Year: 1886

page_text: Date of Application, 8th Nov., 1886
Complete Left, 8th Sept., 1887
Complete Accepted, 11th Oct., 1887
1, JOHN HAMMOND,
declare the nature of my said invention to be as follows
The object of this invention is to continuously and automatically to distill and
recover from gas tar its valuable light giving hydro carbon vapours and return the
same to the ordinary coal gas leaving the hoiled tar or pitch to be drawn off and
burned in the retort furnaces and other fires.
To carry out this invention the ordinary gas tar is passed through a coarse strainer
into a suitable vessel heated by means of coil and the waste steam derived from the
distilling chamber herein after described. When the tar is sufficiently fluid it is
raised by any suitable means to an overhead tank fitted with strainers so arranged
that the sedimentary matter may fall away from strainer to the bottom of tank
leaving strainers clear and free to the flowing tar. From this tank the strained tar
flows by simple gravitation in distilling chamber or vessel so constructed as to quickly
boil off by means of high pressure steam. The light hydro carbon vapours and the
ammonical liquors, leaving the hot pitchy tar to flow away direct to the retort furnace
or other fires to keep up the temperature and fluid condition of the tar the pipes are
carefully covered with nonconducting material but immediately over the furnaces they
are encased in an iron pipe; stop taps are arranged to each furnace and suitable
regulators fitted with set screws and needle for clearing tar flow hole and capable of
rapid adjustment. Small syphon tubes may also be used or if preferred the apparatus
described in a former Patent No. 85488 the continuous and regulated stream of tar
is conducted to an opening above the ordinary furnace door and falls direct on the
incandescent coke in the furnace. This point is of great importance viz. that the tar
should fall direct from the delivery pipe into furnace. A cast iron hood surrounded
by brickwork secures and helps to protect the tar pipe from the direct action of the
fire at the same time admits with the flowing tar a proportion of air heated by passing
through the hot iron hood. A supplementary air pipe closely surrounds the tar pipe,
to admit air under pressure and assist in dispersing tar and protect exit of tar pipe

page_text: from fierce heat of furnace, heated air to further assist in the proper combustion of
the tar in the furnace is admitted through two small iron pipes built from front wall
into each side of furnace and the proper regulation of the air is governed by a
balanced iron ash pit damper easily adjusted to meet requirements. The above
arrangement being easily applied to ordinary furnaces but in instances where there
is not sufficient room for iron hood or where the iron hood would be too close to the
furnace the tar pipe exit may be further protected by an extra tube containing water
circulating through from an overhead tank or the form of furnace may be modified
to meet the required condition for burning tar as set forth above. The construction
of the tar distilling chamber and the arrangement of the inlet and outlet pipes is a
matter of great importance the hydro carbon and ammonia vapours evolved from the
boiling tar are conducted direct into the hot gas mains and mixes with the ordinary
gas in course of manufacture. An automatic water jet blower is used to force a
measured quantity of air heated to a temperature slightly above the temperature of
the distilling chamber to assist in carrying off the hydro carbon vapours to the gas
mains a small jet of steam may be used direct when necessary to wash and agitate
the boiling tar and further assist in removing from the tar its light hydro carbon and
ammonia vapours the heated condition of the still prevents the condensation of the
steam.
The two entering the still flows in at the top and the pitchy or boiled tar flows out
from the bottom of still the waste water passing from the steam heated tubes within
the chamber may be utilized to warm up the tar previous to its distillation &c.
The plant described can also be utilised to distill for sale or otherwise the light
hydro carbon liquids and ammonia from gas tar to effect this a suitable condensing
tank and pipes can be added to distilling chamber in like manner the boiled tar can
be drawn from still for asphalting purposes when it is not desired to burn the same.
To withstand the intense heat developed by tar firing, the furnace may be lined with
a mixture of oxide of magnesia and silicate of soda with or without a small quantity
of suitable fire clay this mixture can also be used to stop cracks in leaky retorts and
bricks formed of a similar material can be used to withstand the cutting action
developed by too close tar firing when it is not convenient to enlarge the furnace to
a more suitable size for the use of liquid fuel.
Dated 8th November 1886

