Improvements in Tubular Boilers.
Year: 1892

page_text: Date of Application, 12th Apr., 1892-Accepted, 21st May, 1892
COMPLETE SPECIFICATION.
[Communicated from abroad by James PierpoinT, of Pittsburg, Pennsylvania,
United States of America, Manufacturer of Steam Boilers.]
Improvements in Tubular Boilers.
I JAMES JOHNSON of 4 Clayton Square, Liverpool in the County of Lancaster,
Patent Agent, 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 :--
Fig. 1 is a transverse vertical sectional view on the line I-I of Figure 2.
Figure 2 is a longitudinal sectional view on the line II-II of Figure 1 ; and
Figure 3 is a detached view of a segment of the drum at the points where the
water pipes are connected therewith.
Like symbols of reference indicate like parts in each.
I will now proceed to describe my invention so that others skilled in the art
may manufacture and use the same.
In the drawing, 2, 3 and 4, are the steam and water drums and 5 and 6 are the
mud drums. Extending from the bottom of the water drum 2 to the top of the
mud drum 5 are a series of water tubes 7; from the mud drum 5 to the water
drum 3, a series of tubes 8; and from the water drum 4 to the mud drum 6 a
series of water tubes 9. These drums and tubes are suitably set in the walls 10
of the furnace. Situate above the firebox 11 is the arch 12 and in rear of the
series of tubes 9 is a partition wall 13, which causes the flames and heat from the
fire-box to circulate between the tubes and to impinge against the drums 3 and 4.
On the other side of the partition 13 is a shelf 14, and a partition 15 in rear of the
tubes 8 which cause the heat to pass down between these tubes to the shelf 16,
from which point it passes up between the tubes 7 and in rear of the partition 17
to and against the drum 2. The mud-drums 5 and 6, are connected with each other
by the water-tubes 18, and the water drums 3 and 4 may be connected with each
other by a water tube 19. The drums 2 and 3, and 3 and 4, are connected with
each other by the steam tubes 20 and 21. Water is admitted to the drum 2 by
the pipe 22 and thence passes through the tubes 7 to the mud drums 5 and 6 and by
the tubes 8 and 9 to the drums 3 and 4 and owing to this circulation and the
location of the drums, the sediment in the water is deposited in the mud-drums
before the water passes to the drums 3 and 4, which are located in the hottest
part of the furnace. Not only is this deposit of sediment more fully accomplished
by my improvement than in prior boilers, but there is also a greater and more
regular amount of heat imparted to the water contained in the tubes and drums.
Heretofore in boilers of this class it has been customary to employ water tubes
having a curve or bend at or near the point where the tubes are connected with
the drums, as, in order to obtain the necessary support, the tubes must enter the
drums on a line with the centre. This curve however prevents the tubes from
being readily cleaned and besides this, the tubes are not interchangeable with each
other, and in order to replace a damaged tube, one of special construction and
shape must be furnished. To obviate this difficulty and to permit of the use of
straight tubes which are easily cleaned and any one of which may be substituted
for another, I form a segment of the drums in the shape shown in Figure 3 where
the outer surface of the plate presents a plane surface and the inner conforms
with the curvature of the drum. Owing to the plane outer surface the tubes are
readily attached to the plate so that the tubes may be straight and parallel to each
other and at the same time, owing to the curvature of the inner surface, the strength
of the drum is in nowise impaired as is the case where a segment of the drum is
replaced by a flat plate, which plate can only be successfully held, so as to resist

page_text: the pressure of the steam, by stays or other equally objectionable means.
Although this is an important feature of construction in my improved boiler and
is herein fully described, I do not desire to claim the same, as I am aware that it
is not new to employ tubes which enter and connect with drums on a line parallel
with each other.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is -
A watertube boiler, consisting of the drums 2, 3, 4, having connecting pipes,
mud-drums 5 and 6 and water tubes 7, 8, 9 in combination with the partition
walls 13 and 15; substantially as and for the purposes described.
Dated the 11th day of Anuil 1900
J. JOHNSON.