CA2734884A1 - Mass measurement feeder - Google Patents

Abstract

A Mass Measurement Feeder for mass measurement feeding of dry solids material by means of microwaves attenuation of material density within gas-tight pockets of cylinder weigh feeder. The Mass Measurement Feeder generally includes Helical Cylinder Rotor, Seat Cage, Bearing, Housing, Sealing Elements, Electric Drive, Microwave Transceiver, and Microcontroller.

Description

MASS MEASUREMENT FEEDER

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.
61/212,083, filed April 7, 2009, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION
1. Field of the Invention [0002] The present invention relates generally to rotary feeders and more particularly it relates to mass measurement cylinder feeders for feeding of dry solids material by means of microwaves attenuation of material density within air-tight pockets of cylinder feeders.
The feeder of the present invention provides true density, mass measurement feeding in real time.

2. Description of the Related Art [0003] Conventional feeders utilize batch, weight based measurement of the feed material which may negatively affect process speeds and measurement accuracy.

BRIEF SUMMARY OF THE INVENTION

[0004] The invention relates to a cylinder feeder which includes Helical Cylinder Rotor 10, Seat Cage 20, Bearing 30, Housing 40, Sealing Elements 50, Electric Drive 60, Microwave Transceiver 70, and Microcontroller 80. In an embodiment the feeder includes a seat cage 20 which includes a rotor 10; a pair of end plates 21; a plurality of side plates 22 in communication with the end plates, the side plates having a matching radius to the radius of the rotor 10 and covering approximately 270 degrees of the surface of the rotor 10; and wherein the seat cage 20 and the surface of the rotor 10 communicate to provide an air-tight interface and the seat cage 20 in conjunction with a compression seal 51 provides an air-tight seal with a top retainer 43, such that static leakage through the feeder is prevented.

[0005] There has thus been outlined, rather broadly, some of the features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter.

[0006] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.

[0007] An object is to provide a Mass Measurement Feeder for feeding dry solids material by means of microwaves attenuation of material density within air-tight pockets of rotating cylinder.

[0008] Another object is to provide a Mass Measurement Feeder that measures in real time changes in density as dry solids material transfers through rotating cylinder feeder.

[0009] Another object is to provide a Mass Measurement Feeder that enables a revolving cylinder to speed up or slow down with changes in density.

[0010] Another object is to provide a Mass Measurement Feeder that provides true density, real time, feeding of material into processes.

[0011] Another object is to provide a Mass Measurement Feeder that provides a practical alternate to "loss-in-weight" batch feeding of dry solids materials.

[0012] Another object is to provide a Mass Measurement Feeder that provides accurate dry solids material measurement feeding not dependent on the force of gravitational pull.

[0013] Another object is to provide a Mass Measurement Feeder that provides accurate, real time, dry solids material measurement not subject to changes in gravitational forces with change of location.

[0014] Another object is to provide a Mass Measurement Feeder that provides accurate measurement of dry solids material that is not dependent on mechanical devices, such as load cells and weigh scales.

[0015] Another object is to provide a Mass Measurement Feeder that self calibrates with each revolution of the cylinder rotor.

[0016] Another object is to provide a Mass Measurement Feeder, having no static as is inherent with traditional rotary feeders and traditional screw feeders.

[0017] Another object is to provide a Mass Measurement Feeder that provides real time outputs of data as material feeds into process.

[0018] Another object is to provide a Mass Measurement Feeder that compensates for changes in density in real time.

[0019] Other objects and advantages of the present invention will become obvious to the reader, and it is intended that these objects and advantages are within the scope of the present invention.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of this application.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

[0021] FIGURE 1: is a side view of the preferred embodiment of the Mass Measurement Feeder of the present invention. Also shown in this view are Microwave Transceiver 70, and Electric Drive 60. Transceiver 70 and Electric Drive 60 will be explained in later views and text.

[0022] FIGURE 2: is end view of the preferred embodiment of the Mass Measurement Feeder of the present invention. Microwave Transceiver (s) 70 shows in this view. Also, Seal Retainer 46 and Drive Spacer 45 are shown attached in this view.

[0023] FIGURE 3: is a top view of the preferred embodiment of the Mass Measurement Feeder of the present invention. The top surface of Seat Cage 20 and the top surface of Helical Cylinder Rotor 10 are seen in this view. Rotor 10 and Seat Cage 20 will be explained in later views and text.

[0024] FIGURE 4: is a bottom view of the preferred embodiment of the Mass Measurement Feeder of the present invention. The bottom surface of Helical Cylinder Rotor 10 and the bottom surface of Seat Cage Assembly 20 show in this view.

[0025] In comparison with the top opening, it can be seen that the bottom opening is larger than the top opening. This is purposeful design to ensure that no material remains within the feeder.

[0026] FIGURE 5: is a cross-sectional top view of the preferred embodiment of the Mass Measurement Feeder of the present invention. This view shows Rotor 10, Seat Cage 20, Reflective Cylinder 12, Microwave Transceiver (s) 70, Housing 40, Bearing 30, Axial Seal 31, Radial Seal 32, Seal Retainer 46, and Transceiver Enclosure 72. These elements will be explained in later views and text.

[0027] FIGURE 6: (TOP VIEW) is a cross-sectional end view of the preferred embodiment of the Mass Measure Feeder of the present invention. Rotor 10, Seat Cage 20, Microwave Transceiver (s) 70, Reflective Cylinder 12, Transceiver Enclosure 72, Housing 40, Drive Screw 52, Compression Seal 51, Compression Pad 53, Top Retainer 43, Tie Rod 23, and Bottom Retainer 44 show in this view. These elements will be explained in later views and text.
Shown in bottom view is a cross-sectional view of Tubular Shell 11 and Reflective Cylinder 12 of the present invention. This view illustrates the common radial point as it relates to the concentricity of Shell 11 and Cylinder 12. The requirement for concentricity relates to the Law of Reflection as it applies to the present invention and will be made clear in later text.

[0028] FIGURE 7: is end view and top view of the preferred embodiment of Rotor 10 of the Mass Measurement Feeder of the present invention. The outside surface of Reflective Cylinder 12 shows in the bottom of the rotor pocket. Trunnion 13 shows in left view.

[0029] FIGURE 8: is end view and cross-sectional side view of the preferred embodiment of Rotor 10 of the Mass Measurement Feeder of the present invention. This view also shows Tubular Shell 11, Reflective Cylinder 12, Trunnion 13, and Cap Screw 14.

