Improvements in Apparatus for Heating and Purifying the Feed Water Supplied to Steam Boilers.
Year: 1886

page_text: Date of Application, 2nd Dec., 1886.
Specification Accepted, 5th Jan., 1887.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Heating and Purifying the Feed
Water Supplied to Steam Boilers.
I, CHARLES ALBERT KNIGHT of 107 Hope Street, Glasgow, Engineer, do hereby
declare the nature of my invention for IMPROVEMENTS IN APPARATUS FOR HEATING
AND PURIFYING THE FEED WATER SUPPLIED TO STEAM BOILERS, and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement and accompanying sheet of drawings in which:-
Figure 1 is a vertical sectional elevation. Figure 2 is a horizontal section taken on
line A, B, Figure 1. Figure 3 is a horizontal section on line C, D. Figure 1, and
Figure 4a vertical section shewing a modified construction and arrangement of
the base to that shown at Figure 1 :-
The device forming
a feed water heater, according to my Invention comprises an
outer shell A preferably of wrought iron or steel, built up in sections to the height
required. Said sections are connected by expansion rings B, to meet the propor-
tionately greater elongation of the tubes of the heater when said tubes are made of
brass or copper.
At the top of the heater is a chamber C with plate C₁ perforated
with a given number of holes of any suitable diameter, to receive tubes of a corresponding
size.
The portion forming the bottom of the heater, assumes the shape of a hollow casting
divided into two parts 1) and E, through the centre of which is an annular opening F
forming a well K, terminating with a bolted dome-shaped cover K, K; which allows,
when required of ready access to the interior of the beater. Said bottom portion of
the heater is provided with inlet and outlet passages as shewn at G and H respectively;
the top plate I of the hollow casting above mentioned is also perforated with holes of a
size corresponding with those in the plate Cat the top of the heater, and into which
the tubes are tightly expanded. I arrange within, and concentrically with the outer
shell a cylindrical chamber J of smaller diameter relatively to the outer shell; said
chamber resting loosely in à recess provided in the top plate C, and made of thin metal,
in sections so arranged that the lower sections telescope into the upper ones, and allow
free ingress to the interior of the heater for cleaning or other purposes.

page_text: A tight fitting cover T is provided at the top of the heater, to allow access to the
interior thereof and serving also at the same time to keep in position the cylindrical
chamber J. The lower end of said cylindrical chamber opens into the well K before
mentioned at base of the heater. The lower portion K¹ K of said well is, as before
indicated, dome-shaped and being thus shaped, the collection of the sediment in the
water is facilitated. Said lower portion K', K, is provided with a mud cock L.
Through the dome-shaped cover K, K₁, aforesaid, and leading from the pumps, by way
of the lower three way cock M, is a pipe N which rises centrally from the well K,
upwards to nearly the top of the cylindrical chamber J, within which it rises and is
terminated by a scum collector N', in the shape of an inverted bell mouth which, serves
to allow of the climination of the lighter impurities in the water, and which will now
be confined in the space above the said collector N1, in the chamber J. The outlet O,
to the boilers, is situated, as will be seen on reference to the drawings, near the top of
the heater, from whence naturally, the hottest water will always be obtainable. Said
outlet 0,
provided with a three way cock P, (the functions of which will be hercin-
after described,) similar to that of the inlet M, to which it is connected by a pipe Q
provided with an expansion joint S. The heater is also further provided with a glass
water guage for the purpose of ascertaining the height of the water within it, and to
facilitate the operation of blowing through whether by means of the bottom blow off
cock L, or through the surface blow off cock L'.
Referring to the hereinbefore modified form and arrangement of the base of the
heater, shown at Figure 4, whereby I propose to facilitate the descent of sediment
contained in the water into the well K, it will be seen that I incline the upper plate 1,
of the base wherein the tubes are expanded in the manner shown; the upper plate C¹,
in that case is also inclined in the same degree to ensure the length of the tubes being
the same.
I also, it will be seen, on reference to the figure, arrange the orifices in the
plate I for the expansion of the tubes in such manner that the expanding seats shall
be at right angles to the axis of the tubes, and-likewise in the upper plate-which
would correspond with the plate C', in Figure 1.
The working of the heater may be described as follows: assuming the latter ready
to be started, and filled with water up to the working level, the feed water is discharged
by the pump at the mouth N¹, of the internal tube N; and, as the feed water may be
assumed to be colder than the surrounding body of water in the heater at this point, it
must necessarily descend within the cylindrical chamber J, passing out and upwards at
its lower extremity, which all but enters the well K, and thus supplies the regular flow
of water to the boilers. By the introduction of the cylindrical chamber J, in combination
with the internal tube N, I am enabled to secure three important features of advantage,
namely First, any impurities in the feed water, of a relatively lower gravity than
the latter, are confined in the upper part of the chamber J. Second. The comparatively
cold entering feed water is discharged at a point where the surrounding body of water
is hottest and, descending by reason of being confined in a chamber, separate from
the main body of water in the heater, a circulation of the water is established which
produces Third-The additional advantage that in the descent of the water within
the said cylindrical chamber much, if not all the solid matter in solution will find its
way to the lowest point of the heater in the well K. I propose further that the
heater shall be cleansed according to my Invention. Firstly of the accumulation of the
lighter impurities, in the water confined in the upper part of the Chamber J, by
means of the tube N, and the three way cock M, discharging through the cock I, and
secondly, of the heavier deposits concentrated at the well K by means of the bottom
cock L. In both cases this may be effected whilst the heater is in operation.
Further, by means of the external pipe Q, and the three way cocks M and P, the
heater may be shut off from use. The pump in such case would be feeding direct to
the boilers, and the water in the heater may in such case be emptied, and its internal
surface cleaned as follows, (a) The interior proper of the heater by setting properly
the three way cocks M and P, and pumping water at O, and (b), by setting as in
ordinary use the three way cock M, so that the discharge of the pump shall take place
at N', whereby all sediment or scum would be washed down, and in both cases

page_text: discharged through L. In this manner the heater may be made practically self cleaning,
and the necessity of examining it internally reduced to a minimum. The heating of
the water will take place in the usual manner by means of the exhaust steam entering
at say G, and passing through one half of the tubes into the upper chamber C, descending
through the other half and passing out through H. A relief valve G, in one of the
divisions between the chamber D and E is provided, to regulate the direct passage of
the exhaust steam to the atmosphere as it may be desired. Suitable drip pipes R, R,
to drain the condensation from D, and E are provided as shown.
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. The device substantially as herein described and shown in the accompanying
drawings for heating and purifying the feed water supply for steam boilers.
Secondly. In such a device as above referred to, the combination and use therewith
of the central cylindrical chamber J, and inner tube N, NI, and outer pipe Q with three
way cocks M, and P, substantially as and for the purposes herein described and shown
in the accompanying drawings.
JAMES
STEVENSON,
Gray's Inn Chambers,
20, High Holborn, London, W.C.,
Agent for Applicant.