IMPROVE⭑ MENTS IN THE PROCESSES OR MEANS OF EVAPORATION, CONCENTRATION, AND PRESERVATION OF LIQUIDS AND OTHER SUBSTANCES, BY DESICCATED WARM AIR
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Gostwyck Gard at the Office
of the Commissioners of Patents on the 19th August 1879.
WILLIAM GOSTWYCK GARD, of Dunstable, in the County of Bedford. " IMPROVE⭑
MENTS IN THE PROCESSES OR MEANS OF EVAPORATION, CONCENTRATION, AND
PRESERVATION OF LIQUIDS AND OTHER SUBSTANCES, BY DESICCATED WARM AIR."
My Invention consists in evaporating down or concentrating all kinds of liquids
and solutions, extracts, natural, or artificial products in a fluid form, as require a
comparatively low temperature to prevent their alteration or decomposition during
such process of evaporation or condensation, and the same applies to the preservation
of solid substances requiring the moisture to be withdrawn at a temperature below
that at which their constituents are altered or deteriorated. It bieng particularly
adapted and applicable to the manufacture of sugar from the original juice, the
concentration of lemon juice, vegetable acids and extracts, the condensation of milk,
preparation and preservation of albumen, preservation of meat and vegetables,
drying of colours, etc.
The air, desiccated and heated, is brought in contact with the fluid or solid
substances under treatment, by means of pipes, tubes, or other similar means, and
passed over or round about them placed in pane or trays, said pans or trays being
heated from without by steam, hot water, or other suitable means, provision being
made for the escape of waste steam, condensed water, etc., when required.
The action is as follows:-A fan or blower is set in motion by steam or other
power, and forces the air through sulphuric acid; from thence it passes into the
heating chamber, and from thence over the substance being acted on, and from the
new condition imparted to it by the chemical treatment and after heating, combined
with the velocity with which it traverses the surface or surfaces it is brought into
contact with, it produces most remarkable results, both as regards rapidity, cleanliness,
purity, and economy of evaporation.
In carrying out my Invention, I adopt mainly the following arrangement of
means, viz-A suitable receptacle containing an absorbent such as pumice stone,
coke, or asbestos, kept saturated with sulphuric acid, is placed at one end in commu-
nication with a fan or blower, and the other end in communication with a heating
chamber by means of a pipe or tube. The air is forced through (or it may be drawn
through, but I prefer the former) the sulphuric acid for the purpose of desiccating
it, and at the same time removing all germs and impurities into the heating

page_text: chamber, which is provided with a suitable furnace; or advantage may be taken of
the waste heat from the steam boiler, and the air thus desiccated and heated is
carried by suitable pipes and tubes on to and over the substance or substances to be
evaporated or dried, and contained in the pans or trays as before described, such
pans or trays having covers placed at a convenient height above the surface, but
open at the ends for the proper ingress of the desiccated hot air, and egress of the
products of evaporation. I may here remark that although I have described the
form of apparatus which I prefer to adopt, yet as I intend to lay no claim to the
use of such apparatus, per se, but only as and for the purposes of my said Invention,
so also, I do not purpose, to limit myself to such form of apparatus; and further,
although the nature of my said Invention is mainly for the evaporation or
desiccation of fluids and substances, at comparatively low temperatures, still I do
not confine myself to any temperature, but it can be modified so as to suit any heat
that may be required.