Improvements in the Construction and Working of Double, Triple, and Multiple Effect Evaporating Apparatus.
Year: 1890

page_text: Date of Application, 5th Apr., 1890-Accepted, 10th May, 1890
COMPLETE STEINATION.
Improvements in the Construction and Working of Double, Triple,
and Multiple Effect Evaporating Apparatus.
We ALFRED CHAPMAN of 17 York Street, Liverpool Engineer and SAMUEL
VICKESS Junior of 163 Chatham Street Liverpool, 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 :—
In a double, triple or multiple effect evaporating apparatus constructed and worked
in the ordinary manner, the liquid which is to be evaporated or concentrated, or is
being evaporated or concentrated goes from the pans, pan or vessel of higher
pressure to those or that of lower pressure, while the steam or vapor of greater
pressure goes from the pans, pan or vessel containing liquid of less density to those
or that containing liquid of greater density.
Now according to our invention we construct and work double, triple or multiple
effect evaporating apparatus so that the liquid which is to be evaporated or concen-
trated, or is being evaporated or concentrated goes from the pans, pan or vessel of
lower pressure to those or that of higher pressure and the steam or vapor from the
pans, pan or vessel containing liquid of greater density to the pans, pan or vessel
containing liquid of a lower density. We are thereby enabled to concentrate liquids
to a greater density than can be done by apparatus constructed and worked in the
ordinary manner because steam of the greatest heat is applied to evaporate water
from the solution of the greatest density and therefore of the highest boiling point,
and steam of the least heat is applied to the solution of the least density and there-
fore of the lowest boiling point and by this means a greater difference of temperature
is obtained between the heat of the steam and the boiling point of the solution to
which it is applied, than in the ordinary way, more especially in the pan or vessel
containing the solution of highest density.
This arrangement we do not consider suitable for treating such solutions as are
liable to be injured by great heat except when they are weak."
The manner in which our invention can be carried into effect will be understood
on reference to the annexed diagram of a quadruple effect apparatus arranged for
the purpose. It is composed of four pans a, b, c, d, each fitted with an ordinary
steam drum e through which pass the tubes that communicate between the upper
and lower portions of the pan. The liquid to be concentrated enters the pan a just
above the upper tube plate by the pipe, the liquid being drawn in by the vacuum
in the pan. The liquid passes down through the tubes in pan a and then passes
from this pan by the pipe g to pan b in which the pressure is higher, a pump or
injector at forcing it forward. From pan the liquid passes in like manner to
pan c and then to pan d the last of the series from which it is expelled through the
pipe by the pressure in pan d which is higher than that in the other pans and is
greater than that of the atmosphere. The live steam on the other hand enters by
the pipe the drum e of the last pan d which contains liquid of the greatest density.
The vapor evolved from the liquid in pan d is conducted by the pipe k to the drum
of pan c; in like manner the vapor evolved in pan c is conducted to the drum of
pan b and the vapor evolved in pan b is conducted to the drum of pan a in which
the pressure is the lowest, and in which the liquid is at the lowest density; the
vapor evolved from the liquid in pan a passes by the pipe to the condenser.
The diagram shows pans with the liquid inlet just above the upper tube plate and
the outlet situated at the pan bottom, the liquid while being heated flowing down the
tubes that pass through the drum, this being the ordinary construction of pan. Other
constructions of pan may, however, be used with our present invention such for
example as those described in Alfred Chapman's Specification No. 1752 of 1888 in

page_text: which the liquid enters the pan below the tubes, then passes np the tubes and issues
from the pan at a point above the tubes, going thence to the lower part of the next
pan of the series.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The mode of working double, triple or multiple effect apparatus which consists
in causing the liquid to be evaporated or concentrated to go from the pans, pan or
vessel of lower pressure to those or that of higher pressure and the steam or vapor to
go from the pans, pan or vessel containing liquid of greater density to the pans, pan
or vessel containing liquid of a lower density, as set forth.
2. Constructing double triple or multiple effect apparatus, substantially as herein-
before described for carrying out the mode of working referred to in Claim 1.
Dated this 5th day of Anril 1890
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.