PARTICLE JET APPARATUS

Abstract

A particle jetting apparatus includes a metering portion, a sprayer, and a feed portion; each of the metering portion and the sprayer may be configured to provide uniformity in particle discharge; the metering portion controls the particle feed rate and may include a rotor, which may have V-shaped or chevron-shaped pockets; the sprayer includes at least one movable roller, including a position where the sprayer gap is at its maximum and a position where the gap is at its minimum; the metering portion may discharge directly into the feed portion without a sprayer being present; the sprayer may receive particles directly from a jetting medium source without a metering portion being present.

Description

PARTICLE JET APPARATUS TECHNICAL FIELD The present invention relates to methods and apparatus for carrying particles of a jet medium in a flow, and is directed particularly to methods and apparatus for controlling the feed rate of the jet medium as well as for controlling the size of the cryogenic jet medium. BACKGROUND OF THE INVENTION Carbon dioxide systems, including apparatus for creating solid carbon dioxide particles, for entraining particles in a carrier gas, and for directing entrained particles toward objects, are well known, as are the various component parts associated with them, such as nozzles, shown in U.S. Patents. 4,744,181, 4,843,770, 5,301,509, 5,473,903, 6,695,685, 6,726,549, 5,018,667, 5,050,805, 5,520,572, 6,024,304, 6,739,529, 6,824,450, 5,071,289, 5,188,151, 6,042,458, 6,346,035, 7,112,120, 7,950,984, 5,249,426, 5,288,028, 6,524,172, 6,695,679, 8,187,057, 8,277,288, 8,869,551, 9,095,956, 9,592,586 and 9,931,639 all of which are incorporated herein in their entirety for reference. In addition, U.S. Patent Application Serial No. 11 / 853,194, filed on September 11, 2007, for Particle Blast System With Synchronized Feeder and Particle Generator; U.S. Provisional Patent Application Serial No. 61 / 589,551, filed on January 23, 2012, for Method And Apparatus For Sizing Carbon Dioxide Particles; U.S. Provisional Patent Application Serial No. 61 / 592,313, filed on January 30, 2012, for Method And Apparatus For Dispensing Carbon Dioxide Particles; and U.S. Patent Application Serial No. 13 / 475,454, filed on May 10, 2012, for Method And Apparatus For Forming Carbon Dioxide Pellets; United States Patent Application No.of Serial No. 14 / 062,118 filed on October 24, 2013 for Apparatus Including At Least An Impeller Or Diverter And For Dispensing Carbon Dioxide Particles And Method Of Use; United States Patent Application Serial No. 14 / 516,125, filed on October 16, 2014, for Method And Apparatus For Forming Solid Carbon Dioxide; United States Patent Application Serial No. 15 / 062,842 filed on March 7, 2015, for Particle Feeder; United States Patent Application Serial No. 14 / 849,819, filed on September 10, 2015, for Apparatus And Method For High Flow Particle Blasting Without Particle Storage; and the. United States Patent Application Serial No. 15 / 297,967, filed October 19, 2016, for Blast Media Comminutor, all of which are incorporated herein in their entirety for reference. U.S. Patent 5,520,572 illustrates a particle jetting apparatus that includes a particle generator that produces small particles by shaving them from a block of carbon dioxide and carries the carbon dioxide pellets in a carrier gas flow without storing the pellets. U.S. Patents 5,520,572, 6,824,450, and U.S. Patent Publication No. 2009-0093196 disclose particle jetting apparatuses that include a particle generator that produces small particles by shaving them from a block of carbon dioxide, a particle feeder that receives the particles from the particle generator and carries them, and a particle feeder that carries the particles in a moving flow of carrier gas.The entrained particle stream flows through a supply hose to a jet nozzle for end use, such as being directed against a workpiece or other target. For some jetting applications, a range of small particles, such as those in the 3 mm to 0.3 mm diameter range, may be desirable. U.S. Patent Publication 2017-0106500 (corresponding to U.S. Patent Application Serial No. 15 / 297,967) discloses a sprayer that reduces the size of frangible jetting medium particles from their initial size to a second size smaller than a desired maximum size. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate methods that serve to explain the principles of this innovation. Figure 1 illustrates in diagram form a particle jet apparatus. Figure 2 is a perspective view of a hopper, a feed assembly, and a pressure regulator that can be carried by the particle jet apparatus of Figure 1. Figure 3 is a perspective view of the hopper and feed assembly of Figure 2, with impellers and pressure regulator omitted for clarity. Figure 4 is a perspective cross-sectional view of the feed assembly of Figure 3 taken through a vertical plane passing through the midline of the feed assembly. Figure 5A is a cross-sectional side view of the feed assembly of Figure 4 taken in the same vertical plane as in Figure 4. Figure 5B is an enlarged fragmentary cross-sectional side view of the measuring and guiding element. Figure 5C is a cross-sectional view taken along line 5C of Figure 5A. Figure 6 is an exploded perspective view of the feed portion of the feed assembly. Figure 7 is an exploded perspective view of the metering portion and pulverizer of the feed assembly. Figure 8 is an exploded perspective view of the measuring portion and the sprayer. Figure 9 is a perspective cross-sectional view of the feed assembly similar to Figure 4, taken at a different angle and through a different vertical plane, one that does not pass through the midline of the feed assembly. Figure 10 is a perspective cross-sectional view of the feed assembly, similar to Figure 9, taken through a vertical plane passing through the midline of the feed assembly, illustrating a larger gap between the pulverizer rollers. Figure 11 is a cross-sectional side view of the feed assembly taken in the same vertical plane as in Figure 10, illustrating the equal-sized spacing between the pulverizer rollers. Figure 12 is a cross-sectional side view of the feed assembly similar to Figure 11, illustrating a space size smaller than the maximum space size and larger than the minimum space size. Figure 13 is a top view of the sprayer rollers illustrating the diamond pattern formed by the raised flanges in the convergence region. Figure 14 is a bottom view of the sprayer rollers illustrating the X pattern formed by the raised flanges in the diverging region. Figure 15 is a top view of the measuring element through the guide. Figure 16 is a perspective view of the measuring element. Figure 17 is a plan view of the end profile of the measuring element in Figure 16, taken on line 17-17 of Figure 16. Figure 18 is a plan view of a profile of the measuring element of Figure 16, taken on line 18 - 18 of Figure 16. Figure 19 is a plan view of a profile of the measuring element of the Figure 16, taken on line 19 - 19 of Figure 16. Figure 20 is a bottom view of the measuring element through the guide. Figure 21 is a perspective view of a pressure regulator assembly. Figure 22 is a top cross-sectional view of the pressure regulator assembly actuator of Figure 21. Figure 23 is a schematic diagram of a pneumatic circuit. Figure 24 is a top cross-sectional view of the actuator similar to Figure 21. Figure 25 is a cross-sectional side view of a ball valve. DETAILED DESCRIPTION OF THE INVENTION In the following description, similar reference characters designate similar or corresponding parts across the various views. Also, in the following description, terms such as front, back, interior, exterior, and the like are words of convenience and should not be considered limiting terms. The terminology used in this patent is not intended to be limiting, as the devices described herein, or portions thereof, may be mounted or used in other orientations. With reference to the drawings in more detail, one or more embodiments constructed in accordance with the teachings of the present invention are described. It should be noted that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated herein by reference is incorporated herein only to the extent that the incorporated material does not conflict with the definitions, statements, or other disclosure material set forth herein. Therefore, to the extent necessary, the description as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Although this patent specifically relates to carbon dioxide, the invention is not limited to carbon dioxide but can be used with any suitable frangible material, as well as any suitable cryogenic material or other types of particles such as frozen water pellets or abrasive media. References herein to carbon dioxide, at least when describing embodiments that serve to explain the principles of the present innovation, are necessarily limited to carbon dioxide but should be read to include any suitable frangible or cryogenic material. With reference to Figure 1, a representation of a particle jetting apparatus, generally indicated by 2, is shown, which includes the cart 4, the supply hose 6, ML / a / ZUZZ / U 1 O 1O / manual control 8, and discharge nozzle 10. Inside the carriage 4 is a jetting medium supply assembly (not shown in Figure 1) that includes a hopper and a feed assembly arranged to receive particles from the hopper and to carry particles within a carrier gas flow. The particle jetting apparatus 2 can be connected to a carrier gas source, which can be supplied in the manner represented by the hose 12 that supplies an air flow at a suitable pressure, such as but not limited to 551 kPa (80 PSIG). The jetting medium, such as but not limited to carbon dioxide particles, indicated in 14, can be deposited into the hopper through the top portion 16 of the hopper. The carbon dioxide particles can be of any suitable size, such as but not limited to a diameter of 3 mm and a length of approximately 3 mm.The feed assembly draws the particles into the carrier gas, which then flows at subsonic speed through the internal flow passage defined by the supply hose 6. The supply hose 6 is illustrated as a flexible hose, but any structure can be used to carry the entrained particles in the carrier gas. The manual control 8 allows the operator to control the operation of the particle jet apparatus 2 and the flow of entrained particles. Downstream of the control 8, the entrained particles flow to the inlet 10a of the discharge nozzle 10. The particles flow from the outlet 10b of the discharge nozzle 10 and can be directed in the desired direction and / or to a desired target, such