Improvements in Bakers' Ovens.
Year: 1892

page_text: Date of Application, 20th July, 1892
Complete Specification Left, 20th Apr., 1893-Accepted, 2nd June, 1893
PROVISIONAL SPECIFICATION.
Improvements in Bakers' Ovens.
JOHN ADAIR, Baker, Waterford Ireland, do hereby declare the nature of this
invention to be as follows
The method of heating bakers' ovens when performed by placing a furnace
inside them which must convey a vast amount of smoke dust into such ovens,
especially when such fires continue burning during the process of baking there is a
vast amount of smoke and dust escaping into the bakehouse in the removing of
such fire as well as in the re-kindling of it, not to speak of the time spent in such
an operation.
But a particular disadvantage attends such a method of heating-viz. the
uneveness of the oven-for it is not necessary to say that the part where the fire is,
must be much hotter than the part where the fire is not-and though, the wretched
method of cooling down such over-heated parts with water is adopted, yet we know
that even then the heat of oven is not rendered uniform, as the furnace itself
must continue to throw in the heat which remains in its furnace bars and blocks.
The contracting and expanding of such a furnace, by the drawing off and the
putting on of the fires tends greatly to its destruction and this applies equally to
the oven part which is cooled with water,-even more so-as the water getting
under the tiles and by the great heat of the tiles, being quickly converted into
steam lifts and splits the tiles in a manner which is very injurious, as it is impossible
to clean such uneven parts of oven, and also by the splitting the water has more free
access, to act with an increased injury, thus making such parts of the oven, require
almost constant repair, though in several instances such repairs are neglected, until
the floor of the oven cracks to such an extent, or becomes uneven by the rising and
falling of the tiles, that absolute necessity forces repairs. To do away with the
defects of such ovens, or ovens of like character I construct my ovens as described.
in Sheets Nos. 1. 2. 3 and 4 of accompanying drawings.
Represents that part of oven which is underneath the sole.
understood as that part upon which the bread is baked, or to
that part which is the inside floor of oven.
A is firebox which is lined around inside with fire blocks B.
C is handle of firebox.
Sole of oven will be
speak more correctly
D is dust chest which is packed with ashes or other non-conducting material and
prevents the heat of furnace from escaping through the front wall of oven.
EE are handles of same to lift it out.
F. is draw plate. This plate is shewn broken-but it is a plate which when
pushed in covers the furnace A. in such a manner as to prevent smoke from
entering oven. This plate is on a level with sole of oven, and when pushed in to its
fullest, the parts G. G. come on an exact line with the front of oven-thus there is
no uneveness whatever caused by this front plate.
This plate runs into two grooves in a metal frame H. see Sheet No. 3. Fig. 1.
In the part of this draw-plate which is immediately over furnace I put a fire-block.
In order to represent this oven clearly, I show the dampers, not as they would be
if working, but to illustrate, I place one side of the oven working one current, and
the other side working the reverse.current-the arrows indicating the current, thus
it would be seen the currents marked by the arrows K. flow into the flues M. and
the currents marked by the arrows N. into the flues P. The dampers illustrate how
Price Sal

page_text: to oven.
arrows and N. This method of reversing currents will give an even heat
4th. The plans of front plate and dust chest behind it, as a quick and easy
method of keeping in the heat of furnace and also making a clean and durable
front to oven.
5th. The draw-plate which is an easy method of cokeing the furnace-riz.: by
drawing the plate and also a quick method of closing in such furnace to prevent
the dust and sulphur escaping into oven.
As the expansion of pipes in an oven must be provided for, I place at the end
of each pipe a bend which bend may be attached to pipe by fastenings or may be.
a part of pipe. This bend enters into a sand box, which sand box is so constructed
as to prevent any leakage of sand. The pipe has freedom to contract or expand
in this sand box-this method will be found a quick arrangement for laying pipes
in oven and further as the expansion and contraction of rails upon which the
crown floor of oven rests, and over which crown floor is placed sand, ashes or
some other like material-and it being consequently exceedingly important that
this floor shall not break nor crack by any expansion or contraction of the rails
supporting it. I use what I term compensation rails thus-I place two light rails
say inch in thickness and of a width sufficient to cover the supporting rail-in
the following manner-1 break this covering rail in two parts leaving say an
inch space between-over this space, I put a plate say 6 inches in length with the
edges well filed off so as not to catch the covering block during the expansion.
