Improvements in and relating to Evaporators.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Evaporators.
I, JAMES FOSTER of 11 St. Andrew's Drive, Pollokshields, Renfrewshire,
Engineer, do hereby declare the nature of my invention to be as follows:-
This invention has reference to improvements in and relating to vessels for
evaporating and concentrating liquors, and especially those working on the
multiple effect system.
The bottom cover of the evaporator below the heating vessel would be formed
of a downwardly curved shape towards one end so that the precipitated material
would pass to a vertical duct or flanged mouth to which would be connected a
vertical discharge and settling pipe. The upper tube plate of heating vessel
would be formed of a curved shape gradually falling both ways from the centre,
and dip down to a half channel, or well shape at outer part of vessel where the
outer ring of tubes would be formed of large diameter for about two-thirds of the
circumference of vessel. The smaller tubes would pass through upper curved
tube plate and have their top ends all at the same level. The liquor would flow
down the upper inclined tube plate to the outer channel or "well" and then pass
down the large tubes at the circumference which act as circulating tubes and then
ascend from bottom of vessel up through the smaller tubes. The bottom end of
discharge pipe would be formed of a tapering shape and be bolted or connected to
a chest with duplex branches each leading radially into the barrel of a pump.
A flange or projection would be fitted in bottom of chest opposite the discharge
end of pipe so as to deflect the deposited material into each branch of chest,
which would be fitted with flap or like valves. The plunger of each pump would
preferably be, preferably, connected by a rod and eccentric to a transverse
connecting shaft carried by bearing brackets from frame-work and clutches
would be provided so that either eccen ric could be put into or out of gear with
shaft or a driving pulley on shaft may be operated by a clutch. The end of each
pump barrel would have a discharge valve working against its face and the
plunger of pump would draw away the deposited material through the flap suction
valve in chest into the barrel, and on its return stroke it would open the valve in
barrel and force the precipitated material through a discharge chest on opposite
side of valve, a recoil acting spring bringing said valve back to its closed position
on the return stroke of plunger. Instead of working with duplex pumps only one
need be fitted if so desired; and instead of discharging the precipitated material
through a valve at end of barrel at each action of plunger the material may be
forced into a pipe connected to barrel and of smaller diameter than the latter and
a stop valve may be fitted in this pipe so as to shut off to atmosphere before
sufficient material is deposited and any unconcentrated liquor which may
accumulate may be taken away by a byepass branch to evaporating vessel.
Instead of having the pump with a reciprocating plunger it may be made in the
form of an oscillating quadrant disc working in a chest below discharge end of
pipe from evaporator.
With this arrangement the oscillating disc would close up the orifice while the
material was accumulating in pipe and then move away to permit the material to
drop into chest; while on its return oscillation it would force the precipitated
material through one or more flap valves into a discharge shoot.

page_text: A branch would be formed in the vertical pipe connected to discharge end of
evaporating vessel from which the thin or unconcentrated liquor would pass by a
pipe to an automatic feeding close strapping chamber intermediate between each
evaportator of the series. In this strapping chamber a float vessel is fitted open
at top and at the central part of its bottom. An open frame is fitted at the top
of the float and carries a central guide through which passes a vertical fixed
spindle. This spindle is fitted through a guide at central discharge branch of
trapping chamber and a valve shaped disc somewhat of the sectional shape of an
anchor escapement is formed on this spindle. The lower end of cistern is attached
to a sleeve or collar with flange on top which slides in the discharge branch of
chamber, and, a helical spring is interposed between bottom of fixed chamber and
the flanged top of collar at bottom of cistern. By this means the liquor from
the one vessel passes by a branch pipe into cistern and when it has ascended to a
predetermined level the weight in cistern presses down the central sleeve below
its line of contact with the projecting valve disc on central spindle and thus the
liquor gets drawn away by the vacuum through the discharge branch and is led
into the next evaporating vessel of the series the recoil acting spring bringing the
sleeve back to its upper closed position and this intermittent liquor feeding action
from one vessel to the other will go on in an automatic and continuous manner.
Dated this 28th day of September 1895.
I, JAMES FOSTER, of 11 St. Andrew's Drive, Pollokshields, Renfrewshire,
Engineer, do hereby declare the nature of my invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement in writing that is to say :—
This invention has reference to improvements in and relating to vessels for
evaporating and concentrating liquors and especially those working on the multiple
effect system.
And in order that my said invention and the manuer of performing or carrying
same into practice may be properly understood, I have hereunto appended an
explanatory sheet of drawings in which the same reference letters are used to
indicate corresponding parts in all the figures where shown.
Figure 1 is a section of the lower part of an evaporating vessel consisting of the
steam chamber and bottom thereof as fitted with my improvements.
Figure 2 is a section of the duplex barrel pump as fitted at lower end of
evaporating vessel instead of the single barrel pump shown in Figure 1, and
Figure 3 is a part plan view of same.
Figure 4 is a view of a pipe with valve which may be fitted to pump barrel.
Figures 5 and 6 show sectional elevations of the pump in which the plunger is
made in the form of an oscillating disc, and
Figure 7 is a sectional elevation of an automatic feed trapping chamber.
Referring to these drawings:-
The bottom cover A' of the evaporator A below the heating vessel B would be
formed of a downwardly curved shape towards one side so that the precipitated
material would pass to a vertical duct or flanged mouth A*.to which would be
connected a vertical discharge and settling pipe C. The upper tube plate B' of
heating vessel B would be formed of a curved shape gradually falling both ways
from the centre, and dip down to a half channel or well shape at 13 where the
outer ring of tubes 6 would be formed of large diameter for about two-thirds of

