Patent Publication Number: US-2023158567-A1

Title: Method And Apparatus For Support Removal Using Directed Atomized And Semi-Atomized Fluid

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application 62/908,335 (filed on Sep. 30, 2019), and is a continuation-in-part of U.S. patent application Ser. No. 16/232,955 (filed on Dec. 26, 2018), which claims priority to U.S. provisional patent application 62/612,483 (filed Dec. 31, 2017). 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to a method and apparatus for removing support material from parts that have been made via additive manufacturing techniques, such as 3D printing. 
     BACKGROUND OF THE INVENTION 
     Additive manufacturing processes, such as 3D printing (e.g. Selective Laser Sintering (SLS), Stereolithography (SLA), fused deposition modeling (FDM), material jetting (MJ), electron beam (e-beam), etc.) have enabled the production of parts having complex geometries that would never be possible through traditional manufacturing techniques, such as casting, injection molding, or forging. However, additive manufacturing produces parts that require significant efforts to remove unwanted support material. The support material is needed during the manufacturing process to support portions of the part as the part is being manufactured in order to achieve complex geometries. After the manufacturing process is completed, the unwanted support material must be removed and/or rough surfaces may need to be smoothed. 
     The support material itself can have a complex geometry and can also be extensive. Additionally, since additive manufacturing manufactures a part in discrete layers, the surface of a part is often rough, because adjacent layers may not end in similar locations thereby leaving a rough bumpy outer surface. Such a rough outer surface is unappealing from a visual standpoint, and the uneven surface can create stress concentrations, which could develop during testing or use of the part and lead to pre-mature failure. 
     A current option in the additive manufacturing industry is to manually remove the support material and manually finish the surface of a part in order to produce a smooth exterior surface of the part. Depending on the type of part, using manual labor could be cost prohibitive, and could lead to excessive removal of material, an uneven surface, or both. If a surface is finished unevenly or incompletely, stress concentrations could still be unintentionally prevalent, leading to pre-mature failure of the part. In addition, manual removal of unwanted support material and manual surface finishing lacks consistency over an extended period of time and from part to part. And, such manual removal/finishing may create a bottleneck in the production process since, for example, one technician can remove support material from only a single part at a time. 
     Another option the additive manufacturing industry is moving toward is to use a machine, such as those providing a chemical bath, to remove support material and/or to perform surface finishing. However, such machines are limited in the type of process parameters that can be altered to tailor the process to a specific part, and also such machines require the attention of, and operation by, a technician while the machine is running, which does not completely eliminate the bottleneck issue described above. Additionally, if a technician is unaware that a machine is not set at the proper parameters, excessive material removal could occur, ruining the part. 
     Thus, there is a need for a method and apparatus for automatically removing support material from and smoothing the surface of parts made via additive manufacturing techniques without damaging the part itself. One such approach is to use embodiments of the present invention, which use atomized and semi-atomized fluid, chemical dissolution, and pressurized fluid. Additionally, embodiments of the present invention may provide an alternative that seeks to remove the manual labor bottleneck of processing additive manufactured parts in order to achieve surface finishing and/or support removal (“SF/SR”). 
     SUMMARY OF THE INVENTION 
     The invention may be embodied as an apparatus for removing support material from and/or smoothing surfaces of an additively manufactured part (the “AM part”). The apparatus may include a chamber, a support surface within the chamber, and one or more nozzles within the chamber. The nozzles may be the same size or different sizes. 
     The support surface may be configured to support the AM part. The support surface may have one or more openings sized and configured to allow the fluid to pass through the opening(s). For example, the support surface may be a screen-like surface. 
     The nozzles may be configured to spray a fluid at the AM part, and the spray may be an atomized or semi-atomized spray of the fluid. The nozzles may be arranged in groups, each group being part of a spray header that is fed from a common supply tube. The nozzles of a particular spray-header may be the same size, but they need not be the same size. For example, the nozzles of a particular spray-header may be selected from two or more sizes. 
     The nozzles of one spray-header may be the same size as the nozzles of another spray-header, but the nozzles of one spray-header may be differently sized from the nozzles of another spray-header. For example, with regard to two spray-headers the nozzles of one spray-header may be selected to be of a first size, and the nozzles of the other spray-header may be selected to be of a second size. 
     In one embodiment of the invention, there are two spray-headers of nozzles; one above the support surface (a.k.a. “top spray-header) and one below the support surface (a.k.a. “bottom spray-header”). The top spray-header may point the nozzles to spray downward toward the AM part, and the bottom spray-header may point the nozzles to spray upward toward the AM part. 
     One or more valves may be included in the apparatus so that fluid can flow and spray through a first set of nozzles having one size at the same time that fluid cannot flow to spray through second nozzles of a second size. For example, nozzles of a particular spray-header may be of two or more sizes, and fluid can be made to flow through and to spray from first nozzles of one size at the same time that fluid cannot flow to spray through second nozzles of another size. 
     One or more of the spray-headers of nozzles may be secured to a mount that is adjustable to move the spray-header(s) nearer to or further away from the support surface. One or more of the spray-headers of nozzles may be connected directly or indirectly to an actuator for translating the spray-header(s) back and forth in a planar motion. 
     The apparatus may also include a tank configured to hold a volume of the fluid, and the tank may be positioned (e.g. in the chamber) to capture the fluid after the fluid is sprayed. 
     The apparatus may also include a heater for heating the fluid to a desired temperature. The heater may be at least partially within the tank. 
     The apparatus may include a ventilation system. The ventilation system may be a blower for forcing air into or pulling air out of the chamber. The ventilation system may be a vent for allowing air to leave or enter the chamber. The ventilation system may include both such a blower and such a vent. 
     The invention may be embodied as a method of removing support material from and/or smoothing surfaces of an AM part. Such a method may include providing a chamber, a support surface within the chamber, and one or more nozzles within the chamber. An AM part may be placed on the support surface, and a fluid may be sprayed at the AM part. The nozzles may generate an atomized or semi-atomized spray of the fluid. 
     The nozzles may spray at the same velocity. However, in at least one embodiment of a method according to the invention at least one of the nozzles sprays the fluid at a velocity that is different from the spray velocity created by a different one of the nozzles. 
     The method may be carried out so that one (or more) of the nozzles sprays the fluid at a first flow rate and one (or more) of the nozzles sprays the fluid at a second flow rate. For example, in one embodiment of a method that is in keeping with the invention a first one (or more) of nozzles sprays the fluid at a first flow rate and a second one (or more) of the nozzles sprays the fluid at a second flow rate. 
     The method may be carried out in such a manner that a one (or more) of the nozzles has a first size and one or more of the nozzles has a second size, and a pressure at which the fluid is supplied to the nozzles of the first size is different than a pressure at which the fluid is supplied to the nozzles of the second size. 