as a workpiece (not shown). The discharge nozzle 10 can have any suitable configuration, for example, the discharge nozzle 10 can be a supersonic nozzle, a subsonic nozzle, or any other suitable structure configured to advance or supply the jet medium to the desired point of use. Control 8 can be omitted, and the system operation is controlled via controls on carriage 4 or another suitable location. For example, the discharge nozzle 10 can be mounted to a robotic arm, and the nozzle's orientation and flow can be controlled remotely via controls located on carriage 4. With reference to Figures 2 and 3, the hopper 18 and feed assembly 20 of the particle jetting apparatus 2 are shown. The hopper 18 may include a device (not shown) for imparting energy to the hopper 18 to assist in the flow of particles through it. The hopper 18 is a source of jetting medium, such as cryogenic particles, for example, but not limited to carbon dioxide particles. The outlet of hopper 18a is aligned with guide 22 (see Figure 4) in the seal of hopper 24. Any suitable source of jetting medium may be used, such as, without limitation, a pelletizer. Feed assembly 20 is configured to transport the jet medium from a jet medium source within a carrier gas flow, with the jet medium particles being carried along in the carrier gas as the flow exits feed assembly 20 and enters supply hose 6. In the embodiment shown, feed assembly 20 includes metering portion 26, sprayer 28, and feed portion 30.As discussed later, the sprayer 28 can be omitted from the feed assembly 20 (with the metering portion 28 discharging directly into the feed portion 30), the metering portion 28 can be omitted from the feed assembly 20 (with the sprayer receiving particles directly from a jet medium source such as the hopper 18), and the feed portion 30 can be of any construction that carries particles within the carrier gas, whether from a single hose, multiple hoses, and / or a venturi-type system. The pressure and flow of carrier gas supplied to the feed portion 30 are controlled by the pressure regulator assembly 32. The feed assembly 20 includes a plurality of motors to drive its various portions. These motors may have any suitable configuration, such as pneumatic motors and electric motors, including, without limitation, DC and VFD motors. The metering portion 26 includes impeller 26a, which, in the embodiment shown, provides rotary power. In the embodiment shown, the sprayer 28 includes three impellers, 28a and 28b, which provide rotary power, and 28c, which provides rotary power via the right-angle impeller 28d. In the embodiment shown, the feed portion 30 includes impeller 30a, which provides rotary power via the right-angle impeller 30b. Any suitable number, configuration, and orientation of the impellers may be used, with or without the presence of right-angle impellers.For example, fewer motors can be used with appropriate mechanisms to transmit power to the components at the appropriate speeds (such as chains, belts, gears, etc.). As can be seen in Figure 3, with the drives and right-angle drives removed, locating pins can be used to position the drives. The feed assembly 20 may include one or more actuators 34, each having at least one extendable member (not illustrated), arranged to be selectively extended within the particle flow from the hopper 18 to the feed assembly 20 in the guide 22, capable of mechanically breaking up particle agglomerations, as described in U.S. Patent 6,524,172. Referring also to Figures 4 and 5A, the measuring portion 26 includes the guide 22 and the measuring element 36. The measuring element 36 is configured to receive the jetting medium from the hopper 18, a jetting medium source (in the manner depicted, cryogenic particles) from the first region 38, and to discharge the jetting medium into the second region 40. The guide 22 can be made of any suitable material, such as aluminum, stainless steel, or plastic. The guide 22 is configured to guide the jetting medium from the hopper 18 to the first region 38. The guide 22 can have any configuration suitable for guiding the jetting medium from the hopper 18 to the first region 38, such as without limitation to converging walls. The measuring element 36 is configured to control the flow rate of the jetting medium for the particle jetting apparatus 2.Velocity can be expressed using any nomenclature, such as mass (or weight) or volume per unit of time, such as pounds per minute. The measuring element 36 can be configured in any manner suitable for controlling the flow rate of the jet medium. In the embodiment shown, the measuring element 36 is configured as a rotor—a structure that rotates about an axis, such as axis 36a. In the embodiment shown, the measuring element 36 is supported by axis 36b, with a key / stub wrench arrangement preventing rotation between the measuring element 36 and axis 36b. The drive 26a is coupled to axis 36b and can be controlled to rotate axis 36b about axis 36a, thereby rotating the measuring element 36 about axis 36a.The measuring element 36 will also be referred to herein as rotor 36, measuring rotor 36, or even dosing unit 36. It is understood that references to the measuring element 36 as a rotor or a dosing unit shall not be construed in a manner that limits the measuring element to the illustrated rotor structure. By way of non-limiting example, the measuring element 36 may be a reciprocating structure. The measuring rotor 36, as depicted, includes a plurality of cavities 42, which are also referred to herein as pockets 42. The pockets 42 may have any size, shape, number, or configuration. In the embodiment depicted, the pockets 42 open radially outward and extend between the ends of the measuring rotor 36, as described below.The rotation of the measuring rotor 36 cyclically positions each pocket 42 in a first position adjacent to the first region 38 to receive particles and a second position adjacent to the second region 40 to discharge particles. The sprayer 28 includes roller 44, which is rotatable about an axis, such as shaft 44a, and roller 46, which is rotatable about an axis, such as shaft 46a. In the embodiment shown, roller 44 is supported by shaft 44b, with a key / stub wrench arrangement preventing rotation between roller 44 and shaft 44b. The drive 28a is coupled to shaft 44b and can be controlled to rotate shaft 44b about shaft 44a, thereby rotating roller 44 about shaft 44a. In the embodiment shown, roller 46 is supported by shaft 46b, with a key / stub wrench arrangement preventing rotation between roller 46 and shaft 46b. The drive 28b is coupled to shaft 46b and can be controlled to rotate shaft 46b around shaft 46a, thereby rotating roller 46 around shaft 46a. Rollers 44, 46 can be made of any suitable material, such as aluminum. Rollers 44 and 46 have respective peripheral surfaces 44c and 46c. The gap 48 is defined between each respective peripheral surface 44c and 46c. The converging region 50 is defined upstream of the gap 48 by the gap 48 and rollers 44 and 46. (Downstream is the flow direction of the jet medium through the feed assembly 20, and upstream is the opposite direction.) The converging region 50 is arranged to receive the jet medium from the second region 40 that has been discharged by the rotor 26. The diverging region 52 is defined downstream of the gap 48 by the gap 48 and rollers 44 and 46. The sprayer 28 is configured to receive the jet medium, comprising a plurality of particles (carbon dioxide particles in the depicted embodiment), from the measuring element 26 and to selectively reduce the particle size from their respective initial sizes to a second size smaller than a predetermined size. In the depicted embodiment, the sprayer 28 receives the jet medium from the measuring portion 26 / measuring element 36. In an alternative embodiment, the measuring portion 26 / measuring element 36 may be omitted, and the sprayer 28 may receive the jet medium from any structure, including directly from a jet medium source. As is known, the rollers 44, 46 are rotated to move the peripheral surfaces 44c, 46c in the downstream direction in space 48, the terminus of the convergent region 50.As jet medium particles travel downstream through space 48, particle sizes that are initially larger than the width of space 48 between peripheral surfaces 44c, 46c will be reduced to a size based on the size of the space. The size of space 48 can vary between a minimum and a maximum space. The maximum and minimum spaces can be any suitable size. The maximum space can be large enough that none of the particles traveling through space 48 undergo a size change. The minimum space can be small enough that all particles traveling through space 48 undergo a size change. Depending on the size of the maximum space, there may be a space size, smaller than the maximum space size, at which particle pulverization first begins. At space sizes where fewer than all particles traveling through space 48 are pulverized, the pulverizer 28 reduces the size of a plurality of the particles. In the embodiment shown, the minimum space is configured to pulverize the particles to a very fine size, such as 0.03 cm (0.0.012 inches), which may be referred to in industry standards as microparticles, with the minimum spacing being 0.015 cm (0.006 inches). In the configuration shown, the maximum spacing is set to avoid spraying any particles, with the maximum spacing being 1.77 cm (0.7 inches). Any suitable minimum and maximum spacing may be used. The feed portion 30 can have any design configured to receive jet medium particles and introduce the particles into the carrier gas flow, entraining them in the flow. In the embodiment shown, the feed portion 30 includes the feed rotor 54, the guide 56 disposed between the space 48 and the feed rotor 54, and the lower seal 58. The feed rotor 54 is rotatable about a shaft, such as shaft 54a. In the embodiment shown, shaft 54b (see Figure 6) is integral with the feed rotor 54 and can be of unitary construction. Alternatively, shaft 54b can be a separate shaft that carries the feed rotor 54 such that the feed rotor 54 does not rotate about shaft 54b. The feed rotor 54 can be made of any suitable material, such as stainless steel. As illustrated, the impeller 30a is coupled to shaft 54b, via the right-angle impeller 30b, and can be controlled to rotate shaft 54b and, at the same time, the feed rotor 54 around shaft 54a. The feed rotor 54 comprises the peripheral surface 54c (see Figure 6), also referred to herein as the circumferential surface 54c, which has a plurality of pockets 60 arranged thereon. Each pocket 60 has a respective circumferential width. The guide 56 is configured to receive particles from the sprayer 