Improvements in Regulating the Temperature of Air or Gases proceeding from Stoves, Regenerators, and the like.
Year: 1898

page_text: Date of Application, 14th Feb., 1898
Complete Specification Left, 19th Oct., 1898-Accepted, 7th Jan.,
1899
Improvements in Regulating the Temperature of Air or
Gases proceeding from Stoves, Regenerators, and the like.
other
We, LAWRENCE FARRAR GJERS, of Woodlands Road, Middlesbrough-on-Tees, in
the County of York, Engineer and JOSEPH HUTCHINSON HARRISON, of 2, Exchange
Place, Middlesbrough-on-Tees, in the County of York, Engineer, do hereby declare
the nature of this invention to be as follows:-
It consists in an apparatus by which the varying temperatures of air or other
gases passed through heating stoves or regenerators can be equalized.
The apparatus consists of a chamber with walls of non-conducting material, and
filled with open chequer work of fire brick or other heat absorbing material, through
which the air or other gas is made to pass on its way from the heating stoves or
regenerators to the purpose for which it is required.
The chamber thus becomes heated to the average of the variations of the
temperature of the air or other gas coming into it.
When the temperature of the air or other gas coming from the heating stoves or
regenerators into the chamber, is above the average, the surplus heat is absorbed by
the chequer work in the chamber, and is again given out to the air or other gas
when passed into the chamber from the heating stoves or regenerators at a
temperature below the average.
Thus the temperature of the air or other gas leaving the chamber is maintained
at a mean between the highest and the lowest temperatures at which it goes into it.
Dated this 12th day of February 1898.
LAWRENCE F. GJERS,
JOS. H. HARRISON.
Improvements in Regulating the Temperature of Air or other
Gases proceeding from Stoves, Regenerators, and the like.
We, LAWRENCE FARRAR GJERS, of Woodlands Road, Middlesbrough-on-Tees, in
the County of York, Engineer, and JOSEPH HUTCHINSON HARRISON, of 2, Exchange
Place, Middlesbrough-on-Tees, aforesaid, 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:―
As is well known, the air blast of iron smelting furnaces is usually heated by
means of reversible regenerative stoves, such as Cowper's, Whitwell's, Ford
and Moncur's. and others, which are lined with firebrick and provided
internally with open chequer-work of firebrick arranged so as to leave spaces

page_text: between and amongst the bricks, two or more of these stoves being worked
alternately in such a way that while one is being heated by the combustion of
waste gases from the furnace or by other means, another, having been heated, is
used for heating the blast which is passed through it on its way to the furnace. It
is obvious that from the time the blast is directed into a freshly heated stove to the
time when it is directed into another stove, the temperature of the said blast will
gradually decrease; and also that when the blast is again directed into another
freshly heated stove its temperature will suddenly rise, the difference in
temperatures often amounting in practice to from about 65° to 150° C. (150° F. to
300° F.).
It is now generally admitted that blast furnaces work much more irregularly
when regenerative stoves of the kind mentioned are used for heating the blast than
when the older cast-iron pipe stoves are used through which air and hot gases are
separately passed in a continuous manner and in which the blast is heated to an
approximately uniform degree. Regenerative stoves however possess the advantage
of being able to beat the air blast to a much higher temperature than is possible
with the older pipe stove which results in a reduced fuel consumption in the
furnace. When using regenerative stoves however, the smelting materials in the
blast furnace very frequently form "scaffolds" or ledges of partly fused material
that stick to the sides of the furnace and prevent the proper descent of the charge
to the hearth or crucible below. Sometimes very great trouble is experienced in
removing such "scaffolds."
In other cases on account of the melting and
withdrawal of the portion of the charge below and the increasing weight of the
charge above, the obstruction frequently gives way suddenly thereby causing a rapid
descent of the upper portion of the charge-technically called a slip-into the hearth
below. Meanwhile the proper working of the furnace is not only interfered with,
but there is little or no gas formed to supply the steam generators and stoves used
to supply and heat the blast, with the result that the pressure and temperature of
the blast decrease at a time when the furnace requires the blast to be at its highest
pressure and temperature. With the old form of pipo stoves on the contrary,
scaffolding and slipping rarely take place. Investigation has shown that the
irregularity in the working of blast furnaces when regenerative stoves are used, is
due to the variation in the temperature of the blast heated by such stoves.
Higher temperature of the blast produces quicker combustion of the fuel with
increased temperature in the vicinity of the twyers and a cousequently reduced
height of melting zone, so that the partly fused materials in the region slightly
above the new melting zone are liable to stick together and form a "scaffold"
which is likely to be a very objectionable one when a very hot stove comes into use
after a comparatively cold one.
Now this invention has reference to a method of and means or apparatus whereby
air or other gas heated by being passed through a regenerative stove or chamber of
the kind hereinbefore referred to previously heated by the combustion therein of
gases from a furnace, can be supplied at a nearly uniform and high temperature
notwithstanding that the temperature of the regenerative stove or chamber through
which it is passed and in which it is heated is being gradually reduced.
For this purpose there is provided in connection with regenerative stoves or
chambers of the kind herein before referred to, a heat equalizer, which is or may
advantageously be of similar construction to an ordinary regenerative stove, and
through which the heated air or gas is passed after leaving each of the regenerative
heating stoves in turn and before it reaches the blast or other furnace or place to
which it is to be supplied, the arrangement being such that the excess of heat taken
up by the air or gas upon passing through a freshly heated regenerative stove will
be transferred to and stored in the heat equalizer to be subsequently given up to
cooler air or gas that has passed through the stove after the same has been reduced
in temperature, so that the air or gas delivered from the heat equalizer to the
furnace or other place will be at an approximately uniform temperature.