     A tank may be provided. The tank may be configured to hold a volume of the fluid, and to capture the fluid in the tank after the fluid is sprayed. Such a tank may be well suited to facilitating a cycling of the fluid through the nozzles so that the same fluid may be sprayed many times at the AM part. 
     A heater may be provided, and may be arranged in the tank. The heater may be used to heat the fluid to a desired temperature. The temperature of the fluid may be increased toward the desired temperature while the AM part is sprayed. 
     Spraying of the fluid may occur from a first set of the nozzles that is configured to spray the fluid substantially downward toward the AM part, and also from a second set of the nozzles that is configured to spray the fluid substantially upward toward the AM part. 
     While spraying occurs, the nozzles may be translated. For example, one or more sets of the nozzles may be translated during spraying of the fluid. 
     Air may be blown into or pulled out of the chamber. This may be done during spraying and/or after spraying. 
     For removing support material from parts with internal spaces, such as cavities or passages, the apparatus can include a nozzle at the end of an adjustable flexible hose member that can be adjusted to spray into an internal space of a part. Alternatively, for removing unwanted support material from multiple parts with internal spaces, the apparatus may include a submersion tank. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the invention, reference should be made to the accompanying drawings and the subsequent description. Briefly: 
         FIG.  1    is a schematic depiction of an apparatus that is in keeping with the invention; 
         FIG.  2    is a schematic depiction of an additively manufactured part; 
         FIG.  3 A  is a front view of an apparatus that is in keeping with the invention; 
         FIG.  3 B  is a side view of the apparatus depicted in  FIG.  3 A ; 
         FIG.  3 C  is a top view of the apparatus depicted in  FIG.  3 A ; 
         FIG.  4    is a schematic depiction of an apparatus that is in keeping with the invention; 
         FIG.  5    is a schematic depiction of an apparatus that is in keeping with the invention; 
         FIG.  6    is a flow diagram depicting a method that is in keeping with the invention. 
         FIG.  7    is a schematic depiction of another embodiment of the apparatus; 
         FIG.  8    is a view of a portion of the embodiment shown in  FIG.  7   ; 
         FIG.  9    is another view of a portion of the embodiment shown in  FIG.  7   ; 
         FIG.  10    is a flow diagram depicting a method of operation of the embodiment shown in  FIG.  7   ; 
         FIG.  11    is a schematic depiction of yet another embodiment of the apparatus; 
         FIG.  12    is a perspective view of the submersion tank shown in  FIG.  11   ; 
         FIG.  13    is a top view of the submersion tank shown in  FIG.  11   ; and 
         FIG.  14    is a flow diagram depicting a method of operation of the embodiment shown in  FIG.  11   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. 
     Furthermore, it is understood that this invention is not limited to the particular methodology, materials, or modifications described and, as such, the invention may vary from that which is disclosed herein. It is also understood that the terminology used herein is for the purpose of describing particular aspects, and this invention is not limited to the disclosed aspects. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention pertains. It should be understood that methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the method and apparatus. 
     Furthermore, as used herein, “and/or” is intended to mean a grammatical conjunction used to indicate that one or more of the elements or conditions recited may be included or occur. For example, a device comprising a first element, a second element and/or a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or, a device comprising a second element and a third element. 
     Adverting now to the figures, with specific reference in  FIGS.  1 - 2   , the present invention may be embodied as a method or an apparatus  8  for SF/SR. In such a method or apparatus  8 , one or more additive manufactured parts  10  needing SF/SR are placed on a platform or tray  13  in a chamber  16  of an apparatus  8  for carrying out SF/SR. An SF/SR fluid  22  for dissolving and/or eroding the support material  28  may be sprayed at the part(s)  10  through nozzles  25  situated underneath the part(s)  10  or above the part(s)  10  or both. The nozzles  25  below the part(s)  10  and the nozzles  25  above the part(s)  10  may be referred herein as bottom nozzles  25 B and top nozzles  25 A, respectively. The fluid  22  may be supplied from a tank  31 , open at its upper side. The tank  31  may be situated below the bottom nozzles  25 . A pump  33  may be used to draw fluid  22  from the tank  31  and then force the fluid  22  through a series of pipes  50  connected to the nozzles  25 , which causes the fluid  22  to spray out of the nozzles  25  at the part(s)  10 . Each nozzle  25  may comprise a pipe or tube section having multiple apertures or nozzles through which the fluid  22  sprays, and these arrangements are sometimes referenced herein, as a “spray-header”. The fluid  22  then collects back into the tank  31  where the fluid  22  is recycled back through the apparatus, i.e., drawn from the tank  31 , forced to the nozzles  25 , sprayed at the parts  10 , and collected in the tank  31 . In this mode of operation the apparatus  8  may be a closed-loop system. 
     Additive manufactured parts  10  may be made using numerous different methods, classes of materials (e.g., plastics, metals), specific build materials (e.g., nylon within the plastics class, aluminum within the metals class) and support materials. Each method, class of material, and specific build material can have its own unique qualities and characteristics and thus may require different parameters for effective and efficient removal of support material  28 . Additionally, for a given type, parts  10  made by such an additive manufacturing process and/or materials may have very different geometries, including designs having more delicate features than others, which thus may require adjustments for effective and efficient removal of support material  28 . As explained in more detail herein, the amount of fluid  22  sprayed, the direction of spray (from top and/or bottom), the location of spray (e.g., left versus right side of part or top versus bottom side of part), the pressure at which fluid  22  is pumped to the nozzles  25 , and the degree of atomization, as well as other parameters such as the make-up, temperature and pH of the fluid, can be adjusted to create different combinations or “recipes” of these parameters in order to efficiently and effectively remove a given type of support material  28  for a given type of build material  35  and geometric design of additive manufactured part(s)  10 . In some embodiments of the present invention, an operator can set or change these parameters using a human-machine interface (“HMI”)  38 , such as a touch screen  108  connected to a general-purpose computer having a central processing unit (“CPU”)  102 . The general-purpose computer may have wired or wireless communications links  105  for sending and receiving communications signals to/from components of the apparatus  8 . 
     The fluid  22  is capable of dissolving and/or degrading support material  28 , and may be aqueous-based chemical formulations made with a single chemical or a variety of chemicals. The fluid  22  may, in some embodiments, be referred to as a detergent. Preferably, the fluid  22 , either naturally or aided by the parameter settings, degrades or dissolves support material  28  and the rough surface of the part  10  without also degrading, dissolving or causing damage to the build material  35  of the part  10  that is intended to be preserved. Such fluids  22  can include but are not limited to those fluids that are optimized for SF/SR for parts  10  made by MJ, SLA and FDM, respectively. The fluid  22  can also include an anti-foaming agent to help minimize foaming of the fluid during the SF/SR process. 
     An embodiment of the present invention may be an apparatus  8  having a housing  41  comprising a first section  44 , a second section  47  arranged adjacent to said first section  44 , as illustrated in  FIGS.  1 ,  3 A,  3 B, and  3 C . The first section  44  may include a chamber  16  where the SF/SR of an additive manufactured part  10  occurs. The second section  47  may house many of the plumbing components for the apparatus  8 , such as a pump  33 , valves  59 , and hoses  62 . The second section  47  can be arranged either below or to the side of the first section  44 . 
