Year: 1888

page_text: Date of Application, 3rd July, 1888
Complete Specification Left, 3rd Apr., 1889
Complete Specification Accepted, 11th May, 1889
1, JAMES GRIEVE LORRAIN, of Norfolk House, Norfolk Street, London, W.C.,
Consulting Engineer, do hereby declare the nature of this invention to be as follows :-
A known form of filtering apparatus is what is conveniently termed a centrifugal
aner. In this apparatus the centrifugal force, as it is commonly called, set up when
the apparatus is rotated causes the liquid which is to be filtered to fly outwards and be
forced through a straining medium.
"
In the Complete Specification accompanying my Letters Patent No. 6813 of the
year 1886 I describe a straining or filtering material or medium whose straining or
filtering efficiency varies with the pressure applied to it.
The object of my present invention is to obtain a method and apparatus by which
the efficiency of filtration may be easily varied controlled or governed in accordance
with requirements: and I effect this by varying governing or controlling the speed
with which a centrifugal filter containing a filtering material as aforesaid is rotated.
When such a filter containing such a material is rapidly rotated the material is
pressed outwards with a pressure varying with the speed of rotation: but, being
restrained by the wall of the centrifugal pan, the elastic bodies constituting the filtering
material will be compressed, and will alter their shape, and the interstitial space for the
passage of the fluid to be filtered, and so alter the efficiency of filtration. Thus the
greater the speed of rotation the greater will be the pressure and the efficiency of
filtration; whilst the lower the speed of rotation the less will be the pressure and the
less the efficiency of filtration.
When desired I may, in conjunction with apparatus as above referred to, vary
control or govern the supply of fluid to be filtered to the filtering apparatus, and I may
effect this by causing the position of a valve or the action of a propelling or exhausting
device in a pipe leading to or from the filtering apparatus to be varied.

page_text: When the fluid to be filtered is supplied under sufficient head or pressure I may,
hefore it is filtered, cause it when a liquid to pass through a hydraulic motor, and when
a gas to pass through a pneumatic motor, for the purpose of causing the centrifugal
filtering apparatus to be rotated.
When the fluid to be filtered is a gas 1 take care to enclose the pan or its equivalent
of the centrifugal filter in such manner that the air or gas to be filtered cannot escape
otherwise than through the filtering or straining medium.
COMPLETE SPECIFICATION,
An Improved Method of Straining or Filtering Fluids and Apparatus
therefor.
1, JAMES GRIEVE LORRAIN, of Norfolk House, Norfolk Street, London, W...
Consulting Engineer, 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:—
A known form of filtering apparatus is what is conveniently termed a centrifugal
filter. In this apparatus the centrifugal force, as it is commonly called, set up when
the apparatus is rotatod eanses the liquid which is to be filtered to fly outwards and he
forced through a straining medium.
In the Complete Specification accompanying my Letters Patent No. 6813 of the
year 1886 hereinafter referred to as my previous patent I describe a straining or filtering
material or medium whose straining or filtering efficiency varies with the pressure
applied to it.
The object of my present invention is to obtain a method and apparatus by which
the efficiency of filtration may be easily varied controlled or governed in accordance
with requirements: and 1 effect this by varying governing or controlling the speed
with which a contrifugal filter containing a filtoring material as aforesaid is rotated.
When such a filtor containing such a material is rapidly rotated the material is
pressed outwards with a pressure varying with the speed of rotation: but, being
restrained by the wall of the centrifugal pan, the elastic bodies constituting the filtering
material will be compressed, and will alter their shape, and the interstitial spaco for
the passage of the fluid to be filtered, and so alter the efficiency of filtration. Thus
the greator the speed of rotation the greater will be the pressure and the efficiency of
filtration; whilst the lower the speed of rotation the less will be the pressure and the

page_text: less the efficiency of filtration. In other words, when the centrifugal plan is stationary
the elastic bodies constituting my filtering material (I here for convenience refer to
the case wherein the said filtering material consists of spheres) will have the form
shown in figure 1 of my previous patent. When the centrifugal pan is rotated and a
certain speed attained the shape of the said elastic bodies and the size of the interstitial
spaces will be as shown in figure 2 of my said previous patent. As the speed of
rotation is increased still further the shape of the elastic bodies approaches more nearly
to that shown in figure 3 of my said previous patent and the interstitial spaces tend to
disappear altogether.
When desired I may, in conjunction with apparatus as above referred to, vary control
or govern the supply of fluid to be filtered to the filtering apparatus, and I may effect
this by causing the position of a valve or the action of a propelling or exhausting
device in a pipe leading to or from the filtering apparatus to be varied. A convenient
method of effecting this automatically is to connect an ordinary centrifugal governor
to the rotating centrifugal pan, or any convenient part in connection therewith, by
means of any of the well known transmitting devices such for example as a belt, and
cause this governor to actuate a throttle valve in the fluid supply pipe after the manner
in which an ordinary steam engine governor actuates the throttle valve in the steam
supply pipe, the supply of fluid being lessened as the speed of rotation is increased.
When the fluid to be filtered is supplied under sufficient head or pressure I may,
before it is filtered, cause it when a liquid to pass through a hydraulic motor, and when
a gas to pass through a pneumatic motor, for the purpose of causing the centrifugal
filtering apparatus to be rotated, the said motors serving to drive the centrifugal
filtering apparatus which filters the fluid discharged or exhausted from the said
motors. By this means the mechanical energy stored up in the fluid to be filtered is
utilised.
When the fluid to be filtered is a gas I take care to enclose the pan or its equivalent
of the centrifugal filter in such manner that the air or gas to be filtered cannot escape
otherwise than through the filtering or straining medium. Such a form of air or gas
filter is particularly applicable as a dust-collector or dust separator for flour mills and
for many industrial operations.
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. The improved method of straining or filtering fluids substantially as specified.
2. The improved apparatus for straining or filtering fluids substantially as specified.
3. The employment in a centrifugal filter of elastic bodies substantially as and for
the purpose specified.
4. In combination with filtering or straining apparatus as herein described, the
means of governing the supply of fluid substantially as specified.
A
1100