[0030] FIGURE 9: is a cross-sectional end view, a top view and end view of Rotor Shell 11 of Rotor 10 of the Mass Measurement Feeder of the present invention. Pocket Windows show in these views.

[0031] FIGURE 10: is a side view and end view of Reflective Cylinder 12 of Rotor 10 of the Mass Measurement Feeder of the present invention.

[0032] FIGURE 11: is end view and cross-sectional profile view of Trunnion 13 of Rotor 10 of the Mass Measurement Feeder of the present invention.

[0033] FIGURE 12: is a top view, end view and a side view of Seat Cage Assembly 20 of the Mass Measurement Feeder of the present invention.

[0034] FIGURE 13: is a front view and end view of End Plate 21 of Seat Cage 20 of the Mass Measurement Feeder of the present invention.

[0035] FIGURE 14: is a side view and end view of Side Plate 22 of Seat Cage 20 of the Mass Measurement Feeder of the present invention [0036] FIGURE 15: is a composite view of Tie Rod 23 and Cap Screw 24 of Seat Cage Assembly 20 of the Mass Measurement Feeder of the present invention. The Elongated View, the Differential View, and the Normal View illustrate means of thermal elongation compensation of Seat Cage 20. The means will be explained in greater detail in later text.

[0037] FIGURE 16: is a side view and end view of Bearing 30 of the Mass Measurement Feeder of the present invention. Seal 31 and Seal 32 grooves are shown in these views; their purposes will be explained in later views and text.

[0038] FIGURE 17: is a side view and end view of Axial Seal 31 used with Bearing 30 of the Mass Measurement Feeder of the present invention. The function of this element will be explained in later text.

[0039] FIGURE 18: is a side view and end view of Radial Seal 32 used with Bearing 30 of the Mass Measurement Feeder of the present invention. The function of this element will be explained in later text.

[0040] FIGURE 19: is a fragmented view of Bearing 30, Axial Seal 31, and Radial Seal 32 installed onto Rotor 10 and into Housing 40 of the Mass Measurement Feeder of the present invention. The functionally of these elements will be explained in later text.

[0041] FIGURE 20: is a composite of four views of Housing 40 of the Mass Measurement Feeder of the present invention. Side View, End View, Top View, and Bottom View are shown.

[0042] FIGURE 21: is end view and side view of Side Panel 41 of Housing 40 of the Mass Measurement Feeder of the present invention. Two Side Panel(s) 41 are required for each Housing 40.

[0043] FIGURE 22: is end view and front view of End Plate 42 of Housing 40 of the Mass Measurement Feeder of the present invention. Two End Plate (s) 42 are required for each Housing 40.

[0044] FIGURE 23: is front view and end view of Drive Spacer 45 of Housing 40 of the Mass Measurement Feeder of the present invention. The requirement for this element will be explained in later text.

[0045] FIGURE 24: is end view and side view of Seal Retainer 46 of Housing 40 of the Mass Measurement Feeder of the present invention. The purpose for this element will be explained in later text.

[0046] FIGURE 25: is top view and profile view of Top Retainer 43 of Housing 40 of the Mass Measurement Feeder of the present invention. The purpose for this element will be explained in later text.

[0047] FIGURE 26: is top view and profile view of Bottom Retainer 44 of Housing 40 of the Mass Measurement Feeder of the present invention. The purpose for this element will be explained in later text.

[0048] FIGURE 27: is a cross-sectional end view of Sealing Elements 50 of the Mass Measurement Feeder of the present invention. Compression Seal 51, Drive Screw 52, and Compression Pad 53 show in this view. The functions of these elements will be explained in later text.

[0049] FIGURE 28: is side view and end view of Drive Screw 52 of Sealing Elements 50 of the Mass Measurement Feeder of the present invention. The purpose of this element will be explained in later text.

[0050] FIGURE 29: is side view and end view of Compression Pad 53 of Sealing Elements 50 of the Mass Measurement Feeder of the present invention. The purpose for this Element will be explained in later text.

[0051] FIGURE 30: is top view and profile view of Compression Seal 51 of Sealing Elements 50 of the Mass Measurement Feeder of the present invention. The view will be explained in greater detail later in the text.

[0052] FIGURE 31: is end view and side view of Electric Drive 60 of the Mass Measurement Feeder of the present invention. The function of Drive 60 will be explained in later text. Electric Drive 60 shown is a commercial product manufactured by Sumitomo Drive Technologies.

[0053] FIGURE 32: is a side view of Microwave Transceiver 70 of the mass measurement feeder of the present invention. The view shows Transceiver 70 and Horn Antenna 71 mounted in Transceiver Enclosure 72. The enclosure mounts directly to Side Panel 21 of Housing 40.

[0054] FIGURE 33: is a top view, a side view and an end view of Transceiver 70 of the Mass Measurement Feeder of the present invention. The transceiver illustrated is a commercial product manufactured by MA-COM Technology Solutions.

[0055] FIGURE 34: Figure 34 is a side view, a top view and an end view of Horn Antenna 72 of the Mass Measurement Feeder of the present invention. The horn antenna illustrated is a commercial product manufactured by MDT Corp.

[0056] FIGURE 35: is closed box view and open box view of Microcontroller 80 of the Mass Measurement Feeder of the present invention. The functionally of Microcontroller 80 will become apparent in later text.

[0057] FIGURE 36: is a plain view of Process Flow Diagram 81 of the Mass Measurement Feeder of the present invention. Process Flow Diagram 81 will be explained in later text.

[0058] FIGURE 37: is a plain view of Microcontroller Program 82 of the Mass Measurement Feeder of the present invention. Microcontroller Program 82 will be explained in later text.
Enclosed by reference (Appendix "A") is an example as applied to Allen Bradley Micrologix Software.

[0059] FIGURE 38: is a cross-sectional top view of the First Alternative Variation of the Mass Measurement Feeder of the present invention. New in this view are Cylinder Rotor 110, Waveguide 111, Receiver (s) 112, and Microwave Transmitter 113.

[0060] FIGURE 39: is a cross-sectional end view of the First Alternative Variation of the Mass Measurement Feeder of the present invention. New in this view are Cylinder Rotor 110, Waveguide 111, Microwave Receiver (s) 112. Microwave Transmitter 113 does not show in this view.

[0061] FIGURE 40: is a cross-sectional top view of the First Alternative Variation of the Mass Measurement Feeder of the present invention. This view shows Rotor 110 rotated 180 degrees.

[0062] FIGURE 41: is a cross-sectional end view of the First Alternative Variation of the Mass Measurement Feeder of the present invention. This view shows Rotor 110 rotated 180 degrees.