     The first section  44  may include a door  68  for an operator to access the chamber, and place parts  10  into and remove them from the chamber  16 . The door  68  can be a counter-weighted balanced door to allow for easy access. As discussed further below, the chamber  16  may heat up during the apparatus&#39; operation. The chamber  16  can include a ventilation or exhaust system to provide a heated equalized chamber  16  to aid both in the removal of support material  28  as well as enhancing the evaporation of residual fluid  22  off of the part  10  upon completion of the SF/SR process. A ventilation system may be of any type suitable for venting heat and vapors that can build up in the chamber  16 . As one example, the ventilation system may comprise one or more blowers  75  pulling air from the chamber  16 , such as blowers rated, for example, at 0.5 to 1000 cubic feet per minute (CFM). In this approach the ventilation system may create a negative pressure in the chamber  16  so that when the door  68  is opened, air is pulled inward through the door  68 . In another example, the ventilation system may comprise one or more fans or blowers  75  pushing air into the chamber  16 , combined with a chimney or other exhaust mechanism  78  in the roof of the chamber  16 . The fan or blower  75  may create a positive pressure in the chamber  16  and the chimney  78  allows excess heat and vapors to escape. Additionally, windows  81  may be placed in the sides of the chamber  16  to allow for in-process monitoring by humans and sensors of the SF/SR process. 
     A tray or platform  13  on which the parts  10  can be set while an SF/SR process occurs may be situated in the chamber  16 . A first plurality of nozzles  25  (such as the top nozzles  25 A) may be arranged in the chamber  16 , allowing for fluid  22  to be sprayed downward toward the parts  10  situated on the tray  13 . A second plurality of nozzles  25  (such as the bottom nozzles  25 B) may be arranged in the chamber  16 , directly below the tray  13 , allowing for fluid  22  to be sprayed upward toward the parts  10  situated on the tray  13 . The bottom nozzles  25 B and top nozzles  25 A are thus arranged opposite from each other, spraying in directions toward each other, with the parts  10  situated therebetween. The first section  44  also may include a tank  31  for holding the fluid  22 . The tank  31  may be situated below the bottom nozzles  25 B. 
     The tray  13  may have openings of suitable size, quantity and distribution, such as a mesh screen, so that the tray  13  can support the parts  10 , yet allow fluid  22  to be sprayed at the parts  10  from the bottom nozzles  25 B, allow fluid  22  sprayed from both the bottom and top nozzles  25 B,  25 A to flow down into the tank  31 , and help to prevent support material  28  that detaches from the part  10  from falling down into the tank  31 . A mesh screen  53  may be arranged between the tank  31  and the bottom nozzles  25 B to further prevent pieces of detached support material  28  from entering the tank  31 . 
     In one embodiment of the invention, a first plurality of nozzles  25  comprises a single spray-header of nozzles  25 , and in another embodiment of the invention the first plurality of nozzles  25  comprises more than a single spray-header of nozzles  25 , such as three spray-headers of top nozzles  25 A. The size of the apertures or nozzles in one spray-header of nozzles  25  can be different from the size of the apertures or nozzles in another spray-header, thereby resulting in different fluid velocities spraying from the two different sets of nozzles  25 , with one velocity being higher than the other. For example, in the embodiment with three sets of top nozzle spray-headers  25 A, the first and third sets can each comprise five apertures/nozzles of the same or similar size (or degree of spray angle), while the second set can comprise three apertures/nozzles of a larger size (or degree of spray angle). The top nozzles  25 A can be either mounted to the housing  41  itself, or mounted on a movable track  42  connected to an actuator  43  that allows the nozzles  25  to oscillate in the horizontal direction. The second plurality of nozzles  25  can be identical to the first plurality of nozzles  25  mounted on a movable track  42  that is connected to an actuator  43 , or can be stationary nozzles  25  that cannot move independently on a track. In one embodiment, the second plurality of nozzles  25  comprises a spray-header having thirteen nozzles  25  each of the same or similar size (or degree of spray angle). 
     In another embodiment of the invention, nozzles  25  could be arranged to surround the chamber  16  so that the nozzles  25  are on all six sides surrounding the part  10  in the chamber  16 . Each nozzle  25  can be independently controlled by a separate motor or be connected as a nozzle assembly. In this embodiment there are nozzles  25  mounted both horizontally and vertically. 
       FIG.  4    depicts a further embodiment of the invention in which the bottom nozzles  25 B are arranged as a U-shaped spray-header. As with the embodiment mentioned directly above, the nozzles  25  may spray the AM part  25  from different directions and thereby spray additional sides of the AM part  25  more directly. In a similar manner, the top spray-header of nozzles  25 A may be U-shaped. Or, both the top spray-header of nozzles  25 A and the bottom spray-header of nozzles  25 B may be U-shaped. 
     Servomotors or other actuators may be used to oscillate a spray-header of nozzles  25  through a range of distance about a center point. Interface and control buttons may enable an operator to adjust the location of the center point (by causing the spray-header of nozzles  25  to move forward or backward) and/or the speed at which the nozzles  25  oscillate. For example, the center point could be set anywhere between a range of 0-275 millimeters and the speed could be set anywhere between a range of 0-50 mm/sec. Or, these parameters may be pre-stored in connection with an operating recipe that the operator has the option to select. In one embodiment of the invention the operator can also adjust the distance that the nozzles  25  oscillate. The movement of each nozzle  25  may be tracked by a position sensor. The first plurality of nozzles  25  could be made to oscillate only if at least one of the valves  59  to a nozzle contained in the first plurality of nozzle  25  is open. In such an embodiment, if only the second plurality of nozzles  25  is activated, then the first plurality of nozzles  25  does not oscillate. 
     The nozzles  25  can be individual nozzles  25 , or can be tubes/piping having a plurality of apertures therein, e.g. a manifold (each such aperture is also referred to as a “nozzle”), or could include nozzles  25  secured to the tubes/piping. Additionally, the individual nozzles  25 , including individual nozzles secured to the tubes/piping, may be constructed to rotate independently, using motors, in order to spray parts  10  within the chamber  16  at a variety of angles. Each nozzle  25  may be independently controlled by a separate motor or be connected to each other so as to form a nozzle assembly. Additionally, each nozzle  25  could be controlled by a multi-axis robot. The nozzles  25  may be made to move in horizontal and/or vertical directions. It should be appreciated that each nozzle  25  may be connected to its own pump and plumbing system. 
