AN IMPROVED PROCESS FOR THE CONVERSION OF WHEAT TO FLOUR AND BRAN
Year: 1879

page_text: LETTERS PATENT to John Auguste Arnold Buchholz, of Vauxhall, in the
County of Surrey, Engineer, for the Invention of "AN IMPROVED PROCESS
FOR THE CONVERSION OF WHEAT TO FLOUR AND BRAN."
Sealed the 2nd April 1880, and dated the 29th December 1879..
PROVISIONAL SPECIFICATION left by the said John Auguste Arnold
Buchholz at the Office of the Commissioners of Patents on the 29th December
1879.
JOHN AUGUSTE ARNOLD BUCHHOLZ, of Vauxhall, in the County of Surrey,
Engineer. "AN IMPROVED PROCESS FOR THE CONVERSION OF WHEAT TO FLOUR
AND BRAN."
The object of this Invention is so to treat wheat that it may be converted at one
continuous operation into marketable flour and into clean compressed marketable
bran.
To this end I use a series of machines, the principles of action of which are well
known in the milling trade, but which I now combine in such a manner as will
enable me to carry on the process of crushing, sifting, dressing, and rolling,
simultaneously in an efficient and economical manner.
The wheat I first subject to the action of the crushing or grinding machine
for which I obtained Letters Patent bearing date the 3rd day of June 1879,
No. 2205.
In this machine the wheat is by the action of a pair of crushing rolls partly
reduced to fine and coarse flours which are sifted out from the portion containing
the bran, and this by a crushing action of a second pair of rolls is reduced to flour,
leaving the bran in an uninjured state.
The products from both the first and second pair of crushing surfaces 1 lead to a
bolting or stripping reel covered with silk or fine wire gauze or perforated metal,
by which the flour, both coarse and fine, is separated from the bran.
The flour discharged from the stripping reel I lead to a finishing reel, the first
portion of which is covered with No. 11 silk, for dressing out the second quality
Hour (forming about 50 per cent. of the flour yielded by the wheat). A small
portion of the tail end of the reel is covered with No. 6 silk to dress out the finest
middlings or the smallest particles of the incompletely ground flour particles. The

page_text: coarsest portions of the flour which cannot pass through the silk are conveyed to a
set of sizing sieves where they are sized into five sizes corresponding to the silk
numbers 1, 2, 3, 4, and 5; each size thence drops into a purifier which removes
branny impurities consisting of fine disintegrated portions of the bran in the form
of stive (the main portion of the bran having been kept back by the first stripping
reel) whence it, the purified middlings, is conveyed to a pair of smooth compressing
rollers to be treated as hereafter explained.
The middlings from the purifiers I conduct to a roller mill, the rollers, which will
preferably be three in number, arranged to act as two pairs, being in this case
smooth rollers.
The purified middlings I pass between the upper pair of crushing surfaces, the
surface speeds of which will slightly vary, one roller making 180 rovolutions per
minute to, say, 144 of the other, and I lead the product to a second finishing reel
covered like the first, which separates the flour from fine middlings, as before
explained, the flour which is the first quality forming about 20 per cent. of the
wheat.
The fine middlings obtained from the first finishing reel I submit to a second
crushing action between the lower pair of crushing surfaces of the smooth roller mill,
adding thereto the second quality of flour or fine middlings obtained from the second
finishing reel.
The product from these lower rollers I lead back to the stream which passes from
the firstmill into the first bolting or stripping reel, and I thus ensure the proper
dressing and mixing of the whole of the flour.
.
Having disposed of the flour I now proceed to finish the offals by subjecting
them to the squeezing action of smooth rollers working at rather a higher speeds
than that adopted for crushing middlings. I have found 200 and 250 revolutions
per minute do excellent work with a pair of rollers each 8 inches in diameter.
The bran which is delivered from the tail of the first stripping reel is conveyed
to the upper pair of a mill fitted smooth rollers working with the speeds above
indicated, where it is rolled out into thin smoothly polished flat flakes.
I would have it understood that unless the bran is well cleared of flour in the
first process, i.e., by my patented wheat crushing roller mill, the action of the
smooth rollers on the bran will fail to be satisfactory but will prove exceedingly
wasteful.