[0063] FIGURE 42: is a cross-sectional top view of the Second Alternative Variation of the Mass Measurement Feeder of the present invention. New in this view are Cylinder Rotor 210, and Microwave Transceiver 270. This view depicts a single pocket, single transceiver Variation of the Preferred Embodiment.

[0064] FIGURE 43: is a cross-sectional end view of the Second Alternative Variation of the Mass Measurement Feeder of the present. New in this view are Cylinder Rotor 210, Single Pocket Opening, and Polished Reflective Surface in end of Rotor 210.

[0065] FIGURE 44: is a cross-sectional end view of the Second Alternative Variation of the Mass Measurement Feeder of the present invention. This view shows Single Pocket Opening rotated from the 12 o'clock feeder position to the 3 o'clock feeder position.

[0066] FIGURE 45: is a cross-sectional end view of the Third Alternative Variation of the Mass Measurement Feeder of the present invention. This view depicts a rotor pocket vent variation of the Preferred Embodiment. New in this view is a four pocket variation of Rotor 10, rotor pocket Vent Rod 323, Vent Tube 324, and Vent Cap 325. The rotor pocket at 9 o'clock is shown in the non-vent position.

[0067] FIGURE 46: is a cross-sectional end view of the Third Alternative Variation of the present invention. This view shows the same view as Figure 45, except Rotor 10 is rotated clockwise to show the 9 o' clock pocket in the vent position.

DETAILED DESCRIPTION OF THE INVENTION
A. Overview [0068] Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the figures illustrate Helical Cylinder Rotor 10, Seat Cage 20, Bearing 30, Housing 40, Sealing Elements 50, Electric Drive 60, Microwave Transceiver (s) 70, and Microcontroller 80.

B. Helical Cylinder Rotor [0069] The Helical Cylinder Rotor is comprised of three components: 1) outer cylinder shell, having one or more helical windows, 2) reflective inner cylinder, 3) two trunnions, and 4) cap screws.

[0070] The functions of the rotor are to: 1) to provide an air-tight seal between two different pressure zones, 2) to transfer material from inlet of feeder to outlet of feeder, 3) to provide sealed pocket to enable reading density of material trapped within, and 4) to provide reflective, concentric (Outer shell and inter shell have same radial point.) surface in bottom of pocket to reflect microwaves back into the transceiver.

[0071 ] Helical Cylinder Rotor 10 comprises Tubular Shell 11, Reflective Cylinder Shell 12, Trunnion 13, and Cap Screw 14.

[0072] Although it can be made of other materials, such as stainless steel, the preferred material of construction for Tubular Shell 11 is aluminum, particularly thick wall aluminum tubing. The wall thickness is normally a minimum of 2". In fabrication, the commercial tubing is precision saw cut to a specified length. The work piece is then OD
and ID turned, to dimensions, on a CNC lathe. The blank then goes to a vertical CNC milling machine where one or more windows are milled through the wall - OD to ID. To provide an auguring affect, and a scissoring action to snip dry material particles, windows are made either linear helical - straight line milled or actual helical - contour milled, ranging from 3 to 15 degrees off x-axis, depending on the application requirement. Elimination of parallel closure surfaces prevents mal-functioning of Cylinder Rotor 10 as it revolves within Seat Cage 20.

[0073] The number of windows and type depends largely on the intended application. For fine feed control, there may 8 to 12 windows, for course control, 4 or 6 windows. Each end of Tubular Shell 11 is counter bored, drilled and tapped to accept Tunnion (s) 13. Once this work is complete, Tubular Shell 11 is Type III Aluminum Hard Coated. This is an oxidation process, providing a ceramic-like surface finish with a low coefficient of friction and high wear ability. Both the aluminum and the hard coating process are FDA
compliant.

[00741 Reflective Cylinder 12 is constructed normally either of an engineered plastic, such as TiO2 (titanium dioxide) filled UHMW-PE (ultra high molecular weight polyethylene) or nickel-chrome plated aluminum tubing. If UHMW-PE, it is machined from tubular shapes or water jet cut from flat plate stock, stacked to form a tube. The purpose of the Ti02 additive to the UHMW-PE, or the nickel-chrome plating of the aluminum is to affect a highly microwaves reflective surface.

[0075] The UHMW-PE tube is made 15 to 20 thousandths over the ID of Tubular Shell 11.
The tube is then placed in a freezer for up to 8 hours, shrinking the OD by 20 to 40 thousandths. The tube is then positioned into Tubular Shell 11, allowed to come to equilibrium; the tube returns to its original size, forming an air-tight seal with the ID of Tubular Shell It. The pocket is formed by Reflective Cylinder 12 (bottom surface) and window (s) in Tubular Shell 11 (sides and end surfaces). If made of aluminum, the tube is machined 3 to 5 thousandths oversize and pressed into Tubular Shell 11.

[0076] TiO2 filled UHMW-PE is the material of choice in that it easily forms an air-tight seal in the bottom of the pocket. Additionally, TiO2 is the third most reflective dielectric material known, it provides a dielectric mirror. Generally, the higher the dielectric constant of a material, the more energy it absorbs, hence a dielectric mirror is the converse. TiO2 is also FDA compliant.

[0077] Reflective Cylinder Shell 12 is made 20 to 30 thousandths short on each end to allow for thermal elongation. Non-metallic materials expand at a greater rate than do metallic materials, hence the need for elongation compensation.

[0078] Trunnion 13 is normally machined from aluminum round stock, although it can be made of stainless steel or other metals. The OD of Trunnion 13 is made to a close tolerance -1 to 2 thousands - with the counter bore of Tubular Shell 11. This close tolerance forms a register to ensure that the rotor runs true. Trunnion 13 is secured to Tubular Shell 11 by means of Cap Screw (s) 14, and the torque transfer occurs by the same means.
Cap Screw 14 is a flat socket head type cap screw. Trunnion 13 also provides a drive socket with keyway for revolving (turning) Helical Cylinder Rotor 10. When machine work is complete, Trunnion 13, if made of aluminum, is Type III Aluminum Hard Coated.

C. Seat Cage [0079] The Seat Cage comprises an assembly of two End Plate 21 elements and a determined number of Side Plate 22 elements, each made with one surface having a matching radius to the radius of Rotor 10. The members are normally made from flat plate stock and assembled as a structural cage, covering approximately 270 degrees of the surface of Rotor 10.

