IMPROVEMENTS IN THE MEANS OF SUBJECTING SUBSTANCES TO HEAT FOR EFFECTING CONTINUOUSLY DRYING, ROASTING, CALCINING, EVAPORATING, DIS- TILLING, GAS PRODUCING, AND OTHER LIKE OPERATIONS, AND APPARATUS THEREFOR
Year: 1873

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE MEANS OF SUBJECTING SUBSTANCES TO HEAT FOR
EFFECTING CONTINUOUSLY DRYING, ROASTING, CALCINING, EVAPORATING, DIS-
TILLING, GAS PRODUCING, AND OTHER LIKE OPERATIONS, AND APPARATUS
THEREFOR."
Sealed the 1st April 1873, and dated the 28th January 1873.
PROVISIONAL SPECIFICATION left by the said John Imray at the
Office of the Commissioners of Patents, with his Petition, on the
28th January 1873.
I, JOHN IMRAY, of No. 20, Southampton Buildings, Chancery Lane,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MEANS OF SUBJECTING SUBSTANCES TO
HEAT FOR EFFECTING CONTINUOUSLY DRYING, ROASTING, CALCINING, EVAPORATING,
DISTILLING, GAS PRODUCING, AND OTHER LIKE OPERATIONS, AND APPARATUS
THEREFOR," to be as follows :—
In the various processes of drying, roasting, calcining, evaporating,
distilling, gas producing, and the like, it is usual to charge a pan, boiler,

page_text: Where higher temperatures are required, as for roasting, calcining,
and the like, a metal fusible at a higher temperature can be employed.
A similar method may be adopted for evaporating or concentrating
solutions such as syrup or saccharine or saline liquor. Such liquor being
allowed to flow on to the circulating fluid will be carried along by it,
becoming more and more concentrated until it reaches the discharging
point, where it can be scraped off in a crystalline condition or allowed to
flow off if it retains a liquid form.
For distillation, when the vapours or gases evolved are to be collected,
as for instance for distilling oily, fatty, resinous, or bituminous matter,
the canal is closed over like a pipe or is covered by a hood, within the
cavity of which the gas or vapour is collected, and whence it flows by
an outlet pipe. Sometimes in distilling such substances it is desirable
to perform successive parts of the distillation at different temperatures
so as to obtain various products at different stages of the operation. In
such cases the canal may consist of several portions, cach heated by its
own flue to the required temperature, and the liquid may circulate from
the first to the next, and so on, finally returning to the first, the matter
floating on it being thus in its progress subjected to the different degrees
of heat required. Also the cavity above the circulating liquid may be
divided by diaphragms into compartments or zones, from cach of which
the gaseous or vaporous products can be separately withdrawn.
In the production of inflammable gas by distillation of coal or other
hydrocarbons the circulating liquid may be molten lead or an alloy of
lead with other metal. Coal dust or other solid hydrocarbons in small
pieces or liquid hydrocarbons being dropped on this liquid metal will
give off their gases as they float onwards, becoming reduced to coke,
cinder, or ash, which will be scraped off at the discharging point into
an air-tight receptacle which can be emptied from time to time.
In order that the interior of the apparatus may be easily accessible
for cleansing I prefer to make it in two parts, the lower part being a flat
trough constituting the canal for the circulating liquid, and the upper
part being a hood shaped like an inverted U, the two limbs of which
dip into the liquid, whereby the interior is sealed from the outer air.
The circulation of the liquid may be maintained by a pump or by a
rotating paddle or other propeller, and the residuary matter may be

page_text: scraped off by a revolving or reciprocating scraper, or both the propulsion
and scraping off may be effected by one rotatory or reciprocating
instrument.
The liquid instead of being caused to move with constant velocity
may be made to flow intermittently in pulses so as to break up and more i
effectually carry onward crust formed on its surface or matter tending to
adhere to the sides of the canal.
The canal may be made in various forms so as to produce a closed
circuit; for example, it may be circular or of a curvature returning into
itself, or it may consist of several straight or curved channels, each of
which communicates with the next, the last communicating again with
the first, such communications being made either on or under the general
level of the canal.
The canal can be heated along its whole length by a furnace and fluc
carried under it, and in cases where different temperatures are required
at different parts furnaces and flues can be arranged so as to provide for
such variations of temperature between the fusing and boiling points of
the metal or other substance constituting the circulating liquid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Imray in the Great Seal Patent Office on 2
the 3rd July 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Jonn
IMRAY, of No. 20, Southampton Buildings, Chancery Lauc, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters ?
Patent, bearing date the Twenty-eighth day of January, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Imray, Her special license
that I, the said John Imray, my executors, administrators, and
assigns, or such others as I, the said John Imray, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter, during the term