The small bran particles not dressed through the second finishing reel I lead to
the second pair of compressing rollers, the first pair of which operates on the main
bulk of the bran as above mentioned.
The whole of the compressed bran as it is delivered from this machine passes to
a reel termed the dusting reel, which dusts out the flour particles contained therein
and delivers the same to another reel. This reel separates it into fine and coarse 4
sharps and third quality flour.
I prefer using reels termed "contrifugal reels" because of the tendency to caking
when smooth rollers are used.
The bran obtained by this process is free from dust and is bright and smoothly
polished, a matter of some importance where dry feeding is adopted, and the bran 4
being condensed by this treatment will pack closely for transport, which is also a
material advantage.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Auguste Arnold Buchholz in the Great Seal Patent Office on the
29th June 1880.
"
JOHN AUGUSTE ARNOLD BUCHHOLZ, of Vauxhall, in the County of Surrey,
Engineer. AN IMPROVED PROCESS FOR THE CONVERSION OF WHEAT TO FLOUR
AND BRAN."
The object of this Invention is so to treat wheat that it may be converted by
one continuous operation into marketable flour, and into clean compressed
maiketable bran.
To this end I use a series of machines, the principles of action of which are well
known in the milling trade, but which I now combine in such a manner as will
enable me to carry on the process of crushing, sifting, dressing, and rolling simul-
taneously in an efficient and economical manner without the production in any
appreciable quantity of bran specks, which once formed are extremely difficult of
removal from the flour.
In the accompanying Drawings I have shewn, by three sample diagrams, the
system which I employ in carrying out the object of my Invention. The order in
which some of the machines are arranged, it will be presently seen, varies some-
what to suit the varied requirements of the miller, or the charactor of the wheat
under treatment, but the principle of the continuous process is strictly adhered to
throughout in dealing with the fine middlings and the offuls. Other modifications,
however, of these arrangements will suggest themselves to the experienced miller,
according to the combined requirements of quality of flour and quality of available
wheat as the advantages of the system of the continuous operation become more
fully appreciated.
Referring now to diagram L, I will proceed to explain the course of working so as
to produce in an economical manner satisfactory results.
In converting wheat into flour, and obtaining also a clean compressed bran, I use
three roller mills of the "Mechwart" type, which are indicated at A, A¹, and A³.
I also employ a bolting or stripping reel B of the ordinary construction, and other
reels C, C³, C³, C, for dressing and stripping of the ordinary construction. Besides
these I provide four sizing sieves D, D, D, D, and in connection with these five of
Thompson's, or other efficient purifiers E¹, E, ES, E*, E³.
The wheat I first subject to the action of the crushing or grinding machine A,
which is modified according to the Invention for which I obtained Letters Patent
bearing date the third day of June, One thousand eight hundred and seventy-nine,
No. 2205.
In this machine, which is fitted with three rollers (arranged to act as two pairs)
the wheat is by the upper crushing rolls partly reduced to meal containing a
large proportion of flour. On the removal of this flour by automatic sifting the
remaining meal is submitted to a second crushing action and reduced to four,
leaving the bran in an uninjured state.
The products from both the first and second pair of crushing surfaces I lead to
This reel is covered
the bolting or stripping reel B, as indicated by the red line a.
with silk or fine wire gauze, or perforated metal, and by its action the flour,
whether coarse or fine, is separated from the bran.
The flour delivered from the stripping reel I lead to the finishing reel C, as
indicated by the red line b. The first portion of this reel is covered with No. 11
silk for dressing out the second quality flour. The yield of this quality of flour
will equal about one half the original weight of the wheat. A small portion of the
tail end of the reel is covered with No. 6 silk for the purpose of dressing out the
finest middlings or the smallest particles of the incompletely ground flour particles.
The coarsest portions of the flour which cannot pass through the silk I convey to

page_text: the set of sizing sieves D, D, D, D, as indicated by the red line c, where they are
assorted into five qualities.
The assorted product thence drops according to size into the five purifiers, the
tailings from the upper and lower sieves falling respectively into the purifiers
E, E, E, and the sifted portions into the purifiers E, E. By the action of these
purifiers the branny impurities, consisting of fine disintegrated portions of the bran
in the form of stive, will be removed, the main portion of the bran having been
kept back by the first stripping reel B. The purified middlings, either assorted
according to quality or not, are collected from the several purifiers as indicated by
the red lines d, d. I now subject to the action of the roller mill A¹, containing a 1
group of three rollers set one above the other to act as two pairs, and being in this
case smooth rollers.
