Improvements in Marine Evaporators and Condensers.
Year: 1892

page_text: Date of Application, 5th Feb., 1892
Complete Specification Left, 3rd Nov., 1892-Accepted, 17th Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Marine Evaporators and Condensers.
I, WILLIAM GEORGE CHECKETTS of The Newlands Pershore, Worcestershire,
Machinist, do hereby declare the nature of my said invention to be as follows:-
My invention has for its object improvements in marine evaporators and
condensers by which I am able to more readily obtain fresh water at sea by
evaporation for the purpose of replacing the loss through use in boilers and also for
other purposes. By my improvements a great saving of fuel is effected throughout
the process.
In carrying my invention into effect I expand the steam which may be under a
pressure of say 150 lbs. until expanded to say 15 lbs. thus causing it to contain less
than half the weight than when generated to 15 lbs. To this expanded steam I
admit a jet of water from the boiler in the form of spray with the result that the
spray is instantly evaporated. This arrangement can be applied to each exhaust of
compound engines and I may provide a final exhaust as an evaporator to make up
boiler feed. The hot salt or impure water is admitted to steam as it leaves the
cylinder and then falls vertically down a pipe which forms an evaporator at the
bottom of which is a specially constructed separator. A pipe connects the bottom
of the separator with the brine pump by which means the brine is extracted. The
feed to the evaporator is heated by the condenser which is specially constructed as
follows:-
The condenser is preferably vertical with the vapor passing through the tubes
the outlet for circulating water being sufficiently below the top to allow the upper
part of the condenser to form a heater to heat the feed for the evaporator as the
water above the outlet becomes very hot and by lowering the outlet the volume of
water and consequently the heat is increased and this I utilize to heat the feed for
the evaporator. A plate may be provided above the circulating outlet to separate
the water.
Another form of condenser consists of the ordinary marine condenser with two
or more rows of tubes divided so as to allow a portion of the circulating water to
pass through & by either of these condensers the evaporator feed is heated.
Dated this 4th day of February 1892.
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent.
COMPLETE SPECIFICATION.
Improvements in Marine Evaporators and Condensers.
I, WILLIAM GEORGE CHECKETTS, of The Newlands, Pershore, in the County
of Worcester, Machinist, do hereby declare the nature of my said 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 has for its object improvements in marine evaporators and
condensers by which I am able to more readily obtain fresh water at sea by
evaporation for the purpose of replacing the loss through use in boilers and also for
other purposes. By my improvements a great saving of fuel is effected and of
course my invention may be applied to other engines by which means impurities
are removed from the supply and incrustation on the boiler flues prevented.

page_text: In carrying my invention into effect I expand the steam which may be under a
pressure of say 150 lbs. until expanded to say 15 lbs. thus causing it to contain less
than half the weight than when generated to 15 lbs. To this expanded steam I
admit a jet of water from the boiler in the form of spray with the result that the
spray is instantly evaporated. This arrangement can be applied to each exhaust
of compound engine and I may provide a final exhaust as an evaporator to make
up boiler feed. The hot salt or impure water is connected with the steam as it
leaves the cylinder and then falls vertically down a pipe which forms an evaporator
at the bottom of which is a specially constructed separator. A pipe connects the
bottom of the separator with the brine pump by which means the brine is extracted.
The feed to evaporator is heated by the condenser which is specially constructed as
follows:-
The condenser is preferably vertical with the vapor passing through the tubes the
outlet for circulating water being sufficiently below the top to allow the upper part
of the condenser to form a heater to heat the feed for the evaporator as the water
above the outlet becomes very hot and by lowering the outlet the volume of
water and consequently the heat is increased and this I utilize to heat the feed for
the evaporator. A plate may be provided above the circulating outlet to separate
the hot water at the top from that of the cooler below.
Another form of condenser consists of the ordinary marine condenser with two or
more rows of tubes divided so as to allow a portion of the circulating water to pass
through and by either of these condensers the evaporator feed is heated.
In order that my invention may be clearly understood and more easily carried
into practice I have appended hereunto a sheet of drawings which shews an arrange-
ment in diagram for carrying out my improved system from which its application
will be readily understood.
In carrying my invention into effect the feed for the evaporator is taken at bl
from the circulating water in the condenser K and further heated to the temperature
of the exhaust steam by passing through the upper part or chamber of the said
condenser or in a special heater and at this temperature is mixed with the exhaust
steam A from the cylinder H at say a' being then led down to the chamber E which
forms a separator the portion not evaporated falling to the bottom of the separator
and passing through F to the brine pump the vapor rising through the pipe D to
the condenser through which it passes. The separator is made cone-shaped as
shown at the bottom to brine pipe and provision is made to prevent priming.
The portion of heat available for evaporation depends upon the difference between
the boiling points at the steam pressure used in engines and at the vacuum in
exhaust-pipe the usual pressure being 150 lbs. per square inch in marine engines
less loss by radiation.
-
Example: Steam at 150 lbs. temperature 366° F. being boiling point at that
pressure vacuum 26" boiling point = about 130° ... 366 - 130 = 236 = the
difference in boiling point and taking half the difference as units of heat available
for evaporation there is sufficient heat in 10lbs. of steam to evaporate 1 lb. of
water. I therefore mix 2 lbs. of feed with 10 lbs. of steam 1 lb. being evaporated
and 1 lb. of brine pumped away.
The advantages of my system of evaporation over others being mainly the low
cost of machine as compared with others, and while other evaporators use about
10 lbs. of live heat or steam from boilers to evaporate 9 lbs. of fresh water I use no
live heat except the heat from exhaust steam which is in excess of that required to
maintain it in a state of vapor and which causes the excessive dryness of expanded
steam. Further no scale is formed by my system owing to their being no outside
application of heat as in other evaporators, and the sea water being mixed with the
exhaust steam from the engines the portion which is not evaporated and is pumped
away as the brine brings with it a great portion of the grease from the cylinders
thereby preventing such grease passing to the boilers and forming a thin scale-on
the plates which prevents the free passage of heat.

page_text: 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 :-
The improved mode of and means for evaporating sea and other water substan-
tially as and for the purpose herein set forth and illustrated.
Dated this 2nd day of November 1892.
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent.