A New or Improved Apparatus for Controlling the Cold Air Supply to Heating Stoves for Blast Furnaces and for other like Purposes.
Year: 1889

page_text: Date of Application, 16th Oct., 1889
Complete Specification Left, 15th July. 1890-Accepted, 30th Aug., 1890
PROVISIONAL SPECIFICATION.
A New or Improved Apparatus for Controlling the Cold Air
Supply to Heating Stoves for Blast Furnaces and for other like
Purposes.
I, EMANUEL GREGORY, of Furnace Yard, Station Street, Dudley Port, Tipton,
Staffordshire, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to a new or improved apparatus for controlling the
cold air supply from the blowing engine or engines to heating stoves for blast
furnaces and for other like purposes, the object being to provide an automatic
apparatus which will so act upon the cold air supply valve that when the air pressure
on the inlet or blowing engine side of the said valve is greater than the pressure on
the outlet side thereof, the said valve will by the said apparatus be prevented from
being opened far enough to cause a sudden fall in the pressure on the inlet side of
the valve and consequent racing of the blowing engine or engines; but when the
pressures on both sides of the said valve are equal or thereabouts the said apparatus
will permit the said valve to be fully opened.
I will describe my invention as applied to an air valve which is arranged to be
opened by being moved upwardly and closed by being moved down but it is to be
understood that my invention can be similarly applied to air valves which are opened
and closed by being moved in other directions.
In carrying out my invention I provide. a cylinder containing a piston the said
cylinder being closed at each end with the exception of the air inlets hereinafter
described. The said cylinder is preferably fixed vertically. The said piston is
furnished with a piston rod working through a guide in the cylinder cover and
suitably guided by a bracket fixed to the cylinder cover or otherwise. Air is
admitted to the bottom side of the piston by a pipe leading to the inlet or blowing
engine side of the said air supply valve and air is admitted to the upper side of the
piston by a pipe leading to the outlet or stove side of the said valve. On the said air
valve stalk or rack by which the valve is opened and closed 1 provide a stop which
may consist of a projection which is flat on the top side and inclined underneath.
Adjacent to the valve stalk or rack and carried by a suitable bracket I provide a bolt
which is free to slide to and fro and with which, when the valve is opened through
a short distance as hereinafter described, the said stop comes into contact and prevents
the valve being opened farther. This bolt may be arranged to move to and fro in a
horizontal direction and it is operated from the said piston rod by means of a bell
cranked lever or otherwise. The weight of the piston rod and other moving parts
are partly counterbalanced by a suitable counterbalance weight and lever so that the
piston is slightly the heavier and if unsupported will gravitate to the bottom of the
cylinder.
The apparatus above described operates as follows:-When the said air valve is
closed and the pressure of the air on the inlet or engine side of the air valve is
greater than the pressure of the air on the outlet or stove side thereof the piston
will by the pressure of the air entering underneath as above described be moved
upwardly and cause the said bolt to move forward so that when the air valve has
been opened for a short distance the said stop on its stalk or rack will come into
contact with the said bolt and prevent the valve being opened farther. The air from
the engine side of the valve will now rush through the partly opened air valve but
not so fast as to cause any considerable reduction in the air pressure on the inlet
side of the valve, and the pressure on the outlet side of the valve will gradually
increase until, when it has attained the same or about the same pressure as the air on

page_text: the inlet side of the valve, there will be the same pressures on each side of the said
piston and the piston will then move to the bottom of the cylinder and withdraw
the bolt and allow of the air valve being fully opened. The apparatus above
described thus makes it impossible for the air valve to be opened to a greater
distance than the said bolt will allow which is not sufficient to cause a sudden fall in
the pressure of the air on the inlet side of the valve and thus the blowing engine or
engines is or are prevented from racing or running away.
Elastic cushions are or may be provided on the piston rod to prevent concussion of
the piston or guide at the end of its stroke.
Instead of the cylinder being vertical as above described it may be horizontal
inclined or fixed in any other position.
Dated this 14th day of October 1889.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.
COMPLETE SPECIFICATION.
A New or Improved Apparatus for Controlling the Cold Air
Supply to Heating Stoves for Blast Furnaces and for other like
Purposes.
I, EMANUEL GREGORY, of Furnace Yard, Station Street, Dudley Port, Tipton,
Staffordshire, 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 :-
This invention has reference to a new or improved apparatus for controlling the
cold air supply from the blowing engine or engines of heating stoves for blast
furnaces and for other like purposes, the object being to provide an automatic
apparatus which will so act upon the cold air supply valve that when the air
pressure on the inlet or blowing engine side of the said valve is greater than the
pressure on the outlet side thereof, the said valve will by the said apparatus be
prevented from being opened far enough to cause a sudden fall in the pressure on
the inlet side of the valve and consequent racing of the blowing engine or engines;
but when the pressure on both sides of the said valve are equal or thereabouts the
said apparatus will permit the said valve to be fully opened.
I will describe my invention as applied to an air valve which is arranged to be
opened by being moved upwardly and closed hy being moved down but it is to be
understood that my invention can be similarly applied to air valves which are opened
and closed by being moved in other directions.
On the accompanying drawings Fig. 1 is an elevation (partly in section) and Fig. 2
is a plan of the said apparatus and Fig. 3 is a similar view to Fig. 1 but with the
parts in the positions which they occupy when controlling the opening of the air
valve. Figs. 4 and 5 shew how my invention is applied to an air valve when
arranged horizontally.
The same letters of reference indicate the same or corresponding parts in all the
figures of the drawings.
Referring firstly more particularly to Figs. 1, 2 and 31 provide a cylinder a
containing a piston 6 the cylinder being closed at each end with the exception of the
air inlets c and d hereinafter described. The cylinder a is in this case preferably
fixed vertically to a base plate a¹ bolted to the cover of the cold air supply valve
box y containing the sluice valve z. The piston b is furnished with a piston rod e
working through a guide fin the cylinder cover and suitably guided by a bracket g
fixed to the cylinder cover or otherwise. Air is admitted to the bottom side of the
piston 6 by a pipe c leading to the inlet or blowing engine side of the air supply
valve z and air is admitted to the upper side of the piston by a pipe d leading to the