     Both the first and second plurality of nozzles  25  (e.g., top and bottom nozzles  25 A,  25 B) may be connected to a pump  33 , which may be located within the second section  47  of the housing  41 . After drawing fluid  22  from the tank  31 , the pump  33  can force the fluid  22  through pipes  50  (which may be a flexible hose) to the nozzles  25 . A manifold may be used to separate the fluid  22  output from the pump  33  into separate supplies for each spray-header of nozzles  25 . The individual pipe  50  to each spray-header of nozzles  25  may include a valve  59  to control the flow of fluid  22  to the nozzles  25 . This arrangement allows nozzles  25  to be used selectively (on/off), thereby increasing efficiency where all of the nozzles  25  are not required for SF/SR and/or where it is preferred to have some nozzles  25  at higher or lower pressures than others. 
     For example, an embodiment of the invention may have one bottom spray-header of nozzles  25  and three top spray-headers of nozzles  25 , where at least one of the top spray-headers has narrow-angle nozzles  25  (producing comparatively higher velocity spray) and at least one of the other top spray-headers has wide-angle nozzles  25  (producing comparatively lower velocity spray). In each of the following examples, the valve  59  controlling flow to the bottom spray-header of nozzles  25  may always be open. In one mode of operation, all of the valves  59  controlling flow to the top nozzles  25  can be closed so that fluid  22  sprays only from the bottom spray-header  25 B. This mode can produce the lowest degree of agitation of the additively manufactured parts  10  being SF/SR processed in the chamber  16 , and may be referred to as “ultra-low agitation.” In another mode of operation the valve(s)  59  controlling flow to the top spray-header(s)  25 A having wide-angle nozzles  25  may be open, but the valve(s)  59  controlling flow to the top spray-header(s)  25 A having narrow-angle nozzles  25  may be closed. This mode can produce a higher degree of agitation than where only the bottom nozzles  25 B are used, and may be referred to as “low agitation.” In yet another mode of operation, the valve(s)  59  controlling flow to the top spray-header(s)  25 A having wide-angle nozzles  25  may be open and the valve  59  controlling flow to one (but not more than one) top spray-header having narrow-angle nozzles  25  may be open. This mode can produce a higher degree of agitation than the prior example, and may be referred to as “medium agitation.” In yet a further mode of operation, the valve(s)  59  controlling flow to the top spray-header(s)  25 A having narrow-angle nozzles  25  may be open but the valve(s)  59  controlling flow to the top spray-header(s)  25  have wide-angle nozzles  25  may be closed. This mode can produce the highest level of agitation, and may be referred to as “high agitation.” Other arrangements of spray-headers, varying sizes of nozzles  25 , and open versus closed valves  59  may be used to create additional variations in the levels of agitation. Thus, the use of terms such as “low,” “medium” and “high” are not meant to be limited to the precise arrangements described in the foregoing examples, but rather to exemplify that various, relative degrees of agitation can be accomplished as desired to meet specific needs. 
     An operator can use the HMI  38  to select a desired level of agitation, or the agitation level may be pre-stored in connection with a given operating recipe that the operator has the option to select. By setting the agitation level, the apparatus  8  automatically opens and closes the valves  59  to the nozzles  25  as appropriate to achieve that selected level of agitation. These parameters can be set individually or by selecting a pre-stored recipe. 
     The pressure of the fluid  22  pumped through the system may be a function of a variety of factors including the action of the pump  33 , the length, sizing and configuration of the plumbing between the pump  33  and the nozzles  25 , and the sizes and quantity of nozzles  25 . The apparatus  8  may have one or more sensors  65 C located at or near the inlet to each valve  59  leading to each spray-header of nozzles  25 , or at another suitable location, for measuring and monitoring the pressure of the fluid  22  being forced to the nozzles  25 . This pressure can be, for example, from 0.01 psi to 100 psi. During operation, the pressure can change for a variety of reasons, and the apparatus  8  may include sensors  65 C for measuring the pressure. The apparatus may alert the operator if the pressure begins to decrease or increase from the level expected, or initially achieved, for a given set of SF/SR processing parameters, and also may alert the operator if the pressure drops below or exceeds minimum and maximum levels, respectively. These minimum and maximum levels can be pre-programmed into the apparatus  8 . Additionally, if these minimum or maximum pressure levels are exceeded, the apparatus  8  can to automatically shut down. 
     An embodiment of the invention may simultaneously achieve a high rate of fluid flow through the nozzles  25 , such as 5 to 150 gallons per minute, and a low pressure at which the fluid  22  is provided to the nozzles  25 , such as 15-30 psi. The speed at which support material is removed may be aided by having as much flow of fluid  22  on the part  10  as possible, while protecting the build material  35  of the part  10  from erosion by maintaining the fluid velocity below a desired level. The nozzle aperture sizes (and/or spray angles), quantities of nozzles  25  and specifications for the pump  33  and plumbing may be selected to achieve these multiple goals. Additionally, oscillating the nozzles  25  changes the direction and speed of the spray exiting the nozzles  25 , which provides an additional opportunity for modulating both the force of the fluid  22  impacting the parts  10  as well as the area covered by that fluid  22 . For example, oscillating the nozzles  25  at a higher speed may result in a lower average force at which the fluid  22  impacts the additive manufactured parts  10  and a wider coverage area within the chamber  16 . 
     In another embodiment of the invention as illustrated in  FIG.  5   , a wider chamber  16  is used and there are two systems of top and bottom nozzles  25 , arranged adjacent to each other, effectively defining first processing region  87  and second processing region  90  within the chamber  16 . In this embodiment, fluid  22  is delivered to the first processing region  87  by the first top nozzles  25 A 1  and first bottom nozzles  25 B 1 , and fluid  22  is delivered to the second processing region  90  by the second top nozzles  25 A 2  and second bottom nozzles  25 B 2 . In this embodiment, the tank  31  situated below the bottom nozzles  25 B can be a single tank  31  spanning the two regions  87 ,  90 . A first pump  33 A can be connected to the first top and first bottom nozzles  25 A 1 ,  25 B 1 , and a second pump  33 B can be connected to the second top and second bottom nozzles  25 A 2 ,  25 B 2 . In this embodiment, the pumps  33 , valves  59 , spray-headers of nozzles  25 , and all of the various settings relating thereto can be set and operated in the two regions  87 ,  90  independently. 
     This embodiment enables the apparatus  8  to have different flow rates, pressures and spray velocities (i.e., agitation levels) as between the two regions  87 ,  90 . This can be useful in several ways. For example, some additive manufactured parts  10  are long and have more support material  28  and/or surface areas of build material  35  toward one end of the part  10  (“heavy end”) versus the opposite end (“light end”). If the same flow, pressure levels and spray velocities were applied across the entire part  10 , then either the light end would be at risk for over-processing (which might include degradation or warping of the part  10 ) or the heavy end of the part  10  would be at risk for under-processing (leaving too much support material  28  or un-smoothed surfaces of build material  35  remaining on the part  10 ). By having two independent 
     SF/SR processing regions  87 ,  90 , the part  10  can be situated in the chamber  16  so that the end with more support material  28  and/or surface areas of build material  35  lies in the region that has higher flow, pressure and spray velocity, while the other end of the part  10  with less support material  28  and/or surfaces areas of build material  35  lies in the region that has lower flow, pressure and spray velocity. This protects the second end of the part  10  from over-processing and the first end of the part  10  from under-processing. Another advantage of having two regions is that a given part  10  may have more support material near its bottom area than near its top area. A quantity of these parts  10  could be simultaneously SF/SR processed with a portion of the quantity oriented upright in one region and the other portion oriented upside down in the other region, with each region having flow of fluid  22  and pressure appropriate for those orientations of the parts. 
