Improvements in Fire-bridges for Steam-boiler and other Furnaces.
Year: 1889

page_text: Date of Application, 8 h July, 1889
Complete Specification Left, 24th Dec., 1889-Accepted, 12th Apr., 1890
PROVISIONAL
SPECIFICATION.
Improvements in Fire-bridges for Steam-boiler and other Furnaces.
I THOMAS PLANT of 3 Princes Street Huntingdon, Huntingdonshire, Engineer do
hereby declare the nature of my said invention to be as follows:-
It has heretofore been customary to build the fire-bridges so that the whole forms
one solid and rigid structure. Firebridges of that construction however are liable to
crack and become damaged. Now I construct a fire bridge in the manner hereinafter
set forth whereby ample provision is made for expansion and contraction of the parts
so that the durability of the whole is considerably increased whilst I, at the same time
provide means whereby the smoke is consumed or a more perfect combustion of the
fuel is attained
1 carry my invention into practice as follows: The firebridge up to the level of the
firebar is solid as heretofore but has certain pipes provided in it as will presently be
described. Above the level of the firebars there is no solid brickwork except at the
sides, where it is required to support the other portions of my construction. The
front and back are formed by suitable bars of iron bolted upon the brick sides so that
by the said bars and the brickwork an open chamber is formed.
Into this chamber lead the pipes provided in the solid bottom portion. They supply
air into said chamber and one or more jet-pipes carry steam so as to furnish a forced
draught for this chamber. From the top of the chamber rises an adjustable plate
inclined from front to back of the furnace to make a closer joint between the bars
forming back and front of the chamber their edges may be covered with fireclay.
Now in operation the flames strike the front of the chamber (which forms a hollow
firebridge) rise along it and the inclined plate and then pass over the open mouth of
the chamber. In the latter the air and steam introduced as stated are thoroughly
mixed and become heated. Rising through the mouth of the chamber the air and
steam meet the flame and cause thorough and complete combustion of the solid
particles yet carried thereby thus consuming the smoke.
Dated this 8th day of July 1889
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Fire-bridges for Steam-boiler and other Furnaces.
1, THOMAS PLANT, of 3 Princes Street, Huntingdon, Huntingdonshire, Engineer, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particulariy described and ascertained in and by the following
statement:-
It has heretofore been customary to build the fire bridges so that the whole forms
one solid and rigid structure. Fire bridges of that construction however are liable
to crack and become damaged. Now I construct a fire bridge in the manner herein-
after set forth whereby ample provision is made for expansion and contraction of the
parts so that the durability of the whole is considerably increased whilst I, at the
same time provide means whereby the smoke is "consumed" or a more perfect
combustion of the fuel is attained.
I carry my invention into practice as shown in the accompanying drawings.
In said drawings
Figure 1 is an elevation of so much of a steam-boiler furnace as is required to
illustrate my invention.

page_text: Figure 2 19 a rear view thereof.
Figure 3 a section on line x, a Figures 1 and 2 whilst,
Figure 4 is a plan view of one of the bars hereinafter described.
The fire bridge A up to the level of the fire bars B is solid as heretofore but has
certain pipes provided in it as will presently be described.
Above the level of the fire bars there is no solid brickwork except at the sides A, A¹
where it is required to support the other portions of my construction. The front
and back are formed by bars of iron CC bolted upon the brick sides so that by the
said bars and the brickwork an open chamber D is formed. One of these bars is
shown in plan in Figure 4. The bars are substantially similar to fire bars. They
are set close to one another and at the back are covered with a layer of fire clay C¹ or
the like so as to present a solid surface to the flames as will be seen in Figure 3.
Into this chamber lead the pipes E E provided in the solid bottom portion. They
supply air into said chamber and one or more jet pipes F carry steam so as to furnish
a forced draught for this chamber. The steam may be taken from any suitable part
of the boiler. From the top of the chamber rises an adjustable plate G inclined
from front to back of the furnace. Quadrants G' or the like serving to keep it in
proper position.
Now in operation the flames strike the front of the chamber (which forms a hollow
fire bridge) rise along it and the inclined plate and then pass over the open mouth of
the chamber. In the latter the air and steam introduced as stated are thoroughly
mixed and become heated. Rising through the mouth of the chamber the air and
steam meet the flame and cause thorough and complete combustion of the solid particles
yet carried thereby thus consuming the smoke. Moreover the plates C C being less
rigid than a solid brick wall will yield more readily to expansion and contraction
under variations of temperature without suffering injury thereby and thus the fire
bridge becomes more durable and as the bars can easily be replaced when worn repairs
will be less troublesome and less expensive than heretofore.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is,
1. A fire bridge formed by bars CC capable of yielding to expansion and contraction
as set forth and shown in the drawings.
2. A fire bridge having a hollow chamber D surmounted by an adjustable inclined
plate G into which chamber air and steam are conducted so as to commingle and
become heated therein and meeting the gases from the flames above the chamber
promote complete combustion of the fuel, all as described and indicated in the
drawings.
Dated this 24th day of December 1889.
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicant.