IMPROVEMENTS IN RETORTS FOR OBTAINING PRODUCTS FROM THE DESTRUCTIVE DISTILLATION OF SAW-DUST, SHAVINGS, AND OTHER SMALL WOOD."
Year: 1880

page_text: LETTERS PATENT to Robert Haldano, of Glasgow, in the County of Lanark,
North Britain, Drysaltor and Manufacturing Chemist, for an Invention of
"IMPROVEMENTS IN RETORTS FOR OBTAINING PRODUCTS FROM THE DESTRUCTIVE
DISTILLATION OF SAW-DUST, SHAVINGS, AND OTHER SMALL WOOD."
PROVISIONAL SPECIFICATION left by the said Robert Haldano at the Office
of the Commissioners of Patents on the 8th April 1880.
ROBERT HALDANE, of Glasgow, in the County of Lanark, North Britain,
Drysalter and Manufacturing Chemist. "IMPROVEMENTS IN RETORTS FOR
OBTAINING PRODUCTS FROM THE DESTRUCTIVE DISTILLATION OF SAW DUST,
SHAVINGS, AND OTHER SMALL WOOD."
My Invention relates to improvements in retorts for obtaining products from the
destructive distillation of saw dust, shavings, and other small wood, such as spent
dye woods.
According to the said Invention the retort is formed with a longitudinal shelf
or division extending along the retort, but leaving an opening or space between
itself and the ends of the retort, and forming virtually two chambers in the retort.
The upper part of the endless chain, which passes over sprocket wheels and carries
the scrapers or propellers for giving a progressive motion to the wood under treat-
ment, travels over this shaft, so that its scrapers or propellers are in contact with
the said shelf, the scrapers at the bottom of the chain being in contact with the
bottom of the retort. The hopper by which the wood is fed to tho retort is so
situated that it delivers the said wood onto the shelf, along which the scrapers
move it, until it is turned therefrom and falls on to the bottom of the retort, and
is by the scrapers moved back along the bottom of the retort in the direction
opposite to that in which it travelled along the shelf. The gas driven off during
the treatment escapes from the upper chamber by the ordinary condenser pipes,
and will escape from the lower chamber to the said pipes by openings between the
said chambers. In place of one shelf there may be two or more shelves, chains, and
scrapers or propellers, being arranged in connection with each shelf, so that the
wood is moved in one direction along one shelf, from which it falls on to the next,
and is moved there along in the reverse direction, and so on until the charcoal falls

page_text: from the last shelf or from the bottom of the retort into the well provided for its
reception.
The hopper by which the wood is fed to the retort is provided with a feeding
shaft or funnel constructed with chambers, the chamber or chambers. above com-
municating with those below by doors or valves, which can be opened and again
closed so that the wood is fed from one chamber to another without any direct
opening being established for the escape of gas from the retort. A feeding roller
is provided, constructed with flutings or recesses in its periphery, forming feeders
for receiving the wood and feeding it to the retort, the said roller revolving
between hinged flaps at the sides of the hopper. These flaps are weighted or
equivalently arranged so that they hang in contact with the roller, and prevent
the escape of gas between themselves and the roller, and at the same time allow of
any obstructive matter passing clear. The retort is. furnished with the ordinary
or convenient means of heating, and receptacle or receptacles for the charred
wood.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Haldane in the Great Seal Patent Office on the 8th
October 1880.
ROBERT HALDANE, of Glasgow, in the County of Lanark, North Britain,
Drysalter and Manufacturing Chemist. "IMPROVEMENTS IN RETORTS FOR
OBTAINING PRODUCTS FROM THE DESTRUCTIVE DISTILLATION OF SAW-DUST,
SHAVINGS, AND OTHER SMALL WOOD."
My Invention relates to improvements in retorts for obtaining products from the
destructive distillation of saw dust, shavings, and other small wood, such as spent
dye-woods.
According to my said Invention the retort is formed with a longitudinal shelf
or division extending along the retort, but leaving an opening or space between
itself and the ends of the retort, and forming virtually two chambers in the retort.
The upper part of an endless chain, which passes over sprocket wheels and carries
the scrapers or propellers for giving a progressivo motion to the wood under treat-
ment, travels over this shelf, so that its scrapers or propellers are in contact with
the said shelf, the scrapers at the bottom of the chain being in contact with the
bottom of the retort. The hopper by which the wood is fed to the retort is so
situated that it delivers the said wood on to the shelf, along which the scrapers
move it, until it is turned therefrom and falls on to the bottom of the retort, and
is by the scrapers moved back along the bottom of the retort in the direction
opposite to that in which it travelled along the shelf. The gas driven off during
the treatment escapes from the upper chamber by the ordinary condenser pipes,
and will escape from the lower chamber to the said pipes by openings between the
said chambers. In place of one shelf there may be two or more shelves, chains, and
scrapers or propellers, being arranged in connection with each shelf, so that the
wood is moved in one direction along one shelf, froin which it falls on to the next,
and is moved therealong, and so on until the charcoal falls from the last shelf or
from the bottom of the rotort into the well provided for its reception.
The hopper by which the wood is fed to the retort is provided with a feeding
shaft or funnel constructed with chambers above and below, the chamber abovo
cominunicating with that below by a door or valve, which can be opened and again
closed, so that the wood is fed from one chamber to another without any direct
opening being established for the escape of gas from the retort. A feeding roller is
provided constructed with flutings or recesses in its periphery, forming feeders for
receiving the wood and feeding it to the rotort, the said roller revolving between
hinged flaps at the sides of the hopper. These flaps are weighted or equivalently
arranged so that they hang in contact with the roller and prevent the escape of gas
between themselves and the roller, and at the same time allow of any obstructive
matter passing clear. The retort is furnished with the ordinary or convenient
means of heating, and an exit and receptacle or receptacles for the charred'
wood.
And in order that my said Invention may be properly understood I will now
proceed to describe, with reference to the accompanying Drawings, a system, mode,
or manner, in or under which the samo is or may be used or carried into practical
effect. I will take as an example a retort furnished according to my Invention,
with three shelves forming virtually four chambers in the said retort; but it is to
be understood that a lesser or greater number of such shelves may be employed, as
may be convenient.
Figure 1 represents a longitudinal section of a retort constructed according to my
Invention; Figure 2 is a transverse section of the same taken on the line 1, 2,
Figure 1; Figure 3 is a side elevation of that end of the machine at which the
driving mechanism is situated.

page_text: The retort has in its interior shelves a, a, a, extending from side to side thereof,
but with a space between their ends and the ends of the retort, the said shelves at
the ends at which they receive the wood under treatment from the shelf above
being extended beyond the said shelf above for receiving the said wood. Sprocket
wheels b, b, are carried upon shafts 6 mounted in bearings at either end of the
said shelves. Over these sprocket wheels pass chains c, c, indicated by the dot and
pick lines in Figure 1, and shewn in full lines in Figure 2. The shafts of tho
sprocket wheels b at the driving end of the machine are extended to the outside of
the retort to carry worm wheels, indicated by the dot and pick circles at c, c, with
which worm wheels gear worms d³, d², upon a shaft d, which also carries a worin ³
gearing with a worm wheel (indicated by the dot and pick circle at d) upon the
shaft e, upon which is mounted the feeding wheel or roller e, which is formed with
recesses or box like receptacles e³ for receiving the wood from the hopper f and
feeding it to the retort. The shaft d is driven by a steam engine or other suitable
inotor by means of gearing connected with the said shaft. The said feeding wheel
or roller e revolves between flaps g, g, hinged at g³, g, and extending from side to
side of the hopper and over such portion of the periphery of the feeding wheel that
ench flap covers at least a portion equal to one of the recesses e³ of the said wheel.
These flaps g, g, may be kept in contact with the feeding wheel or roller by their
own weight, or by means of weighted levers h, k, mounted upon the fulcrums or
hinges of the said flaps, pressing the said flaps against either side of the said feeding
wheel or roller, or by other equivalent means. Thus these flaps prevent the escape
of gas, or tend greatly to prevent such escape, and at the same time are capable of
yielding to allow any obstructive matter to pass clear. The chains have affixed to
them, and extending from side to side of the shelves and the bottom of the retort,
and in contact with the upper surfaces or floors thereof, scrapers i, some of which
are shewn in Figure 1. These scrapers may be rigid scrapers fixed between horns
cast at suitable intervals upon some of the links of the chain, as shewn in Figures
1 and 2; or they may consist of chains or a series of plates connected by links,
as shewn with regard to a portion of such a scraper in Figure 4, this latter
arrangement allowing of the yielding of the scrapers on encountering any obstacle.
Or other equivalent arrangement of scrapers or propellers may be adopted.