28 and guide the particles into the pockets 60 as the feed rotor 54 rotates about the axis 54a. As mentioned earlier, in one embodiment, the sprayer 28 can be omitted from the feed assembly 20, with the guide 56 receiving the particles directly from the measuring element 36. The guide 56 includes the sweep edge 56a adjacent to the peripheral surface 54c and extends longitudinally, generally parallel to the axis 54a.The feed rotor 54 rotates in the direction indicated by the arrow so that the sweep edge 56a defines a holding line for the feed rotor 54 and works, with the rotation of the feed rotor 54, to force the particles into the pockets 60. The lower seal 58 seals against the peripheral surface 54c. The lower seal 58 can have any suitable configuration. The feed portion 30 defines the flow path of the carrier gas 62, indicated by flow lines 62a and 62b, through which the carrier gas flows during operation of the particle jetting apparatus 2. The carrier gas flow path 62 can be connected to a carrier gas source either directly or via the pressure regulator assembly 32 (described later), with appropriate external connections to the feed portion 30. The carrier gas flow path 62 can be defined by any suitable structure and configured in any suitable manner that allows particles discharged from the pockets 60 to be drawn into the carrier gas. In mode ML / a / ZUZZ / UI OI Qt represented, the lower seal 58 and piston 64 define at least a portion of the carrier gas flow path 62, with part of the flow path 62 being through the pockets 60, as described in United States Patent Application Serial No. 15 / 297,967. The rotation of the feed rotor 54 introduces particles into the carrier gas flow, entraining them. The entrained flow (particles and carrier gas) flows through the supply hose 6 and out of the discharge nozzle 10. Thus, there is a particle flow path extending from the jet medium source to the discharge nozzle, which, in the embodiment shown, extends through the metering portion 26, the sprayer 28, and the feed portion 30. With reference to Figure 5B, an enlarged fragmentary cross-sectional view of the measuring rotor 36 and guide 22 is shown. The guide 22 includes the sweep edge 22a arranged adjacent to the outer peripheral surfaces 36c of the measuring rotor 36. The outer peripheral surfaces 36c travel past the sweep edge 22a as the measuring rotor 36 rotates. The sweep edge 22a is configured to sweep through the opening 42a of each pocket 42 as the measuring rotor 36 rotates. The sweep edge 22a is arranged at the sweep angle α with respect to a tangent to the measuring rotor 36, with an arcuate section transitioning from the sloping sides of the guide 22 to the sweep edge 22a. In the embodiment shown, this arcuate transition section has a radius of 0.72 cm (0.29 in.), although any suitable radius or transition shape may be used.As used herein, the sweep angle is the angle formed between the sweep edge and a tangent to the measuring rotor as illustrated and measured in Figure 5B. The sweep angle α is configured so as not to result in a retention line between the sweep edge 22a and the outer peripheral surfaces 36c as the measuring rotor 36 rotates in the indicated direction. If a retention line were present at this location, particles could be forced and / or crushed within the pockets 42, which, for carbon dioxide particles, results in the particles tending not to fall out of the pocket during discharge. In the embodiment shown, the sweep angle α is greater than 90°. Figure 5C illustrates the projection of the inlet 22 with respect to the measuring rotor 36, the projection of the housing 94 with respect to the roller 44, and that the roller 44 (and correspondingly the roller 46) is wider than the measuring rotor 36. As shown, the inlet surface 22c projects axially from the first end 36d of the measuring rotor 36, and the inlet surface 22d projects axially from the second end 36e. The upper portions of both ends 36d and 36e are arranged in depressions, defined by surfaces 22c and 22d, in the housings 94f and 94e, respectively. With this construction, particles traveling through the guide 22 are prevented from reaching the ends 36d and 36e. Similarly, surfaces 94a' and 94b' protrude from the ends of roller 44 (and at the same time from the ends of roller 46, not seen in Figure 5C).The upper portions of both ends of rollers 44 and 46 are arranged in depressions. As can be seen in Figure 5C, roller 44 (and also roller 46) is wider than the measuring rotor 36. This design prevents protrusions where ice could accumulate. With reference to Figure 6, an exploded perspective view of the feed portion 30 is shown. In addition to the description above, in the embodiment shown, the feed portion 30 includes the housing 66 and the base 68. The base includes the centrally arranged raised portion 70. Similar to that described in U.S. Patent Application Serial No. 15 / 062,842, an internal cavity of the piston 64 is sealed to the raised portion 70, forming a chamber that is in fluid communication with the carrier gas. The spring 72 is arranged to push the piston upward, with the pilot 74 engaging the piston 64 as shown in Figure 5A. In the embodiment shown, the lower seal 58 is secured to the piston 64 by fasteners 76 with appropriate seals. Housing 66 includes bores 66a and 66b that receive bearings 78a and 78b. Bearings 78a and 78b rotatably support the feed rotor 54. Bearing 78a is retained in bore 66a by retainer 80, which is secured to housing 66. Bearing 78b is retained in bore 66b by retainer / support 82, which is secured to the housing by fasteners 84. The right-angle impeller 30b can be associated with retainer / support 82. Housing 66 can be made of any suitable material, such as aluminum. The inlet 86 and outlet 88 (see Figure 5A) of the transport gas flow path 62 are formed in the housing 66 as shown. Connections 90 and 92 sealably associate the housing 66 at the inlet 86 and outlet 88, respectively, with retainers 90a and 92a securing them to it. With reference to Figures 7 and 8, exploded perspective views of the measuring portion 26 and the sprayer 28 are illustrated. In the embodiment shown, the housing 94 accommodates the measuring rotor 36 and the rollers 44 and 46. The shaft 36b can be rotationally supported by the bearings 36f. The housing 94 can be made of any suitable material, such as aluminum, and in any suitable configuration. In the embodiment shown, the housing 94 comprises six parts. As illustrated, housings 94a and 94b support the roller 44, while housings 94c and 94d support the roller 46. Housings 94e and 94f support the measuring rotor 36. Housings 94c and 94d are movable relative to housings 94a and 94b to vary the width of space 48. Housings 94a, 94b, 96c, and 96d have corresponding supports 96a, 96b, 96c, and 96d. Supports 96a and 96b rotatably support shafts 36b and 44b, and supports 96c and 96d rotatably support shaft 46b. Supports 96a, 96b, 96c, and 96d can be made of any suitable material, such as aluminum. Housings 94a and 94b and supports 96a and 96b are depicted as not being movable relative to the feed portion 30 and the hopper 18. Referring also to Figures 4 and 5A, the feed assembly 20 includes the gap adjustment mechanism 98, which connects to the supports 96c and 96d to move and arrange them in a plurality of positions, including a first position in which gap 48 is at its minimum and a second position in which gap 48 is at its maximum. The gap adjustment mechanism 98 comprises the shaft 100, which is rotatable about an axis, such as the shaft 100, and external teeth or threads 100b arranged to extend longitudinally as illustrated. The drive 28c is coupled to the shaft 100 via the right-angle drive 28d and can be controlled to rotate the shaft 100. The gap-setting mechanism 98 comprises the gear member 102 with internal teeth or threads 102a arranged around the shaft 100a, which are formed complementarily with the external teeth or threads 100b, which are associated therewith.Rotation of shaft 100 causes relative longitudinal movement between shaft 100 and member 102. Member 102 is secured to plate 104 by a plurality of fasteners 106. Plate 104 is secured to support 96c by fastener 108a and to support 96d by fastener 108b. The shaft 100 includes the flange 110, which is captured between the support 112 and the retainer 114, allowing rotational movement about the shaft 100a with little or no axial movement. A plurality of rods 116 secure the support 112 to the supports 96a and 96b, with no movement between them. The rods 116 support the plate 104 so that it can move axially along the rods 116. The plate 104 includes a plurality of guides 104a arranged in complementary formed holes 118c and 118d. Since the plate 104 is secured to the supports 96c and 96d by fasteners 108a and 108b, there is no relative movement between the guides 104a and the supports 96c and 96d. The guides 104a are sized to allow the rods 116 to slide axially in them. Supports 96a and 96b include guides 120a and 120b, respectively, which are arranged in complementary (not visible) formed holes in supports 96c and 96d. These holes are sized to allow guides 120a and 120b to slide axially within them. Guides 102a and 102b support and guide supports 96c and 96d in and between the first and second positions of their travel. Rods 116 extend through guides 104a, holes 118c and 118d, and guides 120a and 120b, which are attached to supports 96a and 96b, such that support 112 is supported and does not move relative to supports 96a and 96b. Rotating axis 100 moves plate 104 along axis 100a and at the same time moves supports 96c, 96d and roller 46 relative to supports 96a, 96b and roller 44, thereby varying the width of space 48. Rollers 44 and 46 may comprise a plurality of rollers. As shown in Figure 8, roller 44 may comprise rollers A and B supported non-rotatingly by shaft 44b, and roller 46 may comprise rollers C and D supported non-rotatingly by shaft 46b. Each individual roller A, B, C, D has a respective peripheral surface A', B', C', and D'. The rollers 44, 46, whether they comprise single rollers or a plurality of rollers, may include a plurality of holes 122 through them. If the rollers 44, 46 comprise a plurality of rollers, the holes 122 within each roller may be axially aligned. The holes 122 reduce the overall mass of the rollers 44, 46. This reduced mass decreases the time required for a temperature change in the rollers 44, 46, such as reducing the time required for any ice accumulated on the rollers 44, 46 during operation to melt during periods when the particle jet apparatus 2 is not in operation. Alternatively, air or another gas may be directed into the flow through the holes 122 to