page_text: therein expressed, should and lawfully might make, usc, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MEANS OF SUBJECTING SUBSTANCES TO HEAT FOR EFFECTING CONTINUOUSLY
5 DRYING, ROASTING, CALCINING, EVAPORATING, DISTILLING, GAS PRODUCING, AND OTHER
LIKE OPERATIONS, AND APPARATUS THEREFOR," upon the condition (amongst
others) that I, the said John Imray, my exccutors or administrators,
by an instrument in writing under my, or their, or one of their hands
and scals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patcut.
NOW KNOW YE, that I, the said John Imray, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Sheet of Drawings and to the figures and letters marked thereon, that
is to say :-
In the various processes of drying, roasting, calcining, evaporating,
distilling, gas producing, and the like it is usual to charge a pan, boiler,
retort, or other vessel with the material to be operated on, and to subject
it to the action of heat until the process is completed, when the
residuary contents are discharged, and the vessel is charged again with
fresh material.
In some cases the operation is rendered continuous by the use of
mechanical contrivances to move onwards the matter operated on.
According to my present Invention I effect such processes in a con-
tinuous manner, and expose the substance to be acted on over an
extended heating surface by causing a current of licated liquid to flow
along a canal returning into itself, so that the liquid makes a complete
circuit therein, and flows continuously round. On to this circulating
liquid at one part of its circuit I drop or otherwise supply the matter to
be operated on, which will float on its surface, and be carried along with
it, subjected during its passage to the action of heat imparted to it by
the circulating liquid. At another part of the circuit, by prefercuce
near the point where the matter is fed, I remove the residuary matter

page_text: from the surface of the liquid, which flows onward to receive a fresh
supply of matter to be acted on.
The liquid employed depends upon the nature of the substance to be
operated on, and the temperature under which the operation has to bo
effected. It must be of greater specific gravity than the matter operated
on, and it must be capable of sustaining a higher temperature than is
required in the process without being evaporated or materially changed
in its condition by such temperature.
The construction and arrangement of such apparatus for working
according to this method will depend much on the nature of the opera-
tion, and of the substances operated on.
For simply drying solid matter, such as grain, when the vapour
evolved has not to be collected, the canal may be open, the grain or
other matter may be dropped continuously on the flowing liquid carried
round by it, and dried in its circuit; and finally lodged on a sloping
bank, whence it can be continuously removed by a revolving or other
scraper, the liquid flowing under the bank to receive a fresh supply.
The liquid used for such purposes may be a molten metal fusible at such
a moderate temperature as is required for drying the matter without
effecting chemical changes.
When higher temperatures are required, as for roasting, calcining,
and the like, a meial fusible at a higher temperture can be employed.
A similar method may be adopted for separating or concentrating
solutions, such as syrup or saccharine or saline liquor. Such liquor
being allowed to flow on to the circulating fluid will be carried along by
it, becoming more and more concentrated until it reaches the discharging
point, where it can be scraped off in a crystalline condition, or allowed
to flow off if it retains a liquid form.
For distillation, when the vapours or gases evolved are to be collected,
as, for instance, for distilling oily, fatty, resinous, or bituminous matter,
the canal is closed over like a pipe, or is covered by a hood, within the
cavity of which the gas or vapour is collected, and whence it flows by
an outlet pipe. Sometimes in distilling such substance it is desirable to
perform successive parts of the distillation at different temperatures, so
as to obtain various products at different stages of the operation. In
such cases the canal may consist of several portions, cach heated by its

page_text: own fluc to the required temperature, and the liquid may circulate from
the first to the next, and so on, finally returning to the first, the matter
floating on it being thus in its progress subjected to the different degrees
of heat required. Also the cavity above the circulating liquid may
be divided by diaphragms into compartments or zones, from cach
of which the gascous or vaporous products can be separately with-
drawn.
In the production of inflammable gas by distillation of coal or other
hydrocarbons the circulating liquid may be molten lead, or an alloy of
lead with other metal. Coal dust or other solid hydrocarbons in small
picces or liquid hydrocarbons being dropped on this liquid metal will
give off their gases as they float onwards, becoming reduced to coko,
cinder, or ash, which will be scraped off at the discharging poiut
into an air-tight receptacle, which can be emptied from time to
timc.
In order that the interior of the apparatus may be casily accessible for
cleansing I prefer to make it in two parts, the lower part being a flat
trough constituting the caual for the circulating liquid, and the upper
part being a hood shaped like an inverted U, the two limbs of which dip
into the liquid, whereby the interior is scaled from the outer air.
The circulation of the liquid may be maintained by a pump or by a
rotating paddle or other propeller, and the residuary matter may be
scraped off by a revolving or reciprocating scraper, or both the pro-
pulsion and scraping off may be effected by one rotating or reciprocating
instrument.
The liquid, instead of being caused to move with constant velocity
may be made to flow intermittently in pulses, so as to break up and
more effectually carry onward crust formed on its surface, or matter
tending to adhere to the sides of the canal.
The canal may be made in various forms so as to produce a closed
circuit; for example, it may be circular or of a curvature returning into
itself, or it may consist of several straight or curved channels, cach of
which communicates with the next, the last communicating again with
the first, such communications being made cither on or under the general
lovel of the canal

page_text: Ine canal can be heated along its whole length ny a furnace and mo
carried under it; and, in cases where different temperatures are required
at different parts, furnaces and flues can be arranged so as to provide
for such variations of temperatures between the fusing and boiling
points of the metal or other substance constituting the circulating
liquid.
DESCRIPTION OF THE DRAWINGS.
1
Fig. 1 represents a section; and Fig. 2, a plan of one form of
apparatus constructed according to my Invention for continuously
drying, heating, or roasting substances in the open in cases where it is
not necessary to collect the gases or vapours evolved from them. A is
a flat trough of circular, elliptic, or other curvature returning into itself,
and containing liquid, which may be fused metal heated by a fire and
flue B, B, arranged under the trough. The trough A at one part of its
circuit is made with a shelving side or bank C, on which is mounted a
wheel D on an inclined axis, having paddles or floats & projecting down
from it, and dipping into the liquid in the trough A. This wheel D is
made to revolve continuously in the direction of the arrow by a worm or
other suitable gearing E; or instead of being made to revolve con-
tinously it may be made to turn a intervals through part of a
revolution, as by the action of a reciprocating lever and pawl on a
ratchet wheel. A diaphragm F fixed across the trough near the peri-
phery of the wheel is made to dip a little into the liquid in the trough.
The action of this apparatus is as follows:-The heated liquid in tho
trough A being made to circulate in the direction of the arrow either
continuously or in pulses by the action of the wheel D matter to be
operated on of less density than the liquid is supplied at or near the
point G. This matter floating on the liquid is carried round the trough
by it being exposed during its movement to the heat of the liquid over
an extended surface. On coming within range of the wheel D the floats
thereof scrape the matter off the surface of the liquid, and discharge it
over the sloping bank C. At the same time cach of the floats & in
passing gives the liquid an impulso in tho direction of the arrow, the
diaphragm F permitting the liquid to flow under it while it arrests the
matter floating on its surface.
Fig. 3 represents diagrammatically a section of similar apparatus
arranged for treating substances in cases where the volatilized products
are to be collected. In this case the trough A containing the circu-

