Reduced noise pressure milling apparatus

Abstract

A milling apparatus which uses air pressure zones to pulverize material into smaller components while still being easy to clean and maintenance. The pressure zones are created by a lobe-lined chamber defined within a housing containing rotating plates affixed with vanes (known as rotor assemblies). When material is fed into the chamber through an inlet, the rotation of the vanes pushes material from high-pressure zones to low pressure zones causing the product to pulverize into smaller components before exiting the chamber through an outlet. The noise emitted by the apparatus is reduced relative to prior art pressure mills by rotationally offsetting the rotating assemblies, covering, shielding, or enclosing the apparatus in sound-absorbent material, and / or by turning the mill into a "closed system" by supplying airflow to the apparatus via desiccator blowers.

Description

REDUCED NOISE PRESSURE MILLING APPARATUSPRIORITY

[0001] This application claims priority to U.S. provisional application serial no. 63 / 520,130, filed August 17, 2023, the entire contents of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This invention pertains to an apparatus for milling or grinding matter into particles and powders and methods of using the apparatus.BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEMS POSED BY THE PRIOR ART

[0003] In the field of material processing, it is often necessary to reduce raw materials (hereafter referred to as “material”), organic or inorganic, to a powder or granular form for use and consumption. The most common form of this grinding process is contact grinding, where the substance being milled is subjected to high amounts of friction or impact force by a hard substance, usually metallic, rock, or ceramic, which smashes the material apart into smaller particle components. Contact grinding, however, is often accompanied with numerous negative side-effects and downsides like product inefficiencies and microbial contamination. The use of a pressure mill addresses these disadvantages of contact milling by using air pressure and shockwaves to pulverize the material being processed. This pneumatic system kills bacteria and reduces production- related milling inefficiencies.

[0004] The noise produced by this pulverization, however, can sometimes make prior art pressure mills difficult and dangerous to operate. Current Occupational Safetyand Health Administration (OSHA) safety standards dictate that workers can safely endure only 90 dBA per eight-hour workday. When prior art pressure mills run, however, the resulting mill shockwaves can exceed a loudness of 130 decibels, making pressure mills of the prior art unsafe for prolonged worker usage.

[0005] The inventors of the present invention have discovered how to provide an improved milling apparatus and method which not only dramatically decreases the noise produced by an operating pressure mill, but also, surprisingly and unexpectedly, improves the ability of the mill to produce low-moisture pulverized final product. These improvements include novel, advantageous features not heretofore taught or contemplated by the prior art, and which can accommodate designs having one or more of the above-discussed benefits or features.SUMMARY OF THE INVENTION

[0006] According to broad aspects of one form of the present invention, the claimed invention is an improved pressure mill apparatus for pulverizing wet or dry material into relatively smaller components, wherein the apparatus is relatively quieter than prior art pressure mills which does not emit as much noise as prior art pressure mills.

[0007] The apparatus defines an enclosed chamber, wherein the chamber has at least one inlet through which material may enter the chamber and at least one outlet through which material may exit the chamber. The interior of the chamber is circumferentially arrayed with at least one lobe that extends inward from the chamber walls toward the center of the chamber. The apparatus includes a rotor shaft crossing from one side of the chamber to the other side and at least one rotor assembly coupled to the rotor shaft, wherein each rotor assembly includes a plate which has a series of vanes which extend across the plates and terminate in at least one vane tip. Each plate has a series of vanes which extend across the plate, and each vane terminates in a vane tip that is located adjacent to the lobe of the chamber wall. The apparatus includes a motor operatively connected to the rotor shaft and adapted to spin the rotor assembly.

[0008] In one preferred form of the present invention, the apparatus reduces the noise emitted by making the pressure mill into a “closed-system” that does not directly pull air directly from the external environment of the mill. Instead, air is fed into the mill inlet via a first fan, blower, or desiccator drier, and then optionally sucked out of the mill outlet via a second fan, blower, or desiccator drier. The claimed invention can be fed new material for pulverization via an airlock valve that lies between the first fan, blower, or drier and the mill inlet. The use of the airlock valve allows the pressure mill to operate without ever directly “opening” into the external environment of the mill. This lack of a direct opening to the mill environment prevents, or at least minimizes, a significant amount of noise from leaving the mill interior and emitting out into the mill environment. In some forms of the present invention, the valve is selected from the group consisting of: an airlock valve; a butterfly valve; a rotary valve; a ball valve; a door valve; a linear valve; a self-actuated valve; a plug valve; a globe valve; a gate valve, needle valve; a solenoid valve; a coaxial valve; and an angle seat valve. Further, the means of externally creating airflow is at least one of: a fan; a jet; a pump; a blower; a drier; a pressurized air system; a desiccator blower or a desiccator dryer; and said means is attached, directly or indirectly, to at least one of the inlet or the outlet. Preferably, the at least one of inlet is connected with a pipe, wherein the pipe is connected to both the means of creating airflow and to a valve that permits material to be fed into the apparatus.

