Improvements in Furnaces for Extracting Potash from the Grease Contained in Sheeps' Wool.
Year: 1894

page_text: COMPLETE SPECIFICATION.
Improvements in Furnaces for Extracting Potash from the Grease
Contained in Sheeps' Wool.
I, (Madame) EMILE RICHARD-LAGERIE, (née C. Douen) of 296, Grand
Rue, Roubaix, Department du Nord, in the Republic of France, Engineer, 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 :-
My invention relates to improvements in the manufacture of potash from the
grease contained in sheep's wool, and more especially to the furnaces used for this
purpose.
These improvements have for their objects
-
1st. To collect aminoniacal products and all those which have an objectionable
smell.
2nd. To suppress the losses caused by priming.
3rd. To recover the heat still remaining in the combustion gases as they leave
the furnace.
4th. To secure regularity in the working of the process by the storage of heat in
a heat conducting mass.
5th. To recover the losses due to leakage and thereby do away with the
infiltrations which frequently pollute the neighbouring waters.
6th. To provide a system of automatic feeding of the sheep's wool grease, so as
to secure a constant level in the upper and lower furnace.
Lastly. To construct a furnace with one, two or more storeys which besides
fulfilling the foregoing requirements shall be easy to repair, require a minimum
amount of motive power, occupy little room, and have a high degree of efficiency,
that is, produce more potash per pound of fuel than any of the furnaces hitherto
known.
In order that my invention may be better understood I will proceed to describe
it with reference to the accompanying drawings, in which:
Figure 1 is a longitudinal elevation of a furnace constructed according to
my invention.
Figure 2 is a longitudinal section.
Figure 3 is a plan.
Figure 4 is a cross section.
Figure 5 is a cross section of a small three storeyed furnace embodying all the
features of my invention.
Figure 6 is a section of an alternative form of "stepped" grate to the one (M²)
illustrated in Figure 5, beneath the lowest concentrating chamber. This grate
differs from the one illustrated in Figure 5 insomuch as it has two tiers of asbestos
or fire brick steps instead of one as shown in that figure.
I will now describe successively and more fully each one of the aforesaid
improvements.
1st. Collection, of ammoniacal products and those having an objectionable
smell. As shown on the drawings Figs. 1, 2 and 5, I fit in the chimney, one, two
or more nozzles A for injecting liquid into it for the purpose of condensing
the aforesaid products.
An alternative arrangement would be to provide a fan to collect the combustion

page_text: "
gases and force them into a column of coke or other absorbent provided with an
upper injector z for condensing the fluid. (Fig. 5.) If the natural draught is
insufficient a steam blower B (Fig. 1) may be added to improve it. The condensed
products are ammoniacal waters which can be utilised for the washing of wool after
they have been treated with salts of sodium and lime. In order to obtain the best
results an excess of condensing liquid must be used.
"
2nd. Suppression of losses caused by priming.-There are losses due to more or
less active evaporation. To overcome this I make use of revolving "stirrers
made of sheets of wire gauze F, F1, F", (Fig. 2) or C in Figure 5, mounted on
transverse shafts Y, Y, Y, provided with cross arms supporting four sheets of wire
gauze. These revolve slowly in a direction opposite to that of the draught, say at
the rate of five revolutions a minute. These sheets of wire gauze are provided with
a transverse channel which periodically dips into the incoming sheep's wool grease,
gathers it and distributes it over the wire gauze whilst they are revolving. The
liquid drops carried off by the draught itself in an atomised state are retained by
the meshes of the gauze.
3rd. Recovery of heat in the escaping gases.-The wire gauze sheets before
mentioned are alternately heated by the escaping gases and cooled by their
immersion into the weak, almost cold, incoming grease. I obtain thus an absorption
of heat by the grease to be concentrated.
4th. Regularity of working.-This is secured by the special arrangement of the top
arch of the furnace. The arch consists of ribbed cast iron panels M (Fig. 2), the
spaces between the ribs being filled with clay, the action of these ribs is to increase
the conductivity of the arch, a result which cannot be obtained with flat cast iron
plates. The clay retains the heat and prevents its outward radiation. It will be
seen that the use of revolving stirrers combined with the cast iron ribbed arch just
described effects a rapid concentration of the grease. There are as a rule as many
stirrers as there are furnaces on the same level or storey. The furnaces on the
same level or storey communicate with each other by means of a special channel R
(Fig. 3). Although only two stirrers are shown on the drawings it is understood
that three, four or more may be used.
5th. Recovery of loss due to leakage etc.-The recuperation of the losses caused
Ly leakage is an important point for said leakages produce infiltrations which
pollute neighbouring waters. To this effect when building the foundations of the
furnaces, I provide therein vacant spaces so as to form small cisterns to catch the
liquids escaping from the furnace. These cisterns communicate with a channel R¹
(Fig. 2 & Fig. 4) which runs round the furnace and has such a slope that the
liquid in it is deposited in a larger cistern in front of the furnace to be thence raised
by the attendant again.
6th: Automatic feeding.-To secure the regularity of working aimed at, it is also
essential that the level of the grease in the concentrating chambers should be kept
constant insomuch as the stirrers only penetrate the liquid to the depth of
about ths of an inch and a very slight fall in the level of the liquid would place
them out of action. To effect this I fit the grease inlet with a light and sensitive
float D (Figs. 1 and 2). This float contains an inverted valve D' on the seating D³.
The action of this portion of my invention is as follows: The grease enters the
concentrating chamber through the pipe D³, valve box D into the small cistern D³
bence by the pipe De to the chamber. To. prevent, the over charging of the
chamber I arrange that, when sufficient grease has passed into it, the increased
depth in the small cisteru.D³ forces upwards, the float D which closes the inverted
valve D' thus preventing the further entry of the grease. When the level of the
grease falls through its rapid concentration the float D again falls and re-opens the
valve D' permitting, a further inlet of the grease!
The feeding of the lower furnace from the upper one is effected by means of
a tube N. (Fig: 4) fitted likewise with, an inverted valve. This tube is provided
with a rod and spring arrangement N₁ allowing of the inverted, valve being closed
as soon as the grease in the lower furnace is sufficiently concentrated, and thus

