IMPROVED MEANS FOR PREVENTING PRIMING IN STEAM BOILERS
Year: 1885

page_text: I, WILLIAM CAMPBELL, Senior, of 9 Clune Brae Foot, Port Glasgow, Renfrew-
shire, Iron Moulder, do hereby declare the nature of my invention for "IMPROVED
MEANS FOR PREVENTING PRIMING IN STEAM BOILERS," to be as follows:-
The object of my invention is to provide means for preventing priming in steam
boilers.
This object I attain by fitting within the boiler mechanical devices whereby the
water it contains may be agitated or broken up at or near the surface in order to
permit of the free disengagement of the steam as it is generated. The agitatora
may be of any suitable form, which will generally vary with the form of
boiler. The form of agitator most generally applicable will be a paddle or series of
paddles rotating on a horizontal, vertical, or inclined axis, such axis being carried
out through the shell of the boiler and operated by cranks, pulleys, or other means.
Reciprocating or oscillating plates or stirrers or analogous devices may in many
cases be applied with equal advantage.

page_text: COMPLETE SPECIFICATION.
Improved Means for Preventing Priming in Steam Boilers.
I, WILLIAM CAMPBELL, Senior, of 9 Clune Brae Foot, Port Glasgow, Renfrew-
shire, Iron Moulder, do hereby declare the nature of my said Invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement in writing, reference being had to the
accompanying Sheet of Drawings and to the letters and figures marked thereon,
that is to say :—
I attain the object of my invention by means of fitting within each boiler
mechanical devices whereby the water it contains may be agitated or broken up at
or near the surface level or from the heating surface to the surface of the water, in
order to permit of the free disengagement of the steam as it is generated. The means
or mechanical agitators I employ, and which form an essential feature of my inven-
tion or improvements, may be of any suitable form, which will generally vary with
the form of the boiler. The form of agitator generally applicable will be a paddle or
series of paddles rotating on a horizontal, vertical, or inclined axis, such axis being
carried out through pressure tight stuffing-boxes in the shell of the boilers, and
operated by cranks, pulleys, or other means on the outside of the boiler. Equivalent
reciprocating or oscillating plates or stirrers or analogous agitating devices may in
many cases be applied with equal advantage.
And in order that the full nature of my said invention and mode and means of
performing, or putting the improvements thereof into effect or practice, may be
properly understood, I shall now proceed to describe the several figures on the
Sheet of Drawings which I have hereunto appended for that purpose, the same
reference letters indicating the same or like parts in all the figures.
Figures 1 and 2 are respectively sectional end and plan views, taken near the
lines 1 1 and 2 - 2 each on the other, and Figure 3 is a longitudinal vertical
section taken on the line 3 3 in and corresponding to Figure Ĭ, all of the shell
of an ordinary construction of cylindrical marine steam boiler A, A¹, A², with
double circular furnace flues A" A", and back flame up-take flues A, A, with
sets of return heating tubes A³, A', having one arrangement of my improvements
shown as applied thereto for carrying out this invention.
Referring to these Figures 1 to 3, this application of my improvements consists
in mounting a reciprocating frame a, a, a³, and b, b, (with agitating blades c, c¹,)
above the longitudinal stays B, secured in the front and back ends A and A' of the
boiler, and of the bar stays B1, B₁, of the flat crown of each up-take flue A¹ and
set of tubes A³. The reciprocating frame of each set of agitators consists of two
flat side bars a, secured, near the back end A of the boiler, to a horizontal cross-
head a', with cottered actuating rod a³, passed out through a stuffing-box a³ in the
end A of the boiler, to be actuated from the outside. The front ends of the
frames a, a, which are fitted to work in guides all on the supporting cross
stay a¹¹¹, secured to the long stays B,-have secured to their under side, all in the
steam space above the water, four or other number of cross bars b, preferably
formed of wood for lightness and strength to carry the flat or transverse vertical

page_text: agitating blades or paddles c, c³, secured in them by mortices and pins at b¹ at the
top or other fixtures, so as to project down some distance into and below the
surface level of the water indicated at ww or down to the heating surface.
These stirring or agitating blades c, c¹, are divided and secured to clear the stays B,
and bent at c, where they require to clear both the stays B and B' over the crown
of the take-up flue A¹. In this double arrangement the agitating frames are here
shown as actuated by a horizontal beam lever d, d, mounted to oscillate on the
joint pin centre e in the outer end e¹ of the standard or bracket & secured to and
projecting out from the back end A² of the boiler. The extreme ends of the two
arms d, d, of the lever are shown connected by a slotted joint and pin at d¹ to the
joint ends of the actuating rods a' passed out through the stuffing boxes a³. This
beam lever may be oscillated by one end of a reciprocating rod, as indicated at d³,
from any convenient crank, eccentric, or vibrating lever action of the engine, or
other equivalent convenient mechanical motion, or motor for the purpose.
Thus when the beam lever d d is oscillated outside, as stated, the two rocking
frames a a' a are reciprocated to and fro within the steam space of the boiler A.
over the water, but with their agitating blades c, c', working down into the water
a few inches or down to the heating surface, so as to stir or break up the water at
the surface and assist the free escape of the steam and prevent "priming" or the
carrying-off of the water with the steam through the pipes. Where there was little
room for working the lever d d outside the end of the boiler, it could be fitted
inside the boiler over any part of the frame, and be secured on the lower end of a
vertical spindle passed out through a stuffing-box on the top of the boiler and be
reciprocated by a lever on this spindle outside, and so oscillate the frame inside.
To suit different circumstances and constructions of land or marine steam boilers,
longitudinal or vertical spindles, actuated on the outside, could be passed in through
stuffing-boxes on the shell of the boiler, and be mounted on bearings inside, with
either vertical or horizontal frames secured on them, working within the steam
space above the water, but having their agitating blades or paddles c, working
vertically down some distance below the surface of the water, so as to agitate or
break it up, and allow of a free escape of the steam, to prevent "priming" or
carrying off the water with the steam through the pipes, all otherwise substantially
as and for the purposes described in reference to Figures 1 to 3 of the accompanying
Drawings.
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,-
First. The new or improved means or mode and arrangement and combination
of mechanism with agitating blades or paddles for preventing "priming" in steam
boilers or generators, substantially as herein described and shown in the accom-
panying Drawings.
Second. The construction and use of reciprocating, oscillating, or revolving frames
within the steam space of steam boilers, having blades or paddles projecting down
into and agitating the water for preventing "priming" in steam boilers, sub-
stantially as herein described.