[0080] The function of the Seat Cage 20 is to provide an air-tight interface with the surface of Rotor 10. Seat Cage 20 in conjunction with Compression Seal 51, provides an air-tight seal with Top Retainer 43. These sealing relationships prevent static leakage through the feeder.

[0081] Seat Cage 20, when urged into compressive sealing engagement with the surface of Helical Cylinder Rotor 10, provides a gas-tight sealing system for the Mass Measurement Feeder of the present invention. Seat Cage 20 is an assembly, comprising End Plate 21, Side Plate 22, Tie Rod 23, and Cap Screw (s) 24. The preferred way of making End Plate 21 and Side Plate 22 is from flat plate stock, on a water jet machine. The plates come off the water jet finished with two exceptions: 1) the radius on each plate is made under sized, each plate is then placed on a tooling fixture on a CNC milling machine. The radius is milled to matching radius with Helical Cylinder Rotor 10, and 2) End Plate 21 holes are counter sunk, one side only, to have matching conical surfaces with Cap Screw 24. Tie Rod 23 is cut to required length from commercial round bar stock, each end is drilled and tapped to accept Cap Screw 24. Even though the preferred material of construction is UHMW-PE, Seat Cage 20 can be constructed of other engineered plastics, composite materials, and metallic materials.

[0082] Seat Cage 20 is an assembled sealing structure, comprising at least two (2) of End Plate 21 and a determined number (based on rotor length) of Side Plate 22, four (4) of Tie Rod 23, and 8 of Cap Screw 24. The holes in the plates are made to a tight sliding fit with Tie Rod 23. When the correct numbers of plates are fitted onto the rods, Cap Screw (s) 24 is installed and tightens, placing End Plate (s) 21 and Side Plate (s) 22 into face to face compressive, sealing engagement, thus preventing fluid leakage between the plates. This finished assembly has structural rigidity. Flat, conical head cap screws are selected for an important reason.

[0083] Referring to Figure 15, there are three views shown at top left. They are: 1) Normal View, 2) Differential View, and 3) Elongated View. The Normal View depicts Seat Cage 20 as assembled at ambient temperature. The Elongated view depicts Seat Cage 20 subjected to thermal elongation. The Differential View depicts the difference in elongation between normal and elongated states. The conical head shape of Cap Screw 24 permits End Plate (s) 21 to slide up and down the sloped surface of the conical as thermal cycling occurs -elongation and constriction. The conical head of the cap screw and the conical counter sunk shape of Plate 21 are matching surfaces. The conical holes of Plate 21 enlarge with rise in temperature, with decrease in temperature, constrict, permitting the sliding action of the two elements with changes in temperature. Without this critical compensating means, End Plate (s) 21 and Side Plate (s) 22 would not remain in face to face, leak tight, compressive, sealing engagement. Before leaving the area of thermal compensation, please look at Figure 12.
You will notice, in the bottom right view, a circle labeled Compression Pad Pocket. These pockets are part of another thermal and wear means that will be taken up in greater detail in Housing 40 section.

D. Bearing [0084] Bearing 30 of the Mass Measurement Feeder of the present invention is normally constructed of UHMW-PE or other engineered plastic, but can be made of metallic materials. It performs two important functions: 1) it provides the pivotal point for Cylinder Rotor 10 of the Feeder, and 2) it provides a sealing face surface and sealing support surfaces for Axial Seal 31 and Radial Seal 32. Axial Seal 32 urges the face of Bearing 30 into continuous sealing engagement with the end (face) surface of Rotor 10. Axial Seal 31 provides a static sealing force. Referring to Figure 19, it can be seen that a clearance exist between the OD of Bearing 30 and the ID of Housing 40, and it can be seen that a clearance exist between the OD of Rotor 10 and the ID of Bearing 30. These clearances represent the ever present requirement for thermal compensation when combining engineered plastics and metallic materials. The OD and ID clearances permit the bearing to increase and decrease in diameters when subjected thermal cycling. Without the clearances, Bearing 30 will lock-up with thermal rise. The use of Radial Seal 32 permits making the OD of Bearing 30 smaller than the ID of Housing 40. The gap between the two surfaces is sealed with Radial Seal 32.
Tests have shown that this bearing-seal combination is highly affective.

E. Housing [0085] Housing 40 of the Mass Measurement Feeder of the present invention comprises:
Side Panel 41, End Plate 42, Top Retainer 43, Bottom Retainer 44, Drive Spacer 45, and Seal Retainer 46.

[0086] The functions of the Housing are: 1) to provide an air-tight enclosure for internal elements of the Feeder and 2) to provide support and mounting surfaces for ancillary external elements of the Feeder.

[0087] Housing 40 is comprised of four base elements: two each of Side Panel 41, and two of End Plate 42. When assembled, these elements form a square cornered, air-tight box.
The ability to utilize a flat sided, square cornered box shaped structure for the casing of the Mass Measurement Feeder of the present invention is important from the standpoints of material costs, material availability, weight, size, and costs of manufacture.
Most traditional rotary feeders are locked-into cylindrical casings, most of which are cast, high cost, long lead times and high machining costs. This is due to fact that traditional rotary feeders depend on the ID of the casing for one-half of the "closure member".

[0088] Referring to Figure 14, it is seen that Side Panel 22 has an Inlet Slope and an Outlet Slope. These two slopes are what make utilization of the flat sided, squared cornered, box shaped Housing 40 possible for the Mass Measurement Feeder of the present invention.
Because of the metal to metal construction of traditional rotary feeders, the inclines have to be cast into the casing or fabricated into for the required circular shape to coincide with the circular rotor or screw shape.

[0089] This is a major structural design factor between the box housing design of the present invention, and the circular design required of traditional rotary and screw feeder designs.
[0090] Side Panel 21, up through a certain size range, is constructed from standard stock, aluminum "C" channel, available in 25 ' lengths. The channel is precision saw cut to specified lengths. Hole work is done on face and flange surfaces, flanges are edged if required. Little if any other machine work is required.

[0091] End Plate 42 is precision saw cut from standard, cast aluminum tooling plate. CNC
hole work is performed on face and edge surfaces. No other machine work is required.

[0092] Top Retainer 43 and Bottom 44 are water jet cut from flat aluminum sheet stock.
With exception of counter sinks, all hole work is done on the water jet. No other machine work is required.

[0093] Drive Spacer 45 and Seal Retainer 46 are also made on a water jet machine from flat aluminum sheet stock. Except for milling hole counter sinks, no other machine work is required.