promote a more rapid temperature change. For clarity, Figure 9 provides a perspective cross-sectional view of feed assembly 20. With reference to Figures 10 and 11, supports 96c and 96d (not visible in Figures 10 and 11) are arranged in the second position where space 48 is at its maximum. Roller 46 is separated from roller 44 by a maximum distance. Regardless of the position of roller 46 and the size of the associated space 48, roller 44 remains in the same position. Roller 44 defines a first edge 48a of space 48, which also remains in the same position regardless of the position of roller 46. The first edge 48a is always positioned midway between the axis 54a and the sweep edge 56a. The sweep edge 56a defines a boundary of the sweep region 56b. Generally, the sweep region 56b extends around the width of a pocket 60 when the leading edge of that pocket 60 is positioned on the sweep edge 56a. The sweep region 56b is aligned with the first edge 48a. When the supports 96c and 96d are positioned at the first location where the size of the space 48 is at a minimum, the entire space is aligned with the sweep region 56b, so that the sprayed particles can fall or be directed into the pockets 60 proximal to the sweep edge 56a. Figure 12 is similar to Figure 11, which depicts spacing 48 at a size between the maximum and minimum spacing. The feed assembly 20 is configured so that the spacing adjustment mechanism 98 can position supports 96c and 96d in a plurality of intermediate positions between the first and second positions, allowing the spacing to be set to a plurality of intermediate sizes between the maximum and minimum spacing. In the embodiment shown, the configuration of the spacing adjustment mechanism 98 essentially allows the size to be set to the maximum, minimum, and any intermediate size. The peripheral surfaces 44c, 46c can have any suitable configuration. In the embodiment shown, the peripheral surfaces 44c, 46c have a surface texture, which can have any configuration. It is noticeable that for clarity, the surface texture has been omitted from the figures except in Figures 13 and 14. Figures 13 and 14 illustrate the rollers 44, 46 having a surface texture comprising a plurality of raised flanges 124. Figure 13 illustrates the rollers 44, 46 comprising rollers A, B, C, and D, viewed from the top within the converging region 50. Each peripheral surface A', B', C', D' comprises a plurality of raised flanges 124 arranged at an angle with respect to any edge. The angle can be any suitable angle, such as 30° with respect to the axial direction.In the represented mode, the angles of each rim of the peripheral surface A', B', C', D' are equal, although any suitable combination of angles can be used. The surface texture in the depicted embodiment is configured to provide uniformity across the axial width of rollers 44, 46 for the pulverized particles discharged by the pulverizer 28 into the feed portion 30. This uniformity is achieved in the depicted embodiment by the surface texture being configured to move the particles entering the pulverizer 28 in the converging region 50 toward the axial half of rollers 44, 46. As seen in Figure 13, the plurality of flanges 124 on roller 44 (rollers A, B) and the plurality of flanges 124 on roller 46 (rollers C, D) form a diamond pattern in the converging region 50. At the interface between rollers A and B and rollers C and D, the individual raised flanges 124 may or may not be precisely aligned. When viewed from the bottom, the plurality of flanges 124 of roller 44 (rollers A, B) and the plurality of flanges 124 of roller 46 (rollers C, D) form an X pattern in the divergent region. Figure 15 shows a top view of the metering rotor 36 through the guide 22. Arrow 126 indicates the direction of rotation of the metering rotor 36. Referring also to Figures 16, 17, 18, and 19, in the depicted configuration, the metering rotor 36 is configured to provide uniformity across the axial width of the metering rotor 36 in the jet medium particles discharged by the metering rotor 36 in the second region 40 to the sprayer 28, and uniformity in the discharge velocity in the second region 40. This uniformity can be achieved in the depicted configuration by the pocket configuration 42. The metering rotor 36 can be made of any suitable material, such as UHMW or other polymers. As shown in Figure 16, the measuring rotor 36 comprises the first end 36d and the second end 36e, which are separated from each other along the axis 36a. The pockets 42 extend from the first end 36d to the second end 36e. When viewed radially toward the axis 36a, the pockets 42 have a general V-shape, also referred to herein as a chevron shape, with the apex 42b pointing in the opposite direction of rotation. When viewed axially, the pockets 42 have a general U-shape. Any suitable axial shape may be used. Any suitable radial shape may be used, including pockets extending straight from the first end 36d to the second end 36e. In the depicted configuration, the pockets 42 are configured to promote particle movement towards the axial center of the pockets 42. As the measuring rotor 36 rotates in the direction of arrow 126, the axial tilt of the chevron shape can cause particles to move towards the axial center, resulting in an even more even distribution across the axial width of the measuring rotor 36. Figures 17, 18, and 19 illustrate the axial profile of pockets 42 at the corresponding locations indicated in Figure 16. Figure 18 illustrates the profile of pockets 42 at apex 42b, the midpoint. At apex 42b, the angle of pockets 42 changes to the opposite, mirror-image angle without a sharp intersection. A radius can be formed at this intersection to create a non-sharp transition 42c. Figure 20 is an upstream view of the metering rotor 36, looking from the bottom through the second region 40. The discharge edge 22b is illustrated as generally extending axially with respect to axis 36a. As can be seen, the V-shaped or chevron-shaped pockets 42 result in the outermost portions 42d of the pockets 42 passing the discharge edge 22b first, before the apex 42b. With this configuration, only a small section of one of the parts of the peripheral surface 36c reaches the discharge edge 22b, providing less pulse than if each part forming the peripheral surface 36c were axially straight. As mentioned earlier, measuring element 36 is configured to control the flow rate of the jetting medium for particle jetting apparatus 2. By separating the flow rate control from the feed rotor, pulsation at lower flow rates can be avoided. When the feed rotor also controls the particle flow rate, its rotational speed must be reduced to deliver lower flow rates. At lower speeds, pulsation occurs due to the relative alignment of the feed rotor pockets. Even with the feed rotor pockets full, at lower feed rotor rotational speeds, the time between the presentation of each discharge opening increases, resulting in pulsation. In configurations where the measuring element 36 is present, the feed rotor 54 can rotate at a constant, typically high, speed, independent of the feed rate. At this constant high speed, the time between the presentation of each opening for discharge is constant for all feed rates. At low feed rates with the feed rotor 54 rotating at a constant high speed, the percentage of fill in each pocket will be smaller than at high feed rates, but pulsation will be reduced. By separating the flow control from the feed rotor, the feed rotor can be operated closer to its optimum speed (based, for example, on component designs and characteristics, such as motor profile, wear rate, etc.). In the configuration shown, the feed rotor 54 can be operated at a constant rotational speed for all feed rates, such as 75 RPM to 80 RPM. In the configuration shown, the pulverizer 28 can be operated at a constant rotational speed for all feed rates, such as 1500 RPM for each roller 44, 46. In the configuration shown, the metering rotor 36 can be operated at a variable rotational speed to control the particle flow rate. For optimal operation, the carrier gas flow must be adequate and consistent, providing the desired controllable flow and pressure. Although an external gas source, such as air, can provide the desired flow and pressure in a controllable manner, external sources are generally unreliable in this respect. Thus, for consistency and control, prior art particle jetting systems have included onboard pressure regulation connected to an external gas source, such as air. Prior art particle jetting systems have used a valve, such as a ball valve, as an on / off control for the incoming gas and regulated the downstream pressure.Prior art pressure regulation was achieved using an in-line pressure regulator in the flow line, with the desired pressure controlled by a fluid control signal, such as an air pressure signal from a pilot-controlled pressure regulator. At higher carrier gas flow rates, the in-line pressure regulator resulted in significant pressure losses. To compensate for this pressure loss at higher flow rates, oversized in-line pressure regulators or alternative unregulated carrier gas flow paths could be used, adding cost and complexity, and resulting in an undesirable increase in the overall weight and size of the design. With reference to Figure 21, the pressure regulator assembly 32 of the represented embodiment is shown. The pressure regulator 32 includes a flow control valve, generally indicated as 202. The flow control valve 202 comprises the actuator 204 and the ball valve 206. The ball valve 206 includes the inlet 208, which is connected to a source The transport gas source, and outlet 210, which is connected via appropriate connections to inlet 90 and can itself be considered a transport gas source. In the embodiment shown, connection T 212 is connected to inlet 208. Connection T 212 includes inlet 212a, which is connected to a transport gas source (not shown) that, in the embodiment shown, is not pressure regulated. Connection T includes outlet 212b, which is connected to another connection T 214, to which pressure sensor 216 is connected and detects the pressure within connection T 214. Outlet 214a is configured to provide pressure and flow to other components of the particle jet system 2. With reference to Figure 22, a cross-sectional top view of the actuator 204 is illustrated, with the ball valve 206 illustrated in diagram form. The actuator 204 is configured to be coupled with a controlled member, in the embodiment shown, the ball 218 (see Figure 25), to move the controlled member between and including a first controlled position and a second controlled position. In the embodiment shown, when the ball 218 is in the second