[0009] In another preferred form of the present invention, the apparatus rotor plates are attached to the rotator shaft at a rotational offset. This angular change, surprisingly and unexpectedly, substantially reduces the vibrational resonance produced by the mill’s operation and increases the ability of the mill to produce finer pulverized particulate. Preferably, the offset of the rotor assemblies is between five degrees and forty-five degrees, and more preferably about 20 degrees.

[0010] According to another preferred form of the present invention, the apparatus is partially or wholly covered with sound-absorbing panels or covers. These panels or covers can be made out of any substance which absorbs sound and will therefore limit the amount of noise the mill emits into its environment. Examples of materials from which the panels or covers can be made include, but are not limited to, acoustic foam, fiberglass, acoustic fabric, acoustic glass, aerated plaster, cellulose, acoustic-to-thermal conversionmembranes, acoustic isolation membranes, open cell cavity insulation, and / or resonance absorbers.

[0011] According to another aspect of the present invention, the housing contains more than one chamber, wherein each chamber has an opening into the next consecutive chamber, and wherein each consecutive chamber contains at least one rotor assembly that is rotationally offset from a rotor assembly in an adjacent chamber. Preferably, each chamber in the housing has more than one rotor assembly, and the rotor assemblies are rotationally offset relative to one another.

[0012] It should be appreciated that the invention may include any or all of the above-described features, include only one of the above-described features, more than one of the above-described features, and any combination of the above-described features. Furthermore, other objects, features, and advantages of the invention will become apparent from a review of the entire specification including the appended claims and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the accompanying drawings forming part of the specification, in which like numerals are employed to designate like parts throughout the same,

[0014] FIG. 1 is an isometric view, taken from above and rear, of an embodiment of a milling apparatus according to the present invention, and FIG. 1 shows the air flow means in the form of a pair of blowers located at the front and the rear of the milling apparatus;

[0015] FIG. 2 is a rearelevation view ofjust the milling apparatus of FIG. 1 whereby certain associated piping has been omitted for better visibility of the internal components, and FIG. 2 shows the milling apparatus in a partially open position showing the offset of the rotor assemblies;

[0016] FIG. 3 is an isometric view, taken from above and rear, of just the milling apparatus of FIG. 2, and FIG. 3 shows the milling apparatus in a non-operative, partially open position showing the offset of the rotor assemblies;

[0017] FIG. 4 is an isometric view, taken from above and rear, of just the milling apparatus of FIG. 2, and FIG. 4 shows the milling apparatus in a non-operative, fully open position;

[0018] FIG. 5 is an enlarged, fragmentary, front elevation view of the tip portions of the offset rotor assemblies of FIG. 2; and

[0019] FIG. 6 is an isometric view, taken from above and rear, of just the milling apparatus of FIG. 1 , and FIG. 6 shows the milling apparatus in an operative position or configuration and covered with a sound absorbing material in the form of an enclosure surrounding the housing.DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The claimed apparatus is an improved pressure mill (hereafter referred to as an “easy-clean” mill) that emits less noise to its surroundings than pressure mills that exist in the prior art. An exemplary embodiment of the pressure mill or apparatus of the inventing is designated with numeral 40 and is illustrated in FIGS. 1 -6.

[0021] The pressure mill 40 is an apparatus that uses air pressure to pulverize material into smaller pieces by moving the material between high- and low-pressure areas inside a chamber. The mill 40 includes the following six basic or central components: a housing 44 comprised of separable parts which collectively define an internal cavity or enclosed chamber 45, an inlet 48 at the front of the housing 44, an outlet 50 at the rear of the housing 44, at least one lobe 54 on the interior circumference of the chamber (though more than one lobe 54 is preferable), at least one rotor plate 60 with vanes or vane blades 64 (collectively known as a rotor assembly 74) affixed to a rotor shaft 70 that runs through the center of the chamber 45 of the housing 44, and a motor 80 to turn the rotor assembly 74 relative to the lobes 54.

[0022] The housing 44 preferably is comprised of pieces or parts that are stacked or assembled to enclose the mill 40. The space between housing parts can have seals which are used to help keep the pressure mill chamber wall airtight or watertight. Thepressure mill functions when the rotor assembly 74 is spun at about 2,500 to about 15,000 RPM, which creates a relatively high-pressure zone in front of the rotor plate assembly 74 near the inlet 48 and a relatively low-pressure zone behind the rotor assembly 74 near the outlet 50. The motor 80 which turns the rotor plate assembly 74 can vary the rotational speed of the assembly 74 to match the desired RPM of the mill operator. The rotor vanes 64 of the rotor assembly 74 should extend from the center of the rotor assembly plate 60 radially towards the edge of the assembly 74. The vanes 64 may extend in a straight line (not illustrated) or in a spiraling design, the choice of which affects efficiency depending on the material being pulverized. The vanes 64 should terminate at the radial edge or end of the plate, though in other embodiments of this invention the vanes terminate near the end of the plate 60 or hang off the end of the edge of the plate 60.

