Improvements in or relating to the Removal of Scale from Boilers.
Year: 1894

page_text: Date of Application, 8th Dec., 1894
Complete Specification Left, 30th Aug., 1895-Accepted, 23rd Nov., 1895
Improvements in or relating to the Removal of Scale from Boilers.
A communication from WILLIAM HENRY TEBEAU, Boiler Maker, and WILLIAM
JESSIE BAKER, Carriage Manufacturer, both of 107 West Cayuga Street,
Oswego City, New York, United States of America.
I ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to remove scale from steam boilers particularly
the tubes or flues and a tool or machine peculiarly adapted by its formation and the
broad method employed, covering analogous devices, to dislodge scale, etc., from
the outside of boiler-tubes or flues whilst they are in position within a boiler, by
means of blows directed against the interior surface of the respective tubes or vice
versa or the blows may be directly upon the scale surface of the tubes.
In carrying out this invention we may employ a device (and the broad method
coincidently appears) consisting of an advance body, preferably cylindrical, whereto
is pivotally secured an elongated hammer arm. Structurally said elongated body
comprises, by preference, forward and rearward heads of disc-shape connected by
bars or rods. Provision is made at the forward end of the body by an opening for
the passage and journalling of the arm of a haminer; said arm disposed longi-
tudinally of the body, the greater part of its length standing in advance of the
body and provided with a hammer whilst its remainder lies within the apertured
advance body and ends contiguous to the body's rear head. Secured by its butt
extremity within or on the body is a preferably plate-spring or equivalent which
bears against (or abuts) the inner side or edge of the arm contiguous to its hammer
or otherwise controls the hammer; and, preferably the spring is wider than the
hammer arm.
Moreover the greater portion of spring's length lies in advance of
body portion. Preferably the back end of the body ends in a boss. Centrally
through the head and boss rotatingly passes an actuating-shaft forwardly
terminating within the advance body and then carrying with a single cam or
multiple or analogous member, which as it revolves operates on the hammer arm.
Rearwardly the shaft continues a considerable distance-sufficiently to ensure a fair
portion of its extremity lying outside the adjacent end of a boiler-mounted tube
when the tool is so disposed in relation to the tube as to admit of its hammer
member operating upon the tube. A pipe, comprising united sections, usually
lengths of gas-pipe joined by couplings, the forward length coupled to the advance
body loosely encloses the actuating shaft from the body to a point outside the
front end of tube being operated on. Preferably a cap with a hole is secured to
the outer end of the protruding pipe-length, and through the cap the shaft passes
outwardly a suitable distance. Upon the outlying pipe-section there is clipped or
otherwise detachably secured, a turning-bar whereby the piping may be turned,
when desired, and cause the turning of the advance body etc. of the instrument.
Mounted longitudinally and movably upon the outer end of the actuating-shaft is
a hanging frame carrying gearing for rotating the before mentioned shaft. A
steadying-handle preferably stands out from a part of the frame. A small gear
wheel is mounted within the frame directly on the actuating shaft, and normally
secured thereto, but adapted by release of its fastening to' slide along the shaft

page_text: concurrently with the frame. Gearing with said wheel is a larger gear wheel
supported by and keyed to a spindle upheld by bearings in the frame. Keyed to
the outer end of the spindle is an operating handle, which, being turned, operates
the gearing and rotates the actuating shaft and works the forward members of the
advance-body. Evidently, when preferred the frame and its gearing may be
dispensed with and instead the operating handle secured directly to the actuating
shaft. The turning of the shaft causes the cam or analogous device to operate
intermittently on the hammer arm, impelling the hammer in a certain direction
toward the inner surface of boiler tube, and each time the arm of the hammer is
cleared of a protuberant rising portion of the cam, the spring against which the
arm has crowded instantaneously impels the hammer-arm and hammer towards the
opposite surface of boiler tube, the springing back of the spring entailing sudden
and requisite impact of the hammer against the tube, causing, through concussion,
the disintegration, loosening and dislodgment of the scale on exterior of tube at
and adjacent to each part struck. The scale dislodged by the incessant rapping
drops to the bottom of boiler whence it may be removed through the hand holes or
by special means. As the penetrable portions of the tool are, by the operators,
gradually progressed farther and farther along the interior of the tube operated on,
the pipe is suitably lengthened by the adding of additional pipe-sections. One
tube is operated on at a time. As the actuating shaft gradually penetrates farther.
and farther into a boiler tube, necessarily the gearing-carrying frame and gear is
moved outwardly along the shaft and secured at each temporary position. The
length of shaft, unless as may be the case several sections are rigidly coupled
together, should be somewhat greater than the length of the particular flues to be
operated on.
This invention obviates the necessity of using unsatisfactory compounds for
intended removal of scale, or the crude and unsatisfactory mechanical means
ordinarily employed, i.e. removal of the tubes from the boiler, then rapping them
externally with a hammer, and replacing them in position by the welding of the
tube ends and resetting in the boiler. By this device and method a saving in
fuel is ensured, as its employment occasionally will keep the tubes practically
freed from scale.
With suitable modifications the invention may be employed for large tubes flues
or shell plates modifications in detail may be made without departing from the
spirit of the invention. The apparatus may be made in multiple form so as to operate
upon more than one tube or flue at a time.
Dated this 8th day of December 1894.
BOULT & WADE,
. Agents for the 'Applicant.
"A" communication from WILLIAM HENRY TEBEAU, Boiler Maker, and WILLIAM
JESSIE BAKER, Carriage Manufacturer, both of 107 'West Cayuga Street,
"Oswego City, New York, United States of America.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Chartered 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 :-
.
This invention relates to the method of and means for removing scale or
incrustation from boiler-tubes whilst same are mounted in position within a steam
or analogous boiler, by percussion action upon the inside or interior surface of the