controlled position, the ball valve 206 is closed. The actuator 204 comprises the body 220, which defines the first internal chamber 222, which is generally cylindrical but can have any suitable shape. At one end, the end cap 224 is connected to the body 220, sealing the first inner chamber 222. At the other end, the body 226 is connected to the body 220, sealing the inner chamber 222. The body 220 may be of unit construction or of assembled parts.Body 220 and body 226 can be of unitary construction. Body 226 defines the second internal chamber 228. Piston 230 is arranged in the first inner chamber 222, sealingly associating with the side wall 222a. Within the first inner chamber 222, piston 230 forms chamber 232 on the first side 230a, and chamber 234 on the second side 230b. Piston 236 is arranged in the first inner chamber 222, sealingly associating with the side wall 222a. Within the first inner chamber 222, piston 236 forms chamber 238 on the first side 236a, and the second chamber 234 arranged on the second side 236b. Piston 230 is formed complementary to side wall 222a and includes extension 230c with teeth 230d. Piston 236 is formed complementary to side wall 222a and includes extension 236c with teeth 236d. Teeth 230d and teeth 236d engage pinion 240, which is rotatable about shaft 240a, which, in the embodiment shown, is aligned with shaft 218b of stem 218a. Pinion 240 is coupled, directly or indirectly, to stem 218a, which in turn is connected to ball 218. Rotation of pinion 240 causes simultaneous rotation of stem 218a and ball 218. Pinion 240 can rotate between and including a first and second position, which correspond to the first and second positions of ball 218—when pinion 240 is in its first position, ball 218 is in its second position. MA / a / ZUZZ / UlOlü / first position; when pinion 240 is in its second position, ball 218 is in its second position.Pistons 230 and 236 also move between and including first and second positions simultaneously due to their association with pinion 240. As pistons 230 and 236 move, they cause pinion 240 to rotate accordingly. In their respective second positions, pistons 230 and 236 are at their minimum separation from each other, causing pinion 240 and ball 218 to be in their respective second positions, thus closing ball valve 206. In their respective first positions, pistons 230 and 236 are at their maximum separation from each other, causing pinion 240 and ball 218 to be in their respective first positions. In the embodiment shown, ball valve 206 is a quarter-turn valve, and when ball 218 is in its first position, ball valve 206 is fully open.Although two pistons 230, 236 are illustrated, piston 236 could be omitted with piston 230 being appropriately sized. The ball valve 206 regulates the pressure of the carrier gas flow into inlet 90. With reference to the pneumatic circuit diagram in Figure 23, chambers 232 and 238 are in fluid communication with the flow passage downstream of ball 218, so the pressure inside chambers 232 and 238 is the same as the actual static pressure in the downstream passage 242. In Figure 22, this is illustrated diagrammatically by line 244, bypass valve 246, and line 248. Activating bypass valve 246 allows the user to set ball valve 206 to fully open, bypassing / disabling the regulating function of ball valve 206. Lines 244 and 248 can be configured in any suitable way. Chamber 234 is placed in fluid communication with a pressure control signal, which is either equal to or proportional to the desired downstream pressure. As shown diagrammatically in Figure 22, the actuator 204 includes port 250 in fluid communication with chamber 234, which is configured to be connected to a pressure control signal via line 252. As illustrated, the quick exhaust valve 254 can be the interposed port 250 and line 252, which allows for the rapid release of pressure within chamber 234 when desired, such as when ball valve 206 is being closed. The pressure of the pressure control signal can be adjusted by the operator. As shown in Figure 23, the pressure regulator 256 controls the pressure supplied to line 252 when control valve 258 is in the appropriate position.The position of the control valve 258 is controlled by the overpressure relief valve 260, which can be manually operated (8). The actuation of the overpressure relief valve 260 supplies regulated pressure flow from the regulator 262 to the control valve 258, causing it to move to the appropriate position so that the controlled pressure flows from the pressure regulator 256 into line 252. The inlet pressure to the pressure regulator 256 can be deregulated as shown in Figure 23; it can be seen that this inlet is regulated upstream by the regulator 264. During operation, the pressure inside chamber 234, controlled by the pressure control signal supplied through line 252, will move pistons 230 and 236 outward, causing ball valve 206 to open, increasing the pressure in downstream flow passage 242. As this pressure increases, the pressure inside chambers 232 and 238 will increase and act on pistons 230 and 236 against the pressure in chamber 234, moving pistons 230 and 236 inward and causing ball valve 206 to close, reducing the flow and pressure in downstream flow passage 242, which is the portion of the flow passage downstream of ball 218, including the portion of the ball within ball valve 206. Ball valve 206 will move to an equilibrium position where the force on pistons 230 and 236 of chambers 232 and 238 equals the force on pistons 230 and 236 of chamber 234.Changes in pressure in chambers 232 and 238, such as due to changes in upstream source pressure, or in chamber 234, such as due to a change by the operator, will result in the ball valve 206 moving to a new equilibrium position. As shown in Figure 22, the piston 266 is disposed in the second inner chamber 228, sealingly associating with the side wall 228a. Within the second inner chamber 228, the piston 266 forms chamber 268 on the first side 266a and chamber 290 (see Figure 24) on the second side 266b. The piston 266 is formed complementary to the side wall 228a and includes the extension 266c that extends through the bore 226a of the end wall 226b, into chamber 232. A pair of separate seals 270 disposed in annular grooves in the bore 266a seal between chamber 232 and 228 against the extension 266c. Vent 272 vents the area between seals 270 so that there will be a pressure difference across the seals for all seals so that they are effectively pressure-loaded in the seal grooves and prevent leakage. The end cap 274 is connected to the body 226, and includes the annular groove 276, which is complementaryly formed and aligned with the annular groove 278. The piston 266 moves between and including a first position in which the internal volume of the chamber 228 is at its maximum and a second position in which the internal volume of the chamber 228 is at its minimum, in which the extension 266c extends to its maximum distance within the chamber 232. The ends of springs 280 and 282 are arranged in annular grooves 276 and 278 and are configured to elastically deflect piston 266 to the second position. In Figure 22, with piston 266 in its first position, springs 280 and 282 are in their most compressed state, pushing the piston to the right to move it to its second position. Although two springs are shown, only one spring member is required to elastically push piston 266 to its second position.To hold the piston 266 in its first position, the chamber 268 can be selectively pressurized with sufficient pressure to overcome the force exerted by the springs 280 and 282. The body 226 includes the port 284 in fluid communication with the chamber 268. The connection 286 is arranged in the port 284, with the line 288 in fluid communication with the chamber 228 through the connection 284. The line 288 is connected to a source of pressurized fluid, such as air, so that the chamber 268 can be pressurized. As shown in Figure 23, the pressure in line 288 is controlled by the overpressure valve 260. The actuation of the overpressure valve 260 supplies pressure to line 288 and finally to chamber 268 so that the piston 266 is held in its first position, overcoming the force exerted by springs 280 and 282. In this position, the piston 230 has its full range of motion from its first position to its second position. With reference to Figures 22, 23 and 24, when the overpressure valve 260 is released, the pressure inside chamber 268 is vented through the overpressure valve 260 via line 288, allowing springs 280 and 282 to immediately move piston 266 from its first position (Figure 22) to its second position (Figure 24). As piston 266 moves from its first position to its second position, part of piston 266, the extension 266c, engages piston 230 and moves piston 230 to its second position, at which point ball valve 206 closes. Simultaneously, with the release of overpressure valve 260, the pressure to line 252 is interrupted, resulting in control valve 258 interrupting the pressurization of chamber 234. With the drop in pressure in chamber 234, quick exhaust valve 254 allows chamber 234 to vent as piston 230 moves along extension 266c. Figure 25 illustrates an exemplary ball valve used to explain one construction of the ball valve 206, so that Figure 25 is numbered accordingly. The ball valve 206 comprises the ball 218 having the stem 218a which is rotatable about the shaft 218b. The carrier gas flows through the ball valve 206 in the direction indicated by arrow 294. The flow passage 296 comprises the upstream flow passage 298, which is located upstream of the ball 218, and the downstream flow passage 242, which is located downstream of the ball 218. The ball 218 is controlled to move between and including a first position, in which the ball valve 206 is fully open with the ball passage 218c aligned with the flow passage 296, and a second position, in which the ball valve 206 is closed with the ball 218 completely blocking the flow passage 296 as illustrated in Figure 25. EXAMPLE 1 A feed assembly configured to transport a jet medium from a jet medium source into a carrier gas flow, the jet medium comprising a plurality of particles, the feed assembly comprising: a measuring element configured to: receive the jet medium from the jet medium source from a first region; and discharge the jet medium into a second region; and a feed rotor, configured to: receive, in a third region, the jet medium discharged by the measuring rotor; and discharge the jet medium into the carrier gas flow. EXAMPLE 2 The feed assembly of Example 1, comprising a sprayer disposed between the measuring element and the feed rotor, the sprayer is configured to receive the jet