[0094] On average, total Housing 40 assembly requires about 20 minutes.
F. Sealing Elements [0095] Sealing Elements 50 of the Mass Measurement Feeder of the present invention comprise: Compression Seal 51, Drive Screw 52, and Compression Pad 53.
Compression Seal 51 and Compression Pad 53 are normally made of silicone rubber. Drive Screw 52 is a commercially acquired fastener.

[0096] The functions of Sealing Elements 50 are: 1) to prevent static leakage through the Feeder, 2) to compensate for thermal cycling and wear of Rotor 10 and Seat Cage 20.
Sealing Elements 50 of the Mass Measurement Feeder of the present invention prevent static leakage, common in traditional rotary and screw feeders.

[0097] Sealing Elements 50 are shown in functional locations in Figure 30.
Compression Seal 51, located at top of Seat Cage 20, applies a downward sealing force on Seat Cage 20, while Drive Screw 52 and Compression Pad 53 apply a side loading force on Seat Cage 20.
[0098] Compression Seal 51 prevents the mixing of pressure zone P2 with pressure zone P1.
Drive Screw 52 and Compression Pad 53, by applying a wrap-around loading force to Seat Cage 20 prevent leakage between Seat Cage 20 and Rotor 10. This wrap around loading also prevents the mixing of pressure zone P2 with pressure zone P1, the end result being no static leakage through the Feeder.

[0099] Sealing Elements 50 also play a critical role in proportional sealing.
On pressure conveying applications, the Feeder may be subject to P2 pressures as high as (pounds per square inch gage), P1 pressure may be near 0 PSIG or it may even be a vacuum, meaning that the Mass Measurement Feeder of the present invention is capable of sealing against differential pressures of 50 PSIG or greater.

[0100] The way proportional sealing works in the Mass Measurement Feeder is that P2 pressure is blocked at Compression Seal 51. When happens, because Drive Screw 52 and Compression Pad 53 are mechanically holding Seat Cage 20 against Rotor 10, P2 pressure acts on the side surfaces of Seat Cage 20. It can be seen that a space exist between Seat Cage 20 and Housing 40. These are the areas where the pressurization of seat Cage 20 to Rotor 10 occurs. At the same time this is occurring, P2 pressure is trying to separate Seat Cage 20 from Rotor 10. The areas of the outside of Seat Cage 20 are designed to be about 20% greater than the interfaced area between Seat Cage 20 and Rotor 10. The 20% greater outside loading force of Seat Cage 20 insures no static leakage between the two surfaces even as P2 pressure increases. This is proportional sealing - as pressure goes up, sealing increases proportionally.

[01011 Sealing Elements 50 play another critically important role in the Mass Measurement Feeder of the present invention, having to do with both thermal cycling and wear. The resiliencies of Compression Seal 51 and Compression Pad (s) 53 acts as shock absorbers for Seat Cage 20. When the temperature goes up, Seat Cage 20 gets larger, when the temperature goes down Seat Cage 20 gets smaller. Compression Seal 51 and Compression Pad (s) 53 take up the slack for these changes; hence Seat Cage 20 always remains in compressive sealing engagement with Rotor 10. As wear occurs between Seat Cage 20 and Rotor 10, Compression Seal 51 and Compression Pad 53 continue to urge Seat Cage 20 against Rotor 10, hence no static leakage between the surface of Seat Cage 20 and the surface of Rotor 10.

[0102]For metal to metal sealing or other specialized requirements, Drive Screw 50 and Compression Pad 53 are replaced with proportional loading actuators. These can take the form of fluid activated piston or diaphragm actuators, electrically driven actuators or other externally controlled, proportional loading devices and means.

G. Electric Drive [0103] Electric Drive 60 is a commercially acquired electric gearmotor. This element is available from a number of manufacturers in both AC and DC currents, and is available in a wide range of sizes and HP's. The function of Electric Drive 60 is to revolve Cylinder Rotor of the Mass Measurement Feeder of the present invention. Its speed of rotation is controlled by the VFD (Variable Frequency Drive) within Microcontroller 80.

[0104] Electric Drive 60 is the means for continuously rotating Rotor 10 of the Mass Measurement Feeder of the present invention. Electric Drive 60 may be set to turn the cylinder rotor at a constant RPM rate, or it may vary the RPM rate by means of VFD control to be discussed later in the text. The speed of the Mass Measurement Feeder varies with changes in density. This too will be explained in greater detail in later text. .

H. Microwave Transceiver [0105] Microwave Transceiver 70 both transmits and receives microwaves within the Mass Measurement Feeder of the present invention. Microwave Transceiver 70 is aided by Horn Antenna 71. Horn Antenna 71 both focuses out going and in coming microwaves, increasing the gain of the transceiver.

[0106] Transceiver 70 and Horn Antenna 71 are mounted in Enclosure 72.
Enclosure 72 is further mounted to Slide Panel 41 of Housing 40. A second Transceiver 70 is mounted on opposite Side Panel 41 of Housing 40.

[0107] Microwave Transceiver 70 as illustrated in the application of the present invention, operates in the K-Band frequency. The K-Band frequency range is from about 18 GHz to about 24. 5 GHz. Other Bands, such as X-Band, Ka-Band, E-Band, and others, may be used, as dictated by application requirements.

[0108] The function and operation of Transceiver 70 will be covered in greater detail in later text. Both Transceiver 70 and Horn Antenna 71 are commercially acquired elements.

I. Microcontroller [0109] Microcontroller 80 is comprised of 5 commercially acquired elements, and are boxed housed as shown in Figure 35. Process Flow Diagram 81 shows the relationship of the elements. Microcontroller Program 82 is not an acquired element, but is a specifically written program for the Mass Measurement Feeder by the inventors of the present invention.
Program 82 is unique to the Mass Feeder.

[0110] The function of Microcontroller 80 is to receive attenuated values from the transceivers, compute the values into meaningful data, such as pounds per hour, and continuously adjust the speed of the Feeder to track with desired process base line set point.
[0111 ] Process Flow Diagram 81 is a typical control schematic of the Mass Measurement Feeder of the present invention. Figure 36 shows Process Flow Diagram (PFD) 81. The Programmable Logic Controller (PLC), 24-Volt Direct Current Power Supply (24VDC), and 5-Volt Direct Current Power Supply (5VDC) all receive power from standard 110/120 Volt Power.
This power is supplied by end user source.

