Improvements in Feed-water Heaters and Purifiers.
Year: 1887

page_text: Date of Application, 25th May, 1887.
Complete Left, 29th July, 1887.
Complete Accepted, 27th Sept., 1887.
[Communicated from abroad by AUGUSTE A. GOUBERT, of Brooklyn, in the County
of Kings and State of New York, United States of America.]
Improvements in Feed-water Heaters and Purifiers.
I, CHARLES ALBERT KNIGHT of 107, Hope Street, Glasgow in the County of
Lanark, Scotland, Engineer, do hereby declare the nature of my Invention to be as
follows:-
My Invention relates to that class of feed-water heaters and purifiers in which the
water therein contained is never brought into direct contact with the steam, but is
heated by the heat being transmitted from the steam to the water through metallic
surfaces.
The better types of such heaters are usually made of a number of tubes placed
longitudinally in a cylindrical shell, the water being inside the tubes and the steam
outside or vice versa. Some parts of my Invention are equally applicable to both
these descriptions of feed water heaters, as also to surface condensers; but, in the
apparatus I am about to describe, I prefer to have the water inside the tubes, these
being surrounded by the steam in the shell.
It is usual in the construction of feed-water heaters, such as above referred to;
for the sake of cheapness, to make the shell and certain other parts of iron; experience
however has shown that when the tubes are also made of iron, namely wrought iron
and necessarily thin, in order to readily transmit the heat, they are soon attacked by
the fatty acids due to the decomposition of the cylinder oil or grease and often by the
salts contained in the water, become pitted, corroded and quickly destroyed. They are
therefore made of copper or brass which metals resist better the action of these
various agents, but, as the ratio of expansion of copper or brass, within the same
ranges of temperature, is greater than that of iron, it has been found necessary to
provide means whereby the tubes may be allowed to expand and contract independently
of the shell. A part of my Invention consists in improved means to effect this
burpose.

page_text: Another part of my Invention relates to an improved method of introducing and
forcing the water through the apparatus, whereby the settling of sediment is facilitated.
A further improvement consists in providing deflectors at the inlet and outlet of the
water, for the purpose of deviating the current, thereby facilitating the settling of
sediment and separation of scum and also equalising the flow.
In the drawings, Figure 1 is a vertical section through the apparatus; Figure 2 is
a horizontal section through the upper water chamber at X, X, and Figure 3 is a
sectional view to an enlarged scale, showing, more particularly the expansion joint,
hereinafter described, which I employ according to my Invention.
the outlet of the heated water.
A. is the shell of the heater, preferably made of cast iron, as that metal is well
adapted to withstand the action of the fatty acids. The shell A is provided_with
nozzles T and U. for the admission and exit of the steam and also with a pipe K for
the removal of the water of condensation. B is the upper water chamber, provided
with an inwardly projecting pipe E, for the admission of the cold water. B' is the
lower water chamber, which is also provided with an inwardly projecting pipe E¹ for
Cis the upper tube plate, made to fit loosely into
the upper part of the shell A. Said tube plate C is firmly bolted to the flange P of
the chamber B. C is the lower tube plate and is securely bolted between the lower
flange of the shell A. and the flange of the chamber B¹. D, D, D are the tubes,
preferably made of brass these tubes are firmly secured at the ends to the tube
plates C and C. G. G₁ are dish shaped deflectors secured to the tube plates (
and C and placed directly opposite the ends of the pipes E. E'. H is a pipe for the
removal of mud and sediment from the chamber B, and I is a similar pipe for the
removal of scum from the chamber B. L. (see detail view figure 3) is a flat ring
or gasket of flexible material preferably made of thin copper, which I also prefer
to make with circular corrugations in order that it be more elastic. Said corrugated
gasket should be of sufficient width to extend across the face of the flange P. and also
across that of the upper flange R of the shell A. M N are annular gaskets of soft
material, preferably vulcanized rubber, which are shown as covering the entire surface
of the metallic gasket L; S is a heavy iron flanged ring, the internal diameter of
which is slightly larger than the external diameter of the flange P. The metallic
gasket L. being placed between the two rubber gaskets M. N. the three are set upon
the top of the flange R with their inner portion extending over the tube plate C ; the
flanged ring S. is placed over them and they are firmly bolted between S and R;
the water chamber B is then placed upon the gaskets and firmly bolted through them
to the tube plate C. A flexible connection is thus made between the shell A. and
the tube plate C. Now, supposing the maximum length of the tubes and shell to be
ten feet, the utmost difference of expansion within the ranges of temperature using
exhaust steam, would be about one sixteenth of an inch; if the apparatus be made
so that when cold, the upper face of the tube plate C, be 3 of an inch below the
upper face of the flange R, the maximum that the flexible metallic gasket will have
to spring, will be 3 of an inch above and below the horizontal position.
When it becomes necessary to clean the interior of the tubes, the upper water
chamber B is removed and a scraper, brush or swab may then be used, the mud or
sediment will fall into the lower chamber B¹, and thence to be blown off through the
pipe H.
I am aware that heretofore a tight joint such as that required between the flange P.
and the tube plate C. has often been made by bolting together the two flanges with a
metallic gasket corrugated or plain-between them; the soft metal, by the pressure,
being forced into the pores of the casting, and producing a tight and effective joint;
it is generally found however, that if such a joint be broken, the flanges cannot be
replaced in exactly the same position and the pressure applied by screwing down the
bolts is insufficient to make the joint tight again.
To provide for this I use, in accordance with my Invention the rubber gaskets M
and N. to protect the metallic gasket L, so that the chamber B. may be removed and
replaced at will, always making a tight joint without the necessity of straining the
bolts and without injury to the metallic gasket L.

