Improvements in or relating to Fuel Economisers for Heating Boiler Feed Water.
Year: 1899

page_text: Date of Application, 10th July, 1899-Accepted, 20th Aug.,
1899
COMPLETE SPECIFICATION.
Improvements in or relating to Fuel Economisers for Heating Boiler
Feed Water.
I, WILLIAM HARRY VERNON, Oxford Road, Wakefield, in the County of York,
Engineer, 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 has reference to the type of fuel economisers for heating boiler
feed water in which the water to be heated is passed through vertical pipes
located in the flue leading from the boiler to the chimney and which pipes absorb
the waste heat in the gases passing off from the furnace.
It is a well known objection in connection with this type of fuel economiser
that the vapour in these waste gases condenses on the outside of those pipes in
which the cold feed water enters and corrosion of such pipes is the consequence.
The object of the present invention is to obviate this result by preventing the
cold feed water coming into direct contact with the pipes upon which the waste
heated gases impinge.
This is effected by the employment of an internal box and communicating
tubes leading therefrom some distance into the central part of the vertical feed
tubes upon which the hot waste gases impinge and through which internal box
and tubes the cold feed water is first admitted and conducted so that it has the
chill taken off it before it passes into the vertical economiser tubes themselves.
The invention will be fully understood from the following further description
in reference to the accompanying drawings in which,
Figure 1 is a view principally in section of three of one row of vertical tubes
and a bottom box of a. fuel economiser of the type hereinbefore described, with
my improvements embodied therein.
Figure 2 is a view partly in elevation and partly in section on the line X X
of Figure 1 showing the end tubes of six rows of vertical tubes and top and bottom
boxes, and top branch pipes, three of the said tubes being feed tubes.
Figure 3 is an elevation from the opposite side of Figure 2 of the tubes
illustrated in the lower part of the said figure and showing the internal feed
pipe extending above three of the series of feed water tubes, and the blow off
valves for clearing the sediment out of the inner and outer boxes.
Figure 4 is a section taken on the line Y Y of Figure 1 of an outer tube, tho
inner feed tube and the stay for maintaining the latter in proper position.
Figure 5 is a section on the line Z Z of Figure 1 of the bottoin box and its
internal box.
Referring to the accompanying drawings:
A. A represent two bottom branch pipes of a fuel economiser, A the bottom
boxes, B Bo the vertical tubes leading from the latter and communicating with
the top boxes C which open into the top branch pipes C¹ C* all of which may be
constructed in the well known manner.

page_text: In the drawings the invention is shown as applied to a fuel economiser or
feed water heater consisting of a series of rows of vertical tubes and for the
purpose of the present invention the first three rows B of the tubes riz.: those
nearest the back of the furnace, are those into which the cold feed water enters.
These three rows of tubes have their own separate and independent bottom
branch pipe A, and top branch pipe C, and the three rows of the remaining
series of rows of vertical tubes Bo through which the water passes after leaving
the feed tubes, also have their own separate and independent top and bottom
branch pipes A and C respectively and communication between the two series
of rows of pipes is effected by a diagonal pipe E leading from the top branch
pipe C of the one series to the bottom branch pipe A° of the other series of tubes.
For the purpose of attaining the object of the present invention as herein-
before stated I introduce into the bottom box of one or more rows of the cold
feed series of pipes an internal or inner box A to which may be attached or
socketted a communicating vertical tube B' for each of the vertical feed pipes B.
These internal tubes B rise upwardly some distance inside the feed pipes B
and being of smaller diameter, there is left between each pair of pipes B B¹
a narrow annular space D containing a thin layer or jacket of water which
becomes readily heated and is maintained in that condition by the hot waste
gases which impinge upon the outer economiser tubes B.
Each of the internal tubes is provided with a stay consisting preferably, as
shown in Figures 1 and 4, of a collar B screwed, shrunk or keyed on the internal
tube B and provided with radial arms B³ extending to the outer tube B so as
to keep the internal tube in its proper vertical position and maintain an equal
annulus D all round it.
The wall of the inner bottom box is thickened at parts as at As thereby forming
feet which raise it above the internal surface of the box A¹ and leave a clearance
or annular space D¹ so that the water may surround it.
According to the present invention the cold feed water enters the bottom
branch pipe A. and passes directly into the internal bottom box A*.
It then ascends the internal tubes B' from whence it passes out and into the
tubes B and into the annular spaces D.
Upon the cold feed water passing into the internal box and the internal tubes
it abstracts part of the heat from the water jacket contained in the annular
spaces D and thus before entering the tubes B it has the chill taken off
sufficiently to obviate or almost entirely prevent condensation taking place on
the exterior of the said tubes.
When the water becomes sufficiently heated it rises in the economiser tubes B
and passes out into the top box C and branch pipe C down through the diagonal
pipe E into the bottom box A° up the vertical pipes Bo into the top boxes C and
into the top branch pipe C which leads to the boiler in the usual manner.
F represents the blow off pipe for removing the sediment in the feed water
from the external bottom box A¹ when the valve F which may be of any of the
well known types is opened for the purpose.
The internal box Ax is also provided with a suitable valve or cock A through
which when opened the sediment is ejected therefrom.
A further advantage in connection with my invention is that owing to the
employment of inner tubes of smaller diameter than the economiser tubes the
volume of water passing through each pipe is reduced and the feed is thus caused
to enter a larger number of the inner tubes thereby insuring a more even
distribution of the feed throughout the economiser tubes.
Although I have shown and described the internal tubes as communicating
with an internal bottom box which is the system I prefer I wish it to be under-
stood that in economisers where the feed takes place in the top box an internal
box would be inserted in the latter instead of the bottom box as will be under-
stood.

page_text: 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:-
1. The construction of fuel economisers in which the feed water is passed
through an internal box and communicating internal tubes surrounded by water
of a higher temperature than the feed water so as to take the chill off the latter
before it reaches the economiser tubes.
2. Admitting the cold feed water of fuel economisers into an internal box
and one
or more internal vertical tubes arising therefrom substantially as
described and illustrated in the accompanying drawings.
3. The combination with the bottom boxes and feed tubes of fuel economisers
of an internal bottom box and one or more internal feed tubes substantially as and
for the purpose described.
4. The improved arrangement of and means for admitting cold feed water into
fuel economisers substantially as described and with reference to the accom-
panying drawings.
11
قيم
1
P
1
1000
WILLIAM HARRY VERNON.
Witness:
E. N. LEWIS.
Boult & Wade,
Agents for the, Applicant