AN IMPROVED MEANS AND APPARATUS FOR DRYING MOIST SUBSTANCES, OR DRYING AND BURNING GRANULAR SUBSTANCES OR EVAPORATING LIQUID SUBSTANCES AND ECONOMIZING THE WASTE HEAT PRODUCED IN THE PROCESSES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by George Gordon at the Office of
the Commissioners of Patents, with his Petition, on the 25th April 1867.
I, GEORGE GORDON, of San Francisco, California, at present residing at
Morley's Hotel, Charing Cross, in the County of Middlesex, do hereby
declare the nature of the said Invention for "AN IMPROVED MEANS AND
APPARATUS FOR DRYING MOIST SUBSTANCES, OR DRYING AND BURNING GRANULAR
SUBSTANCES OR EVAPORATING LIQUID SUBSTANCES AND ECONOMIZING THE WASTE
HEAT PRODUCED IN THE PROCESSES," to be as follows:-
Part of this Invention has for its object to economize heat employed in.
drying any moist substances or evaporating liquids, and is advantageously
applicable in all manufactures in which quantities of moist substances are dried
or liquids evaporated in vessels or chambers by means of. heated air or by
means of directly applied furnace heat. Hitherto when heated air has been.
used in, or direct furnace heat has been applied to vessels containing such
substances, the steam thereby produced has been allowed to escape wastefully
into the atmosphere; by the present Invention the steam or air mixed
with steam so produced is by any convenient appliance made to heat liquid,
solid, or riform matters of lower temperature than itself, or is additionally
heated in order to make it more suitable for the uses herein-before indicated
or for use in obtaining motive power..
In carrying out the Invention the moist substances to be dried are placed
so as to present a large amount of surface in a chamber or vessel which
is closed excepting at the inlet and outlet for the heated air; these

page_text: chambers may or may not have a rotary, oscillating, or other motion to
agitate their contents, or they may have internal agitators for that purpose,
and may have direct external heat applied to them. The air previously
heated (or admitted cold and heated in the chamber itself) is passed
through the substances to be operated upon by any convenient means, and
in its passage in contact with the said substances converts their water
into steam or vapor. When direct heat alone is employed, the chamber
or vessel containing the said substances is closed, (except the outlet for the
steam formed) which communicates with an external pipe conducting the
steam to the apparatus, in which it is to be utilized. When these drying
chambers are arranged to work continuously they are fitted with introducing
hoppers and discharging hoods, in order that the introduction and discharge
of the substances operated upon may be effected with the least possible
escape of the steam. When it is required to secure the removal of the steam
from every part of the mass being operated upon, as fast as possible, per-
forated pipes or chambers are introduced into the mass of the material, which
pipes or chambers communicate with the external conducting pipes named
above. These steam produced in the drying chambers (either by the exterior
heat applied, or by the hot air admitted, or by both) is then conducted by
suitable external pipes or passages into water or other liquid, or amongst
solids of lower temperature than itself and requiring to be heated, or into
enclosed spaces or passages surrounded by or surrounding other spaces or
passages containing liquid or æeriform matters, also of lower temperature and
requiring to be heated, or it is conducted through some heating apparatus of
any convenient kind to enable it to obtain increased heat and pressure so as
to be used in any convenient form as motive power. The steam or steam
and heated air may be caused to pass through the substances or apparatus
by which its heat is extracted by means of a draught, an injection, fan, or
air pump or by any convenient forcing or exhausting contrivance; or its
withdrawal from the chambers where it is formed may be caused by the
condensation effected during its passage in contact with the colder substances
or surfaces to which it imparts its heat as above described.
In the case of liquid substances requiring to be evaporated I employ the
same means for evaporating and saving the waste heat as described above in
the case of moist substances, except that the chambers are placed horizontally,
or nearly so, and made to revolve, are divided into compartments of suitable
length by internal annular flanges, and are provided with internal longitudinal
ribs or projections in such compartments attached to their exterior sides;
which ribs are set at an angle to any line drawn to the said exterior through

page_text: the axis of the vessel in or order that as the vessel revolves portions of the liquid
may be lifted up and showered down through the currents of heated air
introduced; these revolving chambers are provided with inlets for heated air,
and outlets for steam and heated air, and for the material to be evaporated
(as described above) in the drying chambers, and with an internal stationary
apparatus for feeding the material backwards or forwards, and also with
similar means for utilizing the waste beat evolved, as described in connection
with the drying chambers.
In treating solid substances where it is desirable to produce exhaustion of
air, so as more thoroughly to open and desiccate their pores, I employ
chambers with direct heat, and attached to the apparatus (employed for
utilizing the waste heat by passing it through pipes surrounding, or sur-
rounded by the colder material which receives the heat) an air pump or other
exhausting mechanism.
In cases where it is desirable to dry solid substances in open chambers,
either by heated air or external heat, or both, I insert into the mass of the
substances in such chambers perforated pipes or chambers, which communi-
cate with external pipes leading to the apparatus above described in which
the steam given off from the drying mass is utilized as in the case of the
closed drying chambers. When granular substances in addition to being
dried require to be burned, calcined, or carbonized, I either conduct the
material to be operated upon from the drying chambers direct without
contact with the atmosphere into upright pipes or chambers, which I call
retorts, and which are set in a kiln or furnace, where their exterior surfaces
are brought to a red heat; at the bottom of these retorts, and below or
outside of the kiln or furnace, are continuations of such retorts, which are
either brought down through a vessel containing water, or have internal
chambers in which water circulates; or I construct an apparatus which
forms at once drying, calcining, and cooling chambers. Into the upper part
(which I term the drying portion) the material to be treated is received
through hoppers, which admit it while the external air is excluded and the
internal steam kept in. The drying portion of the apparatus is traversed
with passages which permit the currents of a furnace to pass through them, so
as to beat the internal mass of the material to be dried without admitting air.
The calcining portions of this apparatus consist of narrow continuations of the
drying chambers, and the cooling portions consist of still narrower con-
tinuations of the calcining portions. The whole is placed in a furnace in such
a way that the cooling portions shall be below the furnace and descend into
or contain water chambers, the calcining portions are within the hottest

page_text: chamber of the furnace, and the drying portions in the upper chambers sur-
rounded by secondary heat. Within the apparatus, and descending through
the mass of the material in the drying portion (and if necessary into the
calcining portion) are perforated pipes or chambers, communicating with
external pipes which lead to the heat utilizing apparatus herein-before
described, and if need be to an exhausting apparatus also.
The objects to be attained by either of these methods, namely, by connecting
the drying chambers herein-before described with retorts in a kiln, or by
constructing an apparatus which shall be at once dryer, burner, and cooler,
are,-
Firstly, the immediate carrying off of the steam as soon as formed in the
drying chambers, without permitting contact with drier or wetter strata
of the material being dried.
Secondly, the relieving of the calcining or burning chambers of all internal
pressure from steam or gases.
And, thirdly, the production of more or less vacuum in either chamber, if
desired.
And, lastly, the utilization of the heat from the drying and burning, and
also the heat given off in cooling.
I do not restrict myself to make the apparatus of any particular form or
material, nor to place it in any particular position.