Improvements in Furnaces for Water Tube Boilers.
Year: 1896

page_text: Date of Application, 3rd June, 1896
Complete Specification Left, 22nd Feb., 1897-Accepted, 3rd Apr., 1897
Date of Application, 3rd June, 1896
Complete Specification Left, 22nd Feb., 1897-Accepted, 3rd Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in Furnaces for Water Tube Boilers.
I, ANDREW PILLATT, of the Firm of A. Pillatt and Company, of Queen's
Road Works, Queen's Road, in the Town and County of the Town of
Nottingham, Furnace Engineers, do hereby declare the nature of this invention
to be as follows:-
My invention relates to improvements in the furnaces of steam boilers in which
the flame plays outside and around the water tubes, and the object is to so construct
and arrange these furnaces as to ensure perfect combustion of the fuel gases and
promote economy and efficiency in working.
My improvements are particularly applicable to water tube boilers of the Babcock
& Wilcox, Hornsby, and like types.
In carrying out my invention, I employ the hollow fire bars described in the
Specification of my British. Letters Patent No. 13,371, that is to say, hollow fire
bars extending through and opening behind the fire bridge, and formed with series
of air inlets arranged in the web or rib thereof.
The bars extend from the front to the rear wall of the furnace, through the
latter of which they pass and discharge highly heated air into the products of
combustion coming down behind said rear wall.
In combination with these bars, I arrange, in the upper part of the furnace, a
perforated arch or roof of fire brick, gainster, or the like, through the perforations
in which the fuel gases are drawn by the draught of the chimney. The said arch
or roof may be at an incline parallel with the water tubes, or nearly so, and at a
short distance below them, and it may spring from the side walls of the furnace
and extend between the front and rear walls thereof.
This arch, by becoming highly heated, promotes the combustion of the fuel gases
as they pass through the perforations in it, and the combustion is further assisted
by the heated air, from the hollow fire bars (with lateral openings in the web,)
which the said gases meet and mingle with. This air having been drawn in
through the apertures from the space between the bars, and being consequently
highly heated, ensures the complete and instantaneous combustion of all the carbon
and other unconsumed matters in the fuel gases, so entirely preventing smoke,
which has hitherto been a great objection to boilers of this class.
Dated this 3rd day of June 1896.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 54, Market Street, Nottingham,
Agent for the Applicant.

page_text: Improvements in Furnaces for Water Tube Boilers.
I, ANDREW PILLATT, of the Firm of A. Pillatt and Company, of Queen's
Road Works, in the Town and County of the Town of Nottingham, Furnace
Engineers, 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, reference being had to the accompanying drawings and to
the letters and figures marked thereon, that is to say :-
My invention relates to improvements in the furnaces of steam boilers in which
the flame plays outside and around the water tubes, and the object is to so construct
and arrauge these furnaces as to ensure perfect combustion of the fuel gases and
promote economy and efficiency in working.
My improvements are particularly applicable to water tube boilers of the
Babcock and Wilcox, Hornsby, and like types.
In carrying out my invention, I employ hollow fire-bars, preferably those
described in the Specification of my British Letters Patent, No. 13,371 of 1895,
that is to say, hollow fire bars extending through and opening behind the fire
bridge, and formed with series of air inlets arranged in the web or rib thereof.
In combination with these bars, I arrange, in the upper part of the furnace, a
perforated refractory arch or roof of fire brick, ganister, or the like, through
the perforations in which the fuel gases are drawn by the draught of the
chimney.
My invention will be readily understood by reference to the accompanying
drawings, in which :-
Fig. 1 represents a boiler of the type mentioned, fitted with my improved
furnace.
Fig. 2 is a plan, and
Fig. 3 a transverse section of the arch or roof; these figures being drawn to a
larger scale than Fig. 1.
a is the refractory arch or roof, which may be formed in halves or sections, as
indicated by the central division line Figs. 2 and 3, to facilitate fitting in the
furnace, and is perforated with slots or openings b, of any convenient shape and
arrangement, whose total area may advantageously be equal, or approximately
equal to the area for the passage of the furnaces gases between the water
tubes.
The said arch or roof is arranged at a short distance below the water tubes and
at an inclination parallel with the said tubes. It springs from the side walls c of
the furnace, where its edges are fitted in recesses c', and extends from the furnace
front to the rear wall d, so completely closing the upper part of the furnace, save
for the perforations above mentioned."
e are the fire bars (with lateral openings el in the web or rib) which extend
through an opening d¹ in the rear wall d and discharge highly heated air into
the products of combustion as they pass down behind said rear wall.
When the arch and the fire bars are in position, the products of combustion
flow approximately in the direction indicated by the feathered arrows (Fig. 1).
The course of the heated air from the ash pit, through the hollow fire bars, to the
space behind the rear wall d, is as indicated by plain arrows. But, in some
instances the air may be caused to pass up in front of the bridge wall, and to be
discharged over the fire.
The arch a, by becoming highly heated, promotes the combustion of the fuel
gases as they pass through the perforations in it, and the combustion is further
assisted by the heated air from the hollow fire bars c with which the said gases

page_text: meet and mingle. This air, having been drawn in through the lateral openings
from the space between the bars, has consequently a high temperature, and ensures
the complete and instantaneous combustion of all the carhon and other unconsumed
matters in the fuel gases, so entirely preventing smoke, which has hitherto been a
great objection to boilers of this class.
Having now particularly described and ascertained the nature of
invention, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A furnace for water tube boilers, having a perforated arch or roof of
refractory material, and hollow fire bars arranged below the same and extending
through the rear wall of the furnace, the said bars being provided with series
of air inlets in their web or rib, substantially as and for the purpose set forth.
2. In a water tube boiler furnace, the combination of hollow fire bars, having
lateral air inlets, a rear wall through which said bars extend, and a perforated
refractory arch or roof parallel with the water tubes, substantially as described.
3. In a water tube boiler furnace, the combination of the hollow fire bars
having series of lateral air inlets, the rear wall baving an opening through which
said bars extend, an inclined perforated refractory arch or roof, formed in two
parts, and side walls having recesses to support said arch, substantially as
described.
Dated this 22nd day of February 1897
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, Loudon, and 54, Market Street, Nottingham,
Agent for the Applicant.