page_text: preventing the weaker grease in the upper furnace from running into the lower one
when removing the concentrated products from the latter.
The furnace constructed as described in the foregoing is easy to repair, for the
cast iron panels which constitute the upper arch of the furnace are easily removed
and this greatly facilitates internal repairs.
The power required to drive the stirrers is very small, each stirrer absorbs less
than one third H.P. and one man can in twelve hours produce over a ton of potash
from sheep's wool grease.
The principle is applicable to furnaces of any size but I prefer constructing
small three storeyed ones fired in the usual manner with gas or liquid hydro-
carbon.
Figure 5 shows a cross section of such a furnace embodying fully all the main
features of my invention.
A is the upper storey or furnace into which the grease is first admitted.
B, B, B are cast iron troughs forming the bottom of the storeys. C are the
revolving stirrers which dip into the grease and also absorb the heat of the
combustion gases. E is the fire door. F¹ is the fuel injector. G, G, G are
the separating walls of the furnaces. M' is the last concentrating furnace.
M' the aperture through which the finished potash falls onto the stepped grate M³
O the oil reservoir. P are sliding doors which enable the attendant to watch the
progress of the operation. S is the outlet of the condensing fluid. T' is the door
through which the potash is removed. V' the fan for forcing the combustion gases
into the coke column U. X, Fig. 3 is a plan of the grate grid.
In these furnaces the sliding doors V as shown in Figs. 1, 2 and 4 are so arranged
that they balance one another wherever practicable.
Having now particularly described and ascertained the nature of my said inveu-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In furnaces for the extraction of potash from sheep's wool grease the
collection and condensation of the evolved ammoniacal and bad smelling products
by means of an injection of condensing liquid in the chimney of the furnace or in
vertical chambers in which the combustion gases circulate up and down, substantially
as described.
2. In furnaces for the extraction of potash from sheep's wool grease, the
collection and condensation of ammoniacal, and bad smelling products by an
arrangement consisting of a fan fitted at or near the outlet of the gases and forcing
said gases into a coke or other absorbent column, said absorbent column being
provided with a downward injection of condensing liquid all substantially as
described.
3. In furnaces for the extraction of potash from sheep's wool grease, the
arrangement of a crown or upper arch consisting of cast iron ribbed plates the
spaces between the ribs being filled with clay, thus forming a heat retaining mass,
substantially as described.
4. In furnaces for the extraction of potash from sheep's wool grease, having one,
two or more storeys, the provision in each storey of one or more stirrers of wire
gauze revolving in a direction opposite to that of the draught and dipping into the
grease for the purpose of absorbing the heat remaining in the escaping gases and
preventing priming, substantially as described.
5. In furnaces for the extraction of potash from sheep's wool grease, the
arrangement of cavities within the foundations of said furnaces in combination with
a sloping channel or culvert running round the furnace for the purpose of catching
any escaping liquid and returning it to the concentration chambers, substantially as
described.
6. In furnaces for the extraction of potash from sheep's wool grease, automatic
devices for maintaining a constant level of grease in the concentrating chambers and

page_text: preventing the less concentrated products from running into the lower chambers
before the potash has been removed from the latter, all substantially as described.
Dated this Tenth day of July 1894.
JOHN P. O'DONNELL,
70 & 71, Palace Chambers, Westminster, London, S. W..
Agent for the said Applicant.