[0112] The 5VDC Power Supply provides the necessary operating voltage for Microwave Transceiver (s) 70. Microwave Transceiver (s) 70 takes the 5VDC power and produces synthetic electromagnetic energy (microwaves). The microwaves propagate through across the pocket and reflect back to Microwave Transceiver 70 from Reflective Cylinder 12 of Cylinder Rotor 10.
The return signal is measured in millivolts (mV); the values are dictated by the medium that the microwaves travel through. The denser the medium the lesser amount of received signal. The dielectric constant of the material also factors into the energy absorbed, generally, the higher the dielectric, the greater the signal loss. Dielectric is an energy absorbing substance within the material.

[0113] Microwave Transceiver 70 at the 3 o' clock position is reading the pocket with material in it, while Microwave Transceiver 70 in the 9 o' clock position is reading the same pocket without material. Both signals are sent to the PLC. The difference in the two readings is the attenuation or amount of energy absorbed by the material, with this mV value, the PLC
makes the necessary calculations to determine the density of the material.

[0114] Characterized by a base line feed rate chosen by the process engineer, the PLC sends an analog signal to a Variable Frequency Drive (VFD) that sets the proper speed of Electric Drive 60, thereby, causing the Mass Measurement Feeder to feed the desired amount of material. The VFD is powered by a 230/460-Volt source. By varying the frequency and voltage, the VFD
controls the speed of Electric Drive 60.

[0115] The Interface Display (powered by the 24VDC Power Supply) is used as the human interface between the process engineer and the PLC to set base line feed rates and any other process parameters. Microcontroller 80, comprising the elements of the PFD
(Process Flow Diagram) outputs mass measurement converted to PPH (Pounds per Hour).

[0116] Figure 37 shows the Program Flow chart of Microcontroller Program 82.
First a command of the desired feed rate and process parameters are specified and implemented by the process engineer. As incoming measurements are taken from Microwave Transceiver (s) 70, the millivolt values that are above a specified limit are masked and discarded.
These higher value readings are the readings of the rotor between pockets and are neglected to receive readings only from the rotor pockets. Measurements of the rotor pockets are then stored and counted. The measurements must be sequenced before they can be subtracted so that the readings are being compared properly (same pocket filled and empty). The difference of the two readings is then averaged over a set time. The shorter the time which the averaging is taken, the more accurate the measurement (The time period is specified by the process engineer.). Once the millivolt readings are averaged, the results are then compared to a chart relating millivolts to density.
Once the density of the material is computed the correct revolutions per minute (RPM) is determined based on the operating feed rate and the volumetric capacity of Rotor 10. An analog signal is then sent to the Variable Frequency Drive (VFD) scaled to the variables as outlined.
Based on the feed rate of the current operating conditions, the VFD is able to set the proper RPM
so the correct amount of material is fed in PPH (pounds per hour). This information is then displayed on the HMI (Human Interface Screen).

J. Connections of Main Elements and Sub-Elements of Invention [0117] Tubular Shell 11 and Reflective Cylinder 12 of Rotor 10 have an important connection as related to the Law of Reflection. "The Law of Reflection says that electromagnetic waves are reflected at an equal angle, thus the angle of incidence equals the angle of reflection."

[01181 Referring to Figure 6 it can be seen that Tubular Shell 11 and Reflective Cylinder 12 have the same radial point; therefore, they are concentric circles.
Additionally, it can be seen that Transceiver 70 is mounted on the x-axis, meaning that the OD of Reflective Cylinder 12 will always have a normal surface to the incident microwaves and will always have a normal surface to the reflected microwaves. This means that the OD surface of Reflective Cylinder 12 will be at zero degrees with Transceiver 70 throughout the 25 degrees of pocket opening rotation. Further meaning, the transmitted microwaves and the received microwaves will traverse along a zero angle path from and to Transceiver 70, even though Rotor 10.

[0119] End Plate (s) 21 and Side Plate (s) 22, when placed side by side and put into compressive sealing engagement with Tie Rod (s) 23 and Cap Screw (s) 24 are connected in that so doing, a sealing means is affected with Rotor 10 and Housing 40.

[0120] Axial Seal 31 and Radial Seal 32 when fitted onto Bearing 30 and installed into Housing 40 are connected in that sealing is affected with Housing 40 and bearing pivotal support is provided for Rotor 10.

[0121] Housing 40 comprises two of Slide Panel 41, two of End Plate 42, Top Retainer 43, Bottom Retainer 44, Drive Spacer 45, and two of Seal Retainer 46. When assembled, the elements form a flat sided, air-tight, box shaped housing. Side Panel 21 is attached to End Plate 22. Thin wall, light weight box is formed. Flat sides aid in attaching Electric Drive 60, Transceiver 70, and other ancillary elements.

[0122] Sealing Elements 50 comprise Compression Seal 51, Drive Screw 52, and Compression Pad 53. The elements function to prevent static leakage through feeder of invention. Compression 51 is placed on top of Seat Cage 20. (Compression 52 was installed into Seat Cage 20 prior top Side Panel attachment.) Drive Screw 52 is installed into Side Panel 21. (Drive Spacer 45 was installed on End Plate prior to Side Panel 21 attachment.) Retainer Seal 46 is installed on End Plate 22. Sealing Elements 50 prevent through leakage but also provide temperature compensation and wear compensation of Rotor and Seat Cage 20.

[0123] Electric Drive 60 revolves Cylinder Rotor 10. The speed of revolution is controlled by the VDF in Microcontroller 80. Drive 60 mounts directly to End Plate 22.

[0124] Microwave Transceiver (s) 70 both transmits and receives microwaves through material filled Rotor 10 pockets and empty Rotor 10 pocket. The purpose is to determine attenuation of material in filled pockets. Transceiver 70 and Horn Antenna 71 are mounted in Transceiver Enclosure 72. Transceiver Enclosure 72 is mounts directly to Side Plate 21.
[0125] Microcontroller 80 receives attenuation readings from Transceiver (s) 70, computes data, and adjusts speed of Electric Drive 60 to track with base line set-point of process, thereby causing Feeder of invention to feed, in real time, desired amount of material into process. Microcontroller 80 is mounted in end user control room. Cable connections are made between Transceiver 70, Electric Drive 60 and Microcontroller 80.
Interconnections of the Mass Measurement Feeder of the present invention are complete.

K. Alternative Embodiments of Invention First Alternative Variation of Invention [0126] Figure 38 is a cross-sectional top view of the First Alternative Variation of the Mass Measurement Feeder of the present invention. New in this view are Cylinder Rotor 110, Waveguide 111, Receivers (s) 112, and Transmitter 113.

[0127] Figure 39 is a cross-sectional end view of the First Alternative Variation of the Mass Measurement Feeder of the present invention. New in this view are Cylinder Rotor 110, Waveguide 111, and Receivers (s) 112.