page_text: boiler-tubes, said percussion action causing shock and vibration of the tubes and
consequently the jarring-off of the scale therefrom; the apparatus being applicable
to boiler-tubes generally whether the scale be deposited on the exterior surface, or
as in water-tube boilers, on the interior surface thereof.
The following steps or stages are employed ;-
The introduction into the open end of the boiler tube of a device capable of
causing percussion blows to be given to the inside of a given tube throughout its
length and internal circumference; means located externally of the open end of
the tube for operating, through satisfactory connecting and power-transmitting
devices the perenssion device disposed within the tube; insuring coincidently with
the progress of such means due rotation and delivery of hammer-like blows against
the tube's interior surface, means for effecting the requisite lengthening or
extending of the connecting and actuating devices as the percussion device is
moved longitudinally within the boiler-tube, and, finally, the delivering of the
blows at any desired rate by the operator or operators stationed at the front or
exterior of the boiler; and the subsequent withdrawal of the percussive device
from the scaled tube for insertion into another, or incrusted tube and so on.
The invention will be best understood by reference to the accompanying
drawings in which
Fig.
is a view shown in two portions and partly in longitudinally section
and partly in side elevation representing the improved machine in operative
position ;
Fig. 1 ; and
Fig. 2 is a transverse section taken at dotted line x
Fig. 3 is a similar section upon dotted line y y, Fig. 1.
Similar letters and figures of reference denote corresponding parts.
A indicates a cylinder-like open body carrying a pivoted hammer-arm or
lever B, terminating forwardly in a hammer e.
Usually said body comprises two disc-like heads 12, stationed some distance
apart, and connected by preferably integrally-formed bars a a a', longitudinally
disposed, and conveniently at equal distances apart.
c is a slot in the forward head 1 of body A, through which passes and is therein
journalled by a pivot-pin d the hammer-arm B.
The forward portion of the hammer-arm is elongated, whilst the portion
extending back from the head 1 of the body, terminates in a tip f
bindicates the spaces between the bars a a
a a¹.
C is a spring, of any suitable type, actuating the hammer; its butt is secured
conveniently by bolts g to the body A, as shown and passing forward through the
opening in front head 1; abuts at its end against the under edge of the hammer-
arm B adjacent to the hammer e.
Passing centrally through the rear head 2 and boss 3 thereon, is a revolvable
cylindrical shaft D whose forward end at the front of the rear-head has keyed to
it a double cam E (or a cam with only one or with more than two operative
surfaces).
Normally the tip of the hammer-arm rests on a portion of the cam's edge or
periphery midway between the elongations or wings-as delineated. Upon the
cam's rotation and impelling outward of the tip f necessarily a change of position
of the hanımer-arm and its hammer e results.
Rearwardly the shaft D (actuating the cam E) is so elongated-whether in
one piece or in united sections-as ensures at all times a satisfactory portion of its
rear extremity being disposed outside the front of the boiler-tube wherein it is
working irrespective of the position of the advance body and its hammer within
the tube or flue.
F indicates united sections of pipe-preferably lengths of gas-pipe-loosely
enclosing the shaft D from where it leaves the body A to a spot outside of the
front end of the boiler tube being operated upon.
Couplings 4 unite the pipe-sections; and somewhat similar ones may be
employed for the shaft D if the latter consists of sections.

