Improvements in Heating Apparatus for Malt and other Kilns, Drying and Roasting Apparatus, and the like.
Year: 1893

page_text: Date of Application, 24th Apr., 1893
Complete Specification Left, 12th June, 1893-Accepted, 23rd Sept., 1893
PROVISIONAL SPECIFICATION.
Improvements in Heating Apparatus for Malt and other Kilns,
Drying and Roasting Apparatus, and the like.
I, Dr. GUSTAV TOPF, of Schmiedstadter Flur 2 Erfurt, in the German
Empire, Analytical Chemist and Engineer, do hereby declare the nature of this
invention to be as follows:-
In drying malt or the like with horizontal heating appartus (by means of flexible
tubes), if it be desired that the malt lying upon the lower hurdle or frame should be
heated in a uniform manner by radiation, it is necessary that the heating tubes
should be in a raised position, and this arrangement should be gradual i.e. such that
the hottest tubes are farthest from the hurdle or frame, while the coldest are brought
close to it. As however, the air employed for ventilation is admitted from below,
these cold tubes come in contact with the air already heated to the maximum
degree, whereby the radiation of heat is seriously interfered with, so that it becomes
exceedingly difficult to derive full advantage from the fuel employed. The proper
utilisation of the fuel in such heating apparatus is therefore only possible when a
very large heating surface is provided which makes the plant very expensive. A
further inconvenience arising from this is the diminution of the space available in
the heating chamber, which, of course, necessitates a proportionate enlargement of
the whole apparatus, so that in most cases the useful effect realised in the end is
comparatively insignificant and far from satisfactory.
The object of this invention is to remove these drawbacks attending heating or
drying with horizontal heating tubes or pipes.
In the accompanying drawings,
Figs. 1 to 3 represents a kiln provided with two hurdles or frames;
Fig. 1 being a section thereof on lines A B (Figs. 2 and 3);
Fig. 2 a plan of the heating chamber,
Fig. 3 a horizontal section of the air chamber.
The hot gases first pass as usual through a series of pipes H arranged in the
heating chamber but, instead of then passing directly through the channels W and
escaping through the chimney X, they pass through the connecting tubes V into a
second series of horizontal tubes h, arranged in the air chamber L, whereby an
opportunity is afforded for the hot gases to give off whatever surplus heat they may
still carry with them, to the ventilating air and thereby to heat it. The air
employed for ventilation cannot reach the heating chamber S or the upper hurdle O,
otherwise than by passing through the said air chamber L, which is heated in this
way, because this air chamber L is separated from the heating chamber S by an
arch or roof G; adjustable air channels K are however provided in the external
wall of the kiln leading from the said chamber L up to the top of the frame O.
The above mentioned arrangement of heating tubes h moreover offers this advantage,
that the ventilating air, when it reaches the upper hurdle or frame O, is not cold,
but heated to a certain extent. This materially accelerates the drying of the malt
spread over the top hurdle O, so that upon the whole the kiln may be worked to
greater advantage; ensures a uniform temperature throughout the said top hurdle
or upper tier; prevents the malt lying upon the lower hurdle or tier from cooling
at the surface, and compels the whole of the ventilating air-current to come into
contact with the secondary supply of air admitted to the upper tier O, so that in
this respect also the heat produced may be fully utilized. It has hitherto been
attempted, in kilns or ovens fitted with vertical heating tubes or apparatus F, to.
arrange within the chamber S, in combination with such heating apparatus, another
series of tubes or pipes below the hurdle or frame U. The effect of this arrange-

page_text: ment, as before stated, is that the smoke, or gases arising from combustion are here
allowed to come into contact with the ventilating air, whereby the radiation or
supply of heat is retarded. Where therefore vertical heating apparatus are used,
say as represented in Figs. 4 and 5 of the accompanying drawings it is preferable
to employ an arrangement according to this invention such as that shown in which
an additional or secondary series of horizontal pipes is placed in the air chamber L
underneath the heating chamber S, the arch or roof G separating the two chambers.
In an arrangement such as this facility is offered to the smoke or gases to yield or
transfer any available heat they may still embody to the fresh cold air admitted
either below the lower hurdle U for general ventilation, or through the channels K
under the hurdle O for partial ventilation. By such means the full utilization of
the hot gases is facilitated, whilst at the same time a considerable amount of fuel
is saved and the effect of the supplemental ventilation in the upper tier, already
stated with reference to the first arrangement as being particularly useful in the
production of malt, is considerably improved. In the arrangement illustrated in
Figs. 4 and 5 the air chamber L and heating chamber S may if required be formed
in one, the arch or roof G being dispensed with, in which case however the escape
orifice of the main or primary heating chamber M, adapted to discharge the
ventilating air, should be arranged above the secondary series of horizontal tubes h,
so that the said air should not come into contact with the ventilating air already
heated.
.. L
J
A .1 1000
G. TOPF,
By L. W., per F. B.
COMPLETE SPECIFICATION.
Improvements in Heating Apparatus for Malt and other Kilns,
Drying and Roasting Apparatus, and the like.
I, Dr. GUSTAV TOPF, of Schmiedstadter Flur 2 Erfurt, in the German Empire,
Analytical Chemist, 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 drying malt or the like by means of horizontal heating apparatus (by means
of flexible tubes), if it be desired that the malt lying upon the lower hurdle or
frame should be heated in a uniform manner by radiation, it is necessary that the
heating tubes should be in a raised position, and this arrangement of the tubes
should be gradual i.e. such that the hottest tubes are farthest from the hurdle or
frame, while the coldest are brought close to it. As however, the air employed
for ventilation is admitted from below, these cold tubes come in contact with the
air already heated to the maximum degree, whereby the radiation of heat is
seriously interfered with, so that it becomes exceedingly difficult to derive full
advantage from the fuel employed. The proper utilisation of the fuel in such
heating apparatus is therefore only possible when a very large heating surface is
provided which makes the plant very expensive. A further inconvenience arising
from the arrangement referred to, is the diminution of the space available in the
heating chamber, which, of course, necessitates a proportionate enlargement of the
whole apparatus, so that in most cases the useful effect finally realised is com-
paratively insignificant and far from satisfactory.
The object of this invention is to remove these drawbacks, attending heating or
drying with horizontal heating tubes or pipes.
In the drawings filed with my Provisional Specification,
Figs. 1 to 3 represent a kiln provided with two hurdles or frames, and with
heating apparatus according to this invention,
Fig. 1 being a section of the kiln and heating apparatus on the line A B (Figs. 2
and 3);

