Food processing system

A system for pulverizing waste food and converting it into dried animal feed in which the waste food is first passed through a cylindrical chopper comprising a pivotally mounted hammer on a rotating plate which operates in relationship to a fixed cylindrical surface of lands and grooves, and thereafter, the food is passed between horizontally arranged and relatively rotating sets of lands and grooves. The material is then passed to a buffer storage tank where it is agitated to maintain consistency, and thereafter, in a constant flow provided to a rotating drum-type dryer where the material is dried and formed into flakes having a moisture content of 10 to 14 percent.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the conversion of vegetable and animal matter 
into an emulsion, and more particularly to a system which includes 
improved means for pulverizing and emulsifying food stuff. 
2. General Description of the Prior Art 
A principal problem in the construction of a compact and economical system 
for the conversion of waste food, including bones and tough fibers, to 
dried animal feed is that of breaking down the food into sufficiently 
small particles and to accomplish this economically. Heretofore it has 
been found that the particle size should be reduced down to a maximum 
cross section of approximately 0.03 inch in order to achieve consistency 
in drying and sterilization. The applicant is unaware of the existence of 
any single apparatus for accomplishing this, it having been the known 
practice of utilizing staged breakers, cutters, and even then the results 
were not entirely satisfactory. Particularly, it has been most difficult 
to obtain uniformity in particle size from a variety of waste food 
sources. 
Accordingly, it is an object of this invention to provide an improved waste 
food conversion system of the character described wherein there is 
achieved a more uniform pulverization with a variety of waste foods. A 
further object is to provide a pulverizer which is compact and 
sufficiently low in cost for it to be employed at sources of waste food, 
such as in restaurants and cafeterias. 
SUMMARY OF THE INVENTION 
In accordance with this invention, pulverization is achieved by a device 
having two basic parts, a rotor and a stator. The stator has a series of 
vertically and circumferentially spaced lands on an inner surface of a 
tubular portion of it and a series of radially and circumferentially lands 
on the underside of a plate portion which extends radially outwardly and 
horizontally from a bottom end of the tubular portion. The rotor member, 
generally in the form of a rotating plate, includes a pivotally attached 
hammer which operates between lands on the tubular portion of the stator 
and radially and circumferentially spaced lands which rotate within the 
horizontally arranged lands of the stator. As one feature of the 
invention, the hammer has at least one surface region which is inclined at 
an angle of less than 90 degrees with respect to the horizontal.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring to the drawings, pulverizer 10 includes a throat region 12 
through which waste food is supplied. Pulverizer 10 basically consists of 
stator 14 and rotor 16, the latter being driven by motor 18 via shaft 20, 
which is attached by means of nut 22. Hammer assemblies 23, 24, 25, and 
26, spaced 90 degrees apart, each include first and second hammers 28 held 
on frame member 30 by pin 32. Each of these assemblies is attached to a 
generally flat plate central region 34 of rotor 16 by bolt 36. Hammers 28 
have diagonally cut sides 38 with a height dimension which fits with a 
0.020 to 0.030 inch clearance between upper and lower surfaces 40 and 42 
of mating circular lands 44 in a tubular portion of stator 14. Four 
grooves 45, formed between the lands, are shown, as well as only two sets 
of mating hammers; but it is to be appreciated that additional hammers may 
be added above the two shown to operate in the remaining grooves 45 of 
stator 14. An annular extension 46 of stator 14 is formed by a generally 
horizontal stator plate 48, extending radially outward from the lower edge 
50 of the tubular portion of stator 14. The lower surface 52 of this 
extension consists of radially and circumferentially spaced lands 54 which 
form a generally peripheral portion of stator 14. An outer annular portion 
56 of rotor 16 has a like configured, but a complementary set of lands 58 
which rotate within grooves 60 formed by the lands 54 of stator 14. 
Exterior of the outer edge of rotor plate 16 and stator 14 is an annular 
cavity 62 in which vanes 64, attached to rotor plate 16, operate and form 
a pump which picks up pulverized particles. Thus, the waste food, 
progressively pulverized, flows down through tubular cavity 66 of the 
device and out between the horizontally mated lands and grooves 58 and 60, 
respectively, where it is pumped out through exit opening 68. 
