IMPROVE- MENTS IN AND APPLICABLE TO STEAM GENERATORS TO PREVENT PRIM
Year: 1884

page_text: Prevent Priming.
I JAMES JOHNSON of 4 Clayton Square Liverpool in the County of Lancaster
Patent Agent, do hereby declare the nature of the said invention for "IMPROVE-
MENTS IN AND APPLICABLE TO STEAM GENERATORS TO PREVENT PRIMING" to be
as follows:-
-
The invention relates to internally fired steam generators and is more especially
applicable to marine and similar boilers with a horizontal cylindrical or like shell.
The object is to prevent priming, that is to say to prevent water being carried
away from the generator by the steam when the said steam is being rapidly
generated.
The invention consists essentially in providing or constructing steam generators
at or near the water line with horizontal or nearly horizontal plates extending from
the sides of the generators parallel to the longitudinal axis of the furnace or fire
tubes.
The said plates are held in position by stays brackets or other supports
or otherwise secured to the shell of the generator.
rivetted
In generators with two or more internal furnaces it is desirable to have
additional plates between the horizontal side plates above mentioned.
Doted the 17th day of December 1884
JAMES JOHNSON.
Per J. Richman.

page_text: COMPLETE SPECIFICATION.
Improvements in and Applicable to Steam Generators to
Prevent Priming.
I JAMES JOHNSON of 4 Clayton Square Liverpool in the County of Lancaster,
Patent Agent, do hereby declare the nature of the said invention for "IMPROVE-
MENTS IN AND APPLICABLE TO STEAM GENERATORS TO PREVENT PRIMING". and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The invention relates to internally fired steam generators, and is more
especially applicable to marine and similar boilers with a horizontal cylindrical
or like shell.
The object is to prevent priming, that is to say to prevent water being carried
away from the generator by the steam when the said steam is being rapidly
generated.
The invention consists essentially in providing or constructing steam generators
at or near the water line with horizontal or nearly horizontal plates extending
from the sides of the generators downwards parallel to the longitudinal axis of the
furnace or fire tubes.
The said plates are held in position by stays brackets or other supports rivetted
or otherwise secured to the shell of the generator.
In generators with two or more internal furnaces it is desirable to have
additional plates between the horizontal or inclined side plates above mentioned.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a transverse, and fig. 2 a longitudinal section of a two flued steam
generator having my improvements. a are anti priming plates corrugated trans-
versely and extending from the sides of the generator at a slight angle downwards
towards the centre with their lower edges at a small elevation above the water
level. The said plates are carried on the longitudinal stays b, and are secured in
position by clips c, d is an additional plate between, and at a higher level than the
horizontal or inclined side plates a. I find in practice that my invention is best
carried into effect in the manner shown, but it will be evident that the plates might
be plain, and placed horizontal instead of being corrugated and inclined, but I do
not recommend such construction. The plates should be about one eighth of an
inch thick. The corrugations should be transverse, and of about three inches pitch;
and the plates may be galvanized with advantage. The action of the plates is to
prevent water thrown up by ebullition from entering the steam pipe, such water
being arrested by the plates, and caused to flow back, whilst the steam escapes
between the edges of the plates, and the surface of the water.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed I declare that what
I claim is
Constructing or fitting steam generators with anti-priming plates constructed
and fitted substantially as set forth.