[0023] When raw material is placed into the pressure mill 40, the difference between the mill pressure zones creates a suction effect that pulls air in from the mill inlet 48 and pushes it out through the mill outlet 50. This movement of air pulls material from the front to the rear of the mill 40. As material is pulled by the suction effect from the front to the rear of the mill 40, the rotor plate vanes 64 redirect the material flow out to the walls of the chamber 45 defined within the housing 44. This redirection forces the material being processed to flow and circle around the inner surface of the walls of the chamber 45 while simultaneously being drawn towards the rear of the mill 40 by the pressure zone suction. The flow of air from the front of the mill 40 to the back of the mill 40 is measured in cubic feet per minute (CFM), and can be varied to change the properties of the final pulverized product exiting the mill 40.

[0024] As the vanes 64 and the airflow move the material around the perimeter of the chamber 45, the material regularly encounters lobes 54 extending from or embedded in the inner surface of the housing chamber 45. These lobes 54 protrude internally from the walls of the housing 44 such that the top point of each lobe is at a height adjacent (but not touching) to the circumference of the tips of the rotating vanes 64 or the rotor assembly plate 60, whichever is further from the center of the chamber 45 (as defined by the central axis “X” of the rotor shaft 70). Conversely, the base of the lobes (which is the surface of the chamber wall itself) should be at a relatively large distance from the edge of the vane tips.

[0025] The lobes 54 should be sufficiently high so that the top point of each lobe 54 is greater or equal to one one-thousandth of an inch from the tip of the rotating vanes 64 or circumference of the rotating assembly plate 60, but not so low that the top point of the lobe 54 is greater than one inch from the circumference of the rotating vanes 64 or rotating assembly plate 60. Should the lobes 54 fall outside these height limitations, the mill will not pulverize material efficiently.

[0026] Similarly, the base of the lobes 54 (which are at the inner surface diameter of the walls of the chamber) should be at such a distance from the center of the chamber 45 that the base is greater than, or equal to, one quarter of an inch from the tip of the circumference defined by the rotating vanes 64 or the circumference of the rotating assembly plate 60, but not so low that they are greater than fifteen inches from the tip of the circumference defined by the rotating vanes 64 or the circumference of the rotating assembly plate 60.

[0027] The lobes 54 of the mill should have a height between one quarter of an inch and fifteen inches from the base of the lobe 54 (the interior surface of the wall of the housing that defines the chamber) to the topmost point of the lobe 54. This lobe height should be selected such that the top of each lobe 54 is within a distance of greater or equal to one one-thousandth of an inch to one inch from the tips of the circumference of the rotating vanes 64 or circumference defined by the rotating plate 60 of the assembly 74.

[0028] The lobes 54 serve a twofold purpose. First, the narrow distance between the lobe 54 and the vane tips 64 creates a shockwave whenever a vane 64 passes the lobe 54. As material circles the walls of the chamber 45 and enters this space between the lobes 54 and rotor assembly 74, the resulting shockwaves pulverize the material into relatively smaller pieces.

[0029] Second, the angled shape of the lobe 54 redirects the material being pulverized back towards the center of the mill 40 (radially toward or proximate to axis “X”). This redirection forces the material back into the vanes 64, which redistributes the material back onto the surface of the chamber walls to be pulverized again by more shockwaves at the lobes 54.

[0030] Eventually, after being pulverized numerous times, the material reaches a fine enough pulverized condition that the suction effect of the mill 40 is sufficient to drag the material beyond the rotor assembly 74 towards the back of the mill 40. Upon reaching the back of the chamber 45, the suction effect of the mill 40 pushes the pulverized material out of the rear outlet of the housing 44. This ejected material can then be optionally introduced to subsequent pressure mill chambers for further pulverization.

[0031] Importantly, while the illustrated embodiment of the present invention depict a single chamber 45, it will be understood that there is no limit to the number of pressure mill chambers 45 that can be used successively, as each chamber adds to the suction effect of the previous chamber and increases the consistency of the granulate size of the final output of the mill 40.

[0032] In the preferred illustrated embodiment of the claimed invention, the apparatus or mill 40 includes first and second rotor assemblies 74. Both rotor assemblies 74 are positioned parallel to each other and may be placed within the same mill chamber 45, or within separate successive mill chambers 45. The two assemblies 74 are attached to the same rotator shaft 70, which serves as the same rotational axis “X” for both assemblies 74.