     In an embodiment where nozzles are configured to oscillate during a SF/SR process, a motion-monitoring sensor can be used to detect which of the nozzles  25  are moving during the SF/SR process. The apparatus  8  may frequently monitor the position of the nozzles  25  and if no motion is detected, the apparatus  8  may attempt to reset the motor controlling movement of the nozzles  25 . If a reset of the motor is unsuccessful, then the HMI  38  may alert a user and pause the SF/SR process since the apparatus  8  may not be operating properly. The detection of nozzle movement may be done via an encoder arranged on each motor or by other suitable means. 
     The tank  31  may be filled automatically with fluid  22  based on parameters set by the operator or as may be pre-stored in connection with a given operating recipe that the operator has the option to select. To this end, the apparatus  8  may include devices for supplying each of water, support material solvent (also referred to as detergent), and anti-foaming agent supplies. Water may be supplied from a facility&#39;s water supply  19  or from a reservoir or other storage tank. Solvent and anti-foaming agent may be supplied each from their own reservoir or storage tank, such as a 5-gallon bucket  56  connected to the apparatus by a hose  62  or other conduit. The hose  62  for each of the solvent and anti-foaming agent may be connected to a mechanism, such as a water-powered pump, for automatically dispensing such fluids into the tank. 
     A liquid level sensor  65 D may be situated in the tank  31  to detect the level of the fluid  22  in the tank  31 , thereby enabling a determination of when the fluid  22  filling the tank  31  reaches the maximum level, at which point the sensor  65 D sends a signal that is interpreted and results in the filling to automatically stop. The sensor  65 D also may be employed to enable detection of when the fluid  22  drops below a desired level during operation, which can happen for example as fluids evaporate, and may send a signal that is interpreted and may result in alerting the operator to use the interface to cause more fluids to be dosed into the tank (which dosing again stops automatically if the maximum fill level is reached). Alternatively, programming could be provided to cause this dosing to occur automatically. 
     Use of this auto-dose feature ensures that enough fluid  22  is arranged in the apparatus  8  for the SF/SR process to run properly. When an apparatus  8  runs for an extended period of time at high temperatures, the fluid  22  used in the SF/SR process evaporates. Also, amounts of fluid  22  may adhere to interior surfaces of chamber  16  and to surfaces of components within chamber  16 . In order to ensure that enough fluid  22  remains in the system, a configurable desired fluid level may be set in the software of the apparatus  8 , and the fluid level in the tank  31  may be detected using a liquid level sensor  65 D such as a floating sensor to detect the liquid level. If the liquid level falls below the desired level, the apparatus  8  could react by supplying additional amounts of one or more components of the fluid  22  (e.g., water, solvent, anti-foaming agent) into the tank  31 . Additionally, a configurable time interval could be set by a user for checking the liquid level during the SF/SR process. At the end of a configurable time interval, the SF/SR process may pause for an amount of time (for example, 30 seconds) in order to let foam that may have formed in the tank  31  to settle. Once the settling time has elapsed, a liquid level measurement may be taken. If the liquid level has not attained the desired level, the apparatus  8  may automatically add fluid to the tank  31  and in order to fill the tank  31  up to the desired liquid level. 
     A heater  96 , such as an immersion heater, and a sensor  65 B for measuring temperature, may be situated in or in connection with the tank  31 . Additionally, a pH sensor  65 A may be situated in or in connection with the tank  31 . The heater  96  may be used to heat the fluid  22  to a desired temperature and, based on feedback from the temperature sensor  65 B, to maintain the fluid  22  at that temperature. The heater  96  may be used to heat the fluid  22  to a desired temperature within an allowable range, such as for example, 85.degree. F. to 160.degree. F., or another process-suitable range. The fluid  22  in the tank  31  may be heated to the desired temperature prior to starting the SF/SR process to spray the parts  10 , or the fluid  22  can be used before it is heated at all or when it is only partially heated to the desired temperature. In this latter approach, the SF/SR process begins with the fluid  22  at a low temperature and, as time elapses during the SF/SR process, the heater  96  operates to increase the temperature of the fluid  22  to the desired level. The approach of gradually increasing the temperature of the fluid  22  can aid in the removal of support material  28 . This is because the fluid  22  can usually remove support material  28  over a range of temperatures. Thus, by engaging in SF/SR as the fluid temperature rises, the fluid  22  can begin to remove support material  28  as the fluid  22  reaches the lowest temperature suitable for removing support material  28  and then remove the support material  28  more rapidly as the fluid approaches the final desired temperature. In this manner, the build material  35  of the part  10  will not heat up as much as compared to the case where the fluid  22  is at the highest temperature from the start of the SF/SR process. This helps to protect the build material  35  of the part  10  from degradation, such as warping. 
     The pH sensor  65 A can detect the pH of the fluid  22 , which at the outset can be a reflection of the combination of liquids forming the fluid  22  (e.g., solvent, water and, if used, anti-foaming agent) and may be used while filling the tank  31  to achieve the desired pH. The pH can change during the apparatus&#39;  8  operation, for example due to dissolved support material  28  contaminating the fluid  22  or due to evaporation of portions of the fluid  22 . The pH sensor  65 A may be used to detect such changes and to alert the operator when the pH drops below or exceeds a desired level, whereupon the operator may use the HMI  38  to cause dosing of fluids as needed to adjust the pH to the desired level. For example, if the pH is too high (i.e., too basic), then more solvent can be added. But if the pH is too low (i.e., too acidic), then more water can be added. Alternatively, the apparatus  8  may be configured to automatically dose fluids as needed to adjust the pH. The desired temperature and pH may be set by the operator using the HMI  38 , or may be pre-stored in connection with a given operating recipe that the operator has the option to select. 
     As the fluid  22  flows through the apparatus  8 , its temperature can change, which may be undesirable. In particular, it is important to maintain the fluid  22  at the desired temperature as it travels from the tank  31  to the nozzles  25 . Yet, many pumps  33  heat up while they are operating and transfer that heat to the fluid  22  as it moves through the pump  33 . In embodiments of the present invention, it is preferable to use a pump  33  that adds minimal heat to the fluid  22 , such as a magnetically coupled pump  33 . 