page_text: outlet or stove side of the said valve. On the stalk or rack h of the air valve z by
which the valve is opened and closed I provide a stop i which may and by preference
does consist of a projection which is flat on the top side and inclined underneath.
Adjacent to the valve stalk or rack and carried by a suitable bracket ; I provide a
bolt k which is free to slide to and fro and with which, when the valve is opened
through a short distance as shewn in Fig. 3, the stop i comes into contact and
prevents the valve being opened farther. This bolt & may be arranged to move to
and fro in a horizontal direction as shewn in Figs. 1, 2 and 3 and be operated from
the piston rode by means of bell cranked lever l, link m and lever n or any other
suitable arrangement of mechanism may be used. The weight of the piston and
rode and other moving parts are partly counterbalanced by the counterbalance
weight o on the lever p so that the piston and rod are slightly the heavier and if
unsupported will gravitate to the bottom of the cylinder.
The apparatus above described operates as follows:-When the air valve z is
closed and the pressure of the air on the inlet or engine side of the air valve entering
the cylinder by the pipe c is greater than the pressure of the air on the outlet or
stove side thereof entering the cylinder by the pipe a the piston 6 will by the
pressure of the air entering underneath as above described be moved upwardly and by
the levers In and link m cause the bolt k to move forward, so that when the air valve
has been opened for a short distance as shewn by Fig. 3 the stop i on its stalk or
rack h will come into contact with the bolt k and prevent the valve being opened
farther. The air from the engine side of the valve will now rush through the space r
past the partly opened air valve z but not so fast as to cause any considerable
reduction in the air pressure on the inlet side of the valve, and the pressure on the
outlet side of the valve will gradually increase until, when it has attained the same or
about the same pressure as the air on the inlet side of the valve, there will be the
same or about the same pressures on each side of the piston b and the piston will
then move to the bottom of the cylinder and withdraw the bolt k from the stop i and
allow of the air valve z being fully opened as in Fig. 1. The apparatus above
described thus makes it impossible for the air valve to be opened to a greater distance
than the bolt will allow which is not sufficient to cause a sudden fall in the pressure of
the air on the inlet side of the valve and the blowing engine or engines is or are
prevented from racing or running away.
Elastic cushions s are or may be provided on the piston rod e to prevent concussion
of the piston or guide at the end of its stroke.
Instead of the cylinder being vertical as above described it may be horizontal
inclined or fixed in any other position as will readily be understood.
It will be evident that the part k which is operated by the piston b to arrest the
opening of the air valve until an equal or nearly equal pressure at each side of the
piston has been obtained, and the mechanism or parts connecting the part k to the
piston so as to be operated thereby can be constructed and arranged in many
different ways without departing from the nature of my invention, as for instance in
the arrangement shewn in Figs. 4 and 5 applied to a horizontal air valve where the
part k forins the upper end of the piston rod and rises and falls with it. In this
example the piston and rod are made of the proper weight so that the use of a
counterbalance weight is dispensed with.
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 :-
In apparatus for controlling the cold air supply to heating stoves for blast furnaces
and for other like purposes, regulating the amount of opening of the air valve by the
difference of air pressure at the inlet and outlet sides of the said valve acting upon a
piston in a cylinder which cylinder is in communication with the inlet and outlet
sides of the said valve so that an excess of air pressure on the inlet side of the valve
will move the piston in one direction and allow the air valve to be opened only

page_text: through a certain prearranged space and when there is an equal or nearly, equal air
pressure on each side of the air valve the piston will return to its normal position
and allow the air valve to be fully opened, substantially as herein before set forth and
illustrated.
Dated this 14th day of July 1890.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.