Improvements in Domestic Hot Water Apparatus.
Year: 1895

page_text: Date of Application, 28th Nov., 1895
Complete Specification Left. 28th Aug.. 1896-Accepted. 3rd Oct.. 1895
PROVISIONAL SPECIFICATION.
Improvements in Domestic Hot Water Apparatus.
I, HENRY CLAY, of 7, Grant Street, Liverpool, in the County of Lancaster, Hot
Water Engineer and Plumber, do hereby declare the nature of the said invention to
be as follows:-
This invention relates to domestic hot water apparatus, and consists of improved
forms of boilers and safety appliances in connection therewith.
Boilers according to this invention are of a tubulous nature, consisting of a nest
of tubes connected to box ends of cast or wrought iron or steel. Such tubes may
be arranged vertically, horizontally, or inclined, and the tubes and box ends are
of such a size and shape as to suit either close or open ranges, thereby obviating
the difficulty now experienced in the fixing and heating of boilers in close ranges,
as well as providing a much safer and more powerful boiler for both open and
close ranges. Such tubulous boilers moreover expose a larger heating surface and
contain less water than the ordinary domestic boiler.
Owing to the nature of their construction, the flues in connection with my improved
tubulous domestic boilers may be arranged in a variety of ways or directions to suit
the range and boiler, thus the same boiler may be arranged in three different positions
to suit the range to which it is fixed, by merely altering the disposition of the
connections or circulating pipes.
Tubulous domestic boilers according to this invention may be constructed to
supersede the ordinary box, boot, shoe, ell, or saddle boilers now fixed in both open
and close ranges.
A saddle boiler according to this invention may consist of front and back box
ends with tubes running between them. The tubes may be covered by an iron or
fireclay casing, having a flue exit therein; or the flue may be carried as usual in
saddle boilers.
It is intended that the strength of boilers constructed according to this invention
shall be greater than that of their pipe connections; but in case of the boiler itself
yielding, the consequence, owing to its articulated nature, will not be so disastrous
as it would be with a boiler in one piece.
As an additional means of security to the boiler, I may provide an appliance by
which the pressure in the boiler is not allowed to exceed that of the head of water
by which it is supplied. In such an appliance I cause the head of water to
maintain a column of mercury within a syphon. When the pressure within the
boiler exceeds that due to the head of water the mercury column is ejected from
the syphon into an outer tube or receiver which is counterbalanced by weights
and chains passing over pulleys, and which sinks under such additional weight of
mercury plus a small quantity or makeweight of water, leaving the mouth of the
syphon free for the escape of water, or steam and water, from the boiler. Pressure
in the boiler having been thus relieved the small quantity or makeweight of water
has meanwhile been allowed to drain away from the outer tube, which is then
raised by its counterbalance weights and again charges the syphon with a column
of mercury.
Dated this 27th dox of Nanban 100%

page_text: improvements in Domestic Hot water Apparatus.
I, HENRY CLAY, of 7, Grant Street, Liverpool, Plumber, 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 domestic hot-water apparatus, and consists of improved
forms of boilers and safety appliances in connection therewith.
The form of circulating boiler at present commonly employed, i.e. the cast-iron
box boiler, has at no time had a period laid down as its working life, and as such
boiler continues to be used notwithstanding its decay by corrosion, or otherwise,
the inevitable result is an explosion.
I have endeavoured by my present invention to so construct domestic hot-water
boilers that such decay will make itself apparent in a trivial yet unmistakeable
manner, and to effect this, and other objects, construct a boiler in an articulated
or built up form in order that, amongst other reasons, the joints of such articulations
may be the first to fail or give way by natural decay.
Boilers according to this invention are of a tubulous nature, consisting of a nest
of tubes connected to box ends or vessels of cast or wrought iron or steel. Such
tubes may be arranged vertically, horizontally, or on an incline, and the tubes
and box ends are of such a size and shape as to suit either close or open ranges,
thereby obviating the difficulty now experienced in the fixing and heating of
boilers in close ranges, as well as providing a much safer and more powerful
boiler for both open and close ranges. Such tubulous boilers moreover expose a
larger heating surface and contain less water than the ordinary box boiler.
Boilers comprising box ends or sides, connected by nests of water tubes, may
be arranged in a variety of dispositions to suit the ranges to which they are to
be fitted. Thus they may be adapted to supersede the ordinary box, boot, shoe,
ell, or saddle boiler, by merely altering the disposition of such box ends and water
tubes and their circulating pipes; and the illustrations of boilers in the accompanying
drawing must be taken as examples merely of the application of my invention.
In the drawing hereto annexed,
Fig. 1. is a front perspective elevation of a domestic boiler according to this
invention. Fig. 2. is a sectional elevation of a modified form of such boiler.
Fig. 3 shews an alternative method of fitting the water tubes and box ends.
Fig. 4. is a sectional elevation of a mercurial pressure relief device forming part
of my said improvements in domestic hot water apparatus.
Upon reference to Fig. 1. it will be observed that the boiler there shewn consists
of upper and lower box ends or vessels a and b connected by vertical water tubes c.
d is a "manhole" or aperture in the box end a for examination and fitting purposes,
a similar manhole being provided in the box end b. e and are the circulating
or cold water inlet and hot water outlet pipes respectively.
Such a boiler is set in the ordinary manner at the rear of the fire, the fuel resting
against the front tubes of the boiler, the boiler flue being disposed in rear of the
boiler, so that the flame and heated gases of the fire pass between and amongst
the water tubes c. The box ends a and b may be formed of cast iron or steel, whilst
the tubes c may be of iron, steel or copper.
In Figure 2 of the drawing, the front row of tubes c are inclined as shewn, to
correspond with the slope of the fire back, as in the ordinary box boiler.
As a means of fitting the tubes c in the box ends a and b, I prefer to screw
one end of the tube into one box end and secure it with a backnut g thereby
forming a rigid fitting, and instead of screwing the other end of the same tube into
the other box I afford a certain amount of latitude to the joint by employing a copper,