     Atomization of the fluid  22  by spraying it through appropriately sized nozzles  25 , where the fluid  22  separates into small droplets while also spreading out in a flat fan, hollow cone, or full cone spray pattern helps to control the force at which fluid  22  impacts the part  10  while maximizing flow of the fluid  22 . The top nozzles  25 A may be further away from the parts  10  being SF/SR processed than the bottom nozzles  25 B, and in such a configuration, the force of the spray from the top nozzles  25 A as it impacts the parts  10  can sometimes fall below a desired amount. The design of the bottom nozzles  25 B can help with this. The spray from the bottom nozzles  25 B may have enough force to hit the bottom of the parts  10  and then continue to travel upwards to heights above the parts  10 . There, the droplets combine with each other and/or droplets from the top nozzles  25 A into larger droplets, whereupon these larger droplets fall down onto the parts  10 . Aided by both gravity and the force of the drops from the top spray nozzles  25 A, these larger particles may hit the parts  10  with more flow and kinetic energy than drops coming from the top nozzles  25 A alone or the bottom nozzles  25 B alone. Nonetheless, the top nozzles  25 A may be mounted in a way so as to be adjustable closer to or further away from the parts  10 . Likewise, the location of the parts  10  may be adjustable such that parts  10  are set further away from the bottom nozzles  25 B and thus closer to the top nozzles  25 A, or vice-versa. 
     The fluid  22  in the tank  31  may be drained automatically. At the end of each SF/SR process, there may be the option to drain all the fluid  22  from the tank  31  and replace it with new fluid  22 . This option may be pre-set by the operator or selected by the operator upon the completion of an SF/SR process. An auto-drain feature may also be used to drain the tank  31  after a prescribed number of SF/SR processes, which may be set by the operator. 
     After the tank  31  is drained, the tank  31  may be automatically filled with clean water, and used for rinsing the part  10  in order to remove fluid  22  remaining on the part  10 . The water may be heated in the same manner as the fluid  22 . When selecting the parameters for the SF/SR process, the operator may set the temperature for the rinsing water or select the temperature from a pre-stored recipe. In one embodiment, the fluid  22  for removing support material  28  may be automatically drained from the tank  31  after the designated run time and replaced with clean water (using the same auto-fill mechanisms described above), which is then cycled through the apparatus  8  to rinse the parts  10 , at the same agitation level setting as used during the support removal portion of the SF/SR process. During this rinsing process, the water may be pre-heated to the desired temperature or the temperature may be gradually raised while the apparatus is running. 
     During the SF/SR process, heat from the fluid  22  in the tank  31  can heat up air in the chamber  16 . This heated air in the chamber helps, in turn, to maintain the fluid  22  at the desired temperature while fluid  22  is sprayed from the nozzles  25  and collects back into the tank  31 . At the end of a SF/SR and/or rinse cycle, the heater  96  in the tank  31  may be kept operating to maintain the heat in the chamber  16 , which, in turn, may be useful for drying the parts  10  prior to removing them from the chamber  16 . When carried out in this manner, an SF/SR process may be said to be a “dry-to-dry” process: that is the parts  10  placed in the chamber  16  are dry and do not require preparation work to be done on them prior to the SF/SR process, and the parts  10  come out of the chamber  16  dry after the SF/SR process is complete. 
     Operation. A method according to the present invention, illustrated in  FIG.  6   , may comprise the following of steps to remove support material  28  and/or finish a surface of build material  35  of a part  10  and rinse residual material from a part  10  made using additive manufacturing. The operator may use  200  the HMI  38  to cause the tank  31  to fill with fluid  22 . The operator also may use the HMI  38  to set other SF/SR processing parameters for the additive manufactured parts  10  to be SF/SR processed, including temperature (of both the support removal and rinsing fluids), pH of the fluid  22 , the length of run time (in hours and minutes), agitation level (e.g., ultra-low, low, medium or high agitation), center-point position of the top spray-header(s) of nozzles  25 , the range of distance through which the top nozzles  25 A oscillate, and the speed of oscillation of the top nozzles  25 A. Additionally, the operator may place  203  one or more additive manufactured parts  10  on the tray  13  within the chamber  16 . The heater  96  in the tank  31  may operate to heat the fluid  22 , which in turn helps to heat the air in the chamber  16 . The fluid  22  can be brought to full temperature prior to starting the SF/SR process, or gradually after the SF/SR process begins. 
     Next, the pump(s)  33  may activate, drawing fluid  22  from the tank  31 , through the pump(s)  33 , and then forcing  206  the fluid  22  through the manifold (if used) and those of the open valves  59  toward and through the nozzles  25  associated with the open valves  59  in order to spray the fluid  22 . The upper nozzles  25 A may oscillate when the associated valves  59  are open and allow fluid  22  to flow to the nozzles  25 A, and those nozzles  25 A may rotate or otherwise move in accordance with the selected settings. The fluid  22  then exits the nozzles  25  as atomized and/or semi-atomized fluid  22  and collides with the part  10 , including the support material  28 , whereupon the support material  28  begins to dissolve or otherwise separate from the part  10  and/or rough surfaces of build material  35  of the part begin to smooth. The fluid  22  then passes through the openings in the tray  13  and collects  209  in the tank  31  located under the bottom nozzles  25 B, whereupon the fluid  22  cycles  206  through the nozzles  25  again as the pump  33  continues to draw fluid  22  from tank  31 . This cycling  212  of the fluid  22  continues for the duration of the run time set by the operator or until the operator manually stops the SF/SR process. 
     During the SF/SR process, the apparatus  8  may measure the fluid level in the tank  31  to ensure enough fluid  22  is contained in the tank  31 . If there is not enough fluid  22  in the tank  31  (e.g., due to evaporation) the apparatus  8  may add fluid  22  components, such as the water, solvent and/or anti-foaming agent as appropriate. The apparatus  8  also may measure the pH of the fluid  22  and dose the tank  31  with water and/or solvent as needed to maintain the desired pH level. 
     After the prescribed amount of time, the spraying stops, the fluid  22  may automatically drain  215  from the tank  31 , the tank  31  may automatically fill  215  with clean water, and then the spraying may re-start to rinse the parts  10 . The water may be cycled  218  through the system until a prescribed amount of time has elapsed, the rinsing process stops, and the parts  10  may remain in the chamber  16  for drying by the heated air in the chamber  16 . 
     The ventilation system may operate during the SF/SR process to safely exhaust excess vapors and thus prevent them from escaping out of the chamber  16  to areas that could pose a threat to users standing around the apparatus  8  while the SF/SR process is occurring. The ventilation system may be kept running for a time interval (for example, 5 minutes) after an SF/SR process is completed. 
     The method may be carried out so as to determine the agitation level in concert with optimal temperature in order to maximize the speed and efficiency of SF/SR processing. When the fluid  22  is too cool, the support material  28  may not be removed as efficiently, but when the fluid is too hot, the part can experience damage such as shape degradation, including warpage. Additionally, as will be appreciated by the disclosure herein, the hardware, electronics, software and fluid  22  may work together to provide desired levels of efficacy and efficiency, from delicate support removal to more robust removal with higher throughput. 
