Improvements in Vacuum Apparatus for Drying, Distilling, Concentrating, and other like Purposes, and in the Method of and Means for Obtaining and Maintaining Vacuum therein.
Year: 1896

page_text: Date of Application, 30th Apr., 1896
Complete Specification Left, 1st Mar., 1897-Accepted. 17th Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in Vacuum Apparatus for Drying, Distilling,
Concentrating, and other like Purposes, and in the Method of
and Means for Obtaining and Maintaining Vacuum therein.
I, JAMES LONGSHAW of 275 Burlington Street, Liverpool in the County of
Lancaster, Technical Chemist and Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to vacuum apparatus such as is used in drying, distilling,
concentrating, bleaching, dyeing, and for other similar purposes, and to the method of
and means for obtaining and maintaining the vacuum.
According to this invention, I connect the head of the still, vacuum pan or other
vessel in which the vacuum is to be maintained, with a suitable condensing apparatus,
such as a worm in a water tank, and on the connecting pipe I arrange a main valve
and two branches each of which is provided with a cock or valve. These branches
are arranged on opposite sides of the main valve, and for greater clearness of
description, the valve on the side nearer to the vacuum vessel will hereinafter be
called "valve 2" and that on the further side, "valve 3." The lower end of the
condensing apparatus is connected with an air-tight receiver, which may be fitted
with a gauge glass. The lower part of this receiver is connected with either a
vertical dependent air-tight pipe 33 feet long or upwards, and, or, a pump. The
dependent pipe should be of such a length as to contain a column of water balanced
by the atmosphere, and is fitted with a valve at the lower end.
The vacuum vessel is provided with a valve controlled steam inlet, and the receiver
with a valve controlled water inlet.
The apparatus being ready for use, the main valve between the vacuum vessel and
the condenser is closed, valve 2 is opened, and steam is admitted to the vacuum
vessel and blows off through valve 2. As soon as all the air has been expelled,
the steam tap and valve 2 are closed. Valve 3 is then opened, and the valve
admitting water to the receiver receiver is also opened. Water thus passes into the
receiver and up through the condenser to valve 3 out of which it flows. When
the receiver, condenser, and pipe to valve 3 are thus filled with water, the water valve
and valve 3 are closed.
If now, the pump be started, it will withdraw water from the receiver system and
produce a vacuum. The main valve can then be opened and the vacuum extends to
the vacuum vessel. The pump being kept at work so as to maintain the level of the
water in the receiver, it will be obvious that the vacuum will be maintained at a small
expenditure of power as compared with existing practice. The products of evaporation
as condensed flow into the receiver and are removed by the pump.
The pump may in many cases be dispensed with, by utilising the dependent pipe
before mentioned. Instead of starting the pump, the valve at the foot of the dependent
pipe is opened, when if, or as soon as there is a greater height of water in the receiver
than can be balanced by the atmospheric pressure, the surplus water will run out, thus
maintaining the vacuum.
An injector or other suitable apparatus may be employed in substitution for the

