Improvements in Cleaning Apparatus for Steam-boilers.
Year: 1888

page_text: Date of Application, 18th Sept., 1888
Specification Accepted. 30th Nov.. 1888
Improvements in Cleaning Apparatus for Steam-boilers.
I, JOHN SHERMAN ROAKE, Engineer, of Brooklyn, in the County of Kings and
State of New York, United States of America, 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:-
I provide a cleaning chamber adjacent or convenient to the boiler, with its upper
portion receiving water from the boiler at the water level. Another pipe opening into
the cleaning chamber a little lower extends downward and backward to connect with a
low point in the boiler. The arrangement induces a slow circulation, the water moving
outward through the upper connection from the boiler to the cleaning chamber, and
moving back through the other, the lower connection from the cleaning chamber to the
boiler. It is found that with many kinds of water solid or flocculent matter will
accumulate in small masses in the water which will be thrown to the surface by the
ebullition in the boiler and yet will sink if withdrawn with the water into a separate
vessel and allowed to rest. In my apparatus there is a period during which a current
of water carrying such solid particles moves outward and is deposited in the chamber
so that the water returns from the cleaning chamber purified by decantation.
This general principle has been before carried out in apparatus for this purpose.
I have made important improvements. I give such form to the parts that the water
moves down through a large annular space extending around the whole interior of the
cleaning chamber, then is caused to move inward and rise through the whole central
space in the chamber to reach the exit which is in the interior near the top. This
makes the whole horizontal area of the cleaning chamber available for the water to
perform a slow descending, slow inward and slow ascending movement. The conditions
are favorable for the separation of all insoluble matter and the precipitation to the
bottom of all which will sink. The particles which tend to float also find favorable
conditions to allow them to separate and to gather in an annular ring at the top.
I provide for blowing out such insoluble matter at intervals.
In ordinary practice the proportion of solid matter which sinks is much greater than
hat which rises. There is a liability through the neglect of attendants that the solid
natter may gather at first loosely and afterwards more compactly in the lower portion

page_text: of the chamber, and accumulate until the apparatus is clogged.
have devised an
automatic mechanism for blowing out the solid matter from the bottom of the chamber
at intervals. I provide for graduating the frequency of this blowing operation, and
also the length or duration of each.
The accompanying drawings form a part of this specification and represent what I
consider the best means of carrying out the invention.
Figure 1 is a vertical section of a portion of the boiler with the cleaning chamber
and automatic mechanism in elevation.
Fig. 2 is a section through the cleaning chamber.
Fig. 3 is a section partly in elevation showing a modification in the means for
supporting the dome.
Fig. 4 shows a modification in the provision for causing a prompt and full action of
the automatic reversing mechanism, adapted for marine boilers.
Fig. 5 is a vertical section showing a portion of a marine boiler of the return tubular
type with this invention attached. In this, and in all the figures, the drawing shows
the novel parts, with so much of the ordinary parts as is necessary to show their
relation thereto.
Fig. 6 is a vertical section showing a modified form of the cleaning chamber.
Similar letters of reference indicate corresponding parts in all the figures where
they occur.
A. is a portion of the boiler-shell, B the shell of the adjacent chamber, which 1
will call the " cleaning chamber." It is for convenience made in two pieces flanged
together, and secured by bolts. C is the upper pipe. It connects the top of the
chamber B with the boiler-shell at about the height to which the water level is to be
maintained. Within the boiler-shell A is a casing or skimmer C¹ of sheet metal or
other suitable material forming a flared extension of the pipe C. The other end of
this pipe connects with a passage 02 which is cored or otherwise produced in a thick
portion of the shell B. The inner end of this passage C2 is vertical.
Referring to figures 1 and 2, D is an inverted cup of cast iron or other suitable
material, having a diameter about two thirds that of the shell B. It has a general
dome-shape, but its top is pointed, as indicated by D'. It is held in place by rods D²
connecting it with the shell B, and holding it firmly in the position shown. A stream
of water flowing through the pipe C and entering the cleaning chamber through the
passage is divided centrally by the point D'.
E is the bottom pipe. It leads from a low point in the boiler-shell A to the bottom
of the cleaning chamber B. It connects by an elbow and T-coupling with a vertical
pipe E which enters the bottom of the cleaning chamber, and extends up centrally
into the hollow dome D.
9
G is a blow-off pipe controlled by a cock When this cock is open the water escapes
strongly from the bottom of the cleaning chamber, carrying with it any solid material
which has been there deposited. A cock c controls the flow through the pipe C.
His a pipe controlled by a cock h, and allowing an escape from the interior of the
cleaning chamber at the top.
In the use of the apparatus the cleaning chamber B and the connecting pipe C
and E are filled with water, and during the greater portion of the time the cock is
wide open. The water becoming partially cooled in the pipes C and cleaning
chamber B flows downward from the passage C2, being spread by the point DI
and dome D. It descends in a gentle current through the liberal annular space
exterior to the dome, moves gently inward and upward in the interior of the dome,
and flows down through the pipe E' and back to the boiler through the pipe E.
In its passage through the cleaning chamber most of the solid matter settles to
the bottom, but a small portion rises to the top. This latter may be discharged
by opening the cock h.
Bi is a pin or fixed horizontal shaft bolted to the lower portion of the cleaning
chamber, or otherwise firmly supported. On this pin are loosely mounted parts
which are rocked at intervals, as will appear further on.
I is an upright cylinder of cast iron or other suitable material mounted on the