page_text: lating liquid heated by the flue B is covered by a hood H, the lower
edge of which is made to dip into the liquid in the trough, so that tho
interior is scaled from the outer air. A pipe I carries off the vapours or
gases evolved from the matter floating on the surface of the liquid
in A.
In some cases there are certain vapours or gases produced of a light
character, and others of a heavier character. The lighter of these would
flow off by the pipe I, and the heavier might be removed by another
pipe J at a lower level.
The hood instead of being made to cover the whole width of the
apparatus may be made of annular form covering the liquid only as
shown in Figs. 4, 5, 6, 7, 8, 9, 10, 11, 12, which are partial sections
representing various modes of feeding matter to be operated on by the
hot circulating liquid, and of removing residuary matter when the
products are scaled from the outer air. Fig. 4 represents a transverse
section through the trough A containing the hot liquid, the flue Band
hood H, and a reciprocating feeding apparatus for supplying solid matter
in small picces to be acted on by the heated liquid, such as small coal or
other carbonaceous matter for the production of inflammable gas, in
which case the liquid circulating in the trough A might be melted lead
or other metal fusible but not volatilizable at the temperature required.
This feeding apparatus consists of a hopper K supplied with the
substance to be acted on, which opens at bottom into an inclined tube
or cylinder L fitted with a piston M. When this piston is withdrawn
to the position shown in the Figure, a charge of matter falls from the
hopper into the inclined tube in front of the piston. On the piston
being pushed forward this charge is forced along with the liquid in the
inclined tube towards the bend below the trough A, being of less specific
gravity than the liquid; the matter floats upwards from the bend to the
surface of the liquid in the trough within the hood H which is scaled
from the outer air by having its lips dipping into the liquid. The gas or
vapour collected in the hood issues by a pipe I as indicated by the
arrows.
Fig. 5 represents a transverse section of a rotary feeding apparatus
applied to a hooded trough. In this case there is mounted under the
hopper K an inclined wheel N within a casing which forms part of the
trough A. This wheel may be caused to revolve continuously by worm or

page_text: other gearing, or may be made to move by fits by a ratchet and pawl or
other suitable means. In the wheel are formed at intervals round it
hollows or pockets O open at top, when one of these is presented under
the hopper K it receives a charge of the matter to be operated on. By
the rotation of the wheel N this pocket is brought round to the bottom t
of the trough, and its contents float upwards through the liquid. The
bottoms of the pocket may be grated or have perforations through them
so that the dense liquid when they are immersed in it may more casily
enter them and extrude their contents.
When liquids have to be operated on they may be fed by an arrange- 1
ment shewn in Fig. 6, where K is a funnel supplied with the liquid
from which a bent pipe P is led through the bottom of the trough A,
and up through the liquid therein. The pipe P may terminate in a
horizontal branch Q, having a slit or numerous porforations for more
effectually distributing the liquid to be operated on over the surface of 1
the hot circulating liquid.
Fig. 7 represents a partial longitudinal section; and Fig. 8, a partial
transverse section shewing an apparatus for removing residuary matter
floating on the circulating liquid under the hood. In this case a
wheel D like a paddle wheel is mounted within the hood H which may 2
be hollowed upwards as at h for its reception. This wheel is turned by
fits by a reciprocating rod d, having a hooked end engaging the teeth of
a ratchet wheel e fixed on the shaft of the wheel D. The rod d is con-
nected to an arm on a rocking shaft R which lies in a cavity a formed
in the trough A. An arm r on this rocking shaft exterior to the hood H 2
may receive reciprocating movement from a crank or eccentric. Thus
it will be seen that as the shaft R and the lower end of the arm aro
immersed in the liquid in the trough A the parts communicating move-
ment to the wheel D do not interfere with the tight scaling of the
interior of the hood. In front of the wheel D is a curved grating a¹ 3
which permits liquid to pass, but arrests the solid matter floating on the
liquid. As float after float of the wheel D is brought round in the
direction of the arrow, the floating solid matter is scraped from the
surface of the liquid and thrown into an inclined trough a which leads
to an air-tight receiver outside the apparatus. By the same action the 3
liquid in the trough A is propelled in the direction of the arrows through
a passage a¹ under the trough a³. A diaphragm a³ serves to provent any