The purified middlings I pass between the upper pair of crushing surfaces, the
surface speeds of which will slightly vary, one roller making one hundred and
eighty revolutions per minute, to, say, one hundred and forty four of the other, and 1
I lead the product to the second finishing or dressing reel C₁ covered like the first,
which separates the flour from fine middlings, as before explained, the flour, which
is the first quality, forming some eighteen or twenty per cent. by weight of the
wheat under treatment.
The fine middlings obtained from the finishing reel C I submit to a second
crushing action between the lower pair of crushing surfaces of the smooth roller
mill A, as indicated by the red line e, adding thereto the second quality of flour
or fine middlings obtained from the second finishing reel C¹.
The product from these lower rollers I lead back to the stream which passes from
the first mill A into the first bolting or stripping reel B, as indicated by the red 2
linef. This returning of the finest particles of middlings when crushed between
smooth rollers into the whole wheat meal is a leading feature of the process,
because it not only ensures the proper dressing and mixing of the whole of the
flour, but also materially advances the production of a full yield of flour.
Having disposed of the flour I now proceed to finish the offals by subjecting
them to the squeezing action of smooth rollers working at rather a higher speed
than that adopted for crushing middlings. I have found two hundred and two
hundred and fifty revolutions per minute, or two hundred and four hundred,
according to the hardness or mellowness of the wheat, do excellent work with a
pair of rollers, each eight and a half inches in diameter.
The bran, which is delivered from the tail of the first stripping reel B, is con-
veyed, as shewn by the red line g, to the lower pair of rollers of the mill A2, which
is fitted with smooth rollers working with the speeds above indicated. By means
of this mill the bran is rolled out into thin smoothly polished flat flakes.
I would have it understood that unless the bran is well cleared of flour in the 4
first process, ie., by my patented wheat crushing roller mill, the action of the smooth
rollers on the bran will fail to be satisfactory.
The small bran particles not dressed through the second finishing reel C₁ I lead
to the upper pair of compressing surfaces of the mill A², the lower pair of which
operates on the main bulk of the bran, as above mentioned.
"
The whole of the compressed bran as it is delivered from this mill A* passes to a
second stripping reel C³, as indicated by the red line h, which dresses out the flour
particles contained therein, and delivers the same to another reel C³, as indicated
by the red line i. This reel separates the flour into fine and coarse sharps,"
and third quality flour, the proportion being fine sharps five pounds, coarse sharps
six pounds, with the middlings stive mixed in, and third quality flour five pounds,
or thereabouts, for every one hundred pounds of wheat passed through the first
mill A.
I may remark that I prefer to use the reels known as centrifugal reels because
of the tendency to caking when smooth rollers are used.
The bran obtained by this process is free from dust, and is bright and smoothly
polished, a matter of some importance, particularly where dry feeding is adopted,
5

page_text: and the bran being condensed by this treatment will pack closely for transport,
which is also a material advantage.
The blue lines shewn in the diagram indicates the points of delivery of the flour
and of the bran and sharps, which may be received into separate convenient
$ receptacles.
Diagram II. shows a modification of the course of working for the production of a
flour holding an intermediate position in equality between the first and second quality
flour of the preceding diagram, and one other holding an intermediate position between
the second and third flours of diagram I. The apparatus is the same as that indicated
in diagram I, with the exception that three groups of Haggenmacher's No. 4 small
purifiers, four divisions or sizes in each group, or similar mechanism marked
D', D, D³, are used, each group being connected with a "Thompson's" or other
efficient purifler. In this arrangement also the flour removed by the automatic
sifter of the mill A passes directly to an additional finishing or dressing reel C*
which delivers it as first quality Hour, the yield being some sixty pounds for every
one hundred pounds of wheat ground in the mill. The middlings sifted out by
this reel are passed to the upper pair of cushing surfaces of the roller mill A¹, and
the product is led thence to join in the stream of four which passes to the wheel C.
The tailings from the reel C are conducted to the two groups of purifiers D³, D³.