page_text: bracket B2 cast or otherwise firmly attached on the side of the cleaning chamber B.
It is equipped with a tight-fitting cover I through a stuffing-box, on which plays a
piston-rod J connecting to a piston J, shown in dotted lines. The piston-rod J¹ is
guided by a bracket B³, and connects by links J2 with an unequally divided lever K,
which latter turns on a pin on the arm f².
L is a pipe communicating with the pipe C, or otherwise having a free connection
with the boiler. It is provided with a branch L' leading into the upper portion
of the cylinder I. The flow through this pipe L and its branch L' is controlled
by a two-way cock having an elbowed passage through it. There are also on
this pipe L two other cocks, f1 and 2, the former above and the latter below
the cock 1.
The lever K carries a weight K' on the long arm, the gravity of which tends
to raise the piston J. A link, 01 connects the long arm of the lever K to a
lever U, turning on the horizontal shaft B₁ before referred to. On a shaft B¹
just above B is loosely mounted an easily rocking cradle M which is adapted
to support a heavy roller N, and allow it to roll freely from one end to the other.
The cradle is formed with an eye M¹. The eye M' connects by a link P to a
link Q, one end of which is attached to an arm on the cock ; the other end
connects to an arm g¹ on the cock g. R is a link leading from the lever ¹ to.
an arm on the cock h.
The water in the pipe L subject to boiler pressure is allowed to slowly pass the
cock f¹, and is directed by the cock into the cylinder I above the piston. Its
entrance depresses the piston and slowly turns the lever K, raising the weight K²
and turning the lever O and consequently the cradle M. When this action has
proceeded to a sufficient extent to bring the cradle level, and a little further the
weight or roller N being actuated by gravity on its inclined support rolls from
one end to the other of the cradle M. The effect of this transfer of its gravity
is to rapidly tilt the cradle and thereby through the links P and Q to shift the
cocks and g. The cock is shifted into such position that the water is allowed
to escape from the cylinder I past the cocks and f. As the water thus slowly
escapes, the gravity of the weight K¹ depresses the long arm of the lever K and
raises the piston J. This movement also through the link O' turns the lever K,
and consequently the cradle M in the opposite direction to that first described.
When this action has proceeded to a certain extent, carrying the cradle M a little
past the level position, the roller N rolls on the inclined track to the other end
of the cradle and induces a rapid shifting of the cradle back to its original
position. In doing so it operates through the links P and Q to again shift the
cock into the position to arrest the escape of water from the cylinder I, and
allow the slow reception of water from the boiler to that cylinder. This move-
ment also closes the cock g, and the entire apparatus is as before, except that the
solid matter which had been deposited in the bottom of the cleaning chamber,
with a small quantity of water has been blown out through the pipe G, and the
cleaning chamber is full of clean water, ready to receive another deposit of heavy
solid matter in the bottom. Any light solid matter which had accumulated in the
top of the cleaning vessel B has been blown out through the pipe H, and the
top of the cleaning vessel is again ready to receive a further accumulation of
light material.
The operation may continue for an indefinite period, the delay between the
discharges being lessened by increasing the opening of the cock and prolonged
by decreasing such opening; and the period of discharge being lengthened by
diminishing the opening of the cock f", and reduced by increasing such opening.
S is an extension of the pipe E controlled by a cock s. The arrangement
allows this pipe S to blow off directly from the boiler at intervals when desired.
U is a small pipe controlled by a cock arranged to allow the blowing out of
ány air which may accumulate in the interior of the dome D.
I attach importance to the fact that the pipe which conveys the water back
from the proper high point in the cleaning chamber to the boiler not only extends