1 turn up each end of this rail and place it solidly against the wall of oven,
the rail must therefore expand inwards instead of outwards and thus during the
process of heating oven draw the covering blocks together.
To further explain-Sheet No. 4 Fig. 1. represents pipe R.- shewing sand-
box S. in which it rests. D. shows a view of sand box-E. being the part into
which the sand enters. This sand box has a connection with the flue of oven
the sand box is bolted on to a metal-box T. which box is built in end wall of oven
and is open at that part which forms the flue.
As for some reasons it may be more economical in space to run these pipes
across the oven which means from side to side, I place a sand box at each side.
of pipe.
Fig. 2. represents compensation rails. B shews main supporting rails. C. shews
wall of oven. H. shews compensation rails, with ends turned up against wall C.
K. is covering plate of space in compensation rails.
And further as it is very important that the flues of oven should be clean-I
make an arrangement for cleaning them thus.
:.
I make deep long pits at the bottom of each flue-into, which the soot or dust
falls these pits are raked out at the bottom by means of a channel which runs
from front of oven. To prevent leakage from one flue into the other I have a
long rod with plates on it which closes up the apertures required.
These channels may be long metal boxes if desired, in which case the long rod
with plates can run more exactly even, than if built with brickwork-for illus-
tration see Sheet No. 1. marked Nos. 1. 2. 3. 4. 5. also Sheet No. 3 shewing
mouth of flue-Figs. 1 and 2 marked No. 3.
Dated this 10th dow of 7
1000
COMPLETE SPECIFICATION.
Improvements in Bakers' Ovens.
I, JOHN ADAIR, Baker of Waterford Ireland, 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:—
In the method of heating baker's ovens by placing a furnace inside them, a vast

page_text: amount of smoke and dust is conveyed into such ovens, especially when the fires
continue burning during the process of baking, and in the removing of such fire as
well as in the rekindling of it, not to speak of the time spent in such operations.
But a particular disadvantage attends such a method of heating, viz.,-the
unevenness of the oven, for it is not necessary to say that the part where the fire is,
must be much hotter than the part where the fire is not. And though the
wretched method of cooling down such over-heated parts with water is adopted
yet we know that even then the heat of the oven is not rendered uniform, as the
furnace itself must continue to throw in the heat which remains in its furnace
bars.
The contracting and expanding of such a furnace by the drawing off and the
putting on of the fires tends greatly to its destruction; this applies equally to the
part of the oven which is cooled with water, or even more so, as the water getting
under the tiles and by the great heat of the tiles being quickly converted into
steam, lifts and splits the tiles in a manner which is very injurious. It is impossible
to clean such uneven parts of the oven, and further by the said splitting of the
tiles the water has free access to act afterwards with an increased injurious effect
thereon, thus making such parts of the oven require almost constant repair, though
in several instances such repairs are neglected until the floor of the oven cracks to
such an extent or becomes so uneven by the rising and falling of the tiles that
absolute necessity forces repairs. Now do away with the defects of such ovens
or ovens of like character I construct my improved ovens according to this
invention as described with reference to the accompanying drawings, wherein
Figure 1 is a plan view of that part of an improved oven which is underneath
the sole. By "sole" is understood the part of the oven upon which the bread is
baked, that is to say the inside floor of the oven.
Figure 2 is a sectional plan of an improved oven upon a plane which is a foot or
eighteen inches above the sole.
Figure 3 is a front elevation of a portion of the oven illustrated in Figure 2.
Figure 4 is a vertical section on the line aa of Figure 1.
Figures 5, 6, and 7 are views of details which will be hereinafter particularly
referred to.
Like reference letters indicate corresponding parts throughout the drawings.
With reference first to Figures 1 and 2, A is the removable fire-box which is
lined around the inside with fire blocks B. C is the handle of the fire box. D is
a dust chest which is packed with ashes or other non-conducting material and
placed in front of the firebox; it prevents the heat of the furnace from escaping
through the front wall of the oven. E E are the handles of the dust chest to
enable it to be lifted out.
