IMPROVEMENTS IN APPARATUS FOR PRODUCING POPPED CORN
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Thomas Bannerman Kinder and
Edmund Richard Southby at the Office of the Commissioners of Patents on
the 8th February 1883.
THOMAS BANNERMAN KINDER of 11 Queen Victoria Street in the City of
London Architect and EDMUND RICHARD SOUTHBY of 24 Holborn Viaduct in the
City of London Analytical Chemist "IMPROVEMENTS IN APPARATUS FOR
PRODUCING POPPED CORN
"
"
"
It is well known that by exposing certain varieties of Indian Corn or maize
(hereafter called corn in this specification) to a high temperature for a short time
that the corn is "popped as it is technically termed that is to say burst and
expanded so as to become a porous mass but the forms of apparatus in which this
popping has been hitherto effected have been only adapted for operating on sinall
quantities
The object of this invention is the construction of apparatus by which large
quantities of popped corn can be manufactured by mechanical means so as to save
manual labour and thus reduce the cost of the operation
In the construction of apparatus for popping corn we find that the following
general principles must be observed viz:
1st The corn must be rapidly exposed to a high temperature for a short time and
withdrawn from the heat directly the popping has been effected
2nd The corn must be exposed in a thin layer not more than 2 or grains deep
and the best results are obtained when it is exposed in a layer one grain deep
3rd The corn should be kept moving during the time it is exposed to the heat
and the most suitable movement is one of a jerky character the object being to
roll the grains of corn over and so expose the whole surface of each rapidly and
equally to the heat
It has been attempted to pop corn in revolving cylinders but corn inside a
cylinder tends to collect at the lowest portion of its circumference and is con-
sequently not exposed to the heat with sufficient regularity to produce good
results. This objection to cylinders may be partially obviated by fixing longitudinal
Septa so as to divide the inner surface into a series of narrow cells of 2 or 3
inches in depth but we find that we can produce the best results by popping the
corn on flat or nearly flat surfaces A revolving cylinder however of very large
diameter with only a portion of its lower circumference exposed to the heat may
be employed
This cylinder must be placed at such an incline as to cause the corn to traverse

page_text: its length during the time that is required for popping it and very narrow septa
may be fixed longitudinally to its inner surface to assist in distributing the corn
and in causing its grains to roll over or spiral septa of several inches in depth may
be fixed inside the Cylinder so as to cause the corn to traverse the length of the
spiral channels formed by such septa during the time required to complete the
popping
In non cylindrical machines we expose the corn to the heat on a surface as flat as
possible and in order to prevent the corn from collecting on any one portion of this
flat surface and to keep it distributed over the surface as evenly as possible We
divide this surface by means of septa into cells of a few inches in width and depth
These cells may be of considerable length and we usually make their length
extend to the whole width of the surface-The top of these cells is closed by a
moveable perforated cover during the time the corn is being popped so as to
prevent the corn from being ejected from the apparatus
Motion is communicated to the flat surface by any well known mechanical
means and this motion we prefer to be of such a character and speed as will cause
the grains of corn to roll over and expose the whole surface of each as evenly as
possible to the heat We find that a rapid jerky movement at or nearly at right
angles to the width of the cells effects this object-Care must be taken to avoid
any movement in the direction of the length of the cells which will cause the corn
to collect in any portion of their length.
