Improvements in Direct Combustion Motor Engines Working with Multiple Compression of the Air Required for Combustion.
Year: 1895

page_text: Date of Application, 25th June, 1895-Accepted, 27th July, 1895
Improvements in Direct Combustion Motor Engines Working with
Multiple Compression of the Air Required for Combustion.
I, RUDOLF DIESEL, of 153 Kantstrasse, Charlottenburg, Prussia, 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:
My invention relates to motor engines, such as were described in the Specification
to my Patent No. 7241 of 1892, operating with direct combustion of fuel in the
motor cylinder and with multiple compression of the air required for the
combustion.
In the said Specification I described an arrangement in which the air, after
having been partially compressed, was conveyed into a compressed air reservoir
whence it was supplied to one or more cylinders in which the complete compression
was effected.
According to my present invention I so construct such compressed air reservoir
that it shall serve at the same time either for imparting to the compressed air
within it the heat contained in waste fluids, such as waste steam, waste combustion
gases &c. so as to increase its heat and expansive force, before its final compression
and combustion, or, for the sake of reducing the size of the motor engine, I
arrange such vessel so as to abstract from the partially compressed air the heat
which is generated by such compression thus reducing its volume in proportion.
The said vessel for effecting this interchange of temperature may be constructed
in a variety of ways, one arrangement being shewn on the accompanying drawing
which represents by way of example the vertical section of an engine of the same
construction as that shewn at Fig. of the drawings of my former Patent
No. 7241 of 1892, from which it only differs in that, in place of the ordinary air
vessel there shewn, the vessel L in this case is constructed as an apparatus for the
interchange of heat, for which purpose it has a number of tubes 11 passing through
it, communicating at one end with a chamber into which the hot waste fluid is made
to enter through a branch while at the other end the tubes communicate with a
chamber from which the said fluid escapes through the branch after having given
off more or less of its heat.
The atmospheric air drawn into the cylinder B through valve d by the upstroke
of the piston is compressed to a certain extent by the downstroke and is forced
through valve g and pipe 13 into the vessel L, where it comes in contact with the
outer surfaces of the tubes l, and consequently takes up the heat from the fluid
passing through them, after which the heated and compressed air passes off through
pipes and valves a a into the cylinders CC where it is still farther compressed,
finally entering into combustion with the charges of combustible matter supplied
from the hoppers above.
I am aware that it has been before proposed to heat the air in engines of this
kind before its preliminary compression, but the essential feature of my invention
consists in effecting such heating of the air after its preliminary compression and
before its final compression.
When it is desired to keep the motor engine as small as possible, even if
sacrificing somewhat of the useful effect, the apparatus L can be used for abstracting
heat from the partially compressed air coming from cylinder B, by causing cold
water to flow through the pipes l. By such cooling, the volume of the compressed

page_text: air is greatly reduced, and consequently also the dimensions of the compression
cylinders into which it subsequently passes, and the mechanism connected therewith.
When cold water is used for such cooling, it may be applied to the compressed
air directly in the form of spray, instead of transmitting the heat from the air
through tubes as described.
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 :-
In direct-combustion motor engines working with multiple compression of the air
required for combustion, the use of apparatus for effecting the interchange of heat
for heating or cooling the air after its preliminary compression and before its final
compression, substantially as described.
Dated this oth
Г T 100%
ABEL & IMRAY,
Agents for the Applicant.