page_text: Improvements in the Method of and in Apparatus for the Utilization
of Gas Tar.
I JOHN HAMMOND, late of Lewes, but now of Eastbourne, both the County of
Sussex, Gas Engineer do hereby declare the nature of my said invention and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The object of this invention is to continuously and automatically distil, and recover
from Gas Tar, its valuable light-giving hydro-carbon vapours, and convey the same
to the ordinary Coal Gas for the purpose of enriching and increasing the volume of
the same; leaving the boiled tar or pitch to be drawn off and burned in retort
furnaces, or other fires.
To carry out this invention, the ordinary Gas Tar is passed through a coarse
strainer, in a suitable vessel, heated by means of a coil of pipe supplied with waste
steam from the distilling chamber hereinafter described. When the tar is sufficiently
fluid it is raised, by any suitable means to an overhead tank fitted with strainers so
arranged that the sedimentary matter may fall away from the strainers to the bottom
of the tank, leaving the strainers clear and free for the inflowing Tar. From this
tank the strained Tar flows by simple gravitation to a distilling chamber or vessel,
so constructed as to quickly evaporate, by means of high pressure steam, the light
hydro-carbon vapours and the ammoniacal liquors, leaving the hot, pitchy tar, to
flow away direct to the retort furnace or other fires. To keep up the temperature
and fluid condition of the tar, the pipes are carefully lagged with non-conducting
material. Stop cocks are arranged to each furnace, and also suitable regulators
consisting of needles passing through stuffing boxes for clearing the flow pipe, with
rapidity. Small syphon tubes may also be used, or, if preferred, the apparatus
described in my former patent No. 834886. The continuous and regulated stream
of Tar is conducted to an opening above the ordinary furnace door, and falls direct
on to the incandescent coke in the furnace. It is of great importance that the Tar
should fall direct from the delivery pipe on to a fire brick arch or channel where it is
partially gasefied, and flows into the furnace, aided by the draught. Supplementary
air pipes are provided to admit air and assist in the combustion of the gases arising
from the Tar. Heated air is also admitted, to further assist in the proper combustion
of the Tar in the furnace through two small iron pipes built into the front wall at
cach side of the furnace, and the proper regulation of the air is governed by a
balanced damper, easily adjusted to admit the required quantity. The above arrange-
ments may be readily applied to ordinary furnaces, but in cases where there is not
sufficient room for Tar and air channels above the furnace door, the form of furnace
may be modified. The construction of the Tar distilling chamber and the arrangement
of the inlet and outlet pipes is of great importance; the hydro-carbon and ammoniacal
vapours evolved from the boiling tar are conducted direct into the hot gas mains, and