page_text: the circumference of vessel. The smaller tubes 6 would pass through upper
curved tube plate B' and have their top ends all at the same level. The liquor
would flow down the upper inclined tube plate B' to the outer channel or "well" B*
and then pass down the large tubes 6 at the circumference which act as circulating
tubes and then ascend from bottom of vessel up through the smaller tubes b. The
bottom end C¹ of discharge pipe C would be formed of a tapering shape and be
bolted or connected to a chest C' with duplex branches c c¹ as shown in Figure 2
each leading radially into the barrel D of a pump, or this tapering branch may
be formed on the pump as shown in Figure 1. A flange or projection c² would be
formed or fitted in bottom of chest opposite the discharge end C₁ of pipe C, so as
to deflect the deposited material into each branch o c¹ of chest C' which would be
fitted with flap or like valves C³ as shown in Figure 2.
The plunger of each pump would preferably be connected by a rod E and eccentric E¹
to a transverse connecting shaft E' carried by bearing brackets from framework,
and clutches e would be provided so that either eccentric could be put into or out
of gear with shaft E, as shown in Figure 3. The end of each pump barrel D
would have a discharge valve working against its face such as d shown in Figure 1
and the plunger E3 of pump would draw away the deposited material through the
flap suction valve c or c¹ in chest into the barrel and on its return stroke it would
open the valve d in barrel and force the precipitated material through a discharge
chest D on opposite side of valve d à recoil acting spring at d¹ bringing said
valve d back to its closed position on the return stroke of plunger. Instead of
working with duplex pumps as shown in Figure 2 only one need be fitted if so
desired as shown in Figure 1 and instead of discharging the precipitated material
through a valve d at end of barrel at each action of plunger the material may as
shown in Figure 4 be forced into a pipe F connected to barrel and of smaller
diameter than the latter and a stop valve F¹ may be fitted in this pipe so as to
shut off to atmosphere before sufficient material is deposited and any unconcentrated
liquor which may accumulate may be taken away by a bye pass branch F 2 to
evaporating vessel.
Instead of baving the pump with a reciprocating plunger E 3 it may as shown in
Figures 5 and 6 be made in the form of an oscillating quadrant disc G working in
a chest C 2 below discharge end C₁of pipe from evaporator. With this
arrangement, the oscillating disc G would close up the orifice in discharge end C
while the material was accumulating in pipe and then move away to permit the
material to drop into chest C 2 while on its return oscillation it would force the
precipitated material through one or more flap valves g g' into a discharge shoot g 2
and as shown in Figure 6 the valve g' may be fitted with a recoil acting counter-
weighted lever g 3. A branch h would be formed in the vertical pipe C connected
to the discharge end of evaporating vessel as shown in Figure I from which the
thin or unconcentrated liquor would pass by a pipe to an automatic feeding close
trapping chamber H shown in Figure 7 and which would be placed intermediate
between each evaporator of the series. In this trapping chamber H a float vessel H
is fitted open at top and at the central part of its bottom. An open frame H 2 is
fitted at the top of the float and carries a central guide H 3 through which passes a
vertical fixed spindle h¹. This spindle is fitted through a guide 2 at central
discharge branch of trapping chamber and a valve shaped disc 3 somewhat of the
sectional shape of an anchor escapement is formed on this spindle. The lower
end of float H' is attached to a sleeve or collar 1 with flange l' on top which slides
in the discharge branch of chamber and a helical spring or springs I 2 is interposed
between bottom of fixed chamber H and the flanged top 11 of collar 1 at bottom of
float vessel H'. By this means the liquor from the one vessel passes by a branch
pipe into cistern and when it has ascended to a predetermined level the weight in
cistern presses down the central sleeve I below its line of contact with the projecting
valve disc 3 cn central spindle and thus the liquor gets drawn away by the
vacuum through the discharge branch and is led into the next evaporating vessel
of the series, the recoil acting spring 12 bringing the sleeve 1 back to its upper

page_text: closed position; and this intermittent liquor feeding action from one vessel to the
other will go on in an automatic and continuous manner.
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 :-
First. In evaporators, the arrangement and use of the upper tube plate inclining
towards its edge circumference which is formed of a "well" shape, substantially as
herein described in reference to and shown in the accompanying drawings.
Second. In evaporators, the construction and arrangement of pumps, substantially
as herein described in reference to and shown in the accompanying drawings.
Third. In evaporators, the construction and arrangement of automatic feed
trapping chamber substantially as herein described in reference to and shown in
Figure 7 of the accompanying drawings.
Dated 18th day of June 1896.
W. R. M. THOMSON & Co.,
96 Buchanan Street, Glasgow, Agents.
W. R. M. THOMSON & Co.,
96 Buchanan Street, Glasgow, Agents.