page_text: The operation of my apparatus is as follows:- -the steam being admitted into the
shell at T circulates among the tubes D, D, impinging upon their outer surfaces and
finally passes out at V. In the normal condition the water chambers B, B¹, and the
tubes D. D, are kept filled with water which can only pass out when forced through
the heater into the boiler against steam pressure. The cold water introduced through
the pipe E by means of a pump or other forcing apparatus is diverted in an upward
direction by the deflector G, when the floating particles of vegetable and other light
matters are enabled to rise to the surface from whence they may be periodically blown
off through the pipe I. It is a well known principle in hydraulics, that if a vessel be
completely filled with a fluid, the pressure exerted at one point is equally distributed
in all directions and becomes the same throughout the mass; therefore a uniform
pressure is exerted in the chamber B, and the incoming water, as fast as supplied, is
distributed evenly to all the tubes and moves downward forcing the heated water
before it and becoming heated in its turn, until it arrives into the lower water
chamber B, from whence it passes out through the pipe E¹ to the boiler. As the
water becomes heated, many of the salts in solution, such as carbonates of lime and
magnesia aro precipitated and these with the particles of mud and sand mechanically
carried by the water must be allowed to separate and settle before the water goes to
the boiler, thus avoiding the formation of an injurious scale. This has been many
times attempted with varying success. Although these particles are very minute, if
the water be allowed to stand still for a sufficient length of time they will settle by
virtue of their own gravity; but if an ascending current is produced in the water, the
friction of the current against these fine particles of sediment carries them upwards
and out of the vessel without allowing them to settle, and even a very feeble current
will produce this effect. Now, as in accordance with my present Invention I, introduce
the water from above and produce a steady, uniform downward current, if the force of
gravity has a tendency to carry the particles to the bottom, this tendency is increased
by the downward current which is forcing them down instead of retarding their fall,
they therefore have attained upon arriving in the lower water chamber B¹ a com-
paratively considerable velocity, and upon the current being deviated and turning
suddenly around the edge of the deflector G', the said particles are projected down-
ward beyond the path of the current into the still space below, where they settle, to be
removed at intervals through the mud blow off pipe H.
Dated this 22nd day of May 1887
JAMES STEVENSON,
Gray's Inn Chambers,
20, High Holborn, London, W.C.,
Agent for Applicant.