medium from the measuring element and to selectively reduce the size of a plurality of particles of each respective initial particle size to a second size that is smaller than a predetermined size. EXAMPLE 3 The feed assembly of example 1, wherein the measuring element comprises a rotor that is rotatable about an axis, the rotor comprising a plurality of pockets that open radially outwards. EXAMPLE 4 The feed assembly of example 3, wherein the plurality of pockets extends longitudinally in the axis direction. EXAMPLE 5 The feed assembly of example 3, wherein the rotor comprises a first end and a second end separated from each other along the shaft, and wherein a plurality of pockets extends from the first end to the second end. EXAMPLE 6 The feed assembly of example 3, wherein the rotor is rotatable about the axis in a rotational direction, wherein a plurality of the pockets have a chevron shape. EXAMPLE 7 The feed assembly of example 6, where the chevron shape points opposite to the direction of rotation. EXAMPLE 8 A pulverizer configured to selectively reduce the size of cryogenic particles from each respective initial particle size to a second size that is smaller than a predetermined size, the pulverizer comprising being adapted to be disposed between a metering portion and a feeding portion of a feeding assembly, the feeding assembly being configured to transport the cryogenic particles from a cryogenic particle source within a carrier gas flow, the metering portion being configured to receive cryogenic particles from a cryogenic particle source and to discharge the cryogenic particles to the pulverizer, the feeding portion being configured to receive cryogenic particles from the pulverizer and discharge the cryogenic particles within the carrier gas flow. EXAMPLE 9 The pulverizer of example 8, comprising: an inlet adapted to be arranged to receive cryogenic particles from the measuring portion; and an outlet adapted to be arranged to discharge cryogenic particles to the feeding portion. EXAMPLE 10 The sprayer in example 9, comprising a space arranged between the inlet and the outlet, the space is variable between a minimum space and a maximum space. EXAMPLE 11 The pulverizer of example 10, comprising: at least a first roller rotating about a first axis; at least a second roller rotating about a second axis, the space being defined by the at least a first roller and the at least a second roller; a support carrying the at least a second roller, the support being configured to be arranged in a plurality of positions between and including a first position in which the space is the minimum space and a second position in which the space is the maximum space. EXAMPLE 12 A pulverizer configured to selectively reduce the size of cryogenic particles from each respective initial particle size to a second size that is smaller than a predetermined size, the pulverizer comprising: at least one first roller rotating about a first axis, each of said at least one first roller comprising a respective first peripheral surface, each respective first peripheral surface collectively comprising a plurality of first raised flanges; at least one second roller rotating about a second axis, each of said at least one second roller comprising a respective second peripheral surface, each respective second peripheral surface collectively comprising a plurality of second raised flanges; a defined space between each respective first peripheral surface and each respective second peripheral surface;and a convergent region upstream of the space defined by the space, the at least one first roller and the at least one second roller, wherein the plurality of first raised flanges and the plurality of second raised flanges form a diamond pattern in the convergent region.; EXAMPLE 13 The pulverizer of example 12, wherein the at least one first roller comprises a roller A and a roller B, roller A comprises a peripheral surface A, roller B comprises a peripheral surface B, the first peripheral surface comprises peripheral surface A and peripheral surface B. ML / a / ZUZZ / U 1 0107 EXAMPLE 14 The pulverizer of example 13, wherein the at least a second roller comprises a roller C and a roller D, roller C comprises a peripheral surface C, roller D comprises a peripheral surface D, the second peripheral surface comprises peripheral surface C and peripheral surface D. EXAMPLE 15 The sprayer in example 13, wherein peripheral surface A is a mirror image of peripheral surface B. EXAMPLE 16 The sprayer of example 12 comprising a support that carries at least a second roller, the support being configured to be arranged in a plurality of positions between and including a first position in which the spacing is at its minimum and a second position in which the spacing is at its maximum. EXAMPLE 17 The sprayer in example 12, where the diamond pattern is a double diamond pattern. EXAMPLE 18 A particle jetting system comprising: a jetting medium source, the jetting medium comprising a plurality of cryogenic particles; a discharge nozzle for expelling the cryogenic particles from said particle jetting system; a particle flow path extending between the jetting medium source and the discharge nozzle, the particle flow path comprising a sprayer configured to selectively reduce the particle size of each respective initial particle size to a second size that is smaller than a predetermined size, the sprayer comprising: at least one first roller, each of said at least one first roller comprising a respective first peripheral surface, each respective first peripheral surface collectively comprising a plurality of first raised flanges;at least a second roller, each of said at least a second roller comprising a respective second peripheral surface, each respective second peripheral surface collectively comprising a plurality of second raised flanges; a space defined between each respective first peripheral surface and each respective second peripheral surface; and a converging region upstream of the space defined by the space, the at least a first roller and the at least a second roller, wherein the plurality of first raised flanges and the plurality of second raised flanges form a diamond pattern in the converging region. EXAMPLE 19 The particle jet system of example 18, wherein said particle flow path comprises a low-pressure portion and a high-pressure portion disposed downstream of the low-pressure portion, and the lower-pressure portion comprises the sprayer. EXAMPLE 20 The pulverizer of example 18, wherein the at least one first roller comprises a roller A and a roller B, roller A comprises a peripheral surface A, roller B comprises a peripheral surface B, the first peripheral surface comprises peripheral surface A and peripheral surface B. EXAMPLE 21 The sprayer of example 18 comprising a support that carries at least a second roller, the support being configured to be arranged in a plurality of positions between and including a first position in which the spacing is at its minimum and a second position in which the spacing is at its maximum. EXAMPLE 22 The sprayer in example 18, where the diamond pattern is a double diamond pattern. EXAMPLE 23 A feed assembly configured to carry a jet medium from a jet medium source within a carrier gas flow, the jet medium comprising a plurality of cryogenic particles, the feed assembly comprising: a particle flow path comprising a low-pressure portion and a high-pressure portion disposed downstream of the low-pressure portion; and the low-pressure portion comprising a sprayer configured to selectively reduce the cryogenic particle size from each respective initial particle size to a second size that is smaller than a predetermined size, the sprayer comprising: at least one first roller, each of said at least one first roller comprising a respective first peripheral surface, each respective first peripheral surface collectively comprising a plurality of first raised flanges;at least a second roller, each of said at least a second roller comprising a respective second peripheral surface, each respective second peripheral surface collectively comprising a plurality of second raised flanges; a space defined between each respective first peripheral surface and each respective second peripheral surface; and a converging region upstream of the space defined by the space, the at least a first roller and the at least a second roller, wherein the plurality of first raised flanges and the plurality of second raised flanges form a diamond pattern in the converging region. EXAMPLE 24 The pulverizer of example 23, wherein the at least one first roller comprises a roller A and a roller B, roller A comprises a peripheral surface A, roller B comprises a peripheral surface B, the first peripheral surface comprises peripheral surface A and peripheral surface B. EXAMPLE 25 The sprayer in example 23, where the diamond pattern is a double diamond pattern. EXAMPLE 26 A feed assembly configured to transport a jet medium from a jet medium source within a carrier gas flow, the jet medium comprising a plurality of particles, the feed assembly comprising: a sprayer configured to selectively reduce the cryogenic particle size of each respective initial particle size to a second size that is smaller than a predetermined size, the sprayer comprising: at least one first roller rotating about a first axis, each of said at least one first roller comprising a respective first peripheral surface; at least one second roller rotating about a second axis, each of said at least one second roller comprising a respective second peripheral surface;and a defined space between each respective first peripheral surface and each respective second peripheral surface, the space comprising a first edge extending along and adjacent to each respective first of the at least one first roller; a feed rotor rotating about a third axis, the feed rotor comprising: a circumferential surface; a plurality of pockets disposed on the circumferential surface, each of the plurality of pockets having a respective circumferential pocket width; a guide disposed between the space and the feed rotor is configured to receive particles from the space and guide the particles into the plurality of pockets as the feed rotor rotates, the guide comprising: a sweep edge disposed adjacent to the circumferential surface, the sweep edge being generally oriented parallel to the third axis;a sweep region that extends circumferentially away from the sweep edge, the sweep region is arranged in alignment with the first edge.; EXAMPLE 27 The feed assembly of example 26, wherein the sweep region extends circumferentially away from the sweep edges a distance approximately equal to one of the respective