Improvements in Forced or Stimulated Draught for Boiler and other Furnaces, and in Means for Producing or Inducing Air Currents for the same and for Ventilation.
Year: 1890

page_text: Date of Application, 26th Aug., 1890
Complete Specification Left, 20th May, 1891-Accepted, 20th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in Forced or Stimulated Draught for Boiler and other
Furnaces, and in Means for Producing or Inducing Air Currents
for the same and for Ventilation.
WILLIAM ARTHUR GRANGER 15 Foulden Road Stoke Newington London N.
Engineer, do hereby declare the nature of this invention to be as follows:-
:-
My invention relates to a cheap & effective means of producing or inducing
currents of air or other fluid for stimulating boiler & other furnaces & also for
ventilation and kindred purposes and it refers particularly to the effective working
of nozzles or injectors employed for producing or inducing air currents. I have
found by experiments that such nozzles are more efficient if worked by a fluid at a
comparatively low pressure and especially so when the pressure of the fluid does
not exceed 15 lbs. per square inch or thereabouts, while still lower pressure are yet
more economical.
Now steam is the most convenient and cheapest fluid with which to work such
nozzles but the great majority of steam boilers, as is well known, work at much.
higher pressures than the foregoing, consequently if the steam from them be used
directly for working such nozzles great waste must occur.
I therefore in my
improved apparatus employ a steam reducing valve, (of any approved type) fitted
between the boiler and the nozzle for the purpose of reducing the pressure of the
steam to any desired amount (according as the valve may be adjusted) before it
issues from the nozzle. And further, (and especially when used for stimulating
furnace draught) in order to keep the steam as dry and to render it as efficient as
possible 1 superheat it, before it issues from the nozzle, by passing it through
suitable coils, pipes or chambers kept at a high temperature by the furnace or by
an auxiliary fire or other source of heat.
In applying the steam nozzle (preferably of the type for which Letters Patent
were granted me numbered 3657 and dated March 1st 1889) for stimulating or
forcing the draught of furnaces I fix a plate or cover over the ashpit mouth and
insert therein a pipe or pipes of suitable diameter and length, wherein the steam
nozzle or nozzles work, inducing a strong air current to flow through the pipe or
pipes into the ashpit and thence through the fire bars to the fire. Suitable valves
& cocks are provided for regulating the volume and pressure of the air delivered.
A door may be fitted to the plate or cover to permit the ashes &c. being withdrawn
from the ashpit.
For ventilating large buildings, ships, railway carriages &c. by mechanical
means I employ a nozzle (preferably of the type before referred to) fixed centrally
within an air pipe or shaft and worked by the aforesaid low pressure steam. That
portion of the air pipe or shaft which is behind the nozzle communicates with the
space or apartment to be ventilated while its other end is open to the atmosphere.
On supplying steam to the nozzle a powerful air current is induced er drawn
through the pipe in a direction away from or out of the space to be ventilated
tending to create a partial vacuum therein. It is therefore merely necessary to
provide suitable inlets, through which the air may enter to fill the partial vacuum
thus formed, and a constant air circulation and consequently an effective ventilation
is at once secured. I adopt simple means for preventing water (caused by any
steam condensing) running down the air pipe into the apartment being ventilated.
Dated this 26th day of Avot 1800

page_text: COMPLETE
SPECIFICATION.
Improvements in Forced or Stimulated Draught for Boiler and other
Furnaces, and in Means for Producing or Inducing Air Currents
for the same and for Ventilation.
I, WILLIAM ARTHUR GRANGER of 15 Foulden Road Stoke Newington
London N. 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 relates to a cheap and effective means of producing or inducing
currents of air (or other fluid) for stimulating boiler and other furnaces and also
for ventilation and kindred purposes, and refers more particularly to the effective
working of nozzles or injectors employed for producing air currents.
I have found by experiment that such nozzles act more efficiently if worked by
a fluid at a low pressure and especially so when the pressure does not exceed
15 pounds per square inch or thereabouts, while still lower pressures are yet more
economical, for with high pressures there is no proportionate gain in the magnitude
of the resulting current while the weight and volume of the inducing fluid consumed
increase largely with its pressure.
Now steam is the most convenient fluid with which to work nozzles or injectors,
but as is well known the great majority of steam boilers work at much higher
pressures than the foregoing, consequently if the steam from them be used directly
for operating such nozzles great waste must occur.
I therefore in my improved apparatus employ a steam reducing valve (of any
approved type) fitted between the boiler and nozzle for the purpose of reducing the
pressure of the steam passing to the latter to the required point for ensuring
economical working. And further (and especially when used for stimulating
furnace draught) in order to keep the steam as dry and to render its action as
effective as possible I superheat it before it issues from the nozzle, by passing it
through suitable pipes, coils or chambers kept at a high temperature by the furnace
or other source of heat.
In applying the steam nozzle (preferably of the type for which Letters Patent
were granted me dated March 1st 1889 and numbered 3657) for stimulating the
draught of furnaces I fix a plate or cover over the ashpit mouth and insert therein
a pipe (or pipes) of suitable diameter and length, wherein the steam nozzle works
inducing a strong air current to flow into the ashpit and thence through the fire
bars to the fire. Suitable valves for regulating both the supply of air and of
steam may be provided as also a door through which the ashes may be removed from
time to time.
In a modification of my improved apparatus for stimulating draught I fix one or
more nozzles in the uptake or chimney of the furnace in such manner that when
fed with steam its or their action shall exert a powerful stimulating effect upon the
chimney draught.
When air currents are required for ventilating purposes I employ a nozzle
(preferably of the aforesaid type) placed centrally within an air shaft or pipe and
fed with the before mentioned low pressure steam. That portion of the air shaft
which is behind the nozzle communicates with the space to be ventilated while its
other end is open to the atmosphere. On supplying steam to the nozzle a powerful
air current is induced or drawn through the shaft in a direction away from the
space to be ventilated, tending to create a partial vacuum therein. It is therefore
merely necessary to provide suitable inlets through which fresh air may enter to fill
the partial vacuum thus formed and a constant air circulation and consequently an,
effective ventilation will be at once secured.