page_text: As the advance body and hammer advance further along the boiler-tube
additional sections of gas-pipe are added as required.
5 is a cap having a central circular opening and attached to the end of the
pipe F, which protrudes from the boiler tube and through which passes the
shaft D.
To the pipe D, adjacent to the cap 5, a bar or lever G, having two handles i, is
firmly connected by a clamp and bolts k. By turning the handle-bar a partial or
complete revolution of the body A is attained.
H is a gear-carrying frame movable longitudinally of the shaft D at the front
of the cap 5 and provided at one corner with a steadying-handle J. 11 are co-axial
openings through the frame for the passage of the shaft D supporting the said
frame.
L M are gear wheels working in said frame the smaller one L being mounted
adjustably as by a set-screw m, on shaft D and the larger one M meshing with the
smaller one, and supported by a gudgeon or short shaft 6 journalled in the frame H,
and N and 7 is an operating-handle for turning the larger wheel M which in turn
rotates the smaller wheel Land cam shaft D. n is a set-screw in hub of large gear.
The loosening of the set-screw m permits the frame H to be shifted to any requisite
part upon the operating shaft E.
P denotes (by dotted line) a longitudinal section of a boiler-tube-supposed to
be fitted in a boiler and exemplifying the application of the invention for the
removal of scale.
By turning the handle 7, or an equivalent thereof, the cam E is rotated and by
its action against the hammer arm or tip thereof moves the hammer e away from
the inner surface of the surrounding boiler tube, the hammer-arm in its sweep
pressing back the free extremity of the spring C. Immediately after the hammer
arm B is released by the cam É the spring impels the hammer against the inner
surface of the boiler-tube, causing by the concussion and vibration thereby produced
the jarring off of the scale adhering to the exterior of the tube at and adjacent to
the part receiving the blow. If desired the gearing frame H and gearing L M may
be dispensed with and the shaft D rotated by a crank handle keyed thereto, or by
any other suitable means.
The scale detached from the tubes falls to the bottom of the boiler, whence it
may be readily removed through the hand-holes of the boiler.
Prior to starting work on a tube it is advantageous to remove from its interior
any accumulated spot etc. by any convenient tool thereby ensuring a clear passage
and no danger of the clogging of the working parts of the mechanism.
In a boiler wherein the scale is deposited upon the interior of the tubes, as for
example in a water-tube boiler the blows of the hammer e arc delivered directly
upon the scale.
The employment of the fore-going method or process and suitable means for
carrying it out, renders it unnecessary to use any of the usual so-called scale-
removing compounds, or to resort to the troublesome and expensive practice of
removing the tubes from the boiler, and thereafter tapping their external surfaces
with a haminer or other tool for knocking off the scale, and then replacing the
tubes in the boiler by welding their ends and re-setting.
The before described mechanism may be varied without departing from the spirit
of the invention and any suitable power may be employed for operating it.
Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondents, and in what
manner the same is to be performed, I declare that what I claim is ;-
1. Removing scale from boiler tubes while same are in the boiler by subjecting
the inside of the tubes to percussion or hammer-like blows substantially as
described.
2. Removing scale from the outside of boiler-tubes while same are seated in the
boiler which consists through suitable steps or means in the delivery of percussion.

page_text: or hammer-like blows against the interior of the tubes substantially from end to end
as set forth.
3. The method of removing scale from the outside of boiler-tubes operatively
mounted in a boiler, consisting in the progressive delivery through mechanical
means of percussion or hammer-like blows against the interior of the tubes from
end to end as specified.
4. Dislodging scale from the outside of boiler-tubes whilst same are secured in a
boiler consisting in the introduction into said tubes of travelling mechanism adapted
to produce percussion or impart blows throughout the insides of the tubes said
mechanism operating through means located externally of the tubes substantially
as described.
5. The method through quick concussion and vibratory action of detaching scale
from the outside of a boiler-tube mounted within a boiler which consists in the
introduction into an open end of the boiler-tube of adjustable and rotative
mechanism operating means capable of delivering percussion blows upon the
interior of the tube connecting and actuating devices capable of being lengthened
leading from the percussion-device to means disposed outside the open end of the
tube and whereby gradual travel is produced the percussion-device being retracted
from the tube following its passage to the farther end thereof substantially as
described.
6. The mechanism for removing scale from boiler-tubes while same are mounted
in a boiler, comprising a hammer hammer-operating mechanism an advance body
carrying the hammer and hammer-operating mechanism an actuating shaft leading
outwardly from the body tubing or piping connected to the body and loosely
encompassing the actuating-shaft and suitable means at the exterior of the boiler
for operating the shaft substantially as described and illustrated in the accom-
panying drawings.
7. Mechanism adapted by percussion blows to dislodge scale from the outside of
boiler-tubes while same are in the boiler comprising a hammer member a spring a cam
a cam-working shaft leading from an advance body through piping to means at the
exterior of the boiler for operating said shaft and means for advancing the body
and hammer along the interior of the boiler-tube substantially as described and
illustrated in the accompanying drawings.
8. The combination and arrangement of parts constituting the complete device
for removing scale from tubes substantially as described and illustrated in the:
accompanying drawings.
Dated this 21st day of August 1895.
BOULT & WADE,
Agents for the Applicant.