The hopper by which the wood is fed to the retort is or may be provided with
a sliding valve k for charging wood into the retort in such a manner as to prevent the
escape of gas from the retort, the wood being placed in the upper part of the hopper
above the valve k, an upper cover is placed thereupon, the said cover ³ fitting
closely into the said hopper. On the valve being withdrawn the wood falls upon the
feeding wheel or roller, the cover descending with the wood till the said cover
arrives just above the valve k, which may now be closed, and the cover ³ removed
to leave the upper part of the hopper clear for a fresh charge of wood. For actuating
the shaft & for driving the chains c and feeding wheel e I prefer to use steam of
low pressure, so that no injurious effect is caused in the event of pieces of wood
obstructing the scrapers; and an ordinary reduction valve may be employed to
keep the steam at the requisite pressure; or a weighted lever may be employed
to press up each of the worms into position on the worin shaft, as shown with
regard to one worm in Figure 3, so that in the event of any worm wheel coming
to a standstill by the clogging of the scrapers, the worm will run down upon the
worm shaft, and a connection with the steam inlet will shut off steam and stop
the engine.
In order to prevent the clogging of the feeding wheel or roller by the entry of
wood between its end and the sides of the retort at the lower part of the hopper,
the ends of the said wheel may be housed in the sides of the retort, as shewn in
Figure 2, or there may be a saddle piece m on either side projecting a slight extent
over the ends of the feeding wheel, as shewn in the diagrams, Figures 5 and 6,
where the wheel e is shewn as having its recess of a different form from that
Figure 1, it being understood that such recesses may be of any suitable shape, for
example, they may be bucket shaped, as shown in dotted lines with regard to two

page_text: recesses in Figure 1, to prevent the discharge of the wood therefrom until the
recesses are clear of the flaps g.
When in operation the machine is fed at the hopper with the small wood to
be treated until the upper part of the said hopper above the valve is nearly full,
when the cover is placed thereupon, and the valve k being withdrawn the
contents fall into the receptacles e of the feeding wheel e, which as it slowly rotates
discharges the wood onto the top shelf a, along which it is caused to travel by the
slow forward movement of the scrapers until it arrives at the end of the said shelf,
from which it falls onto the second shelf a, along which it is caused to travel in
like manner in the reverse direction, and from which it falls upon the third shelf a,
and is by the second scries of scrapers urged along this and falls therefrom onto the
bottom of the retort, along which it is traversed until it eventually falls in a
charred condition by the outlet n, which may be provided with a wheel or roller
similar to the feeding wheel or roller above. The gases evolved during the process
are carried off at gas outlets, as at p and q, and conducted by tho condenser
pipes to be dealt with in the ordinary manner.
The retort is set in brick, or other setting, provided with furnaces and flues for
effecting the heating of the retort in a manner essentially similar to that ordinarily
adopted for heating retorts.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically carried into effect, I would observe in conclusion that I do
not limit nyself to the precise details herein described and illustrated in the
accompanying Drawings, as the same may be varied without departing from the
nature of my Invention; for example, the retort, as beforementioned, may be
furnished with but one or with two shelves, or with more than three shelves, and
the hopper fmay be a simple hopper, that is to say, the valve k and cover k³ may
be dispensed with. What I consider to be novel and original, and therefore claim
as the Invention secured to me by the hereinbefore in part recited Letters
Patent is,-
First. The employment in retorts for obtaining products from the distillation of
sawdust, shavings, and other small wood, of a shelf or shelves upon which the small
wood under treatment is traversed twico, or a greater number of times through
the length of the retort, essentially as and for the purpose hereinbefore set forth.
Second. The combination with and use in the said retorts of a feeding wheel or
roller with recesses, flutings, boxes, buckets, or equivalent receptacles in its
periphery for the reception from the hopper and delivery into the retort of the
sawdust, shavings, or other small wood to be treated, and having hinged flaps kept
in contact with the sides of the said wheel or ruller to prevent the escape of gas
from the retort and capable of yielding to any obstruction, essentially as herein-
before described and illustrated in the accompanying Drawings.
Third. The general arrangement and combination of parts constituting the
improved retort, essentially as and for the purpose hereinbefore described and
illustrated in the accompanying Drawings.
In witness whereof, I, tho said Robert Haldane, huve hereunto set my hand
and seal, this Seventh day of October, in the year of our Lord Ono
thousand eight hundred and eighty.
ROBERT HALDANE. (L.S.)