circumferential pocket widths. EXAMPLE 28 A feed assembly configured to transport a jet medium from a jet medium source within a carrier gas flow, the jet medium comprising a plurality of particles, the feed assembly comprising: a measuring element comprising: a first surface; and at least one cavity comprising a respective opening in the first surface, the measuring element being configured to cyclically arrange each of the at least one cavity in a first position to receive particles within the at least one cavity and in a second position to discharge the particles, the respective opening moving in a displacement direction when moving between the first position and the second position;and a guide disposed adjacent to the measuring element, the guide being configured to guide the particles within each respective opening in the first position, the guide comprising: a sweeping edge disposed adjacent to the first surface, the sweeping edge being configured to sweep across each respective opening as each of the at least one cavity moves from the first position to the second position, the sweeping edge being disposed at a sweep angle that is configured not to result in a holding line between the sweeping edge and the measuring element. EXAMPLE 29 The feed assembly of example 28, where the sweep angle is at least around 90°. EXAMPLE 30 A metering rotor adapted for use with a feed assembly, the feed assembly being configured to carry a jet medium from a jet medium source within a carrier gas flow, the metering rotor comprising: a first end; a second end separated from the first end along an axis; a plurality of pockets extending from the first end to the second end and opening radially outwards. EXAMPLE 31 The feed assembly of example 30, wherein a plurality of the plurality of pockets has a chevron shape. EXAMPLE 32 A roller adapted for use as one of at least a first roller of a pulverizer, the pulverizer being configured to selectively reduce the size of cryogenic particles from each respective initial particle size to a second size that is smaller than a predetermined size, the pulverizer comprising: at least a first roller; at least a second roller, each of said at least a second roller comprising a respective second peripheral surface, each respective second peripheral surface collectively comprising a plurality of raised second flanges; a space defined between the at least a first roller and the at least a second roller; a convergent region upstream of the space defined by the space, the at least a first roller and the at least a second roller;and a downstream outlet side of the space defined by the space, the at least one first roller and the at least one second roller, the roller comprising a peripheral surface comprising a plurality of first raised flanges which, when the roller is used as the at least one of the at least one first roller, forms part of a diamond pattern in the converging region in cooperation with the plurality of second raised flanges, the diamond pattern extending from the space.; EXAMPLE 33 An actuator configured to engage with a controlled member to move the controlled member between and including a first controlled position and a second controlled position, the actuator comprising: a body defining a first inner chamber, the first inner chamber comprising a first side wall; a first piston comprising a first side and a second side, the first piston being disposed in the first inner chamber and moving between and including a first position and a second position, the first piston sealingly associating with the first side wall thereby forming a first chamber on the first side of the first piston and a second chamber on the second side of the first piston; a second inner chamber, the second inner chamber comprising a second side wall;a second piston comprising a first side and a second side, the second piston being disposed in the second inner chamber and moving between and including a third position and a fourth position, the second piston sealingly associating with the second side wall thereby forming a third chamber on the first side of the second piston and a fourth chamber on the second side of the second piston, the second piston being configured not to associate with the first piston when the second piston is disposed in the third position, the second piston being configured to: associate the first piston with a portion of the second piston; and move the first piston to the second position as the second piston moves from the third position to the fourth position; and at least one elastic member disposed in the fourth chamber and elastically push the second piston towards the fourth position. EXAMPLE 34 The actuator of example 33, comprising a valve, the valve comprising the controlled member, wherein the first piston is connected to the valve. EXAMPLE 35 The actuator of example 34, wherein the valve comprises a rotating member and a stem connected to the rotating member, wherein the first piston is connected to the stem. EXAMPLE 36 The actuator of example 34, comprising a third piston comprising a first side and a second side, the third piston is disposed in the first inner chamber and moves between and including a fifth and a sixth position, the third piston sealably associates the first side wall thereby forming a fifth chamber on the first side of the third piston, the second chamber is disposed on the second side of the third piston, wherein the third piston is connected to the valve. EXAMPLE 37 The actuator of example 33, comprising a third piston comprising a first side and a second side, the third piston is arranged in the first inner chamber and moves between and including a fifth and a sixth position, the third piston sealably associates the first side wall thereby forming a fifth chamber on the first side of the third piston, the second chamber being arranged on the second side of the third piston. EXAMPLE 38 The actuator of example 33, comprising a first port in fluid communication with the second chamber, the first port is configured to be connected to a fluid control signal. EXAMPLE 39 The actuator of example 33, comprising a first port in fluid communication with the second chamber, and a quick exhaust valve in fluid communication with the first port, the quick exhaust valve is configured to be connected to a fluid control signal. EXAMPLE 40 A fluid control valve comprising: a flow passage; a rotating member disposed in the flow passage dividing the flow passage into an upstream flow passage and a downstream flow passage, the rotating member moving between and including a first and a second position, the flow passage being closed when the rotating member is disposed in the first position; a stem connected to the rotating member; an actuator comprising: a body defining a first inner chamber, the first inner chamber comprising a first side wall;a first piston comprising a first side and a second side, the first piston being disposed in the first inner chamber and movable between and including a first position and a second position, the first piston sealingly associating the first side wall thereby forming a first chamber on the first side of the first piston and a second chamber on the second side of the first piston, the first piston being operatively connected to the rod and configured to rotate the rod such that when the first piston is disposed in its first position the rotating member is disposed in its first position and when the first piston is disposed in its second position the rotating member is disposed in its second position; a second inner chamber, the second inner chamber comprising a second side wall;a second piston comprising a first side and a second side, the second piston being disposed in the second inner chamber and moving between and including a third position and a fourth position, the second piston sealingly associating with the second side wall thereby forming a third chamber on the first side of the second piston and a fourth chamber on the second side of the second piston, the second piston being configured not to associate with the first piston when the second piston is disposed in the third position, the second piston being configured to associate with the first piston with a portion of the second piston; and to move the first piston to the second position as the second piston moves from the third position to the fourth position; and an elastic member disposed in the fourth chamber and elastically pushing the second piston towards the fourth position. EXAMPLE 41 The fluid control valve of example 40, wherein the first chamber is in fluid communication with the downstream flow passage. EXAMPLE 42 A method of entraining a plurality of particles from a jet medium into a carrier gas flow comprising the steps of: controlling, at a first location, the flow rate of particles from a particle source, optionally using a measuring element; and entraining the particles into the carrier gas flow at a second location using a feed rotor. EXAMPLE 43 A method for entraining a plurality of jet medium particles in a carrier gas flow comprising the steps of: controlling, at a first location, the flow rate of particles from a particle source, optionally using a measuring element; spraying, at a second location downstream of the first location, a plurality of particles of each respective initial particle size to a second size smaller than a predetermined size; and entraining, at a third location downstream of the second location, the particles into the carrier gas flow at a third location using a feed rotor. The foregoing description of one or more embodiments of the innovation has been presented for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the invention to the precise form described. Obvious modifications or variations are possible in light of prior learning. The embodiment was chosen and described to best illustrate the principles of the innovation and its practical application, thereby enabling a person skilled in the art to make better use of the innovation in various embodiments and with various modifications as suited to the particular intended use. Although only a limited number of embodiments of the innovation are explained in detail, it should be understood that the innovation is not limited in its scope to the details of the construction and arrangement of the components set forth in the foregoing description or illustrated in the drawings. The innovation is capable of other embodiments and can be practiced or carried out in various ways.Specific terminology was also used for clarity. It should be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. The scope of the invention is intended to be defined by the claims presented herein.

