An Improved Filling for Evaporating, Concentrating and Condensing Towers, and similar Apparatus.
Year: 1899

page_text: Date of Application, 20th June, 1899--Accepted, 29th July, 1899
An Improved Filling for Evaporating, Concentrating and Condensing
Towers, and similar Apparatus.
I, LEO OTTO BOEING, of Vallendar on the Rhine, Germany, Managing Director,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to a filling for evaporating, concentrating and condensing
towers and similar apparatus such as acid condensing and absorbing apparatus,
denitrificating towers, drying apparatus for gases &c. The improved filling
differs from the fillings heretofore employed in that downwardly trickling liquid
is caused by the improved filling to present a large surface to ascending gases,
and that the concentrated portion of the liquid is continually conveyed away and
further evaporated, so that by the use of this filling a hitherto unattainable
evaporative effect can be obtained.
The improved filling is composed of a number of shallow dishes arranged in
rows in staggered order upon one another, each dish having inclined channels
which are formed in the underside of the bottom of the dish and preferably become
shallower towards the centre of the dish. These channels communicate with
the upper side of the dish by means of notches formed in the sides of the dish and
in the upper part of the border. The construction is such as to allow of the
formation of a constantly renewed thin sheet or layer of liquid flowing over the
upper and lower surfaces of the dish. The liquid is thus caused to mix without
the formation of mist, with the upwardly travelling finely divided heating gases
or furnace gases, whilst at the same time it cools said gases and becomes itself
concentrated by the expulsion of its volatile constituents, such as nitrous acid,
&c. The concentrated liquid runs off automatically from each dish.
In the accompanying illustrative drawings,-
Figure 1 is a plan of a dish constructed in accordance with this invention.
Figure 2 is an underside view, and
Figure 3 is a section of the same on the line - of Figure 1.
Figures 4 and 5 illustrate in plan and in side elevation respectively the arrange-
ment of the dishes upon one another to constitute a filling..
Figure 6 is a longitudinal section through part of a condensing tower or similar
evaporating apparatus provided with the improved filling.
'
As shown in Figure 6 the filling in the tower &c. is composed of a series of
shallow dishes Carranged upon one another in staggered order as shown on a
larger scale in Figures 4 and 5, so that the liquid which runs off from the upper
rows of dishes will flow into the lower rows where it is further evaporated and
concentrated.
The improved filling forms a complete substitute for the ordinary filling usually
employed in Gay-Lussac and Glover towers, and in "plate-towers" and absorbing
towers and which consists of layers of lumps of coke, or of rows or lead or
earthenware plates, For many purposes, as for instance in sulphite-cellulose

page_text: works, the improved filling may be employed in combination with lime or
magnesite lumps.
The dishes may be made of any suitable acid-proof or fire-proof material, such
as clay or earthenware, ganister, cement, iron, silver, platinum &c. according to
the purpose in view, such as for instance, for concentrating lyes, acids of various
kinds, for sulphite-lyes, and other purposes of commercial chemical manufacture.
They may be glazed or they may be porous.
The dishes are preferably made of circular form and as shallow as possible, and
with raised borders which are formed with three or more semi-circular oppositely
situated notches D which communicate-with channels F situated on the outside
and on the base of the dishes, as shown more clearly in Figures 1, 2 and 3. The
lower discharge channels are preferably made shallower towards the centre of
the dish in order to allow the overflowing liquid to flow off readily.
When the improved filling is employed in Glover towers, it enables the ordinary
filling of fire-clay bricks to be dispensed with, in part, and it effects, a much more
active evaporation and denitrification. If desired the Glover, tower may be filled
up wholly with the dishes, but this is not to be recommended because the draught
in the tower might be reduced too much thereby. It is recommended to con-
struct the lower portion of the filling of bricks and the central portion of cylinders
in the usual way, and to make only the upper portion of the filling of dishes,
instead of the coke lumps that are still frequently employed.
In "plate-towers" these dishes may be employed to great advantage as a
complete substitute for the plates; because the perforated plates have considerable
drawbacks, as the holes are easily stopped up and the heat causes the plates to warp
and crack, and the underside of the plate is not washed by the acid or lye. All
these drawbacks are obviated by the improved filling. A further important
advantage of using the improved filling consists in that a too great concentration
of the acid need not be feared as is the case when lead plates are used.
Referring to Figure 6, the acid is conveyed in the usual manner to the top of
the tower whence it trickles through the apertures A A down on to the dishes C,
and in its descent through the filling becomes freed from its nitrogen compounds
and becomes purified by the action of the gases of combustion and the sulphurous
acid gases which flow upwards from the grate B towards it.
The advantage of the new filling consists in the fact that both surfaces of the
dishes, the inside surface as well as the outside surface and the bottom are
utilized as evaporating surfaces, whereby a more intimate contact with the gases
and also a more active evaporation is effected because the liquid is presented in
thin sheets or layers to the hot gases.
It will be readily perceived that a considerable saving in time and fuel is
gained.
Also, the acid issuing from the tower is much purer and freer from nitrogen
compounds than could be the case with the methods heretofore employed. This
is of especial importance for the use of the acid in the fat and petroleum industry.
The improved filling may also be employed with advantage in apparatus for the
mere concentration of, acids and of alkaline. lyes. In this case also the liquid
enters at the top of the apparatus, and in its passage through the apparatus it
is washed by the hot gases of combustion and it reaches the bottom of the apparatus
in a concentrated condition.
:
The improved filling is also capable of further uses for various other purposes of
commercial chemical industry, thus for instance it is suitable for use in the
preparation of sulphite lye for the manufacture of cellulose and also for such
evaporating or concentrating processes which are based on the rapid evaporation
of a thin sheet of layer of liquid.
If sufficient cooling is provided for, or if the dishes are filled with a suitable
absorbent, then a tower provided with this filling may be employed for con-
densing gases, for instance for the recovery of ammonia in connection with coke
ovens.
1

page_text: The dishes are preferably made of small depth with the object of better
utilizing available space, and of effecting a more thorough denitrification; the
depth of course may vary according to the purpose of use.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a filling for evaporating, concentrating, and condensing towers and similar
apparatus, a number of dishes having inclined channels in the underside of the
bottom which communicate with the upper side of the dish by means of notches
in the sides and border of the dish, substantially as described and shown.
2. The improved filling composed of superposed rows of dishes of the kind
specified in the preceding claim, constructed arranged and operating, substan-
tially as described and shown.
Dated this 20th day of June 1899
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.