Fis a draw plate, this plate is shewn broken, but it is a plate which slides above
the furnace horizontally, and which, when pushed in covers the furnace A in such
a manner as to prevent the heated gases from entering the oven. This plate is on
a level with the sole of the oven and when pushed in to its fullest, the parts G G
come on an exact line with the front of oven; thus there is no unevenness whatever
caused by this front plate. This plate runs into two grooves in a metal frame H
(see Figure 3). In the part of this draw plate which is immediately over the
furnace I put a fire block level with the plate in a recess cast in the metal. In
order to represent the action of this oven clearly I show the dampers in Figure 1
not as they would be if working, but, to illustrate, I show one side of the oven
working with one current and the other side working with the reverse current,
arrows indicate the direction of the currents; thus it may be seen that the currents
marked by the arrows K flow from the furnace, out at a suitable opening, and
along beneath the sole into the flues M and thence back through pipes a above
the sole, (see Figure 2); and the currents marked by the arrows N flow from the
furnace directly into the oven, and thence through the flues S and P. If I draw
out the dampers Q and R I close up the flues P and S and open the flues M and T
thus permitting the currents K to work into the flues M; and if I push in the

page_text: dampers Q and R I then open the flues P and S and shut up the flues M and T,
thus causing the currents N to work from the interior of the oven, above the soles
by the flues S to their exit at the flues P.
Of course when the heat currents pass to and through S the draw plate F must
be out and when the currents are not required to enter at S it must be in, to close
the top of the furnace.
In Figure 2 the pipes extend through the oven at a distance of about 1 ft.
to 18 in. above the sole. The bread is baked between these pipes and the sole.
The arrows N Figure 2 show the heat currents passing from the furnace A into
the flues S and thus as in Figure 1 these currents N must have their exit at
the flues P as in Figure 1. Now these flues P pass their heat through-the
pipe into the main flue W. for though they are also in connection with the.
pipes, yet passage through the flues with which the rear ends of these pipes
communicate is closed by the dampers R so that the said pipes will not take in
any of the hot air.
The exit of such hot air from the flue Pas before mentioned will occur when
the currents N are in operation. But when the draw plate is pushed in and the
dampers and R drawn as in Figure 1 the current K is in operation and its exit
will be at M Figure 2, and, the flue M having a connection with the flue Y the
pipe which enters Y will feed into the flue Z at front of oven as indicated by the
arrows J J and this flue Z feeds into the main shaft W through the pipe V.
I have soot doors on these pipes, marked L in the drawings.
Figure 3 represents the front of an oven shewing the front plate O, with door in
it for clinkering the furnace. Of course this door is at the end of a channel which
passes under the dust chest, as the dust chest is held in a position sufficiently high
to give space underneath for clinkering. The dust chest extends up above the
furnace until it reaches the draw plate F thus keeping the heat from escaping.
The dotted lines show ash pit A. Z; the front plate O is fastened on by bolts to an
iron framework which is built into the front wall of the oven.
HH are side plates with grooves in them for the draw plate F to run in; it will
be seen that this draw plate makes a perfectly even front plate for oven, so that
the peel will not catch in anything.
Though I only shew three pipes a, a, V, in the oven I do not confine myself to
this number. For the purpose of regulating the flow of air into the oven I have a
sliding door at A. Z which admits air, and, if required I can place another such
door on the clinkering hole.
In Figure 4 T T are the flues which run underneath the sole.
It will be seen by the description which I have hereinbefore given ::
1st. That my furnace is at the mouth of the oven and as the cold air enters
at the mouth during the process of putting bread or other materials into the
oven it is consequently the part most cooled, and therefore the part most suitable
to have a furnace underneath.
2nd. That the heat can be made to enter direct from the furnace into the oven
or can be shut off from so entering and be made to pass through flues underneath
the oven and also through pipes which are in the oven, thereby giving a bottom
and top heat to the goods while baking.
3rd. That the flues underneath the sole of the oven are so constructed, together
with the pipes and flues over the sole of the oven and with the arrangement of
dampers, that heat currents can, at different times be set up in different directions
in such flues, as is indicated by the arrows K and N, Figure 1. This method of
reversing the currents will enable the oven to be heated evenly.
4th. That the plau of front plate with dust chest behind it is an efficient appliance
for keeping in the heat of the furnace and also for making a clear and durable
front to the oven.
5th. That the draw plate affords an easy means for coking the furnace, viz., by
drawing the plate; and it also is a quick method of closing the furnace to prevent
the dust and sulphur escaping into the oven.

page_text: As the expansion of pipes employed in an oven must be provided for I place at
the end of each pipe a bend which bend may be attached to the pipe by fastenings
or may be a part of the pipe; this bend enters into a sand-box which sand-box is
so constructed as to prevent any leakage of sand therefrom; the pipe has freedom
to contract or expand in this sand-box.
