IMPROVE- MENTS IN THE METHOD OF AND APPARATUS FOR INDICATING THE POWER OF STEAM ENGINES, APPLICABLE ALSO TO GAS [STEAM] AND HOT AIR ENGINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Thomas Howard Blamires at the
Office of the Commissioners of Patents on the 1st December 1883.
" IMPROVE-
THOMAS HOWARD BLAMIRES of Huddersfield in the County of York
MENTS IN THE METHOD OF AND APPARATUS FOR INDICATING THE POWER OF
STEAM ENGINES, APPLICABLE ALSO TO GAS [STEAM] AND HOT AIR ENGINES,"
This Invention bas reference to apparatus for indicating the amount of power of
steam or other engines, and in recording the variation of the temperature of steam
at the time it enters and leaves the cylinder or cylinders of steam engines; or in
other words to indicate what heat the steam has lost after passing through the
cylinder or cylinders whilst doing its work, from which indication, calculations can
be made giving the amount of power used during the working of the engines.
To accomplish this object I connect a small pipe to the pipe which conveys
steam to the cylinder, or to the steam chest, to the other end of which pipe is
connected a chamber holding a thermometer or other kind of indicator capable of
registering heat; ("heat" and "pressure being convertible into each other by well
known methods), the chamber having a small "blow-off" tap to empty it of
condensation before reading the indications. In connection with the steam exhaust
pipe or outlet from the cylinder I attach another small pipe, the other end of which
is also connected to the same heat registering instrument, and where compound
engines are used, other pipes are connected to the registering instrument whereby
the amount of horse power which is being used can be ascertained according to the
varying degrees of heat used in either cylinder. Stop taps are employed in
connection with each small pipe so that any one of the said pipes can be in
communication with the thermometer or registering instrument.
In order therefore to ascertain the loss of heat or reduced temperature after the
steam has been used, the steam in the inlet pipe is registered by the thermometer,
then the taps are reversed and the temperature of the steam from the exhaust pipe
is afterwards registered on the thermometer, the difference in the two registrations
shewing the amount of heat used or converted into power or energy, consequently
by reference to well known engineering tables, the heat used indicates a given
quantity of power or work done.
In compound engines the high pressure cylinder is tested as above described and
then the low pressure cylinder is put in communication with the indicator by
another pipe from the exhaust or outlet of the low pressure cylinder.

page_text: The exhaust temperature of the high pressure cylinder being the inlet
temperature of the low pressure cylinder, the difference in the temperature between
the two, giving the indication for the low pressure cylinder, from which different
temperatures the amount of power can be readily calculated from the tables as
before described. I thus calculate the amount of work each cylinder is performing.
I do not confine myself to the use of one thermometer or registering instrument
as in case the cylinders are a long way apart I may use another or second
instrument. It is preferable where convenient to do it with one instrument, so as
to avoid any slight differences between two thermometers or indicators.
Therefore by the application of this system of indicating, the actual amount of
horse power which is being consumed by machinery can be readily recorded day
by day with great truth and accuracy and very little trouble.
This method and manner of indicating is applicable to steam, gas or hot air
engines.
The indicating apparatus such as is herein described can be used in conjunction
with the ordinary mechanical spring steam engine indicator as a check on the
indicated pressure, the two apparatuses being connected close_together by a branch
pipe and chamber provided with a small blow off tap so as to remove the condensed
water before testing.
The said apparatus can also be used in conjunction with the steam gauge of a
steam boiler, but the Thermometer or heat indicator in such cases being placed
inside a glass tube, somewhat similar to the water glasses, which shew the height
of water in boilers. When such Thermometer is placed within a glass tube they
may be placed either in the steam space or water space of the boiler.
When this form of apparatus is applied to hot air engines, it is attached to either
pipes or cylinders, much in the same manner as it is attached to the steam engine,
the difference in the two temperatures of the inlet and outlet pipes indicating the
amount of power used.
When applied to gas engines, the temperature is taken during the explosion of
gas in the cylinder or cylinders, and the temperature of the products of combustion
passing through the exhaust pipes is also taken, the difference between the two
temperatures indicating the amount of power used.