[0128] It can be seen in these views that Rotor 110 differs from Rotor 10 of Figure 1. Rotor 110 is made of solid round bar construction with the addition of Waveguide 111. It can further be seen that Waveguide 111 is milled into the core of Rotor 110.
Additionally, it can be seen (Figure 38) that Waveguide 111 makes a 90 degree turn midway in Rotor 110.
Figure 39 shows Waveguide 111 terminating into the bottom of the 3 o'clock pocket.

[0129] The microwave mode in this First Alternative Variation is "transmission," in the Preferred Embodiment, the microwave mode is "reflection".

[0130] In the transmission mode, microwaves from Transmitter 113 are propagated along Waveguide 111, through the material in the 3 o' clock pocket into Receiver 112.

[0131] Figure 40 and Figure 41 show Cylinder Rotor 110 rotated 180 degrees.
What was the 3 o' clock pocket is now the 9 o' clock pocket, emptied of material. The material discharged as the pocket passed over the 6 o'clock position. In this rotor pocket position, it can be seen that Waveguide 1 I 1 is now directed at Receiver 112 at the 9 o' clock feeder position. It is understood that microwaves from Transmitter 113 are now transmitting through the empty pocket into Receiver 112. This permits comparing the 3 o' clock filled pocket reading with the 9 o' clock empty reading - hence the attenuation needed by Microcontroller 80.

[0132] The transmission mode illustrated in this First Alternative Variation has shown to work in extensive testing, however, it only reads one pocket per cylinder resolution, as compared to reading all pockets per revolution in the Preferred Embodiment, therefore, accuracy is somewhat less, and Rotor 110 is somewhat more difficult to manufacture than Rotor 10 of the Preferred Embodiment. The reason for the uneven pocket depths of Rotor 110 is to provide for a longer material path. In Rotor 110, the microwaves pass through the material only once, in Rotor 10, (reflection mode) the microwaves pass through the material twice. Also, the attenuation levels are slightly greater in the reflection mode of the Preferred Embodiment of the present invention.

Second Alternative Variation of Invention [0133] Referring to Figure 42, it is seen that the Second Alternative Variation of the Preferred Embodiment of the present invention is a single rotary pocket variation. Figure 42 shows a cross-sectional top view of this Variation. Figure 43 shows a cross-sectional end view of this Variation. The Single Pocket Window shows in this view at the 12 o' clock feeder position. Figure 44 shows a cross-sectional end view with the Single Window rotated to the 3 o' clock feeder position.

[0134] This Variation differs from the Preferred Embodiment in that it requires only one Transceiver 270 as shown in Figure 42. The microwaves are transmitted against the Polished Surface at the opposite end of Rotor 210 where they are reflected back into Transceiver 270.
In this Variation, the microwaves traverse in the axial plane of the rotor as opposed to the radial plane in the Preferred Embodiment.

[0135] This Variation of the Mass Measurement Feeder fills of material when the Rotor Pocket Window is the 12 o' clock feeder position (Figure 43). Figure 44 shows the Window rotated to the 3 o' clock position. In this rotor position, the material is sealed in the pocket---no further changes in density occur before material is discharged into the process at the 6 o' clock position. At the 3 o' clock position, microwaves are transmitted and received between Transceiver 70 and the Polished Surface of Rotor 210. The angle of incident and reflection are zero. The mV readings are stored in Microcontroller 80. Rotor 20 rotates to the 6 o' clock Window position where material discharges into process. Rotor 210 again rotates to the 9 o' clock Window position, pocket is again sealed, but empty. Empty pocket mV
readings are taken and fed to Microcontroller 80, where they are compared to the filled pocket reading. The difference, attenuation, is related to rotor pocket volume, computed and read out as pounds per cycle or pounds per revolution. Microcontroller 80 functions are similar as with the Preferred Embodiment.

[0136] This Variation can be used in an on-off mode or it can revolve continuously. In the continuous mode of operation, it must turn slower than the multi-pocket Rotor 10, to allow for longer fill and discharge times.

[0137] This Second Variation can be manufactured in very large sizes - 60 inch and larger diameters, having capacities of 8 to 10 cubic feet per cycle. This Variation is intended for use on large batch fill charge applications, such as pellet additives into grain feed, or plastic pellets into process reactors. This Variation is also both pressure and vacuum tight. Rotor 210 can be vented.

Third Alternative Variation of Invention [0138] Figure 45 shows in this variation a means of rotor pocket venting. New in this view are Rod Vent 323, Tube Vent 324, and Vent Cap 325. On pressure conveying and other pressurized systems. The rotor pockets (assuming P2 greater than P1 and clockwise rotation) fill with pressurized air as they pass over the 6 o' clock feeder position. On many applications, the trapped air must be vented or the pockets will not fill properly at the 12 on clock position. This is especially true on pressure conveying systems where P2 pressures may reach 50 PSIG. (If pocket air is not vented, it is call dynamic leakage---pumping action of the rotor.) P1 pressures may be near zero or even a vacuum.

[0139] Figure 46 shows Rotor 10 rotated to expose vent connector into Vent Rod 323. The exposed vent connector permits the trapped pocket air to vent through Vent Tube 324. A
user tube is connected and the air is vented in some suitable location.
Venting occurs automatically as Rotor 10 continues to rotate. Notice Vent Cap 325, when Rotor 10 is turning clockwise, Vent Cap 325 is on right side of feeder, if Rotor 10 is turning counter clockwise, Vent Cap 325 would be placed on left side and right side would vent.

[0140] The pocket vent means illustrated in Figure 45 and Figure 46 may be used to vent and trap toxic gases or prevent dilution of P1 vacuum. The vent means of this Variation can be provided on all Mass Measurement Feeders of the present invention.

L. Operation of Preferred Embodiment [0141] The preferred embodiment of the Mass Measurement Feeder of the present invention is shown in Figures 1, 2, 3, 4, 5, and 6. Figures 1 through 4 are self-explanatory views.
Figures 5 and 6 are top and end cross-sectional views of the Mass Measurement Feeder.