[0033] The first rotor assembly 74 is attached to the rotator shaft 70 at a first fixed orientation relative to the rotator shaft 70. This first rotor 74 assembly orientation is here- forth referred to as the “rotational zero point” of the apparatus 40. The second rotor assembly 74 is affixed to the same rotator shaft 70 at an offset rotational angle to the first rotor assembly rotational zero point. The rotational difference between the two assemblies 74 causes at least one of the second assembly vane tips 64 to be positioned at a rotational offset from the first assembly vane tips 64 as best seen in FIG. 5.

[0034] The rotational offset of the second rotor assembly 74 may be in either the clockwise or counterclockwise direction from the rotational zero point of the first rotor assembly 74, and the offset should lie within a rotational angle between about 5 and about 45 degrees. In the preferred embodiment of the claimed invention, a rotational offset of about 20 degrees (+ / - 5 degrees) has been determined to be optimal.

[0035] The rotational offset of the assemblies 74 offers surprising and unexpected benefits to the apparatus 40. The first of these benefits is that offsetting the assemblies 74 substantially lowers the vibrational resonance produced by the shockwaves developed in the operating mill 40. This decreased resonance lowers the vibrations of the mill 40 during pulverization. The inventors of the claimed invention have demonstrated through experimentation that this reduced resonance vibration decreases the noise produced by the mill 40 by approximately 10 db. This reduced noise emission makes the claimed invention far safer for users of the mill 40, and helps the mill 40 comply with OSHA safety standards. Furthermore, the reduced vibrations increase the longevity of the pressure mill 40 because the reduced vibrations do not wear the bearings of the mill 40 as rapidly as pressure mills of the prior art.

[0036] The second unexpected benefit of offsetting the rotor assemblies 74 is that the offset significantly increases the efficiency and consistency of the pulverization process of the pressure mill 40. When the rotor assemblies 74 are offset by 20 degrees from the zero point, the claimed invention is able to produce pulverized materials that have up to eighteen times less moisture than pressure mills of the prior art (which have all rotor assemblies aligned at the rotational zero point). Similarly, offsetting the rotor assemblies 74 decreases the time needed to mill material and improves the consistency of pulverized particulate size.

[0037] The rotational offset of rotor assemblies 74 is not limited to pressure mills with only two rotor assemblies 74. Any number of assemblies 74 may be attached to the same rotor shaft 70 in the claimed invention, so long as at least two of the assemblies 74 are rotationally offset from each other. However, a claimed apparatus with more than two rotor assemblies 74 will function more efficiently when each rotor assembly 74 is rotationally offset relative to its neighboring rotor assembly or assemblies 74.

[0038] In another advantageous embodiment of the claimed invention, illustrated in FIG. 6, the apparatus is a pressure mill 40 covered, shielded, or enclosed in soundabsorbing material 120 that reduces the amount of noise the apparatus emits into surrounding environment of the mill 40. These covers, shields or enclosures 120 can be affixed to the outside of the apparatus, or can be placed adjacent to the mill 40. The mill40 can either be partially or wholly enclosed by the sound-absorbing material 120, depending upon how many decibels the user wishes to eliminate. Similarly, the thickness of the sound-absorbing material 120 may be increased to further reduce the sound radiating from the pressure mill 40.

[0039] Alternatively, the room in which the mill 40 is operated can be lined with sound-absorbing material 120, or the mill 40 can be shrouded or surrounded with soundabsorbing curtains, boxes, panels, or other structures that contain sound-absorbing materials.

[0040] The substance which causes the absorbent material 120 to block sound may be any substance which is known in the field of acoustics to reduce the decibel loudness of noise. Examples of these noise reducing materials include, but are not limited to, acoustic foam, fiberglass, acoustic fabric, acoustic glass, aerated plaster, cellulose, acoustic-to-thermal conversion membranes, acoustic isolation membranes, open cell cavity insulation, and / or resonance absorbers.

[0041] In yet another broad aspect of the preferred embodiment of the claimed invention, the pressure mill 40 remains a “closed-system” while in operation. For the purposes of this disclosure, a “closed-system” is a pressure mill that has no direct openings (like inlets and outlets) out into the surrounding environment of the mill while the mill is in operation. Similarly, for the purposes of this disclosure, an “open-system” is a pressure mill that has direct openings (like inlets and outlets) to the surrounding environment of the mill while the mill is in operation. The existence of funnels or spouts on inlets or outlets does not change a system from “open” to “closed” because such funnels or spouts each directly open out into the surrounding environment of the mill, thereby creating a direct path from the interior chamber of the mill to the surrounding environment of the mill and preserving the open-status of the prior art milling system. Closed-system mills are more desirable than open-system mills because closed-system pressure mills have no openings from which noise may emit into the pressure mill environment. As a result, closed-system pressure mills are quieter and safer for mill users to operate.

