Improvements in Apparatus for, or in the Method of, Utilizing the Spent Liquor from Esparto, Wood Pulp, and similar Mills as Fuel.
Year: 1898

page_text: Date of Application, 26th May, 1898
Complete Specification Left, 27th Feb., 1899-Accepted, 26th May, 1899
Improvements in Apparatus for, or in the Method of, Utilizing the
Spent Liquor from Esparto, Wood Pulp, and similar Mills as Fuel.
I, RICHARD CREMER, of 25, Cookridge Street, in the City of Leeds, Mining and
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
As is well known continuously working rotary furnaces amongst others are
often employed for burning the incrustations from the spent liquors of esparto-
wood-pulp-, and the like mills; which is carried out for the purpose of recover-
ing the chemicals used in the digesting operations at such mills. Such rotary
furnaces are employed as being much more economical in the consumption of
fuel, in repairs, and in manipulation than the usual stationary incinerating and
calcining furnace.
Hitherto an hinderance to the introduction of such rotary furnaces has been, that
in the case of continuous working, which is necessary for economy and to prevent
offensive smells, the chemicals ashes did not leave the furnace in a fused, but only
in a coke like state.
This is of course very detrimental, not only because the chemicals are thus
rendered impure by coke like and non fused or only partially fused incrustations,
necessitating a troublesome and costly decanting and filtration; but also, because
the use of the furnace is thereby rendered impossible for many of the processes
in such mills, since they must work at a melting temperature in order to ensure
the proper reactions amongst the chemicals. Thus for example, on this account
sulphate cellulose works could not make use of such a, in other respects so very
advantageously suitable, apparatus; though it would do more to get rid of the
offensive smells from these mills; than any other means hitherto known.
According to the present invention,, my communicator has discovered a con-
struction or arrangement of furnace or method of firing, which overcomes this
hindrance, and in which the chemicals may be melted under continuous working.
From calorimetrical experiments my communicator has found, that the incrus-
tations contained in the spent liquors constitute by far the greater part of the
combustibles from the spent liquor; and this he also found confirmed in an
English esparto paper mill, where a rotary furnace was kept burning the whole
week without auxiliary firing. As however with the present usual construction
and working of the rotary furnace, the spent liquor and the chemicals which
are obtained from them pass in the opposite direction to that of the products of
combustion, and the air admitted into the furnace for the combustion; (the spent
liquor being introduced into the furnace at the exit for the gases, and the chemicals
recovered from the liquor by the combustion leaving the furnace at the opposite
end where the air for combustion enters); it is evident, that the chemicals thus
coming in contact with successively cooler gas and air must solidify before the
melting point has been reached, and in most cases also before all the combustible
material has been completely consumed; and consequently that the chemicals
are always, when recovered, in a more or less impure state.

page_text: A knowledge of the above has rendered it possible for my communicator to
give the furnace such a construction and to employ such a method of working that
the above mentioned difficulties are thereby quite overcome.
According to this invention the spent liquor is admitted into the
furnace together with and at the same end as the air for combustion.
The chemicals which are recovered by the incineration pass in the same direction
as the burning gases, which gradually attain a higher temperature as the com-
bustion proceeds; and as this temperature is much higher than is required to
melt the chemicals, they leave the furnace in a melted condition.
The furnace is so designed that within certain limits any designed inclination
can be given to it, so that it is possible to allow the chemicals just the requisite
time for the reduction. If the production is small in proportion to the capacity
of the furnace, or if the chemicals require only a short time, then a greater
inclination towards the outlet is given to the furnace; and if the
production is large, or if the chemicals require a longer time, the inclination is
reduced. In this manner it is possible to adjust the rotary furnace so that the
chemicals leave it in a pure and fused condition; also under continuous working:
and so that the offensive smells from unburnt gases, for example such in which
sulphur is a constituent, and which are a consequence of intermittent working,
are prevented without the provision of special arrangements for the purpose.
A rotary furnace constructed according to this invention comprises a cylindrical
chamber, suitably lined and mounted on rollers, or otherwise supported so as
to be capable of rotation. The front of this chamber is closed except for a central
circular opening, in which is fitted a non rotating flanged plate or casting; an
elastic connection or joint ring being provided, so as to make the joint sufficiently
air tight during the rotation of the chamber. The plate or casting carries con-
nections for admitting the spent liquor in the form of spray, and for admitting
air and fuel such as coal dust, petroleum and the like for commencing
the combustion, or for assisting in maintaining the combustion when
required. The opposite end of the chamber 1S fitted in a circular
opening in a fixed or stationary flue or flues, into the first part of which the fused
chemicals fall, and from which they may be from time to time let off, or constantly
drawn off, by some drainage or syphon channel. The hot waste gases from the
may be passed under a steam boiler, or utilized for other heating purposes.
Dated this 25th day of May 1898.
flue
J. CLARK JEFFERSON,
30 Park Row, Leeds, Agent for Applicant.
Improvements in Apparatus for, or in the Method of, Utilizing the
Spent Liquor from Esparto, Wood Pulp, and similar Mills as Fuel.
I, RICHARD CREMER, of 25, Cookridge Street, in the City of Leeds, Mining and
Mechanical 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:-
As is well known continuously working rotary furnaces amongst others are
often employed for burning the incrustations from the spent liquors of esparto-,
wood-pulp, and the like mills; which is carried out for the purpose of recover-
ing the chemicals used in the digesting operations at such mills. Such rotary
furnaces are employed as being much more economical in the consumption of

