IMPROVEMENTS IN EVAPORATING AND DRYING APPARATUS, ESPECIALLY APPLICABLE TO THE TREATMENT OF LIQUID SEWAGE
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Gerard Wenzeslaus von Nawrocki
at the Office of the Commissioners of Patents on the 25th May 1882 (a
Communication from Stanislaus Adamczewski of Warschau Poland in the
Empire of Russia)
GERARD WENZESLAUS VON NAWROCKI, Proprietor of the firm of J Brandt & G.
W v Nawrocki, Patent Solicitor and Civil Engineer of 124 Leipzigerstrasse Berlin
Germany "IMPROVEMENTS IN EVAPORATING AND DRYING APPARATUS, ESPECIALLY
APPLICABLE TO THE TREATMENT OF LIQUID SEWAGE." (a Communication from
Stanislaus Adamczewski of Warschau Poland in the Empire of Russia)
In the Specification of the patent No 2790 of 1881 are described apparatus for
dessicating substances saturated with water or dissolved in water. In these the
water is removed in two operations, the material under treatment, being first boiled
down and then dried. The drying is performed in stair like drying rooms while
applying heated air and gases the latter being led into the fire place or into the
chimney.
In many cases however the escaping gases contain valuable constituent parts
which cannot in this way be reclaimed; on the other hand it cannot be avoided
that in consequence of the great extent of the drying rooms a great loss of heat
takes place.
The object of this present invention is to avoid these defects. The drying room
is placed directly over the boiling room and is closed like the boiling room. It is
heated in two ways, partly by heated air and partly by a flue under the vessels
containing the substances to be dried, the said flue conveying away the products of
evaporation or the gases and vapours coming from the boiling pans. There is also
a contrivance for leading the said products through a washing apparatus for:
absorbing the gases of same.
When carrying out the principle on a large scale, a number of pans with their
fireplaces and drying rooms are arranged side by side connected in a manner
analogous to and suitable for the continuous mode of working described in the
aforesaid Patent Specification
The present improvements will however be sufficiently understood by reference
to a single apparatus.
The evaporating pan made of sheet iron or other suitable material, is arranged
in the lower part of the furnace in a completely closed chamber and provided with
revolving stirring appliances which are worked by power or by hand. The pan
receives its supply of liquid from a pipe, and there is a sliding door at one side or

page_text: end for discharging the contents. The pan is not exposed directly to the fire or
products of combustion but these pass from the fireplace through a covered flue
situated below the pan in a direction there and back and then by a flue which is
provided in the brickwork around the pan and then to the chimney.
When several pans are arranged side by side, or in a circle, the flue is done away
with and the gases then pass off in the direction shown in the aforesaid Patent
Specification. The evaporation is also as described in the said Specification
furthered by heated air which is led into the evaporating space. This heating is
done by means of a pipe system arranged immediately above the top of the flue
coming from the fireplace
The air enters, first in one of the aforesaid pipe systems, then returns by the
other pipe system and then through a vertical flue into the evaporating space
There is another pipe system which serves for the heating of the air required for
the drying space; There is a horizontal flue which by means of a horizontal
partition and vertical parts inserted, is so arranged that it can serve to convey the
two currents of air separately.
The air for the drying space thus passes through one set of the last-named pipes,
the lower part of the divided flue, the other set of pipes and to a vertical flue and
thence to the drying space. The heated air that has come into the evaporating
space mixes with the gases produced by the evaporation and passes through a flue
under the drying pan. The gases pass thence either into the chimney when a
damper is opened, or into the fireplace or into the washing or absorbing vessel which
will be described further on
The substances left in the evaporating pan are removed therefrom when the
sliding door has been opened and drop into a trough or receptacle whence they are
raised by an elevator. and by a shoot fed into the drying pan
The latter is arranged in the closed upper part of the brickwork and is heated
as described by hot air and by the vapours coming from the evaporating pan
The material to be dried is stirred up by means of a raking tool and when dried
as desired it is removed by an opening fitted with a sliding door.
· The vapours formed in the drying space are either led into the chimney or pass
away at the top by a ventilator
The flues leading to the space under the drying pan are fitted with dampers.
I will now describe the washing or absorbing appliance. As already stated the
gases from the flue below the drying pan pass by the open damper into the chimney.
But if this damper is set so as to shut off communication with the chimney, the
gases will according to the position of a damper either pass into the flue leading
to the fireplace or to a pump.
This latter forces the gases into the washer or absorbing vessel and through the
liquid contained therein.
"The gases after thus having been washed may either pass to the fireplace or
into the chimney all according to whether they still contain combustible parts
or not.
The contents of the washer will be according to the nature of the substances to
be treated therein. If for instance foecal matters are boiled down and dried diluted
sulphuric acid is used for absorbing the ammoniac.
The substances and materials which are to be dried may also be dried in a drying
apparatus provided with a slowly revolving screw. The drying apparatus may be
at the side instead of above the evaporating pan. The special arrangement of the
washer may be as found most suitable but forms no part of this invention.
The firing may be by usual fuel or by means of gas.