A New or Improved Process and Apparatus for Crystallizing Sodium Carbonate and other similar Salts in Small Crystals.
Year: 1898

page_text: Date of Application, 26th Nov., 1898
Complete Specification Left, 9th June, 1899-Accepted, 15th July, 1899
A New or Improved Process and Apparatus for Crystallizing Sodium
Carbonate and other similar Salts in Small Crystals.
I, JAN DEKKER, of Wormerveer, Holland, Inventor, do hereby declare the
nature of this invention to be as follows:-
By means of the process which constitutes the object of the present invention
some salts and especially sodium carbonate can be obtained in small crystals.
The process consists in maintaining the liquid to be crystallized in constant move-
ment in the pan or vessel whilst blowing air upon its surface.
The apparatus, by means of which this process is carried out, consists of a certain
number of pans or reservoirs made of cast or sheet iron and superposed the one
above the other being supported by columns arranged round their peripheries.
Passing, through tight joints, at the centre of these pans is a vertical shaft
from which project, in each pan, arms carrying paddles; this shaft is supported
by a socket arranged upon the lower prolongation of the axle of the pans and
carries, below the lowest pan, a toothed bevel wheel actuated by another toothed
wheel which latter is driven by any suitable motive force.
The solution of the salts to be crystallized is poured, at a degree of concentration
of about 35 to 38 degrees Baume, into the pans and then the vertical shaft is
rotated for the purpose of keeping the liquid in constant agitation. At the
same time cold air is blown upon the pans by means of suitable apparatuses, such
as mechanical blowers, fans, etc.
The crystallization is effected very rapidly.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.
A New or Improved Process and Apparatus for Crystallizing Sodium
Carbonate and other similar Salts in Small Crystals.
I, JAN DEKKER, of Wormerveer, Holland, Inventor, 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: —
By means of the process which constitutes the subject of the present invention
some salts and especially sodium carbonate (in the form Na2CO3 + 10 H2O)
can be obtained in small crystals.

page_text: The process consists in maintaining the liquid to be crystallized in constant
movement in pans whilst blowing air upon its surface.
In order that my invention may be the more readily understood and carried
into effect or practice reference is hereby made to the accompanying drawing
which shows in side view, partly sectioned, the apparatus for crystallizing sodium
carbonate and other similar salts.
In order to obtain a very large evaporating surface in a small space the
apparatus by means of which this process is carried out, consists of a certain
number of flat pans or reservoirs a made of cast or sheet iron and superposed the
one above the other being supported by columns b arranged round their peripheries.
Passing through tight joints at the centre of these pans is a vertical shaft
from which project, in each pan, arms d carrying paddles f.
These paddles are made strong enough to keep the solution (even when it is
converted into a consistent mass) in constant agitation.
In order to empty the pans when the crystallization is completed a slide
valves at the bottom of each pan is opened. The paddles f are constructed and
arranged in such a manner as to push the consistent mass just over the apertures
of said slide-valves.
The paddles are arranged to rotate as near as possible to the bottom and walls
of the pans without being in actual contact therewith in order to prevent large
masses of crystals being formed.
The shaft c is supported at its lower end by a socket k. Said shaft carries
below the lower pan, a toothed bevel wheel m meshing with another toothed
wheel actuated by any suitable power transmission device.
The solution of the salts to be crystallized is poured, at a degree of concentration
of about 36° to 38° Baumé into the pans and then the vertical shaft is rotated
for the purpose of keeping the liquid in constant agitation.
In order to accelerate the crystallizing operation cold air is blown upon the
pans by means of suitable devices such as mechanical blowers, fans, or equivalent
indicated by the reference letter g on the drawing.
Said blowers or fans blow the air through a pipe h and nozzles
solutions contained in the pans a.
upon the
Instead of blowing cold air upon the solutions the hot air above the latter may
be sucked away by means of any suitable devices, in which case each pan is
preferably closed at its upper part by means of a lid or cover provided with
two perforations one of which is connected to the suction-pipe and the other
admits fresh air to the pan.
Tnder this invention the crystallization is effected very rapidly the whole
quantity of solution being converted within half an hour into a consistent masa
of small crystals containing only a very small percentage of mother lye.
The product is ready at once for transportation after drying it in any suitable
manner.
The new results of this method and its great advantages are:-
1st. The whole quantity of solution is converted within half an hour into a
consistent mass of small crystals and the percentage of mother lye which, in
other processes of crystallization, forms an important percentage (with sodium
carbonate about 40 to 50%) is reduced to a minimum of about 10 per cent.
2nd. The whole process of crystallization is completed within half an hour in place
of fourteen days as at present required by the ordinary method of crystallization.
3rd. The product of crystallization is ready for transportation a few hours after
treating the said materials.
4th. The product obtained is of a very superior quality, and better suited for
use in households and in manufactures than the large crystals generally produced.
5th. The fact that the product obtained is ready at once for transportation
permits of a very large quantity being manufactured by means of a comparatively
small plant or apparatus.

page_text: 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 consider novel and desire to claim is:
-
1st. The process of manufacturing salts (specially sodium carbonate) in small
crystals which consists in maintaining the liquid to be crystallized in constant
agitation within pans or vessels and at the same time blowing cold air upon it,
substantially as and for the advantages hereinbefore set forth.
2nd. The improved apparatus for manufacturing salts in small crystals con-
sisting of a plurality of pans or vessels arranged one above the other at suitable
distances apart and serving to contain the liquid to be crystallized; a vertical
shaft passing through the centre of said pans or vessels and carrying suitable
agitating arms or equivalent; and means for blowing air upon the liquid in the
pans or vessels, substantially as hereinbefore set forth.
3rd. The construction of apparatus for crystallizing sodium carbonate and
other similar salts in small crystals, substantially as herein described and shown
on the drawing annexed.
Dated this 8th love of T1000
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.