page_text: I, CHARLES ALBERT KNIGHT, of 107 Hope Street, Glasgow in the County of
Lanark, Scotland, Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particulaly described and
ascertained in and by the following statement, reference also being had to the
drawings accompanying my Provisional Specification.
My Invention relates to that class of feed-water heaters and purifiers in which the
water therein contained is never brought into direct contact with the steam, but is
heated by the heat being transmitted from the steam to the water through metallic
surfaces. The better types of such heaters are usually made of a number of tubes
placed longitudinally in a cylindrical shell, the water being inside the tubes and the
steam outside or vice versa. Some parts of my Invention are equally applicable to
both these descriptions of feed water heaters, as also to surface condensers; but, in
the apparatus I am about to describe, I prefer to have the water inside the tubes,
these being surrounded by the steam in the shell.
It is usual in the construction of feed-water heaters, such as above referred to, for the
sake of cheapness, to make the shell and certain other parts of iron; experience however
has shown that when the tubes are also made of iron, namely wrought iron and necessarily
thin in order to readily transmit the heat-they are soon attacked by the fatty acids
due to the decomposition of the cylinder oil or grease and often by the salts contained
in the water, become pitted, corroded, and quickly destroyed. They are therefore
made of copper or brass which metals resist better the action of these various agents;
but, as the ratio of expansion of copper or brass within the same ranges of
temperature, is greater than that of iron, it has been found necessary to provide
means whereby the tubes may be allowed to expand and contract independently of
the shell. A part of my Invention consists in improved means to effect this purpose.
Another part of my Invention relates to an improved method of introducing and
forcing the water through the apparatus, whereby the settling of sediment is
facilitated. A further improvement consists in providing deflectors at the inlet and
outlet of the water, for the purpose of deviating the current, thereby facilitating the
settling of sediment and separation of scum and also equalising the flow.
In the drawings, Figure 1 is a vertical section through the apparatus; Figure 2 is
a horizontal section through the upper water chamber at XX, and Figure 3 is a
sectional view to an enlarged scale, shewing more particularly the expansion joint
hereinafter described, which I employ according to my Invention.

page_text: A is the shell of the heater, preferably made of cast iron, as that metal is well
adapted to withstand the action of the fatty acids. The shell A is provided with
nozzles T and U for the admission and exit of the steam and also with a pipe K for
the removal of the water of condensation. B is the upper water chamber, provided
with an inwardly projecting pipe E for the admission of the cold water. B¹ is the
lower water chamber, which is also provided with an inwardly projecting pipe E' for
the outlet of the heated water. C is the upper tube plate, made to fit loosely into the
upper part of the shell A. Said tube plate C is firmly bolted to the flange P of the
chamber B. C₁is the lower tube plate and is securely bolted between the lower
flange of the shell A, and the flange of the chamber B¹. D. D. D. are the tubes,
preferably made of brass, these tubes are firmly secured at the ends to the tube
plates C and C. G. G', are dish shaped deflectors secured to the tube plates C and
C', and placed directly opposite the ends of the pipes E. E. H is a pipe for the
removal of mud and sediment from the chamber B¹, and I is a similar pipe for the
removal of scum from the chamber B. L (see detail view Figure 3) is a flat ring or
gasket of flexible material preferably made of thin copper, which I also prefer to
make with circular corrugations in order that it may be more elastic. Said
corrugated gasket should be of sufficient width to extend across the face of the
flange P, and also across that of the upper flange R of the shell A. M. N. are annular
gaskets of soft material, preferably vulcanised rubber, which are shewn as covering
the entire surface of the metallic gasket L; S is a heavy iron flanged ring, the
internal diameter of which is slightly greater than the external diameter of the
flange P. The metallic gasket L being placed between the two rubber gaskets M. N.
the three are set upon the top of the flange R with their inner portion extending
over the tube plate C; the flanged ring S is then superposed and they are firmly
bolted between S and R; the water chamber B is then placed upon the gaskets
and firmly bolted through them to the tube plate C. A flexible connection is thus
made between the shell A and the tube plate C. Now, supposing the maximum
length of the tubes and shell to be ten feet, the utmost difference of expansion within
the ranges of temperature, using exhaust steam, would be about one sixteenth of an
inch; if the apparatus be made so that when cold, the upper face of the tube plate C
be and of an inch below the upper face of the flange R, the maximum that the
flexible metallic gasket will have to spring will be 32nd of an inch above and below
the horizontal position.
When it becomes necessary to clean the interior of the tubes, the upper water
chamber B is removed and a scraper, brush or swab may then be used, the mud or
sediment will fall into the lower chamber B¹, and thence to be blown off through the
pipe H.
I am aware that heretofore a tight joint such as that required between the flange P
and the tube plate (has often been made by bolting together the two flanges with a
metallic gasket corrugated or plain-between them; the soft metal by the pressure,
being forced into the pores of the casting, and producing a tight and effective joint;
it is generally found however, that if such a joint be broken, the flanges cannot be
replaced in exactly the same position and the pressure applied by screwing down the
bolts is insufficient to make the joint tight again. To provide for this I use, in
accordance with my Invention, the rubber gaskets M and N to protect the metallic
gasket L, so that the chamber B may be removed and replaced at will, always
making a tight joint without the necessity of straining the bolts and without injury
to the metallic gasket L.
The operation of my apparatus is as follows:-the steam being admitted into the
shell at T circulates among the tubes D. D. D. impinging upon their outer surfaces
and finally passes out at U. In the normal condition the water chambers B. B' and
the tubes D. D. D. are kept filled with water, which can only pass out when forced
through the heater into the boiler against steam pressure. The cold water introduced
through the pipe E by means of a pump or other forcing apparatus is diverted in an
upward direction by the deflector G, when the floating particles of vegetable and