page_text: gunmetal, or brass gland h, which is forced home by means of the backnut i, and
between such gland and the inner backnut ja packing k of any suitable material,
such as asbestos, may be used. In a stronger class of boiler I may make this latter
joint also a rigid one by employing a brass diminisher and backnut g' as shown
in Fig. 3; but where both ends of the tubes c are screwed into their respective
box ends a and b care must be taken to accurately pitch and tap their sockets.
Circulation of water in the boiler is induced by the front row of tubes c being
relatively more highly heated than the back row, owing to their proximity to the
fire, and the water will therefore ascend the front tubes and descend the rear tubes;
and to assist in such circulation the upper ends of the front tubes c project con-
siderably into the upper chamber a, whilst the lower ends of the rear tubes c project
similarly into the lower chamber b. With the same object in view the cold inlet
pipe e has a continuation el which enters one of such rear tubes for some distance, the
outlet pipe being led directly from the top plate of the chamber u.
It will be understood that instead of arranging the tubes c vertically, or inclined
vertically, as shewn, with upper and lower box ends, they may be arranged horizontally,
or inclined horizontally, with box ends at each side of the fire back, or such tubes
may run endwise in respect of the fire. Thus a saddle boiler according to this
invention may consist of front and rear box ends with tubes running between them.
The tubes may be covered by an iron or fireclay casing having a flue exit therein;
or the flue may be disposed as usual in saddle boilers.
It is intended that the strength of boilers constructed according to this invention
shall be greater than that of their pipe connections; but in the event of the boiler
itself yielding, the consequence, owing to its articulated or built up nature, will not
be so disastrous as it would be with a boiler in one piece.
Unlike the boilers formed by the bending of a continuous tube, which, having but
one duct, are very liable to become blocked, by deposit or otherwise, boilers con-
structed as above described whilst still possessing the advantage of large tube area
would require each and every one of their tubes to be stopped before becoming
inoperative.
tube n.
As an additional means of security to domestic hot water apparatus, I may provide
an appliance by which the pressure in the boiler is not allowed to exceed that due to
the head of water by which it is supplied and an allowance for working purposes.
Such an appliance is shewn in sectional elevation in Fig. 4., and consists of an
inverted syphon m which is coupled to the pipe fi forming a branch of the hot water
circulating pipe f. Disposed around such syphon is a tube n of oval section with a
closed end and a cistern head o. I cause the normal pressure of the boiler to maintain
a column of mercury p in the syphon m, such mercury being supplied by the outer
When the pressure within the boiler exceeds the working pressure above
referred to, the mercury p is ejected from the syphon m into the cistern o of the tube n,
which tube being counterbalanced by the weights g and chains passing over pulleys s,
sinks under such additional weight of mercury plus a small quantity or makeweight
of water ejected from the pipe fi, leaving the mouth of the syphon free for the escape
of water or steam from the boiler. Pressure in the boiler being thus relieved, the
small quantity or make weight of water has meanwhile drained out of the cistern o
through the small hole t, and the container n with its complement of mercury is then
raised by its counterbalance weights g, into position for re-charging the syphon in
with the mercury ejected from it, which is effected by closing the stop-tap u and
opening the drain tap v, which allows the mercury to flow into the syphon m and eject
the water before it.
.
The tubes m and n are preferably formed of glass and the front of the containing
case wis glazed, so that the condition of the regulator or relief device may be noted.
Thus when the mercury rises to the point x there is excessive pressure in the boiler;
when at the point y there is the normal pressure existing, which signifies that the
supply cistern is full; and when the mercury falls to the point, on a level with the
orifice of the syphon m there is a reduced pressure in the boiler, which signifies that
the supply cistern is empty or its connections blocked by ice or otherwise.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The method of constructing a boiler for domestic hot water apparatus herein
described and illustrated, which method consists of building such a boiler of articular
members, substantially as and for the purposes herein described.
2. A domestic hot water boiler comprising a nest of water tubes whose respective
ends are fitted into boxes or vessels forming water chambers by a screw or gland
connection, substantially as and for the purposes herein described.
3. A domestic hot water boiler comprising upper and lower water chambers a and b,
having a water communication by means of a nest of tubes c, said tubes being fitted
to said lower chamber by a screw connection with or without a backnut, and to said
upper chamber by means of a gland connection, or vice versa, substantially as and for
the purposes herein described with reference to Figures 1 and 2 of the drawings.
4. A mercurial pressure relief device for domestic hot water apparatus, the
characteristic features of which are, an inverted syphon in one leg of which a column
of mercury is maintained by the normal pressure in such apparatus, a mercury
container surrounding such syphon and provided with a cistern head and counter-
balanced by weights, chains and pulleys, in such a manner that when the said column
of mercury and a small quantity of water are ejected into such cistern head the
container sinks and uncovers the orifice of said syphon, and a drain aperture in said
cistern, all in combination and adapted to operate substantially in the manner described
with reference to Figure 4 of the drawings.
5. For the purposes of a domestic hot water apparatus, the use in combination of
an articular boiler comprising water vessels or box ends connected by water tubes,
with a mercurial pressure relief device comprising an inverted syphon and a counter-
"balance mercury container, substantially as and for the purposes herein described
with reference to the annexed drawings.
Dated this way of Augus
J. A. COUBROUGH,
Registered Patent Agent (Qual. by Exam.),
10 St. George's Crescent, Liverpool, Agent for the Applicant.