IMPROVEMENTS IN APPARATUS FOR SUPPLYING OR DISTRIBUTING STEAM FOR HEATING,
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS
IN APPARATUS FOR SUPPLYING OR DISTRIBUTING STEAM FOR HEATING,
LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS
IN APPARATUS FOR SUPPLYING OR DISTRIBUTING STEAM FOR HEATING,
MOTIVE-POWER, AND OTHER PURPOSES, IN TOWNS AND OTHER PLACES.`
A communication from abroad by Birdsill Holly, of Lockport, in the County
A
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 25th June 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN APPARATUS FOR SUPPLYING OR DISTRIBUTING
STEAM FOR HEATING, MOTIVE-POWER, AND OTHER PURPOSES, IN TOWNS AND
OTHER PLACES." A communication from abroad by Birdsill Holly, of Lockport,
in the County of Niagara, State of New York, United States of America.
These improvements relate to apparatus for supplying large districts of dwellings
and other buildings in cities and villages with steam for the purpose of warming,
and for driving machinery. In carrying out this object the method has been to
use a battery of boilers at a central point within the district of buildings, from
which steam mains are carried underground, and the separate buildings supplied by
service from the mains.
Where the steam is used for power purposes in connection with steam engines the
exhaust can be readily utilized for warming, and in that manner the most
economical results will be obtained. The object of the present improvements is to
apply that principle of economy in connection with the whole system of steam
mains, for which purpose I use double mains, one for high pressure, and the other
for low pressure, and in connection therewith apply automatic regulating valves, as
hereinafter described.
In Figure 1 of the accompanying Drawings I have illustrated in plan view a
section or district of a city or town having streets intersecting, in which streets the

page_text: double system of steam mains are laid; Figure 2 is a plan view in larger size,
showing the arrangement of the double mains and regulator valves; Figure 3 is a
vertical section of one automatic regulator valve.
Similar letters of reference indicate corresponding parts.
Referring first to Figure 1, A, A, A, A, A, A₁, represent the streets in the
district; and B, B¹, the steam mains laid underground in the streets from the
central point C, where the boilers are located. The mains consist of pipes, protected
in any suitable manner to prevent condensation, and fitted at suitable intervals
with service boxes a that allow expansion and contraction.
B represents the high pressure main taking steam directly from the boilers at a
pressure of, say, 60 pounds; and B is the low pressure main returning the steam
to the boiler house at a pressure of, say, fifteen pounds. From the service boxes a
in main B service pipes will pass to the building for supply of steam at high
pressure to the engine. The exhaust steam is delivered to the main B¹ by a return
pipe, and in connection with these supply and exhaust pipes I apply the automatic
regulator valve D shown in Figure 3, and next described.
The low pressure pipe D connects with the high pressure pipe c by a short
section c¹ that is fitted with a screw valve e at its connection to pipe d. At the
upper end of pipe d is a valve f hung from a lever g that is weighted to balance
the valve. This valve f is between the pipe d and connection c¹, so that when open
steam may pass from the high to the low pressure pipe. is a cylinder containing
a piston that connects a rod h² with lever g; g¹is a pipe from the low pressure
pipe d to cylinder ; i is a pipe connected to the low pressure pipe d, and provided
with a valve that is hung from a weighted lever that retains the valve closed;
I is a diaphragm in a chamber l' that connects by a pipe 2 with pipes i and d; l³ is
a rod from diaphragm to the lever k.
In case the exhaust steam from the engine does not supply the requisite pressure
in the pipe d and main, such decrease of pressure will allow the valve f to be
partially opened by the weighted lever g, and steam will then pass through the
section c¹ from pipe c to pipe d until the pressure is raised sufficiently.
The increase of pressure is felt by piston ¹ in cylinder h, and the piston will
raise and close valve f more or less until the requisite fifteen pounds is reached,
when the valve will be entirely closed. If from any cause the steam in the low
pressure main and pipe d increases above the normal point, such increase will act
to raise diaphragm l, move lever k, and open valve i¹, thereby allowing steam
to pass to pipe i. The pipe i will preferably connect with heaters for warming, or
in case the regulator valve is placed at the boiler house the steam will go to the
feed water heaters.
A cylinder m with piston m¹ is applied in connection with lever g as a dash pot
to prevent vibration of the lever. This cylinder is to contain oil; and its piston is
made a trifle smaller than the cylinder to allow passage of the oil from one side to
the other, and thus ensure a slow steady movement.
With these valves arranged in connection with the engines the low pressure
main B¹ is supplied with the exhaust steam at the required pressure.
The main B¹
distributes the steam throughout the district, and returns the surplus to the central
boiler house, where it is used for heating the feed water of the boilers.
I place in the mains near the boiler house one of the regulator valves D for the
purpose of supplying live steam from the boilers in case the consumers require
more than is furnished by the engines. This is shown in Figure 2.
At street intersections, or wherever the mains cross, I provide for keeping both
at the same level a device shown at E in Figures 1 and 2, most clearly in Figure 2.
This device consists of a casting made with branch tubes connected at each end,
and forming an opening for the other main to pass. The casting is preferably
applied to the heat main, and allows the two mains to be set at the same level.
With this double system of steam mains the steam is utilized to the greatest
possible extent. The devices and apparatus used in connection with the service
pipes c, d, for measuring the quantity, and for utilizing the low pressure steam for

page_text: heating do not need particular described, as they will be similar to those used in
the single system of mains heretofore invented by the said Birdsill Holly.
In this system of double mains I find it desirable to connect the two mains at a
remote point, as shown at n in Figure 1, and fit the connection with a valve that
may be opened and closed by hand. The object of this is to prevent injury to
either main when the engines do not use steam for a length of time, as, for instance,
at night, and on holidays. In such case the power main might become filled with
water. The valve at n is to be opened, and the direct supply to the low pressure
main cut off at the boiler house. This will at once start a positive circulation in
the heating main from the remote point towards the boiler, and in the reverse
direction in the power main. The water of condensation takes the following
course: The water from the power main passes by the connection n to the
heating main, and from thence to the consumers and boiler house. The pressure is
regulated by the valves, as before described. This ensures perfect operation when
the power or a large part of it is not in use.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as new and desire to secure by Letters
Patent is,
1st. The combination of steam supplying apparatus and a double system of
underground mains, one supplying steam under high pressure for power purposes,
and the other receiving the exhaust steam, and supplying steam at low pressure for
heating purposes, substantially as described.
2ndly. The combination with a steam supplying apparatus and a high pressure
steam main of a low pressure main connected with the steam generator, and with
the exhaust pipes of the system and regulator valves fitted for automatically
regulating the pressure in the low pressure main, substantially as described.
3rdly. The combination with a low and high pressure steam main of a regulator
valve fitted for being opened by decrease of pressure below the normal point, for
admitting steam from the high to the low pressure main, substantially as
described.
4thly. The regulator valve D, consisting of balanced valve f, cylinder h,
diaphragm, lever k, valve i¹, with the connections, substantially as described,
combined with the high and low pressure steam pipes for operation, as set forth.
5thly. The connection n and circulation valve, combined with the high and low
pressure steam mains B, B¹, substantially as shown and described for operation, as
set forth.
6thly. The branched tubular castings E combined with the double main,
substantially as and for the purposes set forth.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Twenty fourth day of June, in the year of our Lord
One thousand eight hundred and eighty one.
A. M. CLARK. (L.S.)