Improvements in or Appertaining to Water Circulating Fire Grates for Steam Boilers.
Year: 1886

page_text: Date of Application, 8th June, 1886.
Complete Left, 4th Mar., 1887.
Complete Accepted, 5th Apr., 1887.
PROVISIONAL SPECIFICATION.
Improvements in or Appertaining to Water Circulating Fire Grates
for Steam Boilers.
I, JOHN JAMES CAM, of Excelsior Works Worcester in the county of Worcester,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention has reference to steam boiler fire grates of the kind in which water
is caused to circulate through the grate and in the boiler itself, and in order that the
nature of my invention may be readily understood I append herewith a sheet of illus-
trative drawings in which Fig. 1. shows in front elevation a Cornish boiler fitted with
a simple form of my water circulating grate. Fig. 2. is a vertical section through
line a. b. Fig. 1. A. is a hollow "dead-plate" with extended ends, communicating with.
the interior of the boiler at the level of the fire bars, through the front plate to which
it is bolted. B. is a hollow bridge communicating with the crown of the furnace by
means of the ascension pipe C. The hollow fire bars D. complete the communication
between the front of the boiler and the furnace crown. E. is an iron plate for closing
the space underneath the bridge. t. and t¹ are stays to strengthen the flat surfaces of
the hollow chambers, is a deflector to prevent the ascending current rushing into
the steam space in such a manner as to cause priming. Screwed plugs are inserted
in the front edge of the dead-plate, one opposite each fire bar, to facilitate the fixing
of the latter, as also examination or cleaning. The bars may be cylindrical in cross
section and screwed into the hollow bridge, and expanded, or ferruled into the dead-
plate chamber.
Fig. 3. shows in front elevation a Cornish boiler fitted with an arrangement of my
water circulating grate designed to take its water supply from below the level of the
fire bars, by the two connections or tubes F. and which may be made of any
desired shape or length, to extend as low down the boiler front as is desired.
In case
of a two flued or Lancashire boiler, I make the two inner connections, or right and
left hand end connections respectively, of the two hollow dead-plates, by one V or Y
shaped connection or tube in such a way that there is required one joint only on the
boiler for the two inner end' communications. The front edge of the hollow dead-
plate is fitted with a cover-plate, bolted on as shown, instead of employing the row of
screw plugs represented in Fig. 1. When the cover-plate is removed the whole
interior of the dead-plate chamber is exposed as are also the ends and interiors of the
hollow bars. Fig. 4. is a vertical section. through. line c. d. of Fig. 3. Fig. 5. is a
sectional plan through line e. f. of Fig. 4.

page_text: .
Figs. 6. and 7. are respectively a vertical section, and a sectional plan, the latter
through line g.
1. of Fig. 6. of a vertical boiler, fitted with my water circulating grate.
A. is a hollow chamber communicating at one end with the lower part of the boiler
by the bent pipe F. and at the opposite end, by the ascension pipe C. either at the
side of the fire box well above the bars, or at the crown plate. The chamber A. is
divided crosswise at the centre of its length with the exception of a small hole or
passage v. which prevents or carries off any steam accumulating in the top of the
chamber, and which may not circulate through the bars. The hollow fire bars D. are
bent to a semicircular form in plan as shown, and are cast or otherwise suitably fixed
at their respective ends, into the sides of the chamber A.
Fig. S. is a sectional plan of a vertical boiler fitted with my water circulating grate,
and having semicircular hollow chambers A. and B. and straight hollow fire bars D.
The chamber A. is shown fitted with two water supply pipes F. and F1 and the
chamber B. with two ascension pipes C. and C1, but, there may be more pipes or one
only of each kind may be used.
Fig. 9. is a longitudinal section and Fig. 10. a sectional plan in line i.j. of Fig. 9.
of a multitubular boiler of the locomotive type, fitted with my water circulating grate,
the hollow chamber A. communicating with the lower part of the boiler by tubes one
of which is shown at F. The collecting chamber B. communicating with the boiler
by two ascension pipes one of which is shown at C. through the tube plate; the bent
ends of these pipes may be secured by expanding and ferruling, or by any other well
known method, or they may be carried up through the crown plate if desired; the
hollow fire bars D. connect the two chambers A. and B.