Referring to FIG. 4, pulverizer 10 is supported in cabinet 70 (by means not 
shown) with its opening aligned with an opening 72 in tray 74 hinged on 
the back by hinges 75. With tray 74 in an operating horizontal position as 
shown, waste food to be processed is placed on tray 74 in an opposite end 
region 76. The top region 78 around opening 72 is generally covered, in 
operation, by cover 80 hinged by hinges 82 and 86. A gate 88, pivotally 
supported by rod 90, is electrically operated by solenoid 92 which 
generally holds gate 88 open; but in the event of the occurrence of a 
piece of metal in waste food placed on tray 74, solenoid 92 is 
de-energized, closing gate 88. Metal is detected by metal detector 94 
positioned on the underside of tray 74, and it provides a control output 
to solenoid 92. In addition to providing a gated opening, cover 86 also 
acts as an anti-kickback barrier to protect personnel from any articles 
which might be expelled through opening 72 from pulverizer 10. 
The output 68 of pulverizer 10 is connected to the input 96 of buffer 
holding tank 98, which is configured with a rounded bottom and lower 
center region 100. Blade assemblies 102 and 104 conform to the bottom of 
tank 98 and are driven through axle 117 by motor 106. Buffer holding tank 
98 is employed to accept an uneven flow of material from pulverizer 10 and 
to provide an even output flow. Inasmuch as material may be retained in 
holding tank 98 for a significant period of time, the blades function to 
maintain a uniform consistency and moisture in the pulverized material. 
Where this is not done, there would result stratification of the moisture, 
and this would complicate the drying process. Drying of the material is 
effected by double drum dryer 108 which is supplied from tank 98 at a 
selected rate by pump 110 through pipe 112 from a central, low point, 
output of tank 98. 
OPERATION 
Food waste is collected from plates, dishes, and trimming areas of a food 
service operation, and it is poured or placed on end region 76 of sorting 
tray 74. By visual inspection, non-edible matter is observed and removed 
by hand prior to the food waste being moved, by a hand-operated paddle, to 
the left toward drain opening 72. As a further procedure to remove harmful 
matter, both from the point of view of the contents of the final product 
and the operation of the pulverizer, the waste food is passed over metal 
detector 94; and when metal is detected, as, for example, because of the 
presence of a knife or fork, the metal detector is energized; and it 
applies a signal to solenoid 92 which operates gate 88 to block further 
movement of food waste to the left. 
With gate 88 open, food waste is moved through tray drain 72 where it falls 
by gravity into throat 12 of pulverizer 10. Food waste is then deposited 
on rotor plate 16 where, by centrifugal force, it is moved laterally to 
inner circular wall 114, forming with rotor plate 16 a grinding bowl. The 
radially extending hammers 28, extended by centrifugal force, force the 
waste food between lands 44 of wall 114, causing the waste food to be 
reduced to small particles. The waste food is also forced downward and 
along inclined planes 38 of hammer 28. This motion is continuous until the 
waste food is essentially liquified and forced downward to the radial 
space formed between mating lands 58 of rotor 16 and lands 54 of stator 
14. The material is then forced outward between these lands and further 
reduced in particle size. It then reaches vane pump cavity 62 where the 
pump vanes 64 force the material out through outlet 68 to tank 98. 
In tank 98, emulsified food material is agitated continuously by mixing 
blades 116. The offset (not parallel with respect to drive axle 117) 
geometry of blades 116 is such that the food material is swept to the 
interior or center of mixing tank 98, which is directly over drain 118, 
and this facilitates movement through drain 118 into positive 
displacement-type pump 110. Low level sensor 120 is positioned at a point 
122, and it senses food level dropping to this point; and when this 
occurs, sensor 120 turns off pump 110 (by means not shown) in order to 
prevent pumping without material present which may destroy the pump. In 
order to prevent overflow of tank 98, high level sensor 124 senses level 
at its indicated position and is connected (by means not shown) to turn 
off pulverizer 10 when material rises above the position of this sensor. 
The emulsified food waste supplied to pump 110 is pumped at a selected rate 
to dehydrator 108 where the emulsified food is dried to a selected degree 
of dryness or moisture content (8 to 10 percent) and ejected through 
outlet 126 as a dried animal feed. 
Safety cut-off switch 128 inhibits emulsifer motor 18 and mixing motor 106 
(by means not shown) when tray 74 is raised for cleaning or service. This 
thus prevents any manual contact with the interior of emulsifier 10 or 
tank 98 when either is operating.