page_text: Fig. 1 of the accompanying drawings illustrates diagrammatically in plan, an
arrangement of combined blast furnace 1, regenerative air heating stoves 2, 2ª, 2b
and heat equalizer 3 according to this invention. Fig. 2 is a vertical section on the
line xx of Fig. 1.
The heat equalizer 3 has an inlet 4 in communication with a hot blast main 5 into
which hot air is delivered from each of the regenerative stoves 2, 2ª, 2b in turn
which are heated by the combustion therein of hot gases from the blast furnace as
well understood. 6 is a blowing engine by which air is delivered through piping 7
alternately to each stove. 8 is the outlet of the heat equalizer in constant
communication with the horse shoe hot blast main 9 of the furnace 1.
The heat equalizer 3 shown is similar in construction to a regenerative stove and
comprises an iron shell or casing lined with firebrick and containing open fire-brick
chequer work 3º. It may consist of a single chamber or it may be divided
vertically into two or more sections or chambers; in the drawings it is shown
divided into two chambers by a division wall 3b, such chambers being connected
together at the top so that when the hot air from one of the stoves 2, 2ª, 2b enters
at the inlet 4, it ascends one chamber and descends the other to the outlet 8 and
When the blast
thence passes to the horse shoe hot blast main 9 and furnace 1.
passes from one of the freshly heated regenerative stoves at its highest temperature
into the heat equalizer 3, the portion of the chequer work in the latter with which
it first comes into contact will be at a temperature corresponding approximately to
the reduced temperature of the stove last used. The blast will consequently give
up some of its heat to the heat equalizer and pass out to the furnace 1 at about a
mean between the highest and lowest temperatures given by the stores. When the
temperature of the regenerative stove through which air for the time being is
passing, and consequently also that of the blast, decreases, the heat equalizer will
give up some of its accumulated heat to the blast which will thus pass out to the
furnace with its temperature raised to about a mean between the highest and
lowest temperatures given by the stoves. Thus it will be seen that during the first
portion of a stove's run, the heat equalizer will absorb heat from the blast, and
during the latter portion of the run it will give up heat to the blast, after which
the blast is directed through another regenerative stove that has in the meantime
been heated, and the same process of absorbing and giving up heat is repeated.
A further advantage gained by the use of a heat equalizer according to this
invention is that should the furnace work badly from any cause and there is little
or no gas given off therefrom to the stoves, the stored up heat in the heat equalizer
will prevent the sudden decrease in the temperature of the blast which would
otherwise occur.
It will be obvious that heat equalizers such as described can also be used with
advantage for equalizing the temperature of heated air employed for drying and
preserving timber, and other uses where a uniform or practically uniform
temperature is desired. Such heat equalizers can also be used with regenerative
stoves heated by flame and hot gases from special heating furnaces instead of by
the hot waste gases from blast furnaces.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. The herein described method of regulating the temperature of heated air or
other gases proceeding from stoves, regenerators and the like that have been
previously heated and the temperature of which falls whilst acting to heat air or
other gases flowing therethrough, by passing the air or other gases after leaving
a heated stove, regenerator or the like, through a heat equalizer wherein heat will
be absorbed and stored from air or other gases the temperature of which is above
the average temperature of the hot air or other gases proceeding from the stove
regenerator or the like, and heat will afterwards be given up to air or other gases
the temperature of which is below the said average temperature, as set forth.

page_text: 2. For regulating the temperature of heated air or other gases as referred to in
the preceding claim, the combination with stoves, regenerator or the like that are
heated intermittently and the temperature of which is variable in uso, of a heat
equalizer constructed, arranged and operating, substantially as hereinbefore
described with reference to the drawings.