This method of making a joint permits of the laying of pipes very quickly in an
oven.
To further explain this device I will now refer to Figure 5 in which R' represents
a pipe, one end of which is made' fast (though not shewn in drawing) to a metal
cross girder, flue, or any other arrangement convenient for the attachment of pipes
thereto.
S is a sand-box, which sand-box is a metal girder part of which is built into the
wall and part of which projects therefrom as shown.
.1
This girder is open at one side, giving free access by the said opening to
flue F.
E is a hole in the sand-box, having a rim around it, over which the pipe loosely
fits so that the said pipe may be able to expand or contract.
The sand-box S has a ledge T on it, which runs along the whole front side
and the two ends. Within the ledge T around the pipe, sand is placed.
The pipe R can therefore expand and contract in this sand.
The ledges T may project to any desired height.
The arrow indicates the direction of the heat current.
It may sometimes result in economy of space to run such pipes as the pipes.
(Figure 2) across the oven, that is to say from side to side, instead of from end to
end. In such a case I place a sand-box at each end of the said pipes.
Further, as there will be expansion and contraction of the rails upon which the
crown floor of the oven rests, over which crown floor is placed sand, ashes or some
other like material, and it being consequently exceedingly important that this floor
shall not break nor crack by any expansion or contraction of the rails supporting
it I use what I term compensation rails, thus:-I place two light rails say of an
inch in thickness and of a width sufficient to cover a supporting rail (which is not
fixed at its ends, but merely supported) upon the said supporting rail in the
following manner.
I make this covering rail in two parts, which are laid in line with each other
upon the supporting-rail leaving, say, an inch space as an opening between their
ends, and over this space I put a plate say six inches in length, with the edges well
filed off so as not to catch in the material above them during the expansion.
I turn up each end of the divided covering or compensation rail and place it
solidly against the wall of oven; the said rail must therefore expand inwards,
instead of outwards and thus during the process of heating the oven, draw together
the covering-blocks or the like which rest upon them.
Figure 6 represents the aforesaid arrangement of compensation rails, in a side
elevation; B is the main or supporting-rail, CC are the walls of the oven,
HH shews a divided compensation-rail with its ends turned up against the walls C.
K is the covering plate placed over the space between the compensation rails.
As it is very important that the flues of the oven should be kept clean I make
an arrangement for facilitating the cleaning thereof thus:-1 make deep long pits
or depressions at the bottom of each flue into which the soot or dust falls; these
pits are raked out at the bottom by means of a rod introduced into a channel which
runs from the front of the oven into the said pits.
These channels may be long metal boxes, if desired, in which case the long rod
with metal plug hereinafter described can fit more exactly therein than if the
channels are merely-made in the brickwork. The said channels are indicated in
the drawings by the numerals 1, 2, 3, 4 and 5. In Figure 2 the soot-door is removed
from the end of channel 3.
To prevent leakage from one flue into the other, where the channels are con-
tinuous along the bottom of two flues which are in other respects independent, I

page_text: provide a rod with a metal plug on it; the said rod lies in the aforesaid channel
and the plug closes the portion of the channel which connects the two flues and
closes up the aperture required for their connection.
Figure 7 shews such a rod with metal plug t on its end.
Where more than one
disconnection has to be made in the flues, I make the plugs square and put as many
of the plugs on the rods as are needed. The plugs are set in the exact position
required, by set screws which pass through them and engage with the rod.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. An oven provided with improved means for setting up and directing the flow
of the heating medium therein, substantially as hereinbefore described for the
purpose specified.
2. In baker's ovens the combination of the furnace with a dust chest and with or
without the front plate O, substantially as herein before described, for the purpose
specified.
3. A furnace provided with a draw-plate arranged and operating substantially
as hereinbefore described, for the purpose specified.
4. The improved pipe-joint substantially as herein before described with reference
to Figure 5 of the accompanying drawings for the purpose specified.
5. Compensation-rails for the crown of the oven, arranged and operating sub-
stantially as hereinbefore described, for the purpose specified.
6. The combination of cleaning-channels in the flues, and rods therein provided
with suitable plugs, substantially as hereinbefore described for the purposes
specified.
7. The improved oven, substantially as hereinbefore described with reference to
Figures 1, 2, 3, and 4, of the accompanying drawings for the purpose specified.
Dated this 12th day of 4th month 1893.
JOHN ADAIR.