page_text: Fig. 2 a sectional plan of the heating chambers; and
Fig. 3 a sectional plan of the air heating chamber.
The hot gases first pass as usual through a series of pipes H arranged in the
heating chamber but, instead of then passing directly through the channels W and
escaping through the chimney X as heretofore, they pass through the connecting
tubes into a second series of horizontal tubes h, arranged in the air chamber L,
whereby an opportunity is afforded for the hot gases to give off whatever surplus
heat they may still possess, to the ventilating air, and thereby to heat such air.
The air employed for ventilation cannot reach the heating chamber S or the upper
hurdle or frame, O, otherwise than by passing through the said air chamber L,
which is heated by the tubes h, this air chamber L being separated from the
heating chamber S by an arch or roof G. Adjustable air channels K are however
provided in the external wall of the kiln leading from the said chamber L upward
to near the hurdle or frame O. The above mentioned arrangement of heating
tubes therefore offers the advantage, that the ventilating air, when it reaches
the upper hurdle or frame O, is not cold, but heated to a certain extent. This
heating of the air materially accelerates the drying of the malt spread over the
top hurdle or frame O, so that upon the whole the kiln may be worked to
greater advantage than otherwise; it ensures a practically uniform temperature
throughout the said top hurdle or frame; and it prevents the malt lying upon the
lower hurdle or frame from cooling at the surface and the whole of the ventilating
air-current is impelled to come into contact with the secondary supply of air
admitted to the upper hurdle or frame O, so that in this respect the heat produced
may be fully utilized.
It has hitherto been attempted, in kilns or ovens fitted with vertical heating
tubes or apparatus F (Fig. 1), to arrange within the chamber S used in combination
with such heating apparatus, another series of tubes or pipes arranged below the
hurdle or frame U. The effect of this arrangement is that the smoke or gases
resulting from combustion are here allowed to come into contact with the
ventilating air, whereby the radiation or supply of heat is retarded. Where
therefore vertical heating apparatus is used, say as represented in Figs. 4 and 5 of
the said drawings, there is employed according to this invention an arrangement
such as that shown in the said Figs. 4 and 5 in which the vertical heating
apparatus F is placed within a special or additional heating chamber M and
an additional or secondary series of horizontal pipes is placed in the air
chamber L, below the heating chamber S, the arch or roof G separating the two
chambers Ĺ and S. In an arrangement such as this, facility is offered to the
smoke or gases to yield or transfer any available heat they may still contain to
the fresh cold air admitted either below the lower hurdle U for general ventila-
tion, or through the channels K under the hurdle O for partial ventilation. By
such means the full utilization of the heat of the hot gases is facilitated, whilst
at the same time a considerable amount of fuel is saved, and the effect of the
supplemental ventilation in the upper tier, already stated with reference to the
first arrangement as being particularly useful in the production of malt, is con-
siderably improved. In the arrangement illustrated in Figs. 4 and 5 the air
chamber L and heating chamber S may if required be formed in one, the arch or
roof G being then dispensed with. In this case however the exit orifices O of the
main or primary heating chamber M, adapted to discharge the ventilating air into
the chamber 3, should be arranged above the secondary series of horizontal
tubes h, so that the said air should not come in contact with the ventilating air
already heated in the chamber L.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In malt and other kilns, drying or roasting ovens and the like provided with
horizontally arranged heating tubes, the arrangement below the first series of

page_text: heating tubes H and within an air chamber L, of a second series of heating tubes h
through which the heating gases passing from the main series of heating tubes H
are caused to pass, whereby these gases are caused to impart to the incoming
ventilating air any surplus heat they may still contain and whereby the ventilation
of the material placed upon the upper hurdle or frame O, or in the upper tier, by
air at too cold a temperature is avoided substantially as described.
2. The modification of the malt kiln, oven or the like referred to in the
preceding claim according to which the vertical heating apparatus. F is placed
within a special or additional heating chamber M, and a secondary series of
heating tubes h are placed either within a separate air chamber L or within a
chamber S forming a combined air chamber and heating chamber, so that the heat
of the smoke or products of combustion escaping through the heating apparatus F
and tubes h is utilized to heat cold ventilating air admitted to the chambers L and M
substantially as described.
3. In a malt kiln and drying and roasting oven of the kind referred to in the
preceding claim and having a chamber S serving at the same time as a heating
chamber and as an air chamber, the arrangement of a secondary series of heating
tubes h below the discharge orifices of the primary or main heating chamber M
for the hot ventilating air substantially as described.
Dated this 12th day of June 1893.
GUSTAV TOPF,
By L. W., per F. B.