The purified middlings collected from these purifiers are led, as indicated by the
rod line d, to the bottom pair of crushing surfaces of the roller mill A¹. In other
respects the manufacture proceeds as described with reference to diagram I.
Diagram III shows an arrangement for attaining three qualities of flour, each
superior to that obtained by the arrangement shewn at diagram I. by the aid of
more complete purifying apparatus. Here also in place of the sizing sieves and five
Thompson purifiers we have three groups of Haggenmacher's purifiers one group
of No. 4 small and two of No. 4 large purifiers, with each of which groups a
Thompson or other efficient purified is connected. The product of the roller
mill A passes off in two separate streams as in No. 2 in diagram; the first flour by b
to the reel C, the second by a to the bolting reel B. The flour delivered from the
cylinder C will in this case be second quality flour, its yield being about forty
pounds to the one hundred pounds of wheat.
The middlings and the tailings from the reel C* follow the course described with
reference to diagram II. The flour delivered from the bolting reel B is conducted
to the finishing reel C. The yield of flour from this reel and from C³, as hereafter
mentioned, will be about thirteen pounds to the one hundred pounds of wheat, and
will be third quality flour.
The fine middlings delivered from the reel C are conducted, as indicated by the
red line d, to the top pair of crushing surfaces of the mill A¹, and the flour
there produced passes by the line b to join the stream which passes to the
reel C*.
The tailings or coarse middlings from the reel C pass to the first group of
purifiers D', and when purified join the stream indicated by the line d*.
The purifiers D, D³, yield two qualities of purified product, viz., first and
second quality middlings. The second quality, indicated by the line f*, joins
the stream from the purifiers D', but the first quality, indicated by the line g*, is
led to the second pair of crushing surfaces in the mill A¹, and passing thence it
reaches the finishing reel C¹ which delivers it as first quality flour, the yield being
about twenty pounds to the one hundred pounds of wheat.
The fine middlings dressed through the end silk of this reel C' following the
ine D' are ground in connection with the first quality middlings g*.
In some cases it may be advantageous to run the second quality coarse
niddlings f* and the fine middlings d, which join at h, when crushed into the
neal at a instead of causing them to unite with b, or they may be dressed still
nore advantageously on a separate reel. The above will illustrate how the
rinciple of dealing with the crushed fine middlings for dressing must be
dhered to.

page_text: The tailings from the reel C" pass to the pair of crushing surfaces of the mill A³,
and the product is led thence to the second stripping reel Č³.
The siftings from this reel are led to the finishing reel C³, whence they are led
into the stream of flour delivered from the reel C, and go to make up the before
mentioned yield of thirteen.pounds of third quality flour.
It will be understood that the bran and the sharps are obtained and delivered in
the same manner as explained with reference to diagram I., the stive joining the
fine sharps as before.
The course of all the products is clearly indicated by coloured lines in this as in
the preceeding diagrams.
From the above description it will be understood that my improved mode of
working embraces the following features, vis. :-
First. By removing the finest middlings at the tail end of the silks means are
provided for returning those particles of middlings which have been incompletely
ground between the smooth rollers to the grinding apparatus in a form comparatively
free from bran mixture.
Second. By the above provision the coarser middlings sent forward to the
purifiers are absolutely free from dust, while the whole process of dusting the
middlings and redressing the flour is made at once unnecessary.
Third. None except the very last grindings treat low grade intermediate
products, consequently the rollers are but slightly into contact with bran particles.
Fourth. By treating every description of offal on smooth rollers provision is
made against the escape of unground middlings through any disturbance in the
mill or a change in the adjustment of the machinery or negligence on the part of
the attendants. All the products here treated are almost free from flour, and there
will be accordingly only an inconsiderable proportion of inferior flour.
Having now set forth the nature of my Invention of "An Improved Process for
the Conversion of Wheat to Flour and Bran," and explained the manner of carrying
the same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim, the reduction of wheat to flour of various qualities, and
the conversion of the bran obtained therefrom into clean flat flakes by a continuous
process, in which well known crushing, bolting, dressing, and purifying apparatus
is used, as explained with reference to the accompanying Drawings.
In witness whereof, I, the said John Auguste Arnold Buchholz, have hereunto
set my hand and seal, the Twenty sixth day of June, in the year of our
Lord One thousand eight hundred and eighty.