Figs. 11. and 12. show a method whereby I make each fire bar independent, and
removable, by simply removing two nuts. The two chambers A. and B. have a series
of holes in the top, corresponding with the pitch of the fire bars; the ends are
continued at right angles, sufficiently to admit of connecting shorter bars as shown,
and leaving room to connect the water supply pipes F. and F¹ and the ascension
pipes C. and C at the corners; smaller holes are provided at the underside,
directly underneath the top holes, sufficiently large for the passage of the bolts
that hold the bars, the undersides of the holes being made conical, or countersunk.
The hollow fire bars are provided at each end with a connector G. having a hole
in the underside, to correspond with the holes in the tops of the chambers A.
and B.; each end is also provided with a bolt passing through the hole and which
is fixed in the upper part of the connector, and extends down through the holes
in the chambers A. and B. and is secured by a nut and washer underneath, the
conical part of the hole being occupied by a soft copper washer of corresponding
shape, or by an asbestos washer. The joints between the chambers A. and B. and the
connector G. may be made with asbestos cloth or other suitable material.
Figs. 13. and 14. illustrate a modification of the arrangement shown in Figs. 11.
and 12, according to which the collecting chamber B. is placed above the fire bars,
the receiving ends of the hollow fire bars being fixed as before on the top of the
chamber A. but the delivery ends of the bars are fixed underneath the chamber B, the
securing bolts at this end being fixed in the upper part of B. and the bar connector G.
being slipped up over it. The nut and washer are underneath the bar connector.
With this arrangement any steam generated in the bars will not have to make the
small downward course in entering the collecting chamber B. as it must do in the
arrangement shown by Figs. 11. and 12.
Dated this 8th day of June A.D. 1886.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in or Appertaining to Water Circulating Fire
Grates for Steam Boilers.
1, JOHN JAMES CAM, of Excelsior Works, Worcester, in the County of Worcester,
Engineer, 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:-
My invention has reference to steam boiler fire grates of the kind in which water is
caused to circulate through the grate and in the boiler itself, and in order that the
nature of my invention may be readily understood, reference is made to the sheet of
illustrative drawings filed with my Provisional Specification in which,
Fig. 1 shows in front elevation a Cornish boiler fitted with a simple form of my
water circulating grate.
Fig. 2 is a vertical section through line a, b, Fig. 1. A is a hollow" dead-plate"
with extended ends, communicating with the interior of the boiler at the level of the
fire bars, through the front plate to which it is bolted. B is a hollow bridge com-
municating with the crown of the furnace by means of the ascension pipe C. The
hollow fire bars D complete the communication between the front of the boiler and
the furnace crown. E is an iron plate for closing the space underneath the bridge.
t and are stays to strengthen the flat surfaces of the chambers.
u is a deflector to
prevent the ascending current rushing into the steam space in such a manner as to
cause priming. Screwed plugs are inserted in the front edge of the dead-plate, one
opposite each fire bar, to facilitate the fixing of the latter, as also examination or
cleaning. The bars may be cylindrical in cross section and screwed into the hollow
bridge, and expanded, or ferruled into the dead-plate chamber.
Fig. 3 shows in front elevation a Cornish boiler fitted with an arrangement of my
water circulating grate designed to take its water supply from below the level of the
fire bars, by the two connections or tubes F and F which may be made of any
desired shape or length, to extend as low down the boiler front as is desired. In case
of a two flued or Lancashire boiler, I make the two inner connections, or right and
left-hand end connections respectively, of the two hollow dead-plates, by one V
or Y shaped connection or tube in such a way that there is required one joint only
on the boiler for the two inner end communications. The front edge of the hollow
dead-plate is fitted with a cover-plate, bolted on as shown, instead of employing the
row of screw plugs represented in Fig. 1. When the cover-plate is removed the
whole interior of the dead-plate chamber is exposed as are also the ends and interiors
of the hollow bars.
Fig. 4 is a vertical section through line c, d, of Fig. 3.
Fig. 5 is a sectional plan through line e, f, of Fig. 4.
Fius. 6 and 7 are respectively a vertical section and a sectional plan tha lattan

page_text: grate. A is a chamber communicating at one end with the lower part of the boiler
by the bent pipe F, and at the opposite end, by the ascension pipe C, either at the side
of the fire box well above the bars, or at the crown plate. The chamber A is divided
cross-wise at the centre of its length with the exception of a small hole or passage v,
which prevents or carries off any steam accumulating in the top of the chamber, and
which may not circulate through the bars. The hollow fire bars D are bent to a
semi-circular form in plan as shown, and are cast or otherwise suitably fixed at their
respective ends, into the sides of the chamber A.