     Settable parameters can be different and/or customized for particular build and support materials  35 ,  28  out of which the additive manufactured parts  10  are made, the part geometries including the geometries of support structures, and the degree and speed of support material removal desired. Balancing and varying these parameters increases the efficacy and efficiency at which support material  28  can be removed. The apparatus  8  can be pre-programmed at a factory with “recipes” of the parameter settings known to be suitable for various support and build materials  28 ,  35 , part geometries, etc. Thus, by a single activation operation, e.g. pressing one button or a short sequence of buttons, the operator may be able to set all of the parameters for a given SF/SR process. Additionally, the operator can set parameters and save them as a recipe, which the operator can then select in the future rather than re-inputting each of the settings. 
     The present invention may further include a logic controller  99  to monitor communication between a central processing unit (“CPU”)  102  and the HMI  38 . In such an embodiment of the invention, a signal may be sent from the HMI  38  to the CPU  102 , and vice-versa. The logic controller  99  may monitor this signal to make sure the signal changes during the SF/SR process. If the signal stops, the logic controller  99  may react by either shutting down the apparatus  8 , or the HMI  38  will inform the operator to restart the apparatus  8 . The HMI  38  and CPU  102  may be connected to the Internet in order to be operated and evaluated remotely. Additionally, this Internet connection could enable the use of a database that contains a plurality of test parameters and additional recipes that may be used to optimize the SF/SR and rinse processes. The database may alternatively be contained on a hard drive that may be associated with the apparatus  8  itself and be uploaded periodically to a remotely located storage device. 
     The apparatus  8  may collect and store data about settings and about how the apparatus  8  should or does operate, which can be used to service the apparatus  8  and as feedback for improving SF/SR settings for various types of support and build materials  28 ,  35  and part geometries. 
       FIG.  7    shows another embodiment of an apparatus  100  for surface finishing and support removal of additively manufactured parts. The apparatus  100  is useful for removal of support material from additively manufactured parts that have internal chambers, cavities, or passages. Such internal chambers, cavities, or passages may contain support material produced as part of the additive manufacturing process. It can be difficult to remove support material from internal chambers, cavities, or passages in additively manufactured parts. The apparatus  100  for surface finishing and support removal addresses this need. 
     The apparatus  100  in  FIG.  7    is similar to the embodiment  8  in  FIG.  1    and like numerals refer to like components. In the embodiment in  FIG.  7   , a flexible hose member  104  connects to the lower spray header  110 . The lower spray header  110  has a fitting  112  to which the flexible hose member  104  can attach. The fitting  112  can be in addition to the fittings to which the lower nozzles  25 B are attached. Alternatively, one of the lower spray nozzles  25 B can be removed and the flexible hose member  104  can be connected to the lower spray header  110  in the fitting from which the one lower spray nozzle  25 B was removed. The flexible hose member  104  includes a valve  118  operable to shut off flow through the flexible hose member  104 . At the end of the flexible hose member  104  is a nozzle  124 . 
     Located on and connected to the platform  13  is an adjustable holding member  128 . 
       FIG.  8    shows a view of the interior of the chamber  16 . Located on the platform  13  is the part  10 . The flexible hose member  104  has been adjusted so that the spray nozzle  124  located at the end of the flexible hose member  104  is directed at the part  10 . In this figure, the spray nozzle  124  is adjusted to direct a flow of spray at an interior portion of the part  10 . The part  10  is fastened to the platform  13  by the holding member  128 . In this embodiment, the holding member  128  is comprised of two bolts that can be fastened to the platform  13  at a desired spacing in order to securely affix the part  10  to the platform  13 . 
       FIG.  9    is another view of the interior of the chamber  16 . As shown in  FIG.  9   , the part  10  is located on the platform  13  and the flexible hose member  104  has been adjusted so that the spray nozzle  124  located at the end of the flexible hose member  104  is directed at the part  10 . In  FIG.  9   , the part  10  has not yet been fastened to the platform  13  by the holding member  128 . 
       FIG.  10    is a flowchart  300  showing operation of the embodiment of  FIG.  7   . A part  10  produced by an additive manufacturing process is placed in the chamber  16  (Step  304 ). The part  10  at this stage is surrounded by support material. The support material is produced with the part  10  as part of the additive manufacturing of the part  10 , but is unwanted and needs to be removed before the part  10  can be used for its intended purpose. The part  10  is secured to the platform  13  by the holding member  128  (Step  308 ). The flexible hose member  104  is adjusted so that its spray nozzle  124  is aimed at the part  10  (Step  312 ). If the part  10  has an interior portion, the flexible hose member  101  may be adjusted so that its spray nozzle  124  is aimed directly at the interior portion of the part  10 . The spray nozzle  124  may be inserted inside the part  10  or may be positioned in close proximity to the part  10 , such as less than approximately 5 inches. After the spray nozzle  124  of the flexible hose member  104  is adjusted to spray at the part  10 , the apparatus  100  is operated as described in connection with  FIG.  1   . The chamber  16  is closed and the part  10  is sprayed to remove the support material therefrom (Step  316 ). The apparatus  100  sprays the part  10  with the top nozzles  25 A and the bottom nozzles  25 B, as well as the nozzle  124  at the end of the flexible hose member  104 . In one embodiment, PG1C or PG2C detergents, available from PostProcess Technologies, Inc., may be used in the apparatus  100  to spray at the part  10 . Suitable compositions for these detergents are disclosed in PCT applications Ser. No. PCT/US19/39338, filed Jun. 16, 2019 and PCT/US19/51094, filed Sep. 13, 2019, the entire disclosures of which are incorporated by reference herein. After spraying for a period of time, the part  10  may be inspected to determine whether the support material has been removed (Steps  320  and  324 ). It can be determined that the support material is removed by visual inspection. The visual inspection may be performed by a human operator or may be performed by programming using object recognition software. Alternatively, the spray can be stopped after a predetermined period of time. After the support material is removed from the part  10 , the part is removed from the chamber  16  (Step  328 ). 
     In the embodiment of the apparatus  100  in  FIGS.  7 - 9   , a suitable product for use as the flexible hose member is a Loc-Line hose available from Lockwood Products, Inc. The Loc-Line hose is available in various diameters and nozzle types. The length is adjustable. In one embodiment, the flexible hose member is approximately 5 feet in length and has a diameter of ¼ inches. A suitable nozzle is a Loc-Line nozzle, stainless, adjustable with dimensions 0.160 by 1.25 inches. A suitable valve is a Loc-Line ball valve. As shown in  FIG.  9   , the flexible hose member  104  may be used with clamps  132 . The clamps  132  increase the rigidity of the flexible hose member  104  so that the nozzle  124  remains directed at the part  10 . In one embodiment, the clamps  132  are positioned on every other connection point along the length of the flexible hose member  104 . Alternatively, clamps  132  may be positioned every third connection point, or at various other locations along the length of the flexible hose member. 