[0042] Pressure mills of the prior art have been, by necessity, open-systems. The reason for this open-system necessity was two-fold. First, pressure mills need an open inlet to allow material to be fed into the mill, and an open outlet to expel pulverized particulate from the mill. These inlets and outlets for material insertion and expulsion were therefore open to the prior art mill’s surrounding environment, creating, by definition, open-system pressure mills.

[0043] The second reason prior art pressure mills were open-system is because pressure mills, by necessity, need a constant flow of air through the mill to function. Without the flow of air, material in the pressure mill does not circulate properly, and the mill struggles to pulverize the material into particulate. In prior art pressure mills, the operation of the mill was the sole source of this flow of air. As the rotor assembly rotates, it creates a suction effect that pulls air in through the inlet, and expels air out through the mill outlet. However, if either the inlet or the outlet on prior art pressure mills are covered or closed, then the pressure mill airflow ceases, and the mill therefore ceases pulverizing material effectively. Because this airflow originates from inside the pressure mill, this type of airflow will here forth be referred to as “internal airflow.”

[0044] The inability to cover or close prior art pressure mill inlets and outlets while maintaining the mill functionality has long prevented the milling industry from making pressure mills of the prior art into closed-systems, because covering or closing the inlets or outlets of a mill causes the mill to stop functioning effectively due to the resulting lack of airflow. As stated previously, a significant downside of open pressure mill systems is that the direct-to-environment openings inherent in an open-system mill provide a direct channel for noise to emit from the pressure mill. This open emission of noise out of prior art pressure mill inlets and outlets meant that prior art pressure mills were unavoidably noisy due to their inherent open-system nature.

[0045] The preferred embodiment of the mill 40 of the present invention solves this open-system noise problem by making a pressure mill 40 with a closed-system that supplies the necessary flow of air from an external source or means that is separate from the essential or central components of the mill 40 (which will be referred to hereinafter as an “external airflow”). The apparatus 40 achieves this result by attaching branching orjunction pipes 90 to both the inlet 48 and the outlet 50 of the pressure mill 40. Each junction pipe 90 has a first end attached to the mill inlet 48 or outlet 50, a second end linearly opposite the first end, and a third end transverse (i.e., angled) to the first and second ends. The second end of the inlet pipe is operatively connected or attached to an airflow means or blower 100, which supplies airflow to the pressure mill, while the transverse third end of the inlet junction pipe 90 terminates in an airlock valve 110. More than one blower 100 may be used to supply air to the inlet 48 if the pressure mill user desires more airflow.

[0046] Conversely, the outlet junction pipe 90 connects to a storage container (not illustrated) located on the opposite second end of the outlet junction pipe 90 that receives the pulverized material produced within the housing 44 of the mill 40, while the transverse third end of the outlet junction pipe 90 terminates in a blower 100 that sucks air from the pressure mill 40. More than one blower 100 may be used to suck air from the outlet 50 if the pressure mill user desires more airflow. Other alternatives to the storage container include, but are not limited to an air filter, air filter receiver, air filter separator, filter receiver, bag house, dust cyclone, dust collection equipment, storage bags, filter bags, and / or packaging machines.

[0047] Collectively, the inlet and outlet blowers 100 supply airflow to the pressure mill 40, thereby preserving the function of the mill 40. Simultaneously, the airlock valve 110 and blowers 100 elim inate any direct or indirect openings from the mill interior to the mill exterior, thereby eliminating any openings to the mill environment. The elimination of these openings into the environment means a significant portion of the noise produced by the mill 40 is confined to the mill interior and is unable to emit in the surrounding environment.

[0048] The airlock valve 110 on the inlet 48 allows the user of a pressure mill 40 to feed material into the mill 40. Because airlock valves 110 have two doors or barriers that are never simultaneously open, the airlock valve 110 preserves the closed-system nature of the claimed apparatus even when the mill 40 is being fed new material. When material is fed into the mill 40 the first airlock valve door is opened, and the material is placed into the airlock valve. Then, the first airlock door is closed, and the second valve door isopened, thereby allowing the material to flow into the chamber 45 of the interior of the housing 44 for pulverization. A second airlock valve (not illustrated) can be optionally attached to the far side of the outlet junction pipe 90 to further reduce the noise emitted by the apparatus 40.

