Improvements relating to the Burning of Pulverulent Fuel and to Apparatus therefor.
Year: 1897

page_text: Date of Application, 5th Feb., 1897
Complete Specification Left, 21st Oct., 1897-Accepted, 29th Jan.,
1898
Improvements relating to the Burning of Pulverulent Fuel and to
Apparatus therefor.
I, ANDREAS FREITAG, of 1 Spaarndammerstraat 57, Amsterdam, in the Kingdom
of Holland, Managing Director, do hereby declare the nature of this invention
to be as follows:-
This invention relates to the burning of pulverulent fuel and to apparatus
therefor.
Furnaces for burning pulverulent fuel, which necessitates the transport of the
said fuel to the said furnace, are objectionable on account of the danger of
explosion connected therewith. Moreover further objection to dust furnaces
exists if the additional effect produced is not in proper proportion to the additional
cost caused by the separate operations of drying, grinding and transporting the
fuels.
These defects are obviated in the present method of firing, according to which
the fuel is conducted in the crude condition from the place whence it is taken to
rapidly rotating beaters of a disintegrator which is in connection with the furnace
through a dust separator provided with fine apertures in such a manner that the
dust, with air designed for the combustion and which may if desired be prelimin-
arily heated, passes under the action of the beaters through the fine apertures of
the dust separator into the furnace.
The fuel, whether dry or moist, is conducted through a fuel pipe to the dis-
integrator with admission of air used for the combustion and which may be pre-
liminarily heated if desired, the said disintegrator being in communication with
the fire tube or furnace through a finely perforated sieve grate or dust separator.
The disintegrator suitably consists of a beater mill, the casing of which presents
strong projecting dents which again and again conduct the material to be ground
to the beaters rotating at a great velocity until the particles pass in pulverulent
form under the action of the beaters through the fine apertures of the dust
separator into the furnace.
The material, is conveyed by means of the elevator and conveyor screw into a
feed casing, and is thence conducted to the disintegrator by means of the admission
valve, while the pipe in which the valve is situated is continually shut off from
the ambient air. The admission of air for combustion, which may if desired be
preliminarily heated, takes place from a pipe terminating in the fuel pipe below
the admission valve.
It is a material factor that the disintegrator is in communication with the
furnace through the dust separator furnished with fine apertures, which allows
only finely divided fuel mingled with air for combustion to gain access to the
furnace under the action of the beaters.
Aided by the heat transmitted from the furnace the drying of the fuel, which
must necessarily be perfect for the formation of dust, is accomplished by the
eat produced during the rapid rotation even in cases where the material taken in

page_text: the crude state may not be conducted in quite a dry condition to the disintegrator.
The beaters as well as the admission valve are driven by an upper transmission
shaft, the said valve keeping the fuel pipe always shut off from the ambient air
so that the atomizing will take place without liability to explosion.
By the action of the beaters of the disintegrator the dust produced will be con-
ducted intimately mingled with the necessary air for combustion from the air
pipe through the fine apertures of the dust separator into the furnace where it
will be burned in the most perfect manner.
Dated this 5th day of February 1807
Improvements relating to the Burning of Pulverulent Fuel and to.
Apparatus therefor.
I, ANDREAS FREITAG, of 1 Spaarndammerstraat 57, Amsterdam, in the Kingdom
of Holland, 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 the burning of pulverulent fuel and to apparatus
therefor.
Furnaces for burning pulverulent fuel, which necessitate the transport of the
said fuel to the said furnace are objectionable on account of the danger of explosion
connected therewith. Moreover objection to dust furnaces exists if the additional
effect produced is not in proper proportion to the additional cost caused by the
separate operations of drying, grinding and transporting the fuels.
These defects are obviated in the present method of firing, according to which
the fuel is conducted in the crude condition from the source of supply to rapidly
rotating beaters of a disintegrator which is in connection with the furnace through
a dust separator provided with five apertures in such a manner, that the dust with
air designed for the combustion and which may if desired be preliminarily heated,
passes under the action of the beaters through the fine apertures of the dust
separator into the furnace.
In the accompanying drawings I have shewn an apparatus suitable for carrying
the method into practice.
Figure 1 is a front elevation of a steam boiler furnace provided with my
improvements.
Figure 2 is a partial longitudinal section of the same,
Figure 3 is a vertical section of a portion of the apparatus shewn in Figure 2,
but drawn to an enlarged scale, and
Figure 4 is a vertical section partly in elevation of the disintegrator herein-
after described.
b
In carrying my invention into practice the fuel whether dry or moist, is con-
ducted through a fuel pipe, a to the disintegrator 6 together with the air necessary
for the combustion which air may if desired be preliminarily heated, the said
disintegrator being in communication with the fire tube or furnace d through a
finely perforated sieve grate or dust separator b¹.
The disintegrator b may consist of a beater mill, the casing of which presents
strong projecting dents which again and again conduct the material to the ground
to the beaters rotating at a great velocity until the particles pass in a pulverulent

page_text: form under the action of the beaters through the fine apertures of the dust separa-
tor into the furnace d.
In the example represented in the drawing the material is conveyed from a
suitable source of supply by means of the elevator f and conveyor screw s into a
feed casing g, and is thence conducted to the disintegrator 6 by means of the
admission valve h while the fuel pipe a is continually shut off from the ambient
air. The admission of air for combustion, which may if desired, be preliminarily
heated, takes place through an air pipe c communicating with the fuel pipe a
below the admission valve h.
It is a. material factor that the disintegrator is in communication with the
furnace through the dust separator furnished with fine apertures, which allows
only finely divided fuel mingled with air for combustion to gain access to the
furnace under the action of the beaters.
Aided by the heat transmitted from the furnace the drying of the fuel, which
must necessarily be perfect for the formation of dust, is accomplished by the heat-
ing produced during the rapid rotation even in cases where the material taken
in the crude state may not be conducted in quite a dry condition to the disin-
tegrator.
The beaters as well as the admission valve h are driven from an upper trans-
mission shaft w the said valve h keeping the fuel pipe a always shut off from the
ambient air so that the atomizing will take place without liability to explosion.
By the action of the beaters of the disintegrator b, the dust produced will be
conducted intimately mingled with the necessary air from the air pipe c through
the fine apertures of the dust separator 61 into the furnace d where it will be
burned in the most perfect manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
First. A method of firing with pulverulent fuel, which consists in conducting
the fuel in the crude state from the source of supply to rapidly rotating beaters
of a disintegrator which is in communication with the furnace through a dust
separator furnished with fine apertures in such a manner that the dust will pass
into the furnace with the air necessary for combustion (which may if desired be
preliminarily heated) intimately mixed under the action of the beaters through
the said apertures of the dust separator.
Second. For carrying out the method described in the First Claim a casing b pro-
vided with rapidly rotating beaters, such casing being on the one hand in con-
nection with a pipe a for the supply of crude fuel thereto by means of the admis-
sion valve h with the introduction of air by means of the pipe c, and on the other
hand with the furnace or fire tube d through the fine apertures in the wall b¹.
Dated this 21st day of October 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.