Year: 1896

page_text: Date of Application, 14th Sept., 1896-Accepted, 12th Dec., 1896
We, Dr. JOHN WALTER, Chemist and CARL LEHMANN, Manufacturer, the
former of Basel, Switzerland, and the latter of Muskan in the Kingdom of
Prussia, German Empire, do hereby declare the nature of our invention and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
In regaining nitric acid from its products of reduction, it is important, that,
apart from the necessary air and water, a large effective damp surface should be
provided. The greater the area of this surface in a given space is, the greater will
be the efficiency of the apparatus. The pumice caps or mantles hitherto employed,
either with or without a filling of potsherds or glass fragments cannot be sufficiently
evenly and slowly moistened to render the attainment of a sufficiently concentrated
acid possible. According to the present invention we regenerate or regain the
nitric acid from its products of reduction by means of an apparatus which consists
of a series of horizontal earthen plates having therein a series of depending earthen
tubes, and a series of caps of earthenware one to cover each depending tube and we
have found that an apparatus of this kind is of greater efficiency than those
hitherto employed.
And in order to render the present specification more casily intelligible, reference
is had to the accompanying drawing in which similar letters of reference denote
similar parts throughout the several views:
Fig. 1 is a vertical section through the apparatus,
Fig. 2 is a vertical section drawn to a larger scale of a portion of one of the
porous plates showing two different kinds of caps covering the depending tubes,
Fig. 3 is a similar section showing further modification of the caps or hoods,
Fig. 4 is a detail perspective elevation of one form of cap or hood,
Fig. 5 a further modification; and
Fig. 6 a still further modification of the hood.
The apparatus, as illustrated, consists of an upper cylindrical section M', and
a lower section M, the upper section being supported on a flange N, of the lower
section which is provided with the gas inlet E, whilst the upper is provided with
the gas outlet A. The cover D, of the apparatus is provided with peepholes V,
covered with glass and a spray head S' for spraying water into the apparatus.
Each section M, and M', is provided with a series of horizontally arranged plates
of porous earthenware P, P, having each a number of orifices, the orifices of each
plate being arranged advantageously vertically above those of the plate beneath it.
In these orifices are arranged a corresponding series of tubes T, loosely suspended
by means of flanges or by their conical form in said orifices, and above each tube T,
is a cap, in the form of an inverted cup K, provided with a series of notches or
recesses at the rim on which it rests, said notches allowing the passage of the
water in one direction and the gas in the opposite direction.
The form of the cups K, is indifferent, and may be plain as shown at the left
haud side of Figure 2, or provided with radially downwardly extending ribs as
shown at the right hand side of this figure, and at Figure 5, in detail, or they may
be provided with horizontal annular ribs as shown at Figure 3, and in perspective
view at Figure 6, or with projections arranged on the outer surface as shown at
Figure 4.

page_text: The lower plate of porous material of the upper section of the apparatus is
supported on an inwardly turned flange of the upper section, and the upper plate P,
of said section is supported on suitable partially circular or circular supporting
plates Z, resting on the lower plate.
The lower plate of the lower section of the apparatus is supported on the arms or
other supporting brackets B, and the upper plate on similar partially circular or
circular supporting plates Z, to those of the upper section.
The suspending tubes T, may be either cylindrical, with an upper flange to
engage over the plate as shown at Figures 1, and 3, or conical, without a supporting
flange as at the left hand side of Figure 2, or with a supporting flange as at the
right hand side of the same figure.
It is obvious that we can arrange any number of horizontal plates P, P¹, in the
apparatus according to requirements. At the bottom of the apparatus, a syphon S,
is arranged to let off the water having passed the plates. The top rim of the
cups K, may also be advantageously provided with recesses or notches as shown at
Figure 5.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An apparatus for regaining nitric acid from its products of reduction, in as
concentrated a state as possible, consisting of a casing having gas inlet and outlet
passages, and having therein a series of horizontal porous plates with a series of
depending tubes and inverted cups one over each tube, said cups and tubes of each
plate being of porous material and a spray head arranged in the cover of the
apparatus, substantially as described.
2. An apparatus consisting of a series of sections M, M¹, having arranged therein
a series of porous earthen plates P, P1, the upper section resting on suitable
flanges N, of the one beneath it, a series of orifices in each plate arranged vertically
above each other, a dependent tube in each orifice of porous earthenware, a cap or
cup of porous earthenware, having recesses in its lower rim arranged over each
depending tube, gas inlets and outlets and a spray head arranged substantially as
described.
3. In the device covered by Claims I, and 2, the arrangement of conical
depending tubes in the plate orifices, substantially as described.
4. In the apparatus covered by Claims 1, and 2, the employment of cups having
horizontal or vertical ribs arranged thereon and with or without notches or recesses
in their upper rims, substantially as described.
Dated this 14th day of Sentember 1906
DAY, DAVIES & HUNT,
Chartered Patent Agents,
321, High Holborn, London, W.C., Agents for the Applicants.