IMPROVEMENTS IN FILTERS
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HERMAN
SCHRODER, of Mark Lane, in the City of London, Broker, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Second day of November, in the fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Herman Schroder, Her especial licence, full power, sole privilege and autho-
rity, that I, the said Herman Schroder, my exors, admors, and assigns, or
such others as I, the said Herman Schroder, my exors, admors, or assigns,
should at any time agree with, and no others, from to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick
upon-Tweed, and also in all Her said Majesty's Colonies and Plantations
abroad, the Invention of "IMPROVEMENTS IN FILTERS," partly communicated
to me by a certain Foreigner residing abroad, and partly of my own Inven-
tion; in which said Letters Patent is contained a proviso that I, the said
Herman Schroder, shall cause a particular description of the nature of the
said Invention, and in what manner the same is to be performed, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said Her-
man Schroder, do hereby declare that the nature of the said Invention, and the

page_text: manner in which the same is to be performed, are fully described and ascer-
tained in and by the following statement thereof, reference being had to the
Drawing hereunto annexed, and to the figures and letters marked thereon;
that is to say:-
The Invention relates to what are called bag filters, and are principally used!
for filtering the syrups of sugar; and the object of the Invention is to obtain a
very extensive surface of fabric as a filtering medium in a given space, and
yet offer great convenience for cleansing. And, in order to give the best
information in my power, I will-proceed to describe the Drawing hereunto
annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 represents a longitudinal section, and Figure 2 a transverse
section, of a filter constructed according to the Invention, and consists of a
mode of applying a series of bags a, a, a. These bags may be plain, but I
prefer that they should be plaited or gathered; and the edges bound, in order
to obtain as extensive a surface as possible; and, for this purpose; when a bag
had been formed I affix a strong web or tape around the mouth or upper part
of such bag, plaiting the bag as closely as conveniently can be done in the act of
sewing the bag to the binding tape or web,, and such plaiting or gathering is
also resorted to in closing the bottoms of bags. b, b, are frames --having
openings through them at c, c. There is one of these frames bintroduced into
the mouth of each bag; and when the number of bags a, with their frames b,
are put into the box or chamber d, the whole of the frames b are wedged
tightly together by the long wedge e, and another similar wedge at one of the
ends and the upper parts of the bags being between the frames b, the whole
will be securely wedged together, and thus prevent the liquor to be filtered
passing in any other direction than through the frames at c, c, and thence
through the bags a. And it should be stated, that the bags should be so long
as to touch the false bottom of of the box or chamber d, and cover the whole
surface thereof, and the sides of the bags should touch all the way up to the
frames b, by which means there will be little strain on the bags, which other-
wise would have a tendency to split the bags. The box or chamber 'd con-
sists of the quadrangular box d, having the perforated false bottom, the
bottom g, and the cover h. The liquor is allowed to flow from a vat above
the pipe i, on which there is a cock to regulate the flow of liquor, and j is a
cock for running off the liquor as it is filtered. The liquor from the pipe i
flows into the trough k, and flows over the top thereof on either side, as well
as through the bottom, and thus equally supplies the liquor to the openings c

page_text: through the frames b. It will be evident, that by using the frames a in com-
bination with bags, and wedging the same in a box or chamber, as above
explained, great facility is offered for removing and cleansing, and such bags
will also be found to be very efficient in action.
The second part of the Invention consists in forming an outer bag with
several smaller bags affixed to the bottom thereof, such smaller, bags, when at
work, being drawn within the outer bag.
Figure 3 shows a longitudinal section, and Figure 4 a transverse section, of
a filter constructed according to the second part of the Invention, the box, or
chamber,d being similarly constructed to that before described. is the outer
bag, which, when full, of liquor, should lie closely against every part of the
interior surface of the box or chamber d, and in such manner that there will
be no drag on the fabric of the bag 1, owing to every part of the bag being
confined by the interior of the box or chamber d. m, m, are a series of
smaller bags affixed to the bottom of the bag 1, so that when completely drawn
through the bag l; and that bag 2 turned inside out for the purpose of cleansing
them of any deposit, the bags m would hang down from the bottom of the
bag 1, like a series of pockets. The bags m, when drawn within the bag 1, as
shewn in the Drawing, are supported by strings o, o, affixed to their two
corners; and these strings o are tied up to two loops p, fixed to the interior of
the bag l, as is shown. The upper part of the mouth of the bag is drawn
together and tied as..shown,at q, and there is an opening at r into which a
short pipe or nozzel of the fabric is sewed, into which the pipe i enters, and
the edges of the nozzel, in opening of the bag 1, are tied tightly around the
end of the pipe i. In this case, although the box or chamber d'is similar to
the previous one, in consequence of its being arranged for receiving the liquor
at a greater pressure than the previous one, the cover of the box is capable of
being more securely fixed to resist such pressure. In this filter I prefer that
the bags should be plaited in place of plain, in order to obtain as extensive a
surface as possible in a given space; and such is the case with the filters here-
after explained. At the same time I would remark, that by my modes of
making bag filters even plain bags will produce very excellent filters.
The third part of the Invention relates to a means of making. bag filters
whereby each bag is drawn into itself one or more times, thus producing very
extensive surfaces of fabric within a given space, and offering great facility of
opening out to cleanse.
Figure 5 shews a longitudinal section, and Figure 6 a transverse section, of
a filter constructed according to the third part of the Invention. In these
Figures the box or chamber d is similar to that of the preceding filters, and

