AN IMPROVED METHOD OF AND APPARATUS FOR EXTRACTING TAR AND AMMONIA FROM THE GASES OF BLAST FURNACES
Year: 1884

page_text: I, JOHN DEMPSTER of the Gas Plant Works Newton Heath, near Manchester,
Lancashire, Gas Engineer do hereby declare the nature of my invention for
"AN IMPROVED METHOD OF AND APPARATUS FOR EXTRACTING TAR AND AMMONIA
FROM THE GASES OF BLAST FURNACES," to be as follows:-
This invention has reference to certain means to be employed for extracting tar
and ammonia from the gases of blast furnaces. It is well known that the heated
gases coming from blast furnaces have been conveyed to steam boilers, and utilized
there for generating steam and for heating stoves; it is also well known that these
blast furnace gases contain chemical compounds from which tar and ammonia can
be extracted; and the object of my invention is to treat such gases and to arrange
and combine certain apparatus for extracting and collecting the said tar and
ammonia.
All the apparati I employ are placed at a position between the blast furnaces,
and boilers, or stoves, and consists in the employment of an ordinary liquor or
ammonia still with its usual sulphate apparatus or other apparatus employed for
utilizing the ammonia gas, such gases being conveyed thereto by pipes from the
furnaces in addition to this "dust boxes" and "condensers " are employed, the
latter being composed of a series of vertical pipes through which the gases are
drawn by means of exhausters.
"
The gases are afterwards conveyed to certain forms of apparatus called "washers
or purifiers, preferably those known as "Liveseys" and finally they are taken to
"scrubbers" which are preferably filled with pieces of wood, or coke, and if 4 of
such "scrubbers' were employed 3 would contain ammoniacal liquor, whilst the
other would contain water for removing the last traces of ammonia but the number
of "scrubbers" will vary with circumstances.
"
After leaving the "scrubbers" the gases would pass into the boiler furnaces, and
assist in the generation of steam.
The various processes and the several forms of apparati through which the gases
pass in order to extract the tar and ammonia free the gases froin particles of dust

page_text: which are unavoidably blown from the furnaces allowing such gases to enter the
boiler furnaces in a more fit state for the purposes intended.
The various forms of apparati herein mentioned are all of ordinary construction
being used and well known and understood in the manufacture of coal gas, and
therefore do not require to be described in detail, as my Invention does not consist
in any improvements made in the various appliances but only in their adaptation
and arrangement for extracting tar and ammonia from the spent gases of blast
furnaces.

page_text: I, JOHN DEMPSTER of the Gas Plant Works Newton Heath, near Manchester,
Lancashire, Gas Engineer, do hereby declare the nature of my invention for
AN IMPROVED METHOD OF AND APPARATUS FOR EXTRACTING TAR AND AMMONIA
FROM THE GASES OF BLAST FURNACES, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement
This Invention has reference to certain means to be employed for extracting tar
and ammonia from the gases of blast furnaces:
It is well known that the heated gases coming from blast furnaces have been
conveyed to stoves for heating purposes and steam boilers and utilized there for
generating steam; it is also well known that these blast furnace gases contain
chemical compounds from which tar and ammonia can be extracted, and the object
of my Invention is to treat such gases and to arrange and combine certain apparatus
for extracting and collecting the said tar and ammonia.
In order that my Invention may be better understood I herein give reference to
the accompanying Sheet of drawings which illustrate the various forms of apparatus
I employ and the manner I propose to arrange them which it will be observed are
all placed at a position between the blast furnaces and the boilers or stoves. The
gases are conveyed by pipe A to the liquor or ammonia still with its usual sulphate
apparatus employed for utilizing the ammonia gas, such still being of ordinary
construction or according to the Specification of a Patent granted to me on the
31st day of July 1884 N° 10,790.
From the liquor still the gases are conveyed by pipes to "dust boxes" which are
employed to damp and arrest the dust which may have passed the large chambers
of the liquor still, also certain parts of ammonia and tar in the gases will be
arrested; the gases now enter the " condensers" where they are cooled by means
of water to the temperature of the atmosphere or lower if necessary whereby the
moisture contained in the gases and the bulk of the tar is removed. At this point
the gases pass to the exhausters which have been the means of drawing the said
gases from the furnaces and through the various forms of apparatus already
described; and now the gases are forced through "washers" which arrest the last
traces of tar and also remove part of the ammonia from the gases. From the
"washers" the gases enter the "scrubbers" which are preferably filled with wood-
boards or coke, and so arranged that if four of such scrubbers were employed,
three would have ammoniacal liquor flowing through them, and the fourth or
remaining one would have clean water flowing through for removing the last traces
of ammonia from the gases, but the number of scrubbers will vary according to
circumstances. After leaving the scrubbers the gases pass into the stoves or boiler
furnaces and assist in the generation of steam, or are utilized for other heating
purposes..

page_text: The various processes and the several forms of apparati through which the gases
pass in order to extract the tar and ammonia, free the gases from particles of dust,
which are unavoidably blown from the furnaces, allowing such gases to enter the
boiler furnaces in a more fit state for the purposes intended.
The various forms of apparati herein mentioned are all of ordinary construction
being used and well known and understood in the manufacture of coal gas and
therefore do not require to be described in detail, as my Invention does not consist
in any improvements made in the various appliances, but only in their adaptation
and arrangement for extracting tar and ammonia from the spent gases of blast
furnaces.
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
The method and arrangement of apparatus for extracting tar and ammonia from
the gases of blast furnaces, arranged in the manner herein set forth, such apparatus
being placed at a position between the furnaces and stoves, or steam boilers.
Dated this 13th day of May 1885.
TASKER & CROSSLEY,
Patent Agents,
Commercial Street, Halifax,
Agents for the Applicant.