page_text: pump. The pump, injector or dependent pipe will be closed whilst the receiver is
being filled with water as herein before described.
Dated this 29th day of April AD 1896
W. E. HEYS & SON,
Agents for the Applicant.
Improvements in Vacuum Apparatus for Drying, Distilling,
Concentrating, and other like Purposes, and in the Method of
and Means for Obtaining and Maintaining Vacuum therein.
1, JAMES LONGSHAW of 275 Burlington Street Liverpool in the County of
Lancaster, Technical Chemist and Engineer, do hereby declare the nature of this
invention, and in what manner the same is to be performed, to he particularly described
and ascertained in and by the following statement:-
This invention relates to vacuum apparatus such as is used for drying, distilling,
concentrating, bleaching, dyeing and for other similar purposes, and to the method of
and means for obtaining and maintaining the vacuum.
I will describe my improvements with reference to the accompanying drawing
which represents a diagrammatic sectional elevation.
A, is the still, vacuum pau, or other vessel in which the vacuum is to be maintained.
This vessel is connected, through the pipe B, with a suitable condenser such as C,
which, as represented, consists of a worm in a water vessel D. Upon the pipe B,
I
arrange a main valve V 6, and two branches which are respectively connected with
the cocks or valves V 2, V 3. The lower end of the condenser is connected, through
the pipe E, with the interior of the air-tight receiver F, which may be fitted
with a water level gauge glass G, a vacuum gauge H, a water supply pipe
controlled by the valve V 4, and an outlet pipe K, controlled by the valve V7.
The vertical dependent outlet pipe K, is at least 32 or 33 feet long, or so long
as to contain a column of water capable of being balanced by atmospheric pressure.
The vessel A is fitted with a steam inlet controlled by the valve V 1, and an outlet
controlled by the valve V 5.
The receiver pipe L, which is indicated by dotted lines only, may be connected
with a suitable pump, an injector, or a water elevator, which is not shewn in the
diagram.
The liquid to be boiled or concentrated under vacuum, having been run into the
vessel A, up to the working level, and heated by steam or otherwise, the valve V 6 is
closed, the valve V 2 is opened, and steam is admitted to the vessel through valve V 1,
blowing off through valve V2. As soon as all the air has been expelled, the
valves V 1 and V 2 are closed. The valves V 3 and V 4 are then opened, allowing
water to enter the receiver F and to pass upwards through the condenser to the
valve V 3, out of which it flows. When the receiver, condenser and pipe B, up to the
valve V3 are thus filled with water, the valves V3 and V4 are closed. If now,
the pump or water elevator be started, it will withdraw water from the receiver
system F, and produce a more or less partial vacuum. The main valve V 6 can then
be opened, whereupon the vacuum extends to the vessel A. The pump or other water
elevator being kept at work, so as to maintain the water level in the receiver, it will
be obvious that the vacuum can be obtained and maintained at a small expenditure as
compared with existing practice, as by this system, water of condensation instead of
steam is pumped. If the pump or water elevator be used as described, the pipe K
may be omitted; but, in many cases it will be found advantageous to dispense with
the water elevator or pump, and to utilise the pipe K in substitution therefor. Or,

page_text: both the pipe K and the pump or elevator can be retained and used alternatively or
simultaneously. When the pipe K is used, then, instead of starting the water
elevator, the valve V 7 is opened, when if, or as soon as, there is a greater height of
water in the receiver than can be balanced by the atmosphere, the surplus water will
run out, thus maintaining the vacuum. The pipe through which the receiver is in
communication with the pump or water elevator, as well as the pipe K, or
whichever of them may be in use, will be closed when the receiver is being filled
with water.
The several valves and cocks may advantageously be contained in suitable receptacles
containing a viscid oil or other non-volatile fluid to prevent possible leakages of air
through them into the apparatus.
If the pipe B be raised above the level of the hood or outlet of the vessel A, and
the valves V 2, V 6, V 3, he also arranged above that level, and if to the branch or
outlet controlled by the valve V 5, there be connected a dependent pipe similar to the
pipe K, or alternatively or additionally, a pump or water elevator, for dealing with the
liquor in the vessel A, then, if that vessel be completely filled with the liquor to
the valve V 6, and the liquor is then run or pumped out through the valve V 5, until
the working level is reached, the use of steam for producing vacuum in A, as
herein before described, may be avoided. In this case, after the liquor is reduced to
the working level the valve V 5 is closed.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. Vacuum apparatus constructed arranged and operating substantially as herein-
before described with reference to the accompanying drawing.
2. In vacuum apparatus of the type set forth, dependent pipes such as K, arranged
substantially as and for the purpose hereinbefore described with reference to the
accompanying drawing.
3. The hereinbefore described method for producing vacuum in vacuum apparatus
by the aid of a water elevator or of a dependent pipe K, or both, substantially as set
forth with reference to the accompanying drawing.
Dated the 27th day of February 1897.
W. E. HEYS & SON,
Agents for the Applicant.