Claims

1. An actuator configured to engage with a controlled member to move the controlled member between and including a first controlled position and a second controlled position, the actuator comprising: a. a body defining a first inner chamber, the first inner chamber comprising a first side wall; b. a first piston comprising a first side and a second side, the first piston being disposed in the first inner chamber and moving between and including a first position and a second position, the first piston sealingly associating with the first side wall thereby forming a first chamber on the first side of the first piston and a second chamber on the second side of the first piston; c. a second inner chamber, the second inner chamber comprising a second side wall; d.a second piston comprising a first side and a second side, the second piston being disposed in the second inner chamber and moving between and including a third position and a fourth position, the second piston sealingly associating with the second side wall thereby forming a third chamber on the first side of the second piston and a fourth chamber on the second side of the second piston, the second piston being configured not to associate with the first piston when the second piston is disposed in the third position, the second piston being configured to move the first piston to the second position as the second piston moves from the third position to the fourth position; and e. at least one elastic member disposed in the fourth chamber and elastically pushing the second piston towards the fourth position.

2. The actuator according to claim 1, further characterized in that it comprises the second piston configured to associate the first piston as the second piston moves from the third position to the fourth position.

3. The actuator according to claim 1, further characterized in that it comprises a valve, the valve comprising the controlled member, wherein the first piston is connected to the valve.

4. The actuator according to claim 3, further characterized in that the valve comprises a rotating member and a stem connected to the rotating member, wherein the first piston is connected to the stem.

5. The actuator according to claim 3, further characterized in that it comprises a third piston comprising a first side and a second side, the third piston being disposed in the first inner chamber and moving between and including a fifth and a sixth position, the third piston sealingly associating the first side wall thereby forming a fifth chamber on the first side of the third piston, the second chamber being disposed on the second side of the third piston, wherein the third piston is connected to the valve.

6. The actuator according to claim 1, further characterized in that it comprises a third piston comprising a first side and a second side, the third piston being disposed in the first inner chamber and moving between and including a fifth and a sixth position, the third piston sealingly associates the first side wall thereby forming a fifth chamber on the first side of the third piston, the second chamber being disposed on the second side of the third piston.

7. The actuator according to claim 1, further characterized in that it comprises a first port in fluid communication with the second chamber, the first port being configured to be connected to a fluid control signal.

8. The actuator according to claim 1, further characterized in that it comprises a first port in fluid communication with the second chamber, and a quick exhaust valve in fluid communication with the first port, the quick exhaust valve being configured to be connected to a fluid control signal.

9. A fluid control valve comprising: a. a flow passage; b. a rotating member disposed in the flow passage dividing the flow passage into an upstream flow passage and a downstream flow passage, the rotating member moving between and including a first and a second position, the flow passage being closed when the rotating member is disposed in the first position; a stem connected to the rotating member; c. an actuator comprising: i. a body defining a first inner chamber, the first inner chamber comprising a first sidewall; i.a first piston comprising a first side and a second side, the first piston being disposed in the first inner chamber and movable between and including a first position and a second position, the first piston sealingly associates the first side wall thereby forming a first chamber on the first side of the first piston and a second chamber on the second side of the first piston, the first piston being operatively connected to the rod and configured to rotate the rod such that when the first piston is disposed in its first position the rotating member is disposed in its first position and when the first piston is disposed in its second position the rotating member is disposed in its second position; iii. a second inner chamber, the second inner chamber comprising a second side wall; iv.a second piston comprising a first side and a second side, the second piston being disposed in the second inner chamber and moving between and including a third position and a fourth position, the second piston sealingly associating with the second side wall thereby forming a third chamber on the first side of the second piston and a fourth chamber on the second side of the second piston, the second piston being configured not to associate with the first piston when the second piston is disposed in the third position, the second piston being configured to move the first piston to the second position as the second piston moves from the third position to the fourth position; and v. an elastic member disposed in the fourth chamber and elastically pushing the second piston towards the fourth position.

10. The fluid control valve according to claim 9, further characterized in that it comprises the second piston configured to associate the first piston as the second piston moves from the third position to the fourth position.

11. The fluid control valve according to claim 9, further characterized in that it comprises a third piston comprising a first side and a second side, the third piston being disposed in the first inner chamber and moving between and including a fifth and a sixth position, the third piston sealingly associating the first side wall thereby forming a fifth chamber on the first side of the third piston, the second chamber being disposed on the second side of the third piston, wherein the third piston is operatively connected to the stem.

12. The fluid control valve according to claim 9, further characterized in that it comprises a first port in fluid communication with the second chamber, the first port being configured to be connected to a fluid control signal.

13. The fluid control valve according to claim 9, further characterized in that it comprises a first port in fluid communication with the second chamber, and a quick exhaust valve in fluid communication with the first port, the quick exhaust valve being configured to be connected to a fluid control signal.

14. The fluid control valve according to claim 9, further characterized in that the first chamber is in fluid communication with the downstream flow passage.