[0049] An optional variation of the claimed invention exists where the mill 40 is operated with a blower 100 located on only one of the mill inlets 48 or outlets 50. This reduction in the number of blowers 100 supplying air to the mill does produce less airflow than the use of two blowers 100, but still produces sufficient airflow to operate the mill 40 and is more energy efficient if electricity costs are a concern for the user of the claimed apparatus.

[0050] An alternative variation of the blower configuration exists where the pressure mill 40 has multiple inlets 48 or multiple outlets 50. In this alternative configuration, the airlock valve 110 and inlet blower 100 are attached to separate inlets 48 and do not share the same pipe. Similarly, the outlet blower 100 and outlet storage container (not illustrated) could be attached to separate outlets 50 from the mill 40.

[0051] Surprisingly and unexpectedly, the external airflow of the claimed invention enhances the pressure mill functionality in geographic regions with high ambient humidity. Pressure mills of the prior art were often previously unusable in high humidity environments because the high moisture content of air causes pressure mills to pulverize organic materials like wheat or grain into paste and not the desired powder or particulate. The mill 40 of the present invention surprisingly avoids this problem by allowing the mill operator to remove moisture from the mill airflow via the use of the blowers 100. These blowers 100 allow the user to modify the internal moisture content in the chamber 45 or chambers 45 of the mill during mill operation.

[0052] Optionally, the blowers 100 attached to the mill inlet 48 and outlet 50 can be replaced with desiccator driers, which grant the mill user far greater control over the pulverization process by precisely controlling the amount of moisture in the air entering and leaving the mill 40.

[0053] Although the preferred embodiment of the claimed invention uses blowers 100, a person skilled in the art will recognize that other means of creating airflow throughthe pressure mill are included in the claimed invention. Examples of these other means of creating airflow through the pressure mill 40 include, but are not limited to, fans, jets, pumps, pressurized air systems, and / or driers. Other conventional or special means of generating airflow through the mill 40 may be used.

[0054] Similarly, although the preferred embodiment of the claimed invention uses T-shaped and Y-shaped junction pipes 90 over the inlet 48 and outlet 50 of the mill 40, a person skilled in the art will recognize that other methods of connecting the means of creating airflow with the airlock valves and the mill inlet 48 and outlet 50. Examples of these alternatives include, but are not limited to, branching pipes, straight pipes, crossshape pipes, straight pipes with at least one opening in the side of the pipe, and elbowshape pipes with at least one opening in its side.

[0055] Likewise, although the preferred embodiment of the claimed invention uses an airlock valve 110 to allow material to enter the housing inlet 48, a person skilled in the art will recognize that other valves are applicable and may be used, either independently, or in series, to preserve the closed-system status of the mill 40 while in operation. Similarly, other types of valves may be used for the same purpose. Examples of these alternatives include, but are not limited to, butterfly valves, rotary valves, ball valves, door valves, linear valves, self-actuated valves, plug valves, globe valves, gate valves, needle valves, solenoid valves, coaxial valves, and angle seat valves. Other conventional or special valves may be used to close off the mill 40 from the external environment during operation.References Cited in Specification

[0056] OSHA, 29 CFR §1910.95 - Occupational noise exposure, Occupational Safety and Health Administration, Available at https: / / www. osha. gov / laws- regs / regulations / standardnumber / 1910 / 1910.95

Claims

WHAT IS CLAIMED IS:1 . A pressure mill apparatus, the pressure mill apparatus comprising: at least two rotor assemblies, the at least two rotor assemblies being affixed to a rotor shaft, whereby each of the at least two rotor assemblies is rotationally offset from one another.

2. An apparatus for pulverizing wet or dry material into relatively smaller components, wherein the apparatus comprises: a housing defining a chamber, wherein the chamber has at least one inlet through which material may enter the chamber and at least one outlet through which material may exit the chamber, and wherein the interior of the chamber is circumferentially arrayed with at least one lobe that extends inwards from the chamber walls towards the center of the chamber; a rotor shaft crossing from one side of the chamber to the other side; a first and a second rotor assembly coupled to the rotor shaft, wherein each rotor assembly comprises a plate that has at least one affixed vane which extends across the plate and terminates in at least one vane tip, and wherein the plate of each rotor assembly is affixed to the rotor shaft such that the first rotor assembly is rotationally offset relative to the second rotor assembly; and a motor operatively connected to the rotor shaft and adapted to spin the first and second rotor assemblies.

3. An apparatus for pulverizing wet or dry material into relatively smaller components, wherein the apparatus comprises:a housing defining a chamber, wherein the chamber has at least one inlet through which material may enter the chamber and at least one outlet through which material may exit the chamber, and wherein the interior of the chamber is circumferentially arrayed with at least one lobe that extends inwards from the chamber walls towards the center of the chamber; a rotor shaft crossing from one side of the chamber to the other side; at least one rotor assembly coupled to the rotor shaft, wherein the at least one rotor assembly includes a plate, wherein the plate has at least one vane affixed thereto which extends across the plate and terminates in a vane tip; a motor operatively connected to the rotor shaft and adapted to spin the rotor assembly; and a means of externally creating and directing airflow through the apparatus, wherein the airflow is created outside of the housing, the airflow enters the housing via the at least one inlet, and then the airflow leaves the housing via the at least one outlet.

