Improvements in the Treatment of Coal and Small Coke or Breeze in the Manufacture of Gas and Coke.
Year: 1889

page_text: Date of Application, 24th Jan., 1889
Complete Specification Left, 1st Aug., 1889-Accepted, 21st Sept.,
1889
PROVISIONAL SPECIFICATION.
[Communicated from abroad by CLEMENTE AUGUSTO D'ASSUMPÇÃO and EMILIO
SILVESTRE DIAS, both of the Companhia Lisbonense d'Illuminação a Gaz, in the
City of Lisbon, in the Country of Portugal, Gentlemen.]
Improvements in the Treatment of Coal and Small Coke or Breeze
in the Manufacture of Gas and Coke.
I JOHN GREENFIELD of No. 37 Queen Victoria Street in the City of London
Solicitor do hereby declare the nature of this invention to be as follows :-
By the ordinary methods usually adopted in the distillation of Coal for the manu-
facture of Gas the Coke produced is more or less of a porous and friable nature and
undergoes a considerable loss by pulverization and otherwise, resulting in the
production of a large proportion of small coke and coke dust hereinafter described as
*breeze."
According to my invention I minimize as much as possible the production of breeze
and utilise that unavoidably obtained as follows:-Before the Coal is introduced into
the Retorts or other distilling or carbonizing apparatus I mix with it a certain
quantity of breeze in proportions varying with the quality of the coal employed. The
distillation or carbonization is then carried on in the usual manner. Among the
advantages gained by this method of treatment are
1. When the Carbonization is completed it will be found that the Coke obtained is
of a much superior quality to ordinary Gas Coke, being brighter and firmer, of a
metallic lustre, and is slower of combustion while its heating power remains
undiminished.
2. A greater quantity of Gas per ton of Coal carbonized is obtained.
3. The impurities of the Coal are rendered more easy of collection and consequently
the purification of the gas is easier and cheaper.
4. The breeze when mixed with the coal increases the heating surface, and
consequently the heat is distributed in a much more effective manner than when coal
alone is employed. Thus a more perfect distillation is ensured.
5. The quantity of comparatively worthless breeze is as above mentioned consider-
ably diminished, while that unavoidably produced is converted into coke of a superior
quality and value.
Dated thin 04th day of Tann 1980
JOHN GREENFIELD.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Coal and Small Coke or Breeze
in the Manufacture of Gas and Coke.
I JOHN GREENFIELD of No. 37 Queen Victoria Street in the City of London
Solicitor (being in possession of a communication from Clemente Augusto d'Assumpção
and Emilio Silvestre Dias both of the Companhia Lisbonense d'Illuminação a Gaz in
the City of Lisbon in the kingdom of Portugal Gentlemen) 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 the ordinary methods usually adopted in the distillation of coal for the manu-
facture of gas the coke produced is more or less of a porous and friable nature and
undergoes a considerable loss by pulverization and otherwise resulting in the
production of a large proportion of small coke and coke dust hereinafter described as
"breeze."

page_text: By our invention we minimize as much as possible the production of breeze and
utilize that unavoidably obtained as follows. Before the coal is introduced into the
retorts or other distilling or carbonizing apparatus we mix with it a certain quantity
of breeze in proportions varying with the quality of the coal employed. The pro-
portion of breeze that we have found in practice to give the best results with
Newcastle Coal is from 6 to 8 per cent. of the total weight of the mixture of coal
and breeze employed; but we do not confine ourselves to these proportions. The
coal required for one retort or preferably for a bench of retorts is spread evenly in
any convenient situation and the suitable proportion of breeze accurately weighed or
measured is added thereto in an even layer spread upon the coal. The whole is then
to be thoroughly mixed by turning over with a shove! or coarse rake; but we do not
confine ourselves to this or any other method of mixing, an intimate incorporation
which may be attained by a mixing machine or by any other sufficiently cheap means,
being all that is required. When the coal and breeze are thoroughly mixed, the
mixture may be introduced into the retorts and carbonized or distilled in the usual
manner.
When the stokers or other workmen have gained experience in judging the relative
quantities of coal and breeze, the weighing or measuring may be dispensed with, as
any intelligent workman will in a short time be able to judge with sufficient accuracy
the proportions required.
For the purposes of our invention it is not necessary or advantageous to powder
the coal or the breeze, as has been suggested by previous inventors.
It is only
necessary to pass the breeze in the usual way through an ordinary screen or sieve, so
as to separate any coke of a saleable size.
1
The breeze employed should be as dry as possible, and in order to obtain the best :
results it should be mixed with fresh coal and kept in contact therewith as long as
convenient before carbonizing. By this means the evil effects of the heating of the
coal in the heap are to a great extent prevented. When the coal mixed with the
breeze begins to heat, the more volatile and highly illuminating hydrocarbons which
are given off, are to a large extent absorbed and retained by the coke, until the a
mixture is carbonized or distilled in the retorts. The coke mixed with the coal also to
some extent prevents the heating of the coal and so diminishes the quantity of these
volatile hydrocarbons given off.
The breeze mixed with the coal also plays an important part during the carboni-
zation or distillation in the retort. It is well known that carbonization begins on the
exterior of the charge and that the coal becomes caked on the outside long before the
interior is worked off. The presence of breeze in the mass opens up as it were a
passage for the tarry vapours and gas, absorbing a certain proportion of the former,
which at a later stage, when the breeze agglutinates with the coal, are expelled in the
form of gas.
We are aware that a mixture of finely powdered coke or breeze with the coal to be
distilled or carbonized has been previously suggested; but from the manner or method
of its application the process has hitherto failed to become either a matter of public
utility or a commercial success, and has consequently been entirely abandoned. Our
process on the contrary has since the granting of provisional protection been worked
and is still working most successfully not only on an experimental but also on a large
manufacturing scale, and has entirely fulfilled the various claims set forth in the
provisional specification.
Among the advantages gained by our invention are the following:-
1. When the carbonization is complete, it will be found that the coke obtained is of
a much superior quality to ordinary gas coke, being brighter and firmer, of a metallic
lustre, and slower of combustion, while its heating power is undiminished.
2. A greater quantity of gas per ton of coal carbonized is obtained and its
illuminating power is increased.
3. The impurities of the coal are rendered more easy of collection and consequently.
the purification of the man i

page_text: 4. The breeze, when mixed with the coal, increases the heating surface; and
consequently the heat is distributed in a much more effective manner than when the
coal alone is employed. Thus more perfect distillation is ensured.
5. The quantity of comparatively worthless breeze is as above mentioned consider-
ably diminished, while that unavoidably produced is converted into coke of a superior
quality and value.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is as follows:-
1. The distillation or carbonization of coal previously mixed with breeze for the
purpose of improving the quality of the coke produced, substantially as hereinbefore
described.
2. The distillation or carbonization of coal previously mixed with breeze, for the
purpose of increasing the quantity and improving the illuminating power of the gas
so produced, substantially as herein before described.
3. The distillation or carbonization of coal previously mixed with breeze, for the
purpose of converting such comparatively worthless breeze into coke of a saleable size
and value substantially as hereinbefore described.
4. The mixing of breeze with the coal for the purpose of preventing the excessive
heating of the coal heap and retarding the evolution of and in a great measure
absorbing the gases otherwise lost, substantially as hereinbefore described.
Dated this first day of August 1889.
JOHN GREENFIELD.