page_text: In order that my invention may be fully understood I have annexed drawings
thereof.
Fig. 1 is a front elevation of an ordinary Cornish steam boiler, and Fig. 2
a side elevation of the same, partly in section, my improved draught apparatus
being shown in both figures with the same reference letters applying to like
parts.
Fig. 3 shows a room or portion of a building and Fig. 4 part of a ship both being
in section and having my improved ventilating apparatus applied.
In Figs. 1 & 2, B is a plate or cover fixed over the ashpit mouth and provided
with a door A to facilitate the removal of ashes &c. C is a pipe wherein works a
nozzle D, E is a reducing valve and F, F, pipes which convey steam from the
boiler to the reducing valve and ultimately to the nozzle D. Upon opening the
cock or valve G, low pressure steam issues from the nozzle D inducing a powerful
air current to flow through C, and thence into the ashpit and through the fire bars
(as shown by the arrows) greatly stimulating the fire. It will be observed that the
pipe F F passes through a portion of the furnace before reaching the nozzle, this
is for the purpose of drying & superheating the steam.
Regarding the advantage gained by using low pressure steam in the manner
indicated I have found by experiment that one pound of steam at five pounds
pressure will induce as much air current as four pounds at sixty pounds pressure,
the nozzle and air pipe being the same in both cases. The economy effected by
adopting a properly adjusted reducing valve in the manner and for the purpose set
forth is therefore abundantly obvious. By superheating the steam a still greater
inducing power is conferred upon it.
I sometimes instead of placing the nozzles under the fire bars, prefer to fix them
in the chimney as shown at H. One or more may be employed according to the
size of the chimney, and the latter may be divided by partitions (such as J) into as
many parts as there are nozzles employed. The nozzles are fed with low pressure
steam in exactly the same manner as already described.
A door K may be provided for giving access to the nozzles.
In Fig. 3, L is a nozzle working within a pipe M, and on supplying steam (at
the low pressure already described) through the pipe N, a powerful air current is
drawn out of the room O, O, as shown by the arrows, fresh air simultaneously
entering at inlets such as P P. It will be understood that the outlet Q of the
pipe M is open to the atmosphere.
Condensed steam or rain water falls to the pit at the bottom of M and escapes
through the drip pipe R. S is a valve or cock for regulating the supply of steam
to the nozzle.
In the case of ventilating a ship's hold (or other portions of a vessel) as
illustrated by Fig. 4, the foregoing explanation of Fig. 3 will suffice to show the
method adopted, the nozzle being preferably fixed at T, and the air inlet in any
convenient position to ensure the entrance of fresh air, consequent upon the with-
drawal of foul air by the action of the nozzle. Doors such as W & X (Figs. 3 & 4)
may be provided for giving access to the nozzles.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is
(1) In apparatus for inducing currents of air or the like for stimulating
draught, ventilation and other purposes, by means of jets of steam, the employ-
ment of a reducing valve so as to obtain steam jets at a low pressure substantially
as and for the purpose described.
(2) In apparatus for inducing currents of air or the like by means of steam jets,
the employment of a superheating arrangement in combination with a reducing
valve so as to obtain superheated steam jets at a low pressure substantially as and
for the purpose described.

page_text: (3) In ventilating apparatus worked by steam jets, the general arrangement of
air pipes or shafts, with pits and drip pipes substantially as described, and shown in
Figs. 3 and 4 and for the purposes herein set forth.
Dated this 20th day of May 1891
WILLIAM A. GRANGER.