Improvements in Rotary Blowers.
Year: 1899

page_text: Date of Application, 16th Feb., 1899-Accepted, 18th Mar., 1899
COMIDDIE SPECIFICATION,
Improvements in Rotary Blowers.
I, EDGAR DWIGHT JOHNSTON, of Connersville, Fayette County, Indiana, United
States of America, 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:-
This invention pertains to improvements in rotary blowers and the improve-
ments will be readily understood from the following description taken in connection
with the accompanying drawing, in which:
Fig. 1 is a vertical transverse section of a blower embodying my invention, while
Fig. is a side elevation of the same, part appearing in vertical longitudinal
section.
In the drawing:-
1, indicates the case of a rotary blower of the well known Roots type;
2, the fluid inlet thereto, the same being disposed at the base of the casing and
adapted to admit the fluid, be it air or gas, to the interior of the casing;
3, the fluid outlet at the top of the casing;
4, the usual pair of intermembering impellers arranged on parallel axes between
the fluid inlet and the fluid outlet of the casing, the interior walls of the casing
being of a form to be swept by the extremities of the impellers;
5, a liquid supply-pipe leading to the casing from a source of supply of liquid,
as water or oil, under pressure;
6, spray-heads arranged within the casing in connection with pipe 5, these spray-
heads being located near the fluid inlet 2 and between that inlet and the impellers 4
and being arranged to spray upwardly into the volume of fluid entering the fluid
inlet 2 and approaching the impellers and
7, valves for controlling the flow of liquid to the spray-heads.
During the rotation of the impellers the fluid being dealt with is drawn in at
inlet 2 and gathered by the impellers and compressed and expelled at outlet 3.
Spray-heads 6 inject finely divided liquid upwardly into the fluid prior to its
reaching the impellers, the liquid instantly becoming diffused with the fluid and
going to the surfaces of the impellers and casing and being expelled from outlet 3
with the fluid, the entrained liquid passing onward with the compressed fluid or
being trapped away therefrom by any usual or suitable trap if desired. The liquid
thus becoming entrained with the fluid before the fluid is attacked by the impellers
bathes the contacting surfaces of the machine, lubricating those surfaces and
packing the joints of contact, and serving also in taking up some of the heat due
to compression of the fluid. Valves 7 serve in regulating the amount of the liquid
injected into the uncompressed fluid; surplus liquid not becoming fully entrained
with the uncompressed fluid may freely drain backward through fluid inlet 2.
The amount of liquid received by the impellers is thus only so much as becomes
diffused with the fluid, any excess of liquid returning by gravity without passing
through the blower. The blower thus requires to deal with and deliver only the
liquid entrained with the fluid and the possibilities of liquid in mass in the blower
or discharge is avoided.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be perform d, I declare that what
I claim is:-
1. In a rotary blower, the combination, substantially as set forth, of a casing
having a bottom fluid-inlet and a fluid outlet, a pair of intermembering impellers
mounted within said casing between said inlet and outlet, a pipe leading to the
casing from a source of supply of liquid under pressure, and a spray-head connected
with said pipe and disposed within said casing below said impellers and above said
fluid inlet and adapted to spray and diffuse liquid upwardly into the uncompressed
fluid on its way to the impellers, whereby the fluid inlet serves also as the outlet for
the rejected liquid.
2. In a fluid compressor, the combination, substantially as set forth, of a fluid
inlet, a compressing agent disposed above the level of said fluid inlet, and a liquid
spraying device disposed above said fluid inlet and below said compressing agent,
whereby said fluid inlet performs the double office of admitting fluid and discharging
surplus liquid.
Dated this 16th day of February 1899.
ALLISON BROS.
Agents for the Applicant.