Improvements in Filtering Apparatus.
Year: 1892

page_text: ate of Application, 17th Oct., 1892-Accepted, 18th Mar.,
1893
COMPLETE SPECIFICATION.
Improvements in Filtering Apparatus.
I, HUGO KOHL, Engineer of Euskirchen in the Province of Rhineland, Prussia,
do hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The filter-presses used in sugar-refineries, breweries, yeast, paper and chemical
works have the draw-back, that the filter-cloths close very easily, can only be
changed with difficulty and wear out quickly. As a considerable length of time is
always necessary for cleaning the apparatus and filter-cloths, every factory usually'
needs a whole row of filter-presses, of which a number are always not in use, while.
the others are working.
By means of the following invention these disadvantages are avoided so that for
very large works the installation of only two apparatus of this new form of a con-
venient size would suffice to keep up an entirely uninterrupted working.
The apparatus in its entire arrangement is given in Fig. 1 in upright projection,
Fig. 2 is a side-view, Fig. 3 the upper view, while Fig. 4 shows the position of the
cocks between the first and after-filters, and Figs. 5-14 the separate parts on aj
larger scale.
The substance or fluid to be filtered enters by the pipe at e into the box K₁₁
which is closed all round, and in which there are one or more (in the drawings
three) filter-wheels F. The latter are shown with the box K, in Fig. 5 on a larger
scale, and also in Figs. 6 and 7 in two sections. As will be seen each filter-wheel
consists of two halves separated by a disc transversely to the axle. Each of these
halves is again divided by four radial ribs into four equal parts.
In each of the 8 compartments, formed by the disc and the radial ribs, the corner
which lies towards the axis of the filter-wheel is open because a hole is bored in the
disc and the ribs go only so far as this hole. Thus in the centre of each filter-
wheel a common hollow space is formed. By means of hollow axle-pieces which
lie between each pair of filter-wheels, the hollow spaces of all the wheels are con-
nected with each other. From the external surfaces of the right and left end-
wheel in the box the hollow axle-pieces pass through the top-plates of the box K1,
by means of the stuffing-boxes S₁ S₂.
The ends of the exterior hollow axle pieces between which the filter wheels are
placed lie in the stuffing-boxes S, and S, and the whole receives a slow rotatory
motion by a toothed wheel-work Z.
The juice is thus forced through the filter-cloths and sieves, which cover the open
boxes on both sides of the filter-wheels, into the fan-shaped spaces of the filter-
wheels and thence passes into the hollow axle. The filter-cloths are thus suitably
arranged.
On sieve s₁, provided with fine holes, a filter-cloth, cut to the convenient
form, is laid, and on this the sieve s₁, provided with large holes. The sieve s₂ is
only there in order to save the filter-cloths, when the juice is scraped off. The
scraping off of the juice from the outside of the sieves is done by the scraping-
plates Pr which are fixed between each pair of filter-wheels and between the head-
plates of the box and the nearest filter-wheel. These scraping-plates p (vide
Fig 14) are elastically so bent, as only to allow of the juice being scraped in an
upward direction, and if the motion were reversed would rub against the filter-
wheels. The scraping-plates can be supplied with small spring wires d, which
scrape the hole-margins of the sieves s, by means of the eye-shaped upper end; in
this case the large holes in the sieve s, are. to be countersunk from the outside in
order to prevent the eyes of the wires from catching.

page_text: In the direction of the axle of the above described first-filtering apparatus, two
somewhat larger filter-wheels of the same kind as those in box K, are fixed one
behind the other as after-filters N₁ and N₁. These two wheels are however not
used simultaneously, but the one is cleaned, whilst the other works. For this reason
at each end, next to the two after-filters, there is a cock in the pipe, ₁, h, and h₂.
The middle cock h, is always closed and is only opened, when it is necessary to push
for cleaning purposes right through the hollow axle. When the cock h₁, which in
the drawing is directly connected by the hollow axle with the right end of the first
filter-apparatus, is opened, the juice from the first-filters goes into the first after-
filter N₁; at the same time the cock h, is closed; therefore the after-filter N, is not
in use and may be emptied and cleaned and, if necessary, supplied with new filter-
cloths. On the other hand, when cock h₁ is shut and cock h, is opened, the after-
filter N₁ is not in use and the after-filter N, in work, which is done by means of the
tube U. The two after-filters are moveable in the stuffing-boxes S, and S., so that
each of the filtering divisions can receive the position necessitated by the working.
In these after-filters the juice takes the opposite direction to that in the first-filters;
it enters from the axle, and into those filter-compartments, which are situated below,
and squeezes itself out through the filter-cloths, which shut off the compartments
and are covered on the outside by the sieve s. If one or more compartments are
clogged with mud,-which can be easily ascertained from the outside by the ceasing
of the flow of juice, as the after-filters are not enclosed by a box, the after-filter
is turned round so far, till an empty compartment is below, and the flow is resumed.
If in the turning a compartment, filled with mud, arrives at the top, the mud would
escape back into the axle through the opening at the end of each compartment.
In order to avoid this, a valve v (vide Fig. 13) is fixed to each compartment of these
after-filters, consisting of an angle-sieve w and a strip of filter-cloth, fastened to
it. This valve closes itself by the pressure of the mass, when the compartment is
above, and only allows of the passage of thin fluid; but when the comparment is
below, it opens and permits the fluid coming from the front-filters to flow through
quickly.
When all the compartments of the after-filter-wheels N₁ are filled with mud, one
closes the cock ₁, opens the cock h₂ and lets thus the after-filter N, work, while N₁
is being emptied and cleaned and vice versa. The clear juice issuing from the
after-filters is received by funnel-shaped boxes B B, placed under the filter-wheels
and carried off by troughs. The sides W, and W2 of the boxes B B are removeable.
If an after filter is to be cleaned, the sides W, and W, of the box are removed, and
a large bent sheet-metal pan P (marked with dotted lines in Figs. 1 and 3) is
placed on the bent bottom of the filter and catches the mud that falls out, when the
compartments of the after-filter are opened and hinders any fragments of the mud
getting into the troughs of the clear fluid.
The mud remaining in the box K₁, is conducted from time to time by a spiral to
the hole in the box, the valve raised, and any stagnation of the mass is prevented
by turning the vertical spiral. Thus the mud falls into the box K₁, which is fitted
with an inclined bottom, from which it is removed through the man-hole, after it
has been ascertained by means of the gauge-cock fixed at the top, that the apparatus
is filled only with mud.
If the apparatus is to be stopped for the moment and be cleaned, the unfiltered
mass which may still be present in the boxes K₁ or K, can be poured into the
funnel T and thus be purified by the after-filters.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :
A continuous working rotation mud-press with automatic mud remover, consisting
of first-filters with several compartments, rotating in a tank, which conduct the
pure juice through the hollow axle alternately from the right and from the left to

page_text: the after-filters, which also consist of several compartments, are disconnected and
turn on the axle, while the mud, remaining in the first-filter-tank, is intermittently
removed by transport-spirals.
Dated this Tenth day of October 1892
BERNARD BROCKHUES,
Applicant's Agent.