4. The apparatus of claim 1 , wherein the rotational offset of the rotor assemblies is twenty degrees.

5. The apparatus of claim 1 , wherein the rotational offset of the rotor assemblies is between about five degrees and about forty-five degrees.

6. The apparatus of claim 1 , wherein the apparatus is wholly or partially covered, shielded, or enclosed with material that absorbs sound.

7. The apparatus of claim 1 , wherein the rotational offset of the at least two assemblies is between about five degrees and about forty-five degrees, andwherein the apparatus has a means of externally creating and directing airflow through the apparatus, wherein the airflow is created outside of the mill, the airflow enters the mill via at least one inlet, and then the airflow leaves the mill via at least one outlet.

8. The apparatus of claim 2, wherein the housing contains more than one chamber, wherein each chamber has an opening into the next consecutive chamber, and wherein each consecutive chamber contains at least one rotor assembly that is rotationally offset from a rotor assembly in an adjacent chamber.

9. The apparatus of claim 8, wherein each chamber has more than one rotor assembly, and wherein the rotor assemblies are rotationally offset relative to one another.

10. The apparatus of claim 2, wherein the rotational offset of the rotor assembly is twenty degrees.11 . The apparatus of claim 2, wherein the rotational offset of the rotor assembly is between about five degrees and about forty-five degrees.

12. The apparatus of claim 2, wherein the apparatus is wholly or partially covered shielded, or enclosed with material that absorbs sound.

13. The apparatus of claim 11 , wherein the apparatus has a means of externally creating and directing airflow through the apparatus, wherein the airflow is created outside of the mill, the airflow enters the mill via at least one inlet, and then the airflow leaves the mill via at least one outlet.

14. The apparatus of claim 3, wherein the at least one inlet or outlet is connected to a valve that permits material to be fed into the apparatus, wherein the valveis selected from the group consisting of: an airlock valve; a butterfly valve; a rotary valve; a ball valve; a door valve; a linear valve; a self-actuated valve; a plug valve; a globe valve; a gate valve, needle valve; a solenoid valve; a coaxial valve; and an angle seat valve.

15. The apparatus of claim 3, wherein said means of externally creating airflow is at least one of: a fan; a jet; a pump; a blower; a drier; a pressurized air system; a desiccator blower or a desiccator dryer; and said means is attached, directly or indirectly, to at least one of the inlet or the outlet.

16. The apparatus of claim 3, wherein the airflow through the apparatus is desiccated or moisture controlled before entering the chamber of the housing.

17. The apparatus of claim 3, wherein the at least one of inlet is connected with a pipe, wherein the pipe is connected to both the means of creating airflow and to a valve that permits material to be fed into the apparatus.

18. The apparatus of claim 17, wherein the valve is selected from the group consisting of: an airlock valve; a butterfly valve; a rotary valve; a ball valve; a door valve; a linear valve; a self-actuated valve; a plug valve; a globe valve; a gate valve; a needle valve; a solenoid valve; a coaxial valve; and an angle seat valve.

19. The apparatus of claim 3, wherein the apparatus is wholly or partially covered shielded, or enclosed with material that absorbs sound.

20. The apparatus of claim 3, wherein the apparatus has at least two rotor assemblies, wherein each one of the two rotor assemblies is affixed to the rotor shaft, and wherein each rotor assembly is rotationally offset from one another between about five degrees and about forty-five degrees.21 .A pressure mill apparatus (40), the pressure mill apparatus (40) comprising: at least two rotor assemblies (74), the at least two rotor assemblies (74) being affixed to a rotor shaft (70), whereby the at least two rotor assemblies (74) are rotationally offset from one another.

22. An apparatus (40) for pulverizing wet or dry material into relatively smaller components, wherein the apparatus comprises (40): a housing (44) defining a chamber (45), wherein the chamber (45) has at least one inlet (48) through which material may enter the chamber (45) and at least one outlet (50) through which material may exit the chamber (45), and wherein the interior of the chamber (45) is circumferentially arrayed with at least one lobe (54) that extends inwards from the chamber walls towards the center of the chamber (45); a rotor shaft (70) crossing from one side of the chamber (45) to the other side; a first and a second rotor assembly (74) coupled to the rotor shaft (70), wherein each rotor assembly (74) comprises a plate (60) that has at least one affixed vane (64) which extends across the plate (60) and terminates in at least one vane tip, and wherein the plate (60) of each rotor assembly (74) is affixed to the rotor shaft (70) such that the first rotor assembly (74) is rotationally offset relative to the second rotor assembly (74); and a motor (80) operatively connected to the rotor shaft (70) and adapted to spin the first and second rotor assemblies (74).