page_text: fuel, in repairs, and in manipulation than the usual stationary incinerating and
calcining furnace.
Hitherto an hindrance to the introduction of such rotary furnaces has been, that
in the case of continuous working, which is necessary for economy and to prevent
offensive smells, the chemicals did not leave the furnace in a fused, but only in
a coke like state.
This is of course very detrimental, not only because the chemicals are thus
rendered impure by coke like and non fused or only partially fused incrustations,
necessitating a troublesome and costly decanting and filtration; but also, because
the use of the furnace is thereby rendered impossible for many of the processes
in such mills, since they must work at a melting temperature in order to ensure
the proper reactions amongst the chemicals. Thus for example, on this account
sulphate cellulose works could not make use of such an, in other respects so very
advantageously suitable, apparatus; though it would no more to get rid of the
offensive smells from the mills, than any other means hitherto known.
The present invention provides a construction or arrangement of furnace or
method of firing, which overcomes this hindrance, and in which the chemicals
may be melted under continuous working. From calorimetrical experiments my
communicator has found, that the incrustations contained in the spent liquors
constitute by far the greater part of the combustibles from the spent liquor; and
this he also found confirmed in an English esparto paper mill, where a rotary
furnace was kept burning the whole week without auxiliary firing. As however
with the present usual construction and working of the rotary furnace, the spent
liquor and the chemicals which are obtained from them pass in the opposite
direction to that of the products of combustion and the air admitted into the
furnace for the combustion, (the spent liquor being introduced into the
furnace at the exit for the gases, and the chemicals recovered from the liquor by
the combustion leaving the furnace at the opposite end where the air for com-
bustion enters); it is evident, that the chemicals thus coming in contact with
successively cooler gas and air must solidify before the melting point has been
reached, and in most cases also before all the combustible material has been com-
pletely consumed; and consequently that the chemicals are always, when recovered,
in more or less impure state.
A knowledge of the above has rendered it possible for my communicator to
give the furnace such a construction and to employ such a method of working that
the above mentioned difficulties are thereby quite overcome.
According to this invention the spent liquor is admitted into the furnace together
with and at the same end as the air for combustion.
The chemicals which are recovered by the incineration pass in the same direction
as the burning gases, which gradually attain a higher temperature as the com-
bustion proceeds; and as this temperature is much higher than is required to
melt the chemicals, they leave the furnace in a melted condition.
The furnace is so designed, that within certain limits any designed inclination
can be given to it, so that it is possible to allow the chemicals just the requisite
time for the reduction. If the production is small in proportion to the capacity
of the furnace, or if the chemicals require only a short time, then a greater
inclination is given towards the outlet to the furnace; and if the
production is large, or if the chemicals require a longer time, the inclination is
reduced. In this manner it is possible to adjust the rotary furnace so that the
chemicals leave it in a pure and fused condition; also under continuous working;
and so that the offensive smells from unburnt gases, for example such in which
sulphur is a constituent, and which are a consequence of intermittent working,
are prevented without the provision of special arrangements for the purpose.
And in order that this invention and the manner in which the same is to be
performed may be more readily and clearly understood, I have annexed hereto
the accompanying drawings of a rotary furnace arranged and constructed according
to this invention; the drawing being a longitudinal vertical section.

page_text: The furnace consists of a metal cylinder, A, having a suitable refractory lining,
and carried on two or more pairs of rollers B, or otherwise supported so as to be
capable of rotation. The front end C of the cylinder is closed by the lining except
over the central circular opening in which fits a non-rotating flanged
plate or casting D; an elastic or flexible connection or joint ring E being pro-
vided so as to make the joint sufficiently air tight during the rotation of the
furnace chamber. The plate or casting D carries a connection F passing through
it, for admitting the spent liquor and for admitting air and fuel, such as coal
dust, petroleum and the like for commencing the combustion and for assisting
in maintaining the combustion when required. In the drawing, a coal dust firing
apparatus G is shewn connected to plate D.
The opposite end of the chamber fits with a recessed or rebated end in a circular
opening in a fixed or stationary flue H, the bottom of which is conveniently
formed concave to receive the fused chemicals as they overflow from the furnace
chamber;
and from which flue they may be from time to time let off, or con
tinuously drawn off, by some drainage or syphon channel. The hot waste gases
may be passed through additional flues to deposit any dust carried over by them
and then passed under a steam boiler J, or utilized for other heating purposes.
As I do not wish to limit myself to any special means for tilting the furnace,
nor to any special means for rotating the furnace, as these may be varied without
altering the nature of my said invention, no such means are described or illus-
trated; but 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 apparatus for utilizing the spent liquor from esparto- wood-pulp and
similar mills as fuel, the combination with a rotary working of the furnace of
the introduction of the spent liquor or residuum therefrom into the furnace and
its passage through the furnace respectively at the same end of the furnace and in
the same direction as that of the fuel and air for starting and maintaining the
combustion.
2. In rotary furnaces for the utilization of the spent liquor from esparto-
wood-pulp and similar mills the combination with a rotary furnace of means
for introducing the spent liquor or the residuum therefrom into and passing it
through the furnace respectively at the same end and in the same direction as
the fuel and air for commencing and maintaining the combustion.
3. In rotary furnaces for utilizing the spent liquor from esparto- wood-pulp
and similar mills as fuel the arrangement of a fixed flanged plate fitting in a
central circular opening in the closed end of the furnace and carrying both the
connection for the introduction of the spent liquor or residuum therefrom and
the connections for the introduction of the fuel and air for starting and maintaining
the combustion.
1
1
73 1
1000
J. CLARK JEFFERSON,
30, Park Row, Leeds, Agent for Applicant