The surface on which the corn is popped may be either fixed in a frame or it
may be a portion of a revolving web
The septa forming the Cells may be either fixed to the surface or merely kept in
close juxta position to it so that no grains of corn can get between them and in
the latter case the surface and septa may either move together or the surface may
move and the septa remain fixed or vice versa
A
We find that metals such as copper iron or steel which will stand a heat
approaching to redness without losing their strength or form are the materials
best adapted for the construction of the surface and we find further that the best
results are obtained by perforating the surface so as to allow the heated gases and
reflected heat to come as far as possible into direct contact with the corn
surface formed of wire gauze of a rather fine mesh answers well or it may be
formed of wires fixed side by side with narrow spaces between them as in ordinary
screens and sieves or the surface may be formed of perforated metal The
perforations must in all cases be small enough to prevent the grains of corn falling
through and we find that very small and numerous perforations answer best
If the surface is posed in a frame we adopt some device by which it can be easily
and rapidly removed from the heat and also emptied of its contents
To effect these objects we sometimes hang the frame to which the surface and
septa are attached in a second frame by means of trunnions so that the first frame
may be easily turned over within the second frame in order to empty it The
second frame we hang freely in a third frame by means of chains bans or rods
suspended from standards fixed to the corners of the third frame Two covers are
hinged to opposite sides of the second frame and these covers falling on to the top
of the septa close the Cells and at the same time keep the first frame in a horizontal
position When it is desired to turn over the first frame these covers are thrown
back We generally form these covers of metal frames filled in with coarse wire
gauze The third frame is provided with wheels so that the whole apparatus can
be easily moved as required
We find that the heat is best applied by the direct action of a fire composed of
some smokeless fuel such as coke, charcoal and anthracite but this fuel must be of
such a character as not to give off gases liable to impart an objectionable flavour
to the popped corn When using such a fuel a simple open furnace rather larger
than the surface on which the corn is popped answers well special fuels may be
employed to give special flavours, but if it is desired to use fuel which would give
an objectionable flavour it must be employed in a close furnace and the heat

page_text: passing through the Crown and sides of the furnace utilised for popping the corn
the furnace gases being conducted to a chimney so as not to come in contact with
the corn on each side of the furnace when using the form of apparatus last
described rails are fixed on which the wheels of the third frame run and these rails
extend beyond the furnace so that the apparatus can be run from above the furnace
as soon as the corn is popped over a hopper which is placed between the rails and
into which the popped corn is emptied by turning over the inner or first frame
as already described the covers hinged to the second frame having been first
thrown back
We employ some form of mechanical charging apparatus in order to deliver an
approximately equal quantity of corn into each cell when using this form of
apparatus
In the form of apparatus just described the movement is applied to the second
frame in a direction at right angles to the Septa and the motion must be of such a
character as to roll the grains over in the Cells and keep them in motion so as to
expose the surface of each grain rapidly and as uniformly as possible to the heat.
This motion may be applied by any well known mechanical means
If the surface on which the corn is to be popped is a portion of a revolving web
we make it of either wire gauze or of wires arranged side by side as in a screen or
of narrow perforated metal plates hinged together The septa may be either fixed
to the web and revolve with it or they may be fixed and the web revolve under-
neath them If the septa are fixed to the web it is generally more convenient for
them to run across the width of the web as if they are fixed in the other direction
they must be made up of narrow strips so as to allow the web to revolve The
shaking motion may be applied to a frame in which the rollers work on which the
web revolves
In another form of apparatus we use several narrow webs placed side by side
These narrow webs are exactly the width of the spaces between the septa which
in this case are fixed and run in the direction of the length of the webs which
latter revolve between the septa. The septa and the rollers on which the webs
revolve are fixed on a frame to which the motion for shaking the corn is
communicated
In the various forms of our apparatus in which the surface on which the corn is
popped is formed of a revolving web this web passes over two principal rollers or
drums which are driven by power and which cause the web to revolve One of
these rollers is fixed just beyond the side of the furnace towards which the web
revolves and the other roller is fixed a short distance beyond the opposite side of
the furnace and a hopper is so placed below this latter roller as to catch the popped
corn as it falls from the web. We use the same classes of furnace and the same
classes of fuel as when we employ surfaces fixed in frames and we so regulate the
length of the furnace and the speed of the web that the corn is just thoroughly
popped while passing over the furnace Besides the two principal or driving rollers
we provide sufficient guide rollers to support and guide the web both over the
furnace and external thereto The webb after passing over the second driving roller
descends in a sloping direction towards the bottom of the furnace under which it
passes through a tunnel and returns upwards on the other side of the furnace to
the first driving roller The corn is supplied to the web by a continuous feed
directly the web has passed over the first roller-When we use a continuous web
the cover is fixed above the furnace so that the web revolves beneath it if the
septa are fixed the cover rests on them but if the septa revolve with the web the
cover is so fixed that the septa just clear it but come as close as possible to it