Improvements in Surface Condensers.
Year: 1890

page_text: Date of Application, 11th Feb., 1890
Complete Specification Left, 11th Dec., 1890-Accepted, 17th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Surface Condensers.
We, ROBERT MARSHALL and EDWARD FITZ-GERALD, both of No. 121 Fenchurch
Street, in the City of London, Engineers, do hereby declare the nature of this
invention to be as follows:-
This invention relates to an inproved construction of surface condensers, more
particularly applicable to marine engines. In marine engineering practice it is now
considered desirable to supply the boilers with a supplementary feed of distilled
water, instead of sea water, as, since the introduction of triple-expansion engines and
steam of very high pressures, difficulties have occurred through deposits on the heat-
ing surfaces from the sea water used to make good the losses of the fresh water supply
by leakage &c.
With the adoption of such supplementary distilled water feed however, a difficulty has
still arisen in the endeavour to keep the water of the boilers fresh, owing to the leakage
of some of the circulating sea water used for condensing through one or more
defective tube joints of the surface condenser, thus contaminating the distilled water
feed. This is one of the difficulties or objections to the use of tubulous boilers at
sea, since the resulting deposit of salt or scale to any considerable extent in the tubes
of such boilers would be fatal.
According to the present invention, any such leakage of salt water into the surface
condensers is effectually prevented by constructing the latter with double tube plates
at each end, instead of with single ones as heretofore. The two tube platescare
situated a small distance apart, such distance varying according to the size of the
condenser, and the tubes are made to pass through both, being packed or rendered
water-tight in each plate by any of the well known methods.
In surface condensers, the circulating condensing water is arranged to pass either
inside or outside the tubes, according to design. Assuming the circulation to take
place through the tubes, and consequently, over the outer surface of the outer tube
plate and the steam to be condensed being on the outer surfaces of the tubes and the
inner surface of the inner tube plate, then it will be seen that any salt water that
may leak through a defective joint of the outer tube plate, will flow down in the
space between the two tube plates into a well formed at the bottom thereof below
the level of the bottom tubes, and from this well the water is pumped overboard by
suitable pumps, which may either be made to maintain a partial vacuum in the said
space, or this may be made open to the atmosphere. If on the other hand any tube
joint of the inner plate should leak, only air will pass through into the condenser,
and this would be at once indicated by loss of vacuum on the vacuum gauge.
It will be seen that by the use of the above described invention, and by employing
ample distilling apparatus, boilers at sea may be maintained entirely charged with
fresh water, and the heating surfaces being kept free of deposit greater efficiency
and economy in working will result, and danger or liability to deterioration by over-
heating will be greatly prevented.
Although the above described invention is mainly applicable to marine engines,
yet it is also applicable with advantage for engines on sea coasts where the supply of
fresh water is very restricted.
Dated this 11th day of February 1890.
ABEL & IMKAY,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Surface Condensers.
We, ROBERT MARSHALL and EDWARD FITZ-GERALD, both of No. 121 Fenchurch
Street, in the City of London, Engineers, 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:-
This invention relates to an improved construction of surface condensers, more
particularly applicable to marine engines. In marine engineering practice it is now
considered desirable to supply the boilers with a supplementary feed of distilled water,
instead of sea water, as, since the introduction of triple-expansion engines and steam
of very high pressures, difficulties have occurred through deposits on the heating
surfaces from the sea water used to make good the losses of the fresh water supply
by leakage &c.
With the adoption of such supplementary distilled water feed however, a difficulty
has still arisen in the endeavour to keep the water of the boilers fresh, owing to the
leakage of some of the circulating sea water used for condensing, through some
defective tube joints of the surface condenser, thus contaminating the distilled water
feed. This is one of the difficulties or objections to the use of tubulous boilers at sea,
since the resulting deposit of salt or scale to any considerable extent in the tubes of
such boilers would be fatal.
According to the present invention, any such leakage of salt water. into a surface
condenser is effectually prevented by constructing the condenser with double tube
plates at each end, instead of with single ones as heretofore. The two tube plates are
situated a small distance apart, such distance varying according to the size of the
condenser, and the tubes are made to pass through both, being packed or rendered
water-tight in each plate by any of the well known methods.
In some surface condensers, the circulating condensing water is arranged to pass
inside the tubes, in others it passes outside the tubes. Assuming the circulation to
take place through the tubes, and consequently, over the outer surface of the outer
tube plate and the steam to be condensed being on the outer surfaces of the tubes and
the inner surface of the inner tube plate, then any salt water that may leak through a
defective joint of the outer tube plate, will flow down in the space between the two tube
plates into a well formed at the bottom thereof below the level of the bottom tubes, and
from this well the water is pumped overboard by suitable pumps, which may either
be made to maintain a partial vacuum in the said space, or this may be made open to
the atmosphere. If, on the other hand, any tube joint of the inner plate should leak,
only air will pass through into the condenser, and this would be at once indicated
by loss of vacuum on the vacuum gauge.
It will be seen that by the use of the above described invention, and by employing
ample distilling apparatus, boilers at sea may be maintained entirely charged with
fresh water, and, the heating surfaces being kept free of deposit, greater efficiency
and economy in working will result and danger or liability to deterioration by over-
heating will be to a great extent avoided.
Although the above described invention is mainly applicable to marine engines,
yet it is also applicable with advantage for engines on sea coasts where the supply of
fresh water is very restricted.
Fig. 1 of the accompanying drawings shews this invention applied to one of the
usual forms of marine surface condenser. T and T are the two tube plates at each
end offering between these spaces $ into which some of the circulating water which
flows through the tubes would pass if a joint in the outer tube plate T¹ were defective.
The spaces S may be open to the atmosphere or a vacuum may be maintained in
them.
Fig. 2 shews one method of making the tube joints through the two plates T₁ T³,
by means of a tube A somewhat larger in diameter than the condenser tube. This
tube A serves as a gland for packing in the plate T2 and the plate T¹ has a screw

page_text: gland of the ordinary form, this being sufficiently large to admit the tube A from
outside.
Fig. 3, shews jointing by wood ferrules.
The hole in plate T¹ is larger than in
plate T2, so that the ferrule for plate T2 can be passed through the hole in plate T¹.
Fig. 4 shews the packing by U washers,
Fig. 5 shews packing by screw glands.
In both those arrangements the hole in T¹, being necessarily larger than in T³, is
provided with a metal washer W.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
Constructing a surface condenser with double tube plates at each end, substantially
as and for the purpose set forth.
Dated this 11th day of December 1890.
ABEL & IMKAY,
Agents for the Applicants.