Abstrict Peanut hulls are processed into dust free granules suitable for
use as chemical carriers and moisture absorbent materials, including
cat litter, by being pulverized to a powder. Deodorizer, scent and
mold inhibitor powders are added to the peanut hulls powder. The
powders are compacted into compacted masses which are then crumbled
into granules. The powder is then compacted into compact masses
that are divided into granules and screened.
Claims I claim:
1. A method of processing peanut hulls into substantially dust
free granules suitable for use as cat litter, and with the method
comprising the steps of:
(a) pulverizing the peanut hulls to a powder,
(b) adding an additive in powdered form to the peanut hulls powder,
(c) compacting the peanut hulls and additive powders into compacted
masses, and
(d) crumbling the compacted masses into granules.
2. The method of claim 1 wherein step (d) the compacted masses
are crumbled rolled.
3. The method of claim 1 wherein step (b) a deodorizer additive
in powdered form is added to the peanut hulls powder.
4. The method of claim 1 wherein step (b) a scent additive in powdered
form is added to the peanut hulls powder.
5. The method of claim 1 wherein step (b) a mold inhibitor in powdered
form is added to the peanut hulls powder.
6. The method of claim 1 further comprising the step of
(e) screening the granules to remove those that pass through a
16 gauge screen and those that do not pass through a 6 gauge screen.
7. A method of processing cat litter comprising the steps of:
(a) pulverizing peanut hulls to a powder by milling the hulls through
a substantially 1/16 inch size screen,
(b) adding a powdered additive the peanut hulls powder,
(c) compacting the peanut hulls and additive powders into compacted
masses in the form of compaction sheets or pellets having a pour
weight of at least 36 pounds per cubic foot,
(d) crumble rolling the compacted masses into granules, and
(e) reducing the residual dust content of the granules by shaking
the granules on shaker screens.
8. The method of claim 7 wherein step (b) a deodorizer powder is
added to the peanut hulls powder.
9. The method of claim 7 wherein step (b) a scent powder is added
to the peanut hulls powder.
10. The method of claim 9 wherein step (b) a mold inhibitor powder
is added to the peanut hulls powder.
11. The method of claim 7 further comprising the step of drying
the granules to a moisture level of less than 7% by weight.
12. The method of claim 7 which consists essentially of the recited
steps.
13. The method of claim 7 wherein step (e) the shaker screens remove
granules that pass through a 16 gauge screen and those that do not
pass through a 6 gauge screen.
14. A method of processing peanut hulls into granules suitable
for use as cat litter, comprising the steps of:
(a) pulverizing the peanut hulls to a powder,
(b) adding an additive selected from the group consisting of a
mold inhibitor, a deodorizer, a scent, and mixtures thereof to the
peanut hulls powder,
(c) compacting the peanut hulls powder and additive into compacted
masses, and
(d) crumbling the compacted masses into granules.
15. The method of claim 14 further comprising the step of (e)
screening the granules.
16. The method of claim 15 wherein the screening of the granules
reduces the residual dust content to approximately 2% or less.
17. The method of claim 14 further comprising the step of (f)
controlling the moisture level of the granules so that the granules
have a moisture level of approximately 7% or less by weight.
18. A method of producing cat litter, comprising the steps of:
(a) milling peanut hulls through a screen defining openings of
approximately 1/16 inch to produce a peanut hulls powder,
(b) adding an additive to the peanut hulls powder,
(c) compacting the peanut hulls powder and additive into compacted
masses,
(d) crumble rolling the compacted masses into granules, and
(e) shaking the granules on shaker screens.
19. The method of claim 18 wherein said additive in step (b) comprises
a deodorizer.
20. The method of claim 18 wherein said additive in step (b) comprises
a scent.
21. The method of claim 18 wherein said additive in step (b) comprises
a mold inhibitor.
22. The method of claim 18 wherein the shaking of the granules
on shake screens reduces the residual dust content to approximately
2% or less.
23. The method of claim 18 further comprising the step of (f)
controlling the moisture level of the granules so that the granules
have a moisture level of approximately 7% or less by weight.
24. Animal litter granules, consisting essentially of peanut hulls
and a mold inhibitor, said animal litter granules being formed by
milling the peanut hulls to a powder, adding a mold inhibitor to
the powder to form a mixture composed of the powder and the mold
inhibitor, compacting the mixture into a compacted mass, and crumbling
the compacted mass into granules.
25. The animal litter granules of claim 24 wherein most of said
granules will pass through a 6 gauge screen but will not pass through
a 16 gauge screen.
26. The animal litter granules of claim 24 further comprising
an additive selected from a group consisting of a deodorizer, a
scent and mixtures thereof.
27. The animal litter granules of claim 24 having a maximum dust
content of approximately 2%.
28. The animal litter granules of claim 24 said granules having
a moisture level of approximately 7% by weight.
29. The animal litter granules of claim 28 having a maximum dust
content of approximately 2%.
30. The animal litter granules of claim 29 wherein most of said
granules will pass through a 6 gauge screen but will not pass through
a 16 gauge screen.
31. Animal litter granules, consisting essentially of peanut hulls
and a deodorizer, said animal litter granules formed by milling
the peanut hulls to a powder, adding a deodorizer to the powder
to form a mixture composed of the powder and the deodorizer, compacting
the mixture into a compacted mass, and crumbling the compacted mass
into granules.
32. The animal litter granules of claim 31 wherein most of said
granules will pass through a 6 gauge screen but will not pass through
a 16 gauge screen.
33. The animal litter granules of claim 31 having a maximum dust
content of approximately 2%.
34. The animal litter granules of claim 31 said granules having
a moisture level of approximately 7% by weight.
35. The animal litter granules of claim 34 having a maximum dust
content of approximately 2%.
36. The animal litter granules of claim 35 wherein most of said
granules will pass through a 6 gauge screen but will not pass through
a 16 gauge screen.
37. Animal litter granules, consisting essentially of peanut hulls,
a mold inhibitor and a deodorizer, said animal litter granules formed
by milling the peanut hulls to a powder, adding a mold inhibitor
and a deodorizer to the powder to form a mixture composed of the
powder, the mold inhibitor and the deodorizer, compacting the mixture
into a compacted mass, and crumbling the compacted mass into granules.
38. The animal litter granules of claim 37 wherein mos of said
granules will pass through a 6 gauge screen but will not pass through
a 16 gauge screen.
39. The animal litter granules of claim 37 having a maximum dust
content of approximately 2%.
40. The animal litter granules o claim 37 said granules having
a moisture level of approximately 7% by weight.
41. The animal litter granules of claim 40 having a maximum dust
content of approximately 2%.
42. The animal litter granules of claim 41 wherein most of said
granules will pass through a 6 gauge screen but will not pass through
a 16 gauge screen.
43. The method of claim 1 further comprising the step of
(e) screening the granules.
44. The method of claim 43 wherein the screening of the granules
reduces the residual dust content to approximately 2% or less.
45. The method of claim 1 further comprising the step of (f) controlling
the moisture level of the granules so that the granules have a moisture
level of approximately 7% or less by weigh.
46. The method of claim 7 wherein the shaking of the granules
on shaker screens reduces the residual dust content of the granules
to approximately 2% or less.
47. The method of claim 7 further comprising the step of (f) controlling
the moisture level of the granules so that the granules have a moisture
level of approximately 7% or less by weight.
Description TECHNICAL FIELD
This invention relates to methods of processing peanut hulls into
forms suitable for use as chemical carriers and as moisture absorbent
materials, including cat litter.
BACKGROUND OF THE INVENTION
Commercial peanut shelling operations today create large quantities
of peanut hulls. Since the sale of the hulls has not usually proven
to be profitable, a percentage of shells have normally been disposed
of, as by incineration, which produces air borne pollutants that
degrade the atmosphere, or by dumping with its problems of continuous
accumulations.
There are some situations where peanut hulls are sold on a limited
basis as an economical by-product of the shelling operation rather
than discarded or processed as waste. Heretofore, these have primarily
been limited to the use of peanut hulls for litter, as filler in
artificial fireplace logs, and as cattle feed roughage. These limited
usages however place demand far below shell availability.
It has also been known that peanut hulls have the potential for
profitable commercial use in other applications. This is attributable
to their chemical inertness property which renders them suitable
as carriers for pesticides and fertilizers. Their high liquid absorbing
property also renders them potentially suitable for use in a number
of industrial processes as moisture absorbent agents.
Attempts at transforming peanut hulls into masses of size and weight
suitable for use as chemical, i.e. pesticide and fertilizer carriers
and absorbent agents have been beset with problems. Foremost among
these has been the creation of dust as the hulls are reconfigured
as by milling and pelletizing. The resulting granules have also
been too light in weight for these targeted usages, and have had
variable moisture levels.
SUMMARY OF THE INVENTION
In a preferred form of the invention, a method has now been discovered
for processing peanut hulls into substantially dust free granules
that are suitable for use as pesticide and fertilizer carriers and
as moisture absorbent materials. The method comprises the steps
of pulverizing the peanut hulls to a powder as by milling them through
a screen having interstices no greater than 3/32 inch which size
limitation has been discovered to be of critical importance. Preferably
they are milled through a 1/16 inch screen. After the peanut hulls
have been pulverized the powder is compacted into highly compact,
dense masses of a size greater than the size of the end product.
