IMPROVEMENTS IN APPARATUS FOR THE DISTILLATION OF SOLID SUBSTANCES
Year: 1884

page_text: BERNARD PEARD WALKER of N° 1 Brighton Place Alcester Road Moseley in
the County of Worcester Consulting Engineer and JAMES ALFRED BERESFORD
BENNETT of Valentine Road Kings Heath in the said County of Worcester
Science Master do hereby declare the nature of our invention for IMPROVEMENTS
IN APPARATUS FOR THE DISTILLATION OF SOLID SUBSTANCES to be as follows:-
We have for our object simplification and increase of durability in the apparatus
connected with retorts in which the material to be submitted to distillation is
conveyed through the retort by the action of Screws turning on their axis as
described in Walker and Bennetts Specification Nº 33588.
According to our invention we arrange the retorts in pairs having their' axis in
a straight line.
In the one retort of each pair we make the screw right handed and in the other
retort left handed.
·
Between the inner ends of the pairs of retorts we place the driving gear
consisting of a shaft fitting at either end. into and extending between the inner
ends of the retort screws-these ends are formed into driving squares as regards
the shaft and suitably shaped sockets as regards the screw,ends so that by means
of a spur or worm wheel fixed on the shaft and provided with suitable driving
pinion or worm, actuated by the prime mover, the screws of each pair of retorts
are simultaneously rotated.
The endwise thrust of the screws in the pair of retorts being in opposite
directions is by this arrangement balanced so that the necessity for thrust blocks
with their friction and expence is avoided, and the power required for driving
minimised.
Between the inner ends of the retorts we construct a tunnel of brickwork, or
iron plates the roof of which supports or forms the bottom of the hopper or
receptacle in which the supply of material to be distilled is placed.
The walls of this tunnel form the ends or inner covers of the retorts and have
apertures through which the shaft driving the screws pass, they also form the
supports to the driving gear which is thus protected from dust and weather.
Each retort is furnished at its outer end with a mouth piece, bored to sufficient
size to permit of the ready passage of the screw and to form its outer bearing-
.
་

page_text: the outer end of the body of the screw is enlarged and turned so as to fit and turn
round in the bored part of the mouth piece which is sometimes furnished with a
stuffing box packed with asbestos to prevent any escape of volatile matter.
In some cases in order to allow for the gradual expansion of the material by the
action of heat during its passage through the retort we give a gradually increasing
pitch to the screw beginning at the inner end where the material is supplied for the
purpose of facilitating the forward motion and avoiding any packing of the material
and consequent friction.
We also sometimes arrange the retorts in double pairs one above the other and
feed the material in at the outer end of the upper pair-The material being
conveyed to their inner ends falls into the inner end of the lower retorts and is
conveyed through these and discharged as in the first described arrangement.
7007
We BERNARD PEARD WALKER Consulting Engineer 1 Brighton Place Alcester
Road Moseley near Birmingham, and JAMES ALFRED BERESFORD BENNETT Science
Master, Valentine Road King's Heath, in the County of Worcester do hereby
declare the nature of our invention for IMPROVEMENTS IN APPARATUS FOR THE
DISTILLATION OF SOLID SUBSTANCES and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
Referring to drawings in which the same letters indicate the same parts in the
different figures a. a' fig 2 and 3 shows the screws passing through the retorts b-
The screws a being left-handed and the screws a right-handed so that when by
reason of the shaft and worm wheel c being made to revolve in the direction
indicated by arrows the material placed in the spaces between the screw threads
will be propelled in opposite directions from the inner end of each pair of retorts
The receptacle d for containing the supply of material for distillation being placed
over the inner ends of the retorts and communicating with the retorts delivers the
materials into the spaces between the screw threads.
Fig. 2 being a plan part in section through the axis of the retorts shows
the mode of arranging the retorts in double pairs so that the driving shaft e
communicating with the prime mover will give rotary motion in opposite
directions to the main driving wheels C of each pair of retorts-Thus the end
thrust of each worm on the driving shaft e balances that of the other.
In some cases we construct the screws a with what is known as a gathering
pitch, that is, when the material is of such a nature as to increase in bulk by the
action of heat we make the pitch of the screw to increase beginning at the supply
end that is the inner end as shown in figs. 2 and 4 so that as the material travels
onward more space is provided for it so as to avoid packing-When a light loose
material is to be distilled we make the screw threads diminish in pitch from the

page_text: supply end so that the material during its passage from the supply receptacle to
the hot part of the retort may be compressed as may be desirable to ensure more
efficient action of the heat.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
First the arrangement of the propelling screws described in pairs end to end so
that the resistance of the material in being propelled through one retort is opposed
to the resistance of the material passing through the other opposite retort instead
of being supported by thrust blocks.
Secondly The arrangement of the retorts in parallel pairs so that the driving
worms may by acting in opposite directions have their respective end thrusts
balanced.
Thirdly The construction of the main screws with increasing or diminishing
pitch as described for the purpose of permitting expansion of the material under
distillation or when desirable its compression before reaching the point where
distillation commences.
Fourth-The arrangement of self-acting retorts substantially as described and
illustrated.