AN IMPROVED FILTER
Year: 1885

page_text: I, JOHN HOWIE of Hurlford Fire-clay Works Kilmarnock Ayrshire, Fire-clay
Manufacturer, do hereby declare the nature of my invention for "AN IMPROVED
FILTER" to be as follows:-
This invention consists in forming a filter or filter block for use in filtering and
purifying water or other liquids by mixing together clay and sawdust or similar
carbonaceous substance and baking or firing the same in any suitable shape.
In forming the improved filter or filtering medium I prefer to employ the
following proportions of the ingredients namely 10 parts sawdust and 7 parts of
clay preferably fire-clay.
I also find it advantageous that part of the clay should be calcined or previously
burned; but I do not confine myself to these proportions.
The mixture is ground up and formed into a paste by the addition of water, and
it is then shaped to the desired form and baked, fired, or burned in a kiln, after
which it is ready for use.
The shape in which I prefer to form the filter is that of a vessel capable of
containing the liquid to be filtered, through which the liquid will percolate in a
filtered and purified condition.

page_text: I, JOHN HOWIE of Hurlford Fire Clay Works, Kilmarnock, Ayrshire, Fire Clay
Manufacturer, 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 :-
My invention consists in forming a filter or filter block for use in filtering and
purifying water or other liquids, by mixing together clay and sawdust or other
carbonaceous substance and baking or firing the same in any suitable shape.
In forming the improved filter or filtering medium I prefer to employ the
ingredients in or about the proportion of 2 parts sawdust to 1 part of clay but I do
not confine myself to these proportions. I find it advantageous to add a small
proportion of burnt clay or pulverised biscuit of clay or asbestos and in some cases
silicate of soda.
This mixture is ground up and formed into a paste by the addition of water, and
it is then shaped to the desired form and baked, fired or burned in a kiln after which
it is ready for use.
The shape into which I prefer to form the filter when used as a domestic filter is
that of a vessel capable of containing the liquid to be filtered and through which
the liquid will percolate in a filtered and purified condition.
Such a form of filter is represented in elevation and section in figures 1 and 2
of the accompanying drawings. A being the filter and B, the receptacle for the
filtered water also serving to hold the filter. I may employ the vessel A alone as
a filter or I may use it in conjunction with a layer of pulverulent animal or
vegetable charcoal, patent porous carbon, or other filtering substance which may be
placed in the vessel A, or as represented in figure 3, in a porous saucer C, under the
filter A. The saucer is preferably made of the filter ware above described and rests
upon a filter ware slab so that the water before reaching the bottom of the vessel B
passes three times through the filter ware and once through the porous carbon or
other loose filtering material. The saucer C, and slab are made extra porous to
allow the water to filter through them as quickly as it comes from the vessel A
above.
The filter may however be made in the form of a cistern or of slabs, bricks, or
blocks or in other shapes and be built to form a filter tank, or the porous clay ware
obtained by baking or firing the mixture of clay and carbonaceous matter may be
pulverised and be used in the powdered state and either alone or in conjunction
with other filtering substances to form a filter bed. When water is to be filtered
under pressure I prefer to form the filter as shown in figure 4, of an inner porous
vessel A provided with a cover A¹ and water inlet a, a second porous vessel C, and
an outer casing of solid material provided with an outlet b. The intermediate
space c between the vessels A, C may be filled with porous charcoal or other filtering
material. The filter may however be made for use in filtering water under
pressure, as shown in figure 5, without the second vessel C.
When the filter is made to filter water under pressure I prefer to use a smaller
proportion of sawdust in the mixture in order that the ware formed may be less

page_text: porous, and in making the filter in the form of a cistern or as filter blocks I may
or may not use a proportion of silicate of soda in admixture with the clay and
carbonaceous material.
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
1. An improved filter for use in the filtration and purification of water or other
liquids, formed of porous clay ware produced by baking or firing a mixture of clay
and carbonaceous matter substantially as herein set forth.
2. As an improved article of manufacture a filter block, brick, slab or vessel
formed as herein described by baking or firing a mixture of clay and carbonaceous
matter.