Combined Furnace Grate and Feed Water Heater.
Year: 1897

page_text: Date of Application, 1st June, 1897
Complete Specification Left, 1st Mar., 1898-Accepted, 14th May, 1898
Combined Furnace Grate and Feed Water Heater.
I, JOHN WILLIAM JOHNS, of No. 4, Willoughby Road, Ipswich, in the County of
Suffolk, Engineer, do hereby declare the nature of this invention to be as
follows:-
According to my invention I construct the furnace of a steam boiler or the like
with tubes instead of solid fire bars in such manner that the water is made to cir-
culate through these tubes thereby utilizing as much as possible the units of heat
produced.
The feed water is preferably made to enter a hollow framing which fits into the
flue .or fire box of the boiler and from thence it passes by means of a number of
plain or corrugated pipes of round or flattened section bent into the form of an
arch over the fire and back again from side to side until it finally passes into the
boiler at a higher level than that at which it entered whereby a good circulation
will be ensured. If it be desired to assist the combustion by a blast the aforesaid
hollow framing may conveniently be duplicated and rivetted together and steam
air or the like is or are allowed to enter the lower part of the framing and there
is a number of tubes connected thereto having holes so as to cause the blast to
operate in the most advantageous manner.
A furnace of this kind is very convenient inasmuch as it may be made in various
sizes to suit any sized flues or fireboxes it merely being necessary to make the
connection with the feed pump and with the water space of the boiler.
Or the whole boiler may be constructed in this manner that is to say with the
addition of a steam chest attached to the furnace tubes and the furnace would
naturally be covered in as is usual in the case of water tube boilers.
Datad this First day of June 1897
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
I, JOHN WILLIAM JOHNS, of No. 4, Willoughby Road, Ipswich, in the County of
Suffolk, 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:
-
According to my invention I construct or provide the furnace of a steam boiler
or the like with tubes instead of solid fire bars in such manner that the feed water

page_text: is made to circulate through these tubes thereby utilizing as much as possible the
units of heat produced. The feed water preferably first enters a hollow rectangular
framing which fits into the flue or fire box of the boiler and to which the hollow
furnace bars are connected at each end and from thence it passes by means of a
number of plain or corrugated pipes of round or flattened sections bent into the
form of an arch over the fire and back again from side to side until it finally
passes into the boiler at a higher level than that at which it entered, whereby a
good circulation will be ensured.
If it be desired to assist the combustion by a blast the aforesaid hollow framing
may conveniently be duplicated and the two parts rivetted together, and air by
preference aided by a steam jet is made to enter the lower part of the framing,
a number of tubes being connected thereto provided with exit holes or slits so as
to cause the blast to operate in the most advantageous manner.
'
A furnace of this kind is very convenient of application inasmuch as it may be
made in various sizes to suit any sized existing or other flues or fire boxes it being
merely necessary to make one pipe connection with the feed pump and one pipe
connection with the water space of the boiler.
In the accompanying drawing have shewn my invention applied to an ordinary
Cornish boiler Fig. 1 being a front elevation Fig. 2 a vertical longitudinal section
Fig. 3 a horizontal longitudinal section and Fig. 4 a vertical cross section.
The delivery pipe A from the feed pump enters the front end of a tubular rect-
angular framing B which rests upon lugs C in the boiler flue C. The tubes D
connected at each end to the framing B form hollow furnace bars upon which the
fuel is placed. The arched tubes E are connected to the two sides of the framing B
and are preferably joined to a central tube F which may be a hexagon mild steel
tube. The junctions are by preference made by means of bushes having inner and
outer right and left handed screw threads. The tubes E may be somewhat flat-
tened except at their screw threaded ends so as to offer a larger effective heating
surface.
The feed water having passed through the pipe system described and which may
be called a combined fire grate and feed water heater enters the boiler to the
pipe G at a higher level than that at which it entered the pipe system. The.
frame B may be formed with partitions in each of its side limbs in order to regu-
late the sequel of circulation so that the water would be compelled to pass alter-
nately from one side of the frame to the other by the arched tubes E, and the
frame B may if desired be formed with partitions in its transverse limbs so that
the water would be compelled to pass alternately from one end of the frame to the
other. But as the feed water enters at one side of the frame B and passes out at
a higher level from the central tube F it is in most cases advisable to have only
two or three partitions in the side limbs of the frame and in the central tube,E.
Air for the combustion is supplied by the pipe H and to assist the draught
steam can be admitted by the pipe I. The air or the air and steam pass into the
chamber that communicates with the hollow frame L which is conveniently
made of the same form as the frame B and rivetted thereto with an intermediate
partition plate N. The frame L is provided with a number of tubes M having
slits or holes through which the air issues and enters the fuel on the tubular fur-
nace bars D. By using blast from a fan or blower in conjunction with the steam
jet the draught may be still more increased and smokeless combustion attained.
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. A combined fire grate and feed water heater consisting of a hollow rectan-
gular frame having its transverse members united by longitudinal tubular furnace
bars and having its sides members united by tranverse arched tubes substantially
as set forth.
2. A combined fire grate and feed water heater consisting of a hollow frame

page_text: such as B with tubes D E and F and water inlet and outlet pipes A and G as
described and shewn.
3. In combination with the hollow frame B the partition N, hollow frame L,
chamber K, air supply pipe H, and steam jet pipe I, as described and shewn.
Dated this hirst day of March 1908
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.