[0142] Referring to Figure 6, make the assumption that the Mass Measurement Feeder is installed on a dry, fine powder feed system. On this system, powder flows by gravity from an overhead storage vessel into inlet of Feeder and discharges from outlet of Feeder directly into a mix vessel located underneath. A liquid is fed into the mix vessel to form a paste with the powder. The paste becomes the base material for a downstream end product.
For the paste to work properly, it must consist of the correct amount of liquid and the correct amount of powder. The problem is not measuring the liquid correctly, it's measured in gallons. The problem comes in measuring the powder correctly on a continuous process. The problem is density. Density is an intrinsic part of a material, meaning that the density of the powder is constantly changing. At eight o'clock AM, the powder may weigh 50 pounds per cubic per cubic foot. At two PM, it may weigh 55 pounds per cubic foot.
Changes in density occur for a number of reasons, among them are: temperature, vibration, handling, packing, and variety of other factors. The problem is that traditional rotary feeders and screw feeders do not know that changes in density are occurring; therefore, the process must run on an assumed density value. The Mass Measurement Feeder of the present invention recognizes, in real time, the changes in density, and corrects for them in real time.

[0143] Still referring to Figure 6, Rotor 10 can rotate in either direction, but for illustration purposes, assume clockwise rotation. In this view, Rotor 10 is shown with 8 pockets; it can have more or less. The fine powder, from the overhead storage vessel, flows into the Feeder pockets as they pass under the 12 o'clock feeder position. The filled pockets continue to rotate passed the 3 o'clock feeder position and discharge the powder, into the underneath mix vessel, as they pass over the 6 o'clock feeder position. Without the microwaves enhancement of the Feeder, this would be called volumetric feeding, however, volumetric feeding does not account for changes in density as does the Mass Measurement Feeder of the present invention.

[0144] Staying with Figure 6, it can be seen that Rotor 10 is mounted inside, and turns within Seat Cage 20. Rotor 10 further turns within Bearing (s) 30 shown in Figure 5. With the aid of Sealing Elements 50, shown in Figure 27, the interface between Rotor 10 and Seat Cage 20 form a leak-tight seal. Therefore, once the rotor pockets are within the radius of Seat Cage 20, they are sealed. Therefore, the powder is sealed within these pockets as they pass through the 3 o'clock feeder position. Being in a sealed pocket, no further changes of density occur to the powder within the sealed pocket before that powder discharges into the mix vessel. This is where the microwave transceivers are used.

[0145] Still looking at Figure 6, it be seen that a Microwave Transceiver (s) 70, shown in Figure 32, are mounted on Housing 40 at the 3 o'clock and at the 9 o'clock feeder positions.
Microwave Transceiver (s) 70 and Electric Drive 60, shown in Figure 31 are all connected to Microcontroller 80. Within Microcontroller 80 are an Interface Display, a VFD
(Variable Frequency Drive), a 24 VDC Power Supply, a 5 VDC Power Supply, and a PLC
(Programmable Logic Controller), these elements are seen in Figure 35. Refer to Figure 36 for Process Flow Diagram 81.

[0146] The 3 o' clock pocket is filled and sealed with powder. As the pocket passes the 3 o'clock Feeder position, microwaves are transmitted through the powder from Microwave Transceiver 70. The microwaves go through the powder, hit the surface of Reflective Core 12 and reflex back into Transceiver 70. The received value is stored mV's (millivolts) in Microcontroller 80. The same rotor pocket continues to rotate, discharging the power at 6 0' clock, and when it passes through the 9 o'clock feeder position, microwaves are again transmitted into the (empty) pocket from Transceiver 70 mounted on Housing 40 at 9 o'clock. The microwaves again reflect off the surface of Reflective Core 11, (see Figure 10), and return into Transceiver 70 (Transceiver 70 both transmits and receives microwaves).
The received mV value again goes to Microcontroller 80 where the filled pocket reading is compared with the empty reading the difference (attenuation) is the working number for correcting for changes in density.

[0147] Assume the reading at 3 o'clock (filled pocket) to be 400 mV's, and assume the 9 o'clock reading (empty pocket) to be 600 mV's. The difference between 600 mV's and 400 mV is 200 mV. This difference (200 mV) is called attenuation (Attenuation is the absorption of microwaves by the material.) Another way to look at this is to say that 200 mV's of microwaves were absorbed by the material in the 3 o'clock pocket.
Microcontroller 80 compared the filled pocket reading with the empty pocket reading, and arrived at 200 mV. Microcontroller 80 now compares the fixed volume of the pocket and computes a mass measurement of that pocket. (It is the difference between an empty pocket and a filled pocket, as related to pocket volume, which equals mass measurement.) That value is then compared to the base line set point. If needed, the VFD changes the speed of Electric Drive 60 - if the density is below the set point, the Feeder speeds up, if the density is above the set point, the feeder slows down. This procedure is repeated for each pocket as Cylinder Rotor continues to rotate. It is density (defined as mass per unit volume) of the material, that the Mass Measurement feeder of the present invention is measuring.

[0148] At start up, the Feeder is first run with empty pockets only - no material. The values of the empty readings determine a calibration range. Thereafter, if an empty pocket reading falls outside of that range some precaution takes place, an alarm sounds, feeder shuts down, feeder continues to run but not measuring density.

[0149] Before start up, a sliding chart is prepared that plots known, weighed samples of the material. Chart values and the base line value are programmed into Microcontroller 80.
These variables are reprogrammed for each new or different application requirement.
Microcontroller Program 82 is written for and is specific to the Mass Measurement Feeder of the present invention.

[0150] The Mass Measurement Feeder was developed as an alternate to what is commonly called loss-in-weigh feeding. Loss-in-weigh is a batch process whereby a load cell mounted hopper is filled with material and weighed. The material is fed out - hence loss-in-weigh -until hopper is empty. Process stopped, hopper refilled, hence batch process.

[0151] Mass measurement feeding has certain advantages over loss-in-weigh feeding: 1) it is continuous, 2) it corrects for changes in density in real time, 3) it is more accurate, 4) it requires less operating space, 5) more maintenance free, and 6) it costs less to purchase and to operate.

[0152] The Mass Measurement Feeder of the present invention is unique in that it is a union of highly tested and superior mechanical technology with highly proven radar type microwave technology. The superior mechanical technology does not exist with traditional rotary feeders or with traditional screw feeders.

[0153] What has been described and illustrated herein is a preferred embodiment of the invention along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations.
Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention in which all terms are meant in their broadest, reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.

Claims

THAT WHICH IS CLAIMED IS:

1. A seat cage of a feeder, comprising:
a rotor;
a pair of end plates;
a plurality of side plates in communication with the end plates, the side plates having a matching radius to the radius of the rotor and covering approximately 270 degrees of the surface of the rotor; and wherein the seat cage and the surface of the rotor communicate to provide an air-tight interface and the seat cage in conjunction with a compression seal provides an air-tight seal with a top retainer, whereby static leakage through the feeder is prevented.