If desired the compaction sheets or pellets are dried to limit their
moisture level. The compacted masses are divided into granules as
by being crumbled, flaked or chipped. Finally, the crumbles are
screened into selected granule sizes.
In another preferred form of the invention, a method has now been
discovered for processing peanut hulls into substantially dust free
granules suitable for use as cat litter. The method comprises the
steps of pulverizing the peanut hulls to a powder and adding an
additive in powdered form to the peanut hulls powder. The additive
powders preferably include deodorizers and mold inhibitors. The
peanut hulls and additive powders are compacted into compacted masses
which are then crumbled into cat litter granules.
DETAILED DESCRIPTION
Essentially the new process transforms the weight, density, shape,
size, moisture level and structural integrity of peanut hulls into
granules that are suitable for use as carriers of chemical agents
and as moisture absorbent materials for use in various industrial
processes. After an initial grinding, that is conventionally done
at the commercial sheller, the peanut hulls are further ground or
milled through a screen preferably having 1/16 inch interstices.
A 300 to 350 HP, full cycle hammermill (or two 150 HP hammermills),
are preferably used. This causes the hulls to be ground into powder,
the term "powder" herein referring to hull material passed
through a screen having screen openings no greater than 3/32 inch.
It is critically important that the screen interstices be no more
than 3/32 inch. Screen openings any larger than that, such as even
as small as 1/8 inch, have been found to be ruinous of the process
in that the final product is entirely too dusty, flaky and light
in weight for extensive commercial use.
The peanut hull powder is next compacted by being pelletized or
compacted into compaction sheets. Where the hulls are compacted
a compactor produced by Prater Industries of Chicago, Ill. has been
found to work satisfactorily in producing 48 inch long compaction
sheets 4 to 8 inches wide. Where the hulls are pelletized a large
300 HP pellet mill has been found to work well that produces pellets
of a 5/16 inch diameter and approximately 3/4 inch long size. The
compaction is to such a high degree that the pellets have a pour
weight of between 36 and 42 pounds per cubic foot with 38-40 pounds
per cubic feet being preferred. If required for a specific end use,
the compaction sheets or pellets are dried to limit this moisture
level such as to approximately 7% or less by weight.
Following the compaction step the compacted masses, in the form
of pellets or compaction sheets, are divided and broken up into
granules. A slowly driven large crumble roll or Prater flaker has
been found to create granules of good consistency. Conversely, hammermilling
has been found to be too violent. The compaction of the powder is
such that the weight of the end product granules is between some
26 and 30 pounds per cubic foot, with 27 to 29 pounds being preferred
and 28 pounds per cubic foot being ideal. With less compaction the
end product is too light. Compaction sheets may be broken up by
rotating steel finger tips with the Prater compactor.
Finally the granules are separated as by the use of shaker screens
which divides and separates the granules into selected sizes. This
is done sufficiently slow to remove approximately 2% or less of
residual dust content and preferably less than 1%. For use as carriers
of pesticides, i.e. insecticides, herbicides, fungicides and rodenticides
the granules should be generally round, granular shaped and not
flat. Ninety-nine percent of the end product should pass through
a 14 gauge screen and not pass through a 40 gauge screen.
Again it is emphasized that it is critical for the peanut hulls
to be ground or milled to powder size for this enables the material
to be compacted into sufficiently dense masses. Compaction should
be such as to produce a pour weight of at least 36 pounds per cubic
foot for 5/16 diameter by 3/4 inch long cylindrical pellets. Without
this degree of density the dust content and product weight has been
found to be unsuitable for the above mentioned commercial applications.
Animal litter, particularly cat litter, may be produced by the
just described process with the addition of powders added to the
peanut hull powder prior to compaction. These additives powders
are mold inhibitors, and deodorizers such as those available from
Alltech, Inc. of Nickolasville, Ky. If desired, scent may also be
added in powdered or liquid spray form to the peanut hulls powder
before compaction. These additive powders are mixed with the peanut
hulls powder by a microfeeder which preferably meters one pound
of deodorizer and six pounds of mold inhibitor powders for every
ton of peanut hulls powder. The peanut hulls and additive powders
are compacted into compacted masses in the form of compaction sheets
or pellets having a pour weight of at least 36 pounds per cubic
foot. Once the compactions are broken into granules, most of the
cat litter granules should pass through a 6 gauge screen and not
pass through a 16 gauge screen. Following the step of breaking the
compactions into granules, the above process also may include the
step of screening the granules with the shaker screens to remove
those granules which pass through a 16 gauge screen and those granules
which do not pass through a 6 gauge screen.
Though preferred forms of the invention have been described in
detail, it should be understood that numerous modifications may
be, in addition to those expressly recited, may be made thereto
without departure from the spirit and scope of the invention as
set forth in the following claims. |