42
(EFFICIENCY REPORT)
STEAM PLANT OF THE WHITE MOTOR CAR
By R. C. Carpenter, of Ithaca, N. Y.
Member of the Society
1
The steam plant of the White Motor Car is an example of what can be accomplished on a small scale in the
use of steam of high pressure and with a high degree of superheat in the steam engine and is consequently of interest
to the mechanical engineer irrespective of its special application for the propulsion of motor cars. I take pleasure in
presenting a description of this plant and also the results of a series of tests which I believe will prove of considerable
interest to all engineers who are studying the question of the use of steam at high temperatures and pressures.
2
The White steam system was designed by R. H. White and has been successfully applied by the White
Sewing Machine Company, during the last six years to several thousand motor cars; its essential and novel features
are found principally in connection with the steam generator or boiler which is
adapted to produce steam of high
pressure and high temperature. The system is also of interest in the details of construction of its engine and in one
means for automatically controlling the quantity, temperature, and pressure of the steam produced.
3
It is a well recognized fact that the efficiency of a steam plant is increased by the use of steam at high
temperatures and pressures and there are numerous tests on record which bear testimony to this fact. The development
of the art of producing and using steam of high pressure and of a high superheat has been slow although probably
continuous. So far as I can learn from correspondence, no boilers or engines exceeding 100 HP in capacity which are
adapted to produce and use steam exceeding 300 lb., pressure and 300 degrees superheat are built in this country at
the present time. (Presented at the New York Meeting (December 1906) of The American Society of Mechanical
Engineers, and to form part of Volume 28 of the Transactions. Pages 255-285.)
THE BOILER
5
The steam generator or boiler of the White system is a series of horizontal coils connected so as to form a
continuous tube through which all the water fed to the boiler and all the steam discharged from the boiler must pass. It
is not provided with any reservoir either for water or steam. A perspective view of the boiler as used in the 1906 car is
shown in Fig. 1 with the external casing removed. Its essential distinctive feature from every other boiler is due to the
fact that the water is dept at the top and the steam at the bottom; it differs from al types of stationary boilers by the
absence of a reservoir for steam. The construction of the boiler for the 18 brake horsepower engine which was
used in the 1906 cars is essentially as follows, and is typical of all sizes: Eleven helical coils of drawn steel tubing are
joined in series and connected as shown in the diagram, Fig. 2, so as to produce a system of circulation of such a
character that the water or steam, in order to pass from one coil to that next below must rise to a level above the top
coil before it can pass down again. Fig. 1 shows the external view of the connections referred to, which pass from the
external circumference of the coil upward to a point above the level of the top coil and thence downward in the
central space, where it joins the coil of a lower level. Tubing having a nominal internal diameter of 3/8 inch was used
in the boilers of l9O4-O5 and 1906 and of 1/2 inch in the new boiler recently built for the 1907 car.
1
The joints
connecting the various coils are, it is noted, located in an accessible position. This construction makes it possible to
maintain water in the upper portion of the boiler and steam in the lower. It prevents the water from descending by
gravity and renders the circulation through the generator dependent upon the action of the pumps, which supply the
boiler with water. The general direction of circulation of the water and steam is the reverse of that of the products of
combustion.
6
The White boiler has frequently been classified as a flash or semi-flash boiler; whether this classification is
correct or not depends upon the definition of the term "flash boiler". In the flash boiler, as I understand the term,
water is suddenly converted into steam by contact with a very hot metal surface. And in the operation of such a boiler
the metallic surface with which the steam is brought in contact is maintained at a much higher temperature than that
of the steam. The White boiler, as noted from the description, always contains a considerable amount of water which
is forced downward and over the heating surfaces at a rate proportional to the demand for steam, and under its normal
mode of operation it is doubtful if the metallic surfaces have much or any higher temperature than that of the steam
which they contain. The name Continuous Flow or Single Tube Boiler would, It seems to me, better describe the class
to which the White boiler belongs than the term "flash".
1
The actual dimensions of tubing used in the White boiler are as follows: E and F boiler (1905-06), internal diameter
0.372 inch, outside diameter 0.535 inch; G boiler (1907), internal diameter 0.540 inch, outside diameter 0.72 inch.