Fig. 8 is a sectional plan of a vertical boiler fitted with my water circulating grate,
and having semi-circular chambers A and B, and straight hollow fire bars, D. The
chamber A is shown fitted with two water supply pipes F and F¹, and the chamber B,
with two ascension pipes C and C¹, but there may be more pipes, or one only of each
kind may be used.
Fig. 9 is a longitudinal section and Fig. 10 a sectional plan in line i, j, of Fig. 9
of a multi-tubular boiler of the locomotive type, fitted with my water circulating
grate, the hollow chamber A communicating with the lower part of the boiler by
tubes, one of which is shown at F. The collecting chamber B communicates with the
boiler by two ascension pipes, one of which is shown at C, through the tube plate;
the bent ends of these pipes may be secured by expanding and ferruling, or by any
other well-known method, or they may be carried up through the crown plate if
desired; the hollow fire bars D connect the two chambers A and B.
Figs. 11 and 12 show a method whereby I make each fire bar independent, and
removable, by simply removing two nuts. The two chambers A and B have a series
of holes in the top, corresponding with the pitch of the fire bars; the ends are
continued at right angles, sufficiently to admit of connecting shorter bars as shown,
and leaving room to connect the water supply pipes F and F, and the ascension
pipes C and C at the corners; smaller holes are provided at the underside, directly
underneath the top holes sufficiently large for the passage of the bolts that hold the
bars, the undersides of the holes being made conical, or countersunk. The hollow
fire bars are provided at each end with a connector G, having a hole in the underside,
to correspond with the holes in the tops of the chambers A and B; each end is also
provided with a bolt passing through the hole and which is fixed in the upper part of
the connector, and extends down through the holes in the chambers A and B, and is
secured by a nut and washer underneath, the conical part of the hole being occupied
by a soft copper washer of corresponding shape, or by an asbestos washer. The joints
between the chambers A and B, and the connector G may be made with asbestos cloth
or other suitable material.
Figs. 13 and 14 illustrate a modification of the arrangement shown in Figs. 11
and 12, according to which the collecting chamber B is placed above the fire bars,
the receiving ends of the hollow fire bars being fixed as before on the top of the
chamber A, but the delivery ends of the bars are fixed underneath the chamber B,
the securing bolts at this end being fixed in the upper part of B, and the bar
connector G being slipped up over it. The nut and washer are underneath the bar
connector.
With this arrangement any steam generated in the bars will not have to make the
small downward course in entering the collecting chamber B, as it must do in the
arrangement shown by Figs. 11 and 12.
Having now particularly described and ascertained the nature of the said invention,
and in what manner it is to be performed, I declare that what I claim in water
circulating grates for steam boilers is :-
1. The combination of parts shown in and described with reference to Figs. 1 and 2
for the purpose specified.
2. The combination of parts shown in and described with reference to Figs. 3 to 5
inclusive for the purpose specified.
3. The combination of a divided chamber communicating at one part with the lower
portion of the boiler, and at another part by an ascension pipe with the upper portion

page_text: of the boiler, with semi-circular hollow fire bars, substantially as described and
shown.
4. The combination of two semi-circular, chambers, the one communicating with
the lower outside portion of the boiler by bent pipes F, F, and the other by
ascension pipes with the upper portion of the boiler, with hollow fire bars connecting
the said two chambers, substantially as described and shown.
5. In a boiler of the locomotive type in which a chamber A is used in conjunction
with hollow fire bars D, D, a second chamber B, and an ascension pipe or ascension
pipes C, connecting the chamber A to the interior of the boiler by external pipe For
external pipes F, F, substantially as described with reference to Figs. 9 and 10.
6. The method substantially as described with reference to Figs. 11 and 12 and to
Figs. 13 and 14 and for the purposes specified of connecting a hollow fire bar to a
chamber.
7. The combination of parts shown in and described with reference to Figs. 11
and 12 and to Figs. 13 and 14 respectively for the purposes specified.
Dated this 4th day of March 1887.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.