page_text: it is constructed suitably for receiving two bags a, and each bag has its frame
b, similar to what was described in Figures 1 and 2; but the bags in this
instance, in place of being the same as those described in Figures 1 and 2, in
this case are much longer, and each bag is drawn up into itself, and in fact acts
as two bags, there being strings o, o, at the bottom of each bag, and on the
inside, by which, when the bags are drawn up within, as is shown at Figures 5
and 6, the parts drawn up are supported by fastening the strings o to the short
rods
which rest across the openings c of the frames b, and it will be seen
that this filter is made what I call a pressure filter, by means of the top
fabric r, which is fastened to the end of the pipe i, and its edges placed
around the sides and ends of the frames 6, and are kept tight by the wedging
up of the frames, and the pressure thereof on the ledges which support the
frames within the box or chamber d. In Figures 5 and 6 the bags are each
only drawn once within itself, but I prefer that they should be made of such
length that each may be drawn twice or more times into itself. Figure 7
.shows the section of a bag a suitable for being drawn twice into itself, and
consequently has strings or loops at (1), (1), for one drawing up, and at
(2), (2), for the second drawing up, and these loops or strings are supported
by short rods across the openings c of the frame b, as is shown at Figure 8,
where a similar bag a, drawn within itself, suitable for work, is shown.
Figure 9 shows a side view of this bag, and I have shown straps. or webs
w, w, on the outside to sustain and strengthen the same, particularly when
being removed from the box or chamber d charged with much sediment.
Figure 10 shews a plan of the frame b and a bag a, with the short rods which
support the loops or strings o, o, of the bag a. I would remark, that although
I prefer to make these bags which turn one within the other in the manner I
have described, yet a similar effect may be obtained by extending the bags a
at their two ends, as is shown at Figures 11 and 12, which show a plan and
side view in section of a bag of this description, a being the bag, and a', a¹,
two bags affixed to the two ends, and are drawn laterally into the bag a, as is
shown, and the two side bags a¹ open into the bag a, the other end of each.
bag a' being closed, and the upper and lower edges of the bags a¹ are closed or
sewed; consequently, when the liquor runs into the bag a it passes into the
bags a', and thus the bag a, with the bags a', act as three bags to a single
frame b. Figure 13 shows a box or chamber having four bags made
according to any of the above modes, but so arranged as to act as pressure
bags, either by having the outer bag, as in Figures 3 and 4, tied at the mouth,
or by using an upper fabric similar to Figures 5 and 6, and in such manner any
desired number of bags may be placed in one box or chamber made of a suitable
.

page_text: size for receiving such number. In making the bags for the Invention I prefer
to use strong twill cotton, but other fabrics may be employed, the Invention not
relating. to the material employed, but to the manner of constructing and
applying the bags, in order to get a large extent of surface within a given space.
Figure 14 shews another arrangement of filter made according to my
Invention, and consists of the outer bag w, which I call the pressure bag, and
the inner bags x, which are closed on all sides except at the outlets y, one to
each bags & passing through openings or necks formed in the bag w, as is
shown; and the bags are supported in the bag w by strings and loops, as is
shown, or by other convenient means; and it will be evident, that in using
this construction of filters, that the clear liquor, filtering into the bags a, will
be carried off by the outlets y.
Having thus described the nature of the Invention, I would have it under-
stood that I lay no claim to any of the parts separately, nor do I confine
myself to the precise arrangement shown, so long as the peculiar character of
either of the improvements be retained. But what I claim is,-
First, the mode of employing frames 6 and bags as herein described.
Secondly, I claim the mode of constructing and applying filter bags as
described in respect to Figures 3 and 4. .
Thirdly, I claim the mode of constructing and applying filter bags by
drawing each bag within itself, as herein described..
Fourthly, I claim the mode of combining bag filters as is described in
respect to Fig. 14.
In witness whereof, I, the said Herman Schroder, have hereunto set my
hand and seal, this Twenty-ninth day of April, in the year of our
Lord One thousand eight hundred and forty-one.
HERMAN (L.S.) SCHRODER.

page_text: These Bags show a variation to those shewn at Figs 5 and 6, and
consists in applying the band or tape and gathering the bag at
the middle of its length as well as top and bottom