interface elements  1341  are shown as an annular flange extending axially from a downstream side of the stator casing  140  and interfacing with an annular groove  1343  in the upstream side of an adjacent stator casing  140 . In some instances, a gasket seal is disposed between the interface element  1341  and the annular groove  1343  to further seal the inside of the cavitation boiler  1300 . In operation, and as discussed in more detail above, a flow of fluid (shown as arrow  1398 ) enters the upstream housing  17  via the inlet  12  and is directed by the endcap  160  to an upstream face of the first rotor segment  120  of the rotor assembly  520  and subsequently to the apertures in the rotor drum of the rotor segment  120  (e.g., the inflow of fluid  428  of  FIG. 4 ). 
       FIGS. 14A and 14B  are exploded view of the example cavitation boiler of  FIG. 13 , showing the assembly of the stator assembly and rotor assembly into the cavitation boiler  1300 .  FIG. 14A  shows a plurality of stator segments  630  axially stacked between an upstream housing  17  and a downstream housing  14  prior to assembly. In operation, the stator segments  630  are pressed together and the tension rods  18  secure the assembled stator assembly  840  between the upstream housing  17  and a downstream housing  14 . Next, as shown in  FIG. 14B , a completed rotor assembly  520 , which here includes the inner drum  110  and the input shafts  150 , is inserted into the stator assembly  840 . Afterwards, end plates  1403  seal the open ends of the upstream housing  17  and a downstream housing  14  to form the boiler chamber, and bearing housings  1401  secure the end plates  1403  to the upstream housing  17  and a downstream housing  14  and secure a bearing  1402  to the input shaft  15 . One advantage of the cavitation boiler  1300  having open axial ends is the ability to assemble a completed rotor assembly  520 , with the inner drum  110 , end caps  160 , and input shafts  15  together before final assembly. As discussed previously, control of the tolerances between the rotor segments  120  and stator segments  630  is an important advantage of the overall design, and assembly of a completed rotor assembly  520  enables precise control of the overall runout across the drum surface  323   a,b  of the rotor assembly  520 . In some instances, the runout, or the variability of concentricity over the axial length of the drum surface  323   a,b  of the rotor segments  120 , is less than 0.0001″. This ensures that the tolerances described above (e.g., as low as a 0.002 gap in the cavitation region between each of the combined rotor and segments) is maintained across the entire cavitation boiler  1300 . This precise runout and pre-assembly also enables the rotor assembly  520  to be precisely balanced prior to installation. For example, the rotor assembly  520 , after pre-assembly, can be machined, polished, and balanced as a unit prior to final assembly to form the cavitation boiler  1300 . In addition, the rotor assembly  520  can be easily removed and serviced after operation to check and correct the tolerances and, if necessary, replace a damaged or out of tolerance rotor segment. 
     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.