page_text: other light matters are enabled to rise to the surface from whence they may be
periodically blown off through the pipe I. It is a well known principle in hydraulics,
that if a vessel be completely filled with a fluid, the pressure exerted at one point is
equally distributed in all directions and becomes the same throughout the mass:
therefore a uniform pressure is exerted in the chamber B, and the incoming water, as
fast as supplied, is distributed evenly to all the tubes and moves downward, forcing
the heated water before it and becoming heated in its turn until it arrives into the
lower water chamber B¹, from whence it passes out through the pipe E¹ to the
boiler. As the water becomes heated, many of the salts in solution, such as
carbonates of lime and magnesia, are precipated, and these with the particles of mud
and sand mechanically carried by the water must be allowed to separate and settle
before the water goes to the boiler, thus avoiding the formation of an injurious
"scale." This has been many times attempted with varying success. Although these
particles are very minute, if the water be allowed to stand still for a sufficient length
of time they will settle by virtue of their own gravity; but if an ascending current
is produced in the water, the friction of the current against these fine particles of
sediment carries them upward and out of the vessel without allowing them to
settle, and even a very feeble current will produce this effect.
Now, as in accordance with my present Invention I, introduce the water from
above and produce a steady, uniform downward current; if the force of gravity has
a tendency to carry the particles to the bottom, this tendency is increased by the
downward current which is forcing them down instead of retarding their fall, they
therefore have attained upon arriving in the lower water chamber B a comparatively
considerable velocity, and upon the current being deviated and turning suddenly
around the edge of the deflector G¹, the said particles are projected downward beyond
the path of the current into the still space below, where they settle, to be removed at
intervals through the mud blow off pipe H.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is:-
Firstly. In a feed-water heater and purifier, the hereindescribed method of
promoting the settling of sediment, which consists in introducing the feed-water
at or near the top of the apparatus and carrying an unobstructed downward
vertical flow of the said water through the heating tubes, whereby, the natural
tendency of the salts, as they become precipitated by heat, to fall by their own
gravity, is aided by the downward current instead of its being overcome as is the
case with an upward flow; substantially as and for the purposes herein specified.
Secondly. In a feed-water heater and purifier substantially such as herein
described, an upper water chamber provided with an inlet for the introduction of
the cold water and an outlet for the removal of scum; and a lower water chamber
provided with outlets for the removal of the heated water and sediment; in com-
bination with a set of vertical heating tubes forming a. communication between the
said water chambers; the said tubes being surrounded by the steam; substantially
as and for the purposes herein specified.
Thirdly. In a feed-water heater and purifier, substantially as herein described, the
combination of the shell A provided with the steam inlet T, the steam outlet U," and
the outlet K, for the water of condensation; with the heating tubes D. D. the tube
plates C. C, the water chambers B. B₁, the cold water inlet pipe E, the hot water
outlet pipe E', the scum blow off pipe I, and the mud blow off pipe H, substantially
as and for the purposes herein specified.
Fourthly. In a feed water-heater or condenser, substantially as herein described
the combination of the shell A, the tubes D. D. the water chambers B. B¹ and the
inwardly projecting pipes E. E'; with the dish shaped deflectors G. Gas and for the
purposes herein specified.
Fifthly. In a feed-water heater or condenser substantially as herein described, the
combination of the tubes D, D, the tube plate C, the chamber B, and the shell A ; with

page_text: a gasket of flexible material, firmly bolted between the chamber B and the tube
plate C, and extending across over the end of the shell A and firmly secured
thereto; thus effecting the triple purpose of making a water tight joint between
the chamber B. and the tube plate C, sealing the end of the shell A, and making a
flexible connection between the tube plate and the shell; thus allowing the tubes
to freely expand and contract independently of the said shell; substantially as and
for the purposes herein specified.
Sixthly. In a feed-water heater or condenser, substantially as herein described,
the chamber B, the tube plate C, the shell A and the metallic gasket L, forming a
flexible connection between the tube plate C, and the shell A ; in combination with
the gaskets M, N, made of vulcanized rubber or its equivalent; as and for the purposes
herein specified.
Dated thin 20th day of Jul 1987