     In the embodiment  100  disclosed in  FIG.  7   , the flexible hose member  104  and holding member  128  are provided as removable parts that can be installed in the apparatus  100  by an operator when needed. In an alternative embodiment, the flexible hose member  104  and holding member  128  may be provided as non-removable parts that are permanently installed in the apparatus  100 . 
     In further alternative embodiments, the flexible hose can be adapted for use in a support material removal system like the one disclosed in U.S. Published patent application 20170348910, filed Jun. 1, 2017, the entire disclosure of which is incorporated by reference herein. 
       FIG.  11 - 13    show yet another embodiment of an apparatus  400  for surface finishing of and support removal from additively manufactured parts. Like the embodiment  100  in  FIGS.  7 - 9   , the apparatus  400  in  FIGS.  11 - 13    is useful for removal of support material from additively manufactured parts that have internal chambers, cavities, or passages. The apparatus  400  in  FIGS.  11 - 13    is especially useful for removing support material from multiple parts at the same time. 
     The apparatus  400  in  FIGS.  11 - 13    is similar to the embodiment  8  in  FIG.  5    and like numerals refer to like components. In the embodiment of  FIGS.  11 - 13   , a submersion tank  150  is located on the platform  13 . The submersion tank  150  is generally rectangular with an open top. In one embodiment, the submersion tank  150  has approximately the same width and length as the platform  13 , but in alternative embodiments, the submersion tank  150  is smaller or larger. The submersion tank  150  is made of stainless steel or other suitable non-reactive material. The submersion tank  150  has approximately a 5 gallon capacity. 
     As shown in  FIG.  12   , the submersion tank  150  includes an input port  154  and a drain port  158 . The input port  154  is located at one corner of the submersion tank  150  and the drain port  158  is located at an adjacent corner of the submersion tank  150 . In addition to the drain port  158 , the submersion tank  150  includes a plurality of drainage openings  160  located through its side walls along the upper edges thereof. 
     again to  FIG.  11   , an input hose  162  is connected at one end to a fitting  170  on a lower spray header  166 . The fitting  170  can be in addition to the fittings to which the lower nozzles  25 B 2  are attached. Alternatively, one of the lower spray nozzles  25 B 2  can be removed and the input hose  162  can be connected to the lower spray header  116  in the fitting from which the one lower spray nozzle was removed. The other end of the input hose  162  includes a nozzle  174 . The nozzle  174  is attached to the input port  154  thereby connecting the input hose  162  to the submersion tank  150 . A drainage hose  178  is connected at one end to the drain port  158 . The other end of the drainage hose  178  empties into the tank  31 . 
       FIG.  14    is a flowchart  500  showing operation of the embodiment of  FIGS.  10 - 13   . This embodiment is useful for support material removal from parts made by additive manufacturing processes. With this embodiment, multiple parts can be handled at the same time. In a first step, the submersion tank  150  is installed in the chamber  16  by placing it on the platform  13  (Step  504 ). Next, the input hose  162  is connected between the lower spray header  166  and the input port  154  of the submersion tank  150  and the drainage hose  178  is connected between the drain port  158  of the submersion tank  150  and the tank  31  (Step  508 ). (Steps  504  and  508  are performed when adapting the apparatus  400  for use with the submersion tank  150  and may be omitted if the apparatus  400  already has been adapted for use with the submersion tank  150 .) 
     Multiple parts  10 A- 10 F (shown in  FIG.  13   ) produced by an additive manufacturing process are placed in the submersion tank  150  (Step  512 ). The parts  10 A- 10 F at this stage are surrounded by support material and include support material in inside chambers thereof. The apparatus  400  is operated as described in connection with  FIG.  1   . The chamber  16  is closed and the parts  10 A- 10 F are sprayed to remove the support material therefrom (Step  516 ). The apparatus  400  sprays the parts  10 A- 10 F with detergent from the top nozzles  25 A 1 . The input hose  162  attached to the submersion tank  150  fills the submersion tank  150  with detergent. The detergent used to fill the submersion tank  150  is the same detergent sprayed at the parts from the top nozzles  25 A 1 ,  25 A 2  and bottom nozzles  25 B 2 . As the spray is applied, the submersion tank  150  is filled with detergent up to the level of the drainage openings  160 . Detergent flows from the submersion tank  150  through the drainage openings  160  into the lower tank  31 . As disclosed in the previous embodiment, the detergent used in this embodiment is PG1C or PG2C detergents, available from PostProcess Technologies, Inc. 
     When the detergent in the submersion tank  150  rises to the level of the drainage openings  160 , detergent also flows from the submersion tank out the drain port  158 , through the drainage hose  178 , and into the tank  31 . As shown in  FIG.  13    (by the arrows), the spray of detergent from the nozzle  174  on the input hose  162  into the submersion tank  150  combined with the drainage of detergent out of the submersion tank  150  from the drain port  158  causes a circular flow of detergent in the submersion tank  150 . In addition, the spray of detergent from the upper nozzles  25 A 1  onto the surface of the detergent in the submersion tank  150  (as shown in  FIG.  11   ) pushes the parts  10 A- 10 F below the surface of the detergent in the submersion tank  150 . The combination of the circular flow in the submersion tank  150  and the application of spray from the upper nozzles  25 A 1  causes the parts  10 A- 10 F to tumble in the flow of detergent and to remain under the surface of the detergent in the submersion tank  150 . This action causes support material located in inside chamber of the parts  10 A- 10 F to be removed efficiently and effectively. 
     After application of the spray for a period of time, the parts  10 A- 10 F may be inspected to determine whether the support material has been removed (Steps  520  and  524 ). It can be determined that the support material is removed by visual inspection. The visual inspection may be performed by a human operator or may be performed by programming using object recognition software. Alternatively, the spray can be stopped at a predetermined period of time. After the support material is removed from the parts  10 A- 10 F, the parts are removed (Step  528 ). 
     In the embodiment  400  disclosed in  FIG.  11   , the submersion tank  150 , the input hose  162 , and the drainage hose  178  are provided as removable parts that can be installed in the apparatus  400  by an operator when needed. In an alternative embodiment, the submersion tank  150 , the input hose  162 , and the drainage hose  178  may be provided as non-removable parts that are permanently installed in the apparatus  400 . 
     In the foregoing description, example embodiments are described. The specification and drawings are accordingly to be regarded in an illustrative rather than a restrictive sense. 
     It will be appreciated that various aspects of the above-disclosed invention and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, and/or improvements therein may be subsequently made by those skilled in the art, and those alternatives, modifications, variations, and/or improvements are intended to be encompassed by the following claims. 
     Although the present invention has been described with respect to one or more particular embodiments, it will be understood that other embodiments of the present invention may be made without departing from the spirit and scope of the present invention. Hence, the present invention is deemed limited only by the appended claims and the reasonable interpretation thereof.