page_text: down to a point at or near the bottom of the boiler, but also extends considerably
below and rises again, and that the rising portion of such pipe is bathed in the
gaseous products of combustion flowing past at a high temperature from the
furnace. I will mark that ascending portion of the pipe, E². The heating of
the water in this portion causes it to rise actively, and greatly promotes the
circulation through the system. Indeed, the arrangement insures that if the
circulation is very slow, the heating in the part E² may even be carried to
the extent of generating steam there, in which extreme case the circulation will
be very greatly quickened. Ordinarily the steam will not be made there, but the
heat absorbed from the hot products of combustion actively flowing past this
single pipe will by increasing the levity of the contained water ensures an active
circulation through the entire system.
Another mode of attaining the same end as is attained by my rolling ball is
by employing a spring attached to the tilting lever M at a high point in the
mid-length. Figure 4 shows this modification. The spring T is attached to the
arm M2, and connects to a bracket B below. The tension of the spring may be
adjusted by the nuts 64, 65. This form of the invention is particularly adapted for
use on vessels which are liable to be more or less inclined, in sea-going vessels
often very greatly inclined. The spring will work independent of gravity. When
the apparatus is employed in sea-going vessels, the cleaning-chamber should be
forward or aft of the boiler with which it is connected so that the careening of
the vessel to one side or the other will not materially affect its action.
Further modifications may be made without departing from the principle or
sacrificing the advantages of the invention. I can hold the dome D by other
means than by the rods D².
Fig. 3 shows this dome supported by three or more radial arms extending out
from its lower edge, and received in recesses in the interior of the cleaning
chamber.
Some of the advantages of my invention may be attained without giving a dome
form to the device D. For example, there may be a hanging partition, either
straight or curved, extending downward from the top of the interior of the shell B.
Fig. shows such a modification, the water being admitted from the boiler in a
gentle current through the pipe C on one side of such partition, and taken out
by the pipe E from a high point the other side of such partition. The water
will in such case descend in a slow and gentle current one side of such partition,
move gently across under it, and rise gently on the other side. But there will
be less area for such horizontal movement of the water than with the dome form.
I prefer the dome form.
I attach importance to the fact that the shell B and its several adjuncts are arranged
at or below the level of the water in the boiler. This feature is particularly important
in sea-going steamers, and is vitally essential in small steamers, as tugs, which are
liable to great agitation in heavy weather. The water in the boiler and in the con-
nection Cand in the shell B is in such vessels liable to great fluctuations of level.
In a heavy sea the water in the boiler swashes with great vigor from one side or end
of the boiler to the other. Such agitations sometimes leave the skimmer (entirely
uncovered, and at other times immerse it deeply in the water. During such periods,
my device or any other cannot take the scum successfully from the surface; but by
reason of the arrangement of my shell B with its top down at or below the water
line of the boiler, I avoid all risk of much steam coming into the chamber and
defeating the operation during the brief periods while the water in the boiler is
depressed, leaving the skimmer empty.
A cleaning chamber arranged above the water line is certain to receive steam and
defeat the circulation whenever the water in the boiler sinks away from the skimmer.
It is not practicable to introduce any connection analogous to a plumber's trap, because
in high latitudes the water thus retained would induce mischief by freezing in winter
whenever the boiler is out of use.
Fig. 5 shows the pipe E extending upward within the back connection. The

page_text: function of this portion of the pipe in receiving heat from the hot gases in which it
is bathed, and causing the water within it to be heated and rarified, and thus to quicken.
the circulation, is the same as in the other form.
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:
1. In a cleaning apparatus for steam-boilers, the doune D, D¹, held concentrically
within the cleaning chamber B, in combination with each other, and with a pipe Č
arranged to bring water from near the water line of the boiler, and a pipe E, arranged
to return water from a point within the dome to a point at or near the bottom of the
boiler, arranged to circulate the water and deposit the solid matter in the base of the
cleaning chamber, substantially as herein specified.
2. In a cleaning apparatus for boilers, the cleaning clamber B, and water con-
nections and E, in combination with each other, and with the weighted lever K, K',
cylinder I, piston J, connections J, J2, pipe L, branch L', and cock 1, blow-off pipe G
and cock 9, and connections as P and Q to a tilting frame M actuated by the lever K,
arranged to automatically discharge the sediment from the bottom of chamber B at
intervals, substantially as herein specified.
3. In an apparatus for cleaning boilers, the tilting cradle M and shifting roller N,
connected to the operating cocks as shown, in combination with the separate actuating
lever and connections for operating it from the loaded lever K, and means as
the cylinder I, piston J, and cocks and g, and the pipes L, L' and G for
operating such lever, all arranged for joint operation substantially. as herein
specified.
4. In a cleaning apparatus for boilers, having provisions as the cock / and its
connections for automatically discharging the sediment from the bottom of the cleaning
chamber at intervals, the cock hand its operating lever h³, and link R connected to
a working portion, as l arranged to provide a discharge from the top of the cleaning
chamber, and thereby to periodically eject the light solid matter collecting at the top,
substantially as herein specified.
5. A cleaning apparatus for steam-boilers, having a cleaning chamber B, with its
top at or below the proper water line of the boiler, a connection C, C, from the
water-line of the boiler to the top of said chamber, a connection E from a point in
the interior of the cleaning chamber near the top to a low point in the boiler, provisions
as the dome D for compelling the water received through the connection C to descend
and again rise in a gentle current in the cleaning chamber, allowing the solid matter
to descend as a sediment, in combination with each other, and with provisions as the
cock for blowing out from the bottom of the cleaning chamber, arranged to retain
the water in the cleaning chamber, substantially as herein specified.
6. In a cleaning apparatus for steam-boilers, the cleaning chamber B, con-
nections C, C, from the proper water line to the top of said chamber, a provision as D
for compelling the water to descend and rise again in the cleaning chamber, in com-
bination with each other, and with a pipe E, E, E², the part E' leading from a point
near the top of the cleaning chamber to a low level, thence horizontally through the
part E, and finally upward through the part E3, the latter being immersed in the
gaseous products of combustion, all arranged substantially as shown, so that the heat
received in the part E shall quicken the circulation of water through the apparatus,
as herein specified.