23. An apparatus (40) for pulverizing wet or dry material into relatively smaller components, wherein the apparatus (40) comprises:a housing (44) defining a chamber (45), wherein the chamber (45) has at least one inlet (48) through which material may enter the chamber (45) and at least one outlet (50) through which material may exit the chamber (45), and wherein the interior of the chamber (45) is circumferentially arrayed with at least one lobe (54) that extends inwards from the chamber walls towards the center of the chamber (45); a rotor shaft (70) crossing from one side of the chamber (45) to the other side; at least one rotor assembly (74) coupled to the rotor shaft (70), wherein the at least one rotor assembly (74) includes a plate (70), wherein the plate (60) has at least one vane (64) affixed thereto which extends across the plate (60) and terminates in a vane tip; a motor (80) operatively connected to the rotor shaft (70) and adapted to spin the rotor assembly (74); and a means (100) of externally creating and directing airflow through the apparatus (40), wherein the airflow is created outside of the housing (44), the airflow enters the housing (44) via at the at least one inlet (48), and then the airflow leaves the housing (44) via the at least one outlet (50).

24. The apparatus (40) according to any of preceding claims 21-23, wherein the rotational offset of the rotor assemblies (74) is twenty degrees.

25. The apparatus (40) according to any of preceding claims 21-23, wherein the rotational offset of the rotor assemblies (74) is between about five degrees and about forty-five degrees.

26. The apparatus (40) according to any of preceding claims 21-25, wherein the apparatus (40) is wholly or partially covered, shielded, or enclosed withmaterial (120) that absorbs sound.

27. The apparatus (40) according to any of preceding claims 21-26, wherein the rotational offset of the at least two assemblies (74) is between about five degrees and about forty-five degrees, and wherein the apparatus (40) has a means (100) of externally creating and directing airflow through the apparatus (40), wherein the airflow is created outside of the housing (44), the airflow enters the housing (44) via the at least one inlet (48), and then the airflow leaves the housing (44) via at the least one outlet (50).

28. The apparatus (40) according to any of preceding claims 21 -27, wherein the housing (44) contains more than one chamber (45), wherein each chamber (45) has an opening into the next consecutive chamber (45), and wherein each consecutive chamber (45) contains at least one rotor assembly (74) that is rotationally offset from a rotor assembly (74) in an adjacent chamber (45).

29. The apparatus (40) according to claim 28, wherein each chamber (45) has more than one rotor assembly (74), and wherein the rotor assemblies (74) are rotationally offset relative to one another.

30. The apparatus (40) according to any of preceding claims 21-29, wherein the apparatus (40) has a means (100) of externally creating and directing airflow through the apparatus (40), wherein the airflow is created outside of the housing (44), the airflow enters the housing (44) via the at least one inlet (48), and then the airflow leaves the housing (44) via the at least one outlet (50).31 . The apparatus (40) according to any of preceding claims 21 -30, wherein the at least one inlet (48) or the at least one outlet (50) is connected to a valve (110) that permits material to be fed into the apparatus (40), wherein the valve (110) is selected from the group consisting of: an airlock valve; a butterfly valve; a rotary valve; a ball valve; a door valve; a linear valve; a selfactuated valve; a plug valve; a globe valve; a gate valve, needle valve; a solenoid valve; a coaxial valve; and an angle seat valve.

32. The apparatus (40) according to any of preceding claims 21-31 , wherein said means (100) of externally creating airflow is at least one of: a fan; a jet; a pump; a blower; a drier; a pressurized air system; a desiccator blower or a desiccator dryer; and said means (100) is attached, directly or indirectly, to at least one of the at least one inlet (48) or the at least one outlet (50).

33. The apparatus (40) according to any of preceding claims 21-32, wherein the airflow through the apparatus (40) is desiccated or moisture controlled before entering the chamber (45) of the housing (44).

34. The apparatus (40) according to any of preceding claims 21-33, wherein the at least one inlet (48) is connected with a pipe (90), wherein the pipe (90) is connected to both the means of creating airflow (100) and to a valve (110) that permits material to be fed into the apparatus (40).

35. The apparatus (40) according to claim 34, wherein the valve (110) is selected from the group consisting of: an airlock valve; a butterfly valve; a rotary valve; a ball valve; a door valve; a linear valve; a self-actuated valve; a plug valve; a globe valve; a gate valve; a needle valve; a solenoid valve; a coaxial valve; and an angle seat valve.

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