Year: 1895

page_text: Date of Application, 17th July, 1895-Accepted, 17th Aug., 1895
A communication from RICHARD LEHMANN, Engineer, of 43 Zwickauerstrasse,
Dresden, Saxony, in the Empire of Germany.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 :-
The present invention relates to an oven for baking biscuits and the like wherein
the heating is effected by means of water-pipes, heated by an outside furnace placed
at one side of it.
This invention is illustrated in the two accompanying sheets of drawings
wherein;-
Figure 1 is a longitudinal vertical section of the baking oven and flues;
Figure 2 is a cross section, and
Figure 3 is a plan of the same.
Like letters indicate like parts throughout.
The oven A is accessible from both ends and provided on both sides with
openings communicating with the vaulted baking chamber B. In addition, a
number of channels or passages C are arranged in the longitudinal and transverse
directions of the oven, serving to conduct the heated gases and combustion products
developed by the furnace.
In the baking-space or chamber B there are a number of pipes DD' arranged in
two rows one above the other. These pipes each of which can be separately cut off or
closed, or which may also all be in communication with each other, are bent at right
angles in the direction of the side of the baking chamber and prolonged thence
through the intervening walls and passages into the furnace which is constructed on
either of the longitudinal sides of the oven.
The two series of pipes D D and D₁ D¹ have their ends supported by the cross
wall F which traverses the furnace E throughout its entire width, dividing it
into two portions E and E', in such manner that the pipe-ends project from the
partition wall F into the front part of the furnace or fire-space E.
The partition wall F is pierced by passages G in its upper part above the pipes
and also between the pipes centrally by passages H which latter may all be closed
by discs J operated from outside at one or the other side (Figure 3).
The heated gases and combustion products from the furnace fire maintained on
the fire-grate K, ascend in the direction shown by the arrows, play upon the exposed
projecting ends of the pipes D D', and are then drawn through the upper open
passages G of the partition-wall into the back division E of the furnace E-
assuming that is of course that the central channels or flues H are closed by the
discs J and while descending therein play upon the pipes D D¹ in the opposite
direction; thence they pass away by the flues or passages C towards the chimney.
If on the other hand however the central passages H in the partition wall F are
opened by drawing back the rod and discs J (Figure 3) the major part of the hot
gases and combustion products will naturally take the short cut thus opened to
them, from the portion E of the fire-space to the portion E¹ and consequently play
upon and around the lower layer of pipes D D.

page_text: This arrangement enables my correspondent either to generate and maintain a
uniform top and bottom temperature in the oven, by compelling the heated gases
and combustion products to traverse the upper part of the furnace and the top
passages or flues G (the central flues H being closed) so as to play on and heat
uniformly both the upper and lower series of pipes; or to establish a maximum
temperature at the bottom, with a minimum temperature at the top, of the oven, by
opening the central passages or flues H so that the bulk of the heated gases and
combustion products passes by this short cut and consequently heats the lower
series of pipes D the most, while the upper series of pipes D₁ is less heated by
the much smaller portion of the heated gases and combustion products which still
makes the entire circuit and plays upon the upper series of pipes D'.
The articles to be baked are introduced into the oven from either end and
removed from the other end; and for this purpose a continuously moving surface
on which the articles to be baked are suitably disposed is arranged to traverse
the length of the oven, while a number of endless chains (in this case four, as shown)
run over discs or rollers, rotating outside each end of the oven, and being actuated
in a suitable manuer by any kind of driving mechanism. The baking tins containing
the articles to be baked on them are placed on these chains and pass slowly through
the oven, to be taken out when the baking is complete at the other end. These
endless chains are so arranged as to run above and below the lower series of
heating tubes D which radiate their heat into the lower part of the oven, while
the upper series of tubes D₁ give out theirs into the upper part of the oven.
It will be easily understood as being an integral element of the invention above
described that in place of and in substitution for the said endless chains, any other
suitable mechanism can be employed to effect the slow progress through the oven
of the articles to be baked; e.g. & fixed table, along which the baking-tins carrying
the articles to be baked are pushed; neither is it necessary or essential that the
articles to be baked should be fed in at one end and removed from the other end of
the oven; but both the charging and discharging of the oven may be carried on
simultaneously at each end.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is ;-
11
1. An oven for baking biscuits and the like articles characterised by connecting
the baking chamber B accessible at both ends with a furnace located on one side
of it in which a number of heating pipes D D' arranged in several rows one above
the other are heated and thence extend through the entire length of the oven
substantially as illustrated and described.
2. In the baking oven such as described in Claim 1 the combination of the heating
pipes DD' supported by the partition wall F of the furnace E with the upper and
central passages or flues G and H in the partition wall F the central or lower.
passages H being capable of simultaneous closure by means of discs J. when it is
desired that the baking chamber should be uniformly heated throughout at top and
bottom or alternatively by opening the passages H that the bottom portion of the
baking chamber B should be more and the upper portion less intensely heated
substantially as shown and described.
D
31
1
BOULT & WADE,
Agents for the Applicant.