page_text: mix with the ordinary gas in course of manufacture and storage. A steam injector
is used to drive a measured quantity of air, heated to a temperature slightly above
the temperature of the distilling chamber, to assist in carrying off the hydro-carbon
vapours to the gas mains. A steam injector may also be used when necessary to
wash and agitate the boiling tar, and further assist in removing from the tar its light
hydro-carbon and ammoniacal vapours.
The plant herein described can also be utilized in distilling for sale, or otherwise,
the light hydro-carbon liquids and ammonia from gas tar. To effect this, a suitable
condensing tank and pipes can be added to the distilling chamber. In like manner
the boiled tar can be drawn from the still for asphalting purposes, when it is not
desired to burn the same in a furnace. In order to withstand the intense heat
developed by tar firing, the furnace may be lined with a mixture of oxide of magnesia
and silicate of soda, either neutral or alkaline and with or without a small quantity of
suitable fire clay and lime, or any other suitable mixture; and the same can also be
used to stop cracks in leaky retorts; and bricks formed of a similar material can be
used to withstand the cutting action developed by too close tar firing, when it is not
convenient to enlarge a small furnace to a more suitable size for the combustion of
liquid fuel.
And in order that my said invention may be particularly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1 is an elevation, showing an arrangement for applying my invention to the
furnace of a set of gas retorts; the left hand side of the retorts being shewn in
Section, Fig. 2 is a sectional elevation, on the line xx of Fig. 1 and Fig. 3 is an
enlarged drawing of the fuel regulator L.
A is a tank, fitted with a coil of pipe to which Steam from the Tar still B is
carried by the pipe a.- (in dotted lines) is a sieve or screen, through which the tar
passes on its way to the U-pipe 0. B is the steel or evaporator, consisting of a
tubular vessel, having tube plates cc and chambers d. d' as shewn in Fig. 1. e is a
Steam pipe, through which high pressure steam is carried to the chamber d, such
steam passing downwards through the tubes to the chamber d', heating the tar,
contained in B, in its passage. From the chamber d' the steam is carried, by the
pipe a, to the coil in the tank A. The lower end of the coil is carried outwards at a¹,
whence the condensed water from the steam is drained away.
The tar is kept in a suitable state of fluidity, by the coil in the Tank A, and
receives additional heat when it arrives in the still B; the heat of the steam in the
latter vessel imparts to the tar, by conduction, sufficient caloric to evaporate the
more volatile constituents of the tar, such as the light hydro-carbon oils and amino-
niacal liquors, which are carried by the pipe 2 to the Refrigerator C, where the
naphthalin, ammonia and light oils are condensed. Cold water, air, brine or steam
is passed through the tubes of this condenser either in an upward or downward
direction, and according to the temperature required, the chambers of and f¹ being
utilised for receiving and passing off the same through the pipes g g' g² 9³.
The naphthalin and light oils may be passed in their crude state, through the
pipe G (the cock to the pipe D being shut) and Cock E to the retort and again
distilled with the ordinary coal gas; or may be passed through the Cock F direct
into the hydraulic main R, with the coal gas, and thence to the gas main S; or the
cock F may be shut, and the cock H opened to pass the same to the tank J.
When the light oils have been thus driven off from the Vessel B, the tar or pitch
flows away by the pipes Kk to the fuel regulator L, and thence to the tar channel P,
over the furnace, where arrangements are made for heating a large quantity of air.
By means of the pipe 1 the liquid fuel is carried to the tar channel P, over the fire
brick arch p', to the incandescent coke placed in the furnace at t. h is an iron dead
plate; i is a movable iron dead plate; m is a balanced ash-pit damper to regulate
the passage of heated air to the lower flues.
The furnace is supplied with heated air, by passing air through channels and
passages, whereby the heat of the walls is utilised in effecting perfect combustion

page_text: and consumption of smoke. N, is one of the air entrances leading to flues N¹, built
in the sides of the furnaces. M is one of two pipes leading downwards to the
flues M¹.
Referring to the enlarged section of The Tar Regulator L, Fig. 3 k is the pipe
which receives the supply of tar from the pipes K k. L' is a cylindrical sieve, which
screens the tar as it arrives, the coarser particles being collected in the lower part
of L, and occasionally drawn off by means of the plug . is a pipe leading to the
furnace. is a sight feed to the pipe 1, regulated by the needle y passing through
the stuffing box z, whereby the screened tar is carried to the furnace in such regulated
quantities that perfect combustion is effected.
Should it be desired to bye-pass the refrigerating chamber, by passing the vapours
direct from the Still B to the Coal Gas in the Hydraulic main, it can easily be done ;
but, in that case, I find it convenient and necessary to erect a dry quick Lime catch
purifier for the Coal Gas, either immediately before entering the Store Gas Holder,
or at the outlet of the Gas Holder. The said purifier may be provided in duplicate
and of a sufficient size to prevent back pressure.
I also prefer to pass the gas from the top of the purifier down through the quick
Lime or other suitable absorbing alkaline material, to prevent the formation of
naphthalin Crystals in the gas mains &c.
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. The method of continuously and automatically distilling and recovering from
gas tar its valuable light-giving hydro-carbon vapours, and enriching and increasing
the volume of ordinary coal gas therewith, or otherwise disposing thereof, substantially
as hereinbefore described.
2. The method of and means and appliances for utilising the residuary boiled tar
or pitch as fuel in retort furnaces or other fires, substantially as hereinbefore described
and illustrated on the drawings.
3. The general construction, arrangement and combination of the several and
respective parts, and the methods of working the same, together constituting my
improvements in the method of and in apparatus for the utilisation of gas tar, sub-
stantially as hereinbefore described and illustrated on the drawings.
Dated 8th September 1887.
GEO. DOWNING,
Agent for Applicant.