page_text: of the solid matter thrown into the trough a² from passing to the liquid
beyond.
Fig. 9 represents a partial transverse section; and Fig. 10, a partial
longitudinal section of another form of apparatus for removing floating
3 residuary matter from a hooded trough. In this case a wheel D fixed
on an inclined axis is made to revolve in a cavity in the trough A under
the hood H. This wheel has blades curved and inclined in such a
manner that each in the upper part of its revolution gathers a certain
quantity of the floating matter which it carries down under the surface
of the circulating liquid. As the blade comes under the level of the
immersed lip of the hood H, the matter held by its sloping curve floats
upwards and outwards to a widened portion of the trough outside the
hood, whence it can be removed. The rotation of the blades of the
wheel D also gives an impulse to the liquid, causing it to circulate in
the direction of the arrow. A grating a¹ in front of the wheel while it
allows the liquid to pass arrests the solid matter floating on it.
Fig. 11 represents a partial transverse section, and Fig. 12 a partial
longitudinal section of a reciprocating apparatus for removing residuary
matter from within the hood H. Outside the hood His mounted a
rocking shaft R which is caused to rock by movenient from a crank or
cccentric communicated to an arm fixed upon the shaft. On the
shaft R is fixed another arm S bent so as to work clear under the
immersed lip of the hood H. To this arm is attached a wedge shaped
paddle T open below, but having an inclined cover and a vertical face t,
the paddle T being raised to the position shewn in Fig. 11, residuary
matter floating on the circulating liquid collects under it. The paddle
being then by the action of the rocking shaft R brought down to the
position indicated by the dotted lines T', the matter scooped down by it
floats upwards into the expanded part of the trough A outside the
hood H, whence it can be removed; the paddle being again caused to
rise through the liquid the slope of its cover gives propulsion to the
liquid in the direction of the arrow. A grating a¹ serves to arrest the
passage of solid matter, while it permits the circulating liquid to flow
onward in obedience to the propulsive action of the rising paddle.
It may readily be understood as hercin-before stated that the trough A
containing the circulating liquid may be of form other than circular,
being however arranged so that the liquid can make a complete circuit
therein. It may for example consist of several straight cauals as

page_text: indicated diagrammatically in Fig. 13. The matter to be operated on
may be fed at several points, such as those marked F in Fig. 13, and
residuary matter may be discharged at points such as those marked D in
that Figure. Further, instead of one continuous hood being provided to
cover the whole canal and retain the gases or vapours evolved from the
matter treated therein, the hood may be divided by diaphragms, or
their might be several separate hoods, ouc covering cach branch or
section of the canal.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I would have it understood that I
do not limit myself to the several forms of apparatus described above
for feeding matter to be operated on, removing residuary matter, and
propelling the circulating liquid, nor do I claim such apparatus in
themselves, as many other forms of apparatus for these purposes might
be employed, and those described above are merely intended to shew
arrangements by which my Invention may be carried out in practice; I
would also have it understood that I make no claim to tho use of a
stationary bath of melted metal or other hot liquid for the purpose of
subjecting substances to heat, but I claim,-
First. The method substantially as herein described of subjecting
substances to heat for effecting continuously drying, roasting, calcining,
evaporating, distilling, gas producing, and other like operations by
floating the substances to be treated on a heated liquid, caused to
circulate in a trough or canal, or in a series of trouglis or canals wherein
the liquid can make a complete circuit; the substance treated being
fed at one or more points in the said circuit, and after being carried
onwards and heated by the circulating liquid, the residuary matter
being removed at another point or other points thereof.
Second. The use for treating substances in the manner above referred
to when the gases and vapours evolved from them are not to be collected, :
of an open trough or canal or series of troughs or canals charged with
circulating liquid and heated by the furnaces and flues, and provided with
rolary or reciprocating scrapers for removing residuary matter from
the surface of the circulating liquid, substantially as herein described.
Third. The use for treating substances in the manner above referred a
to when the gases or vapours evolved from them are to be collected, of a
trough or canal or series of troughs or canals charged with circulating

page_text: liquid, and heated by furnaces and flucs, such troughs or canals being
covered by a hood and provided with apparatus for feeding the matter to
bo treated, and for removing residuary matter, and the interior of the
hood being scaled from the outer air, substantially as hercin described.
In witness whereof, I, the said John Imray, havo hereunto set
my hand and scal, this First day of July, in the year of our Lord
One thousand eight hundred and seventy-three.