[MPROVEMENTS IN HOT BLAST FOR METALURGIC FURNACES, AND FOR OTHER PURPOSES
Year: 1878

page_text: LETTERS PATENT to Martin Benson, of No. 9, Southampton Buildings, London,
for the Invention of "[MPROVEMENTS IN HOT BLAST FOR METALURGIC
FURNACES, AND FOR OTHER PURPOSES." A communication from abroad by
Silas Covel Salisbury, of the City, County, and State of New York, United
States of North America.
Sealed the 9th August 1878, and dated the 2nd April 1878.
Sealed the 9th August 1878, and dated the 2nd April 1878.
COMPLETE SPECIFICATION filed by the said Martin Benson at the Office of
the Commissioners of Patents on the 2nd April 1878.
MARTIN BENSON, of No. 9, Southampton Buildings, London.
"IMPROVEMENTS
IN HOT BLAST FOR METALURGIC FURNACES, AND FOR OTHER PURPOSES." A com-
munication from abroad by Silas Covel Salisbury, of the City, County, and State of
New York, United States of North America.
Fig. 1 is a sectional perspective view of my hot-blast apparatus with the attach-
ment for making gas; Fig. 2 is a sectional plan of the same.
Fig. 3 is a sectional perspective view of the Invention for using hot-air circulation
for steam generators.
Fig. 4 is a perspective view (detached) of my hot-air feed pipe.
Fig. 5 is a longitudinal section of my blast injector.
Fig. 6 is a transverse section of the superheater pipe and jacket.
Fig. 7 is a longitudinal section of a puddling furnace fitted for my gaseous fuel.
Fig. 8 is a sectional elevation of a pottery kiln similarly fitted.
Fig. 9 is a perspective view showing my method of drawing waste gases from
top of cupelo.
Fig. 10 is a diagram shewing method of applying my system of hot-air circulation
to domestic and other uses.
Fig. 11 represents a valve made of brick or other refractory material suitable
for an equalizer.

page_text: 6th. Engineers and assistants.
For large plants items 1, 2, 3, 4, and 5 cost from £10,000 and upwards, and
competent engineers command a salary, say £500 per annum, and the wages of
assistants exceeds that sum.
With the best appliances it is impractable to procure pressure exceeding four or
five pounds per inch, and it is impossible to procure a uniform and steady pressure,
and the pressure is not under immediate control of the furnace men.
The object of this part of my Invention is to dispense entirely with the blowing
engine; 2nd, to dispense with the steam engine or inotor; 3rd, to materially reduce
the size of the steam generator, say to th; 4th, to materially reduce the cost of
attendance; 5th, to produce at will any pressure desired up to, say, fifteen to twenty
pounds, and possibly greater; 6th, to produce a blast with perfect steady and
uniform pressure; 7th, to place the whole apparatus under the immediate and direct
management and control of the furnace men. These objects I accomplish by the
joint action of superheated steam, hot air, a heating furnace, and an injector, which
form the essential elements of my Invention.
A is the blast oven, and B, B, are the vertical retorts which I prefer; these
retorts I set in parallel rows in equal numbers, their tubular feet resting in shoes on
the boxes C, C, which receive and transmit the blast from one retort to the next.
By this method of arrangement I economise space and fuel, because there is less of
fluor space of about one-sixth, and of waste heat about one-fourth less when the
retorts are arranged in two rows within the same oven than if arranged in one row.
Dis the inlet pipe, and E is the outlet main extending to the furnace. The
practice heretofore has been to take in cold air at the inlet, but I propose to utilize
a portion of the waste heat in the oven to heat the feed air, and for that purpose I
place the feed pipe F in the oven around the retorts, taking cold air at the gated
end passing it through the hot pipe F, and delivering it to injector G at the inlet
end of the pipe D, heated to, say, 500° Fahrenheit, whereby it is injected and fed
to the retorts with any desired velocity or pressure.
The boiler H may be heated by the waste heat from the oven, substantially in
the manner shewn, or may have its own fire if preferable, and delivers coininon
steam at 90 to 100 lbs. pressure to the superheating pipe I, which consists of a
wrought-iron pipe enclosed in and protected by a cast-iron jacket, and laid in the
oven in coils or folds back and forth between the retorts, until its exposed surface is
sufficient to raise the temperature of all the steam while passing through it to 800°
or 1,000° temperature, and it then discharges this superheated steam into the steam
nozzle of the injector G.
The effect is to blow into the pipe D and through the retorts a current of air
already so healed in the pipe F that there can be no condensation of the steam, and
this current in passing into and through the retorts becomes heated to a still higher
degree and the steam probably decomposed, so that when it passes from the buyers
it not only urges the fire but adds fuel as well.
The velocity and consequent pressure of the blast may be controlled with the
utmost delicacy and ease by the gate f and the throttle i in the steam pipe.
The steam pipe I is divided, and enters the injector at two points in rear and in
front of the main cone, and I hereby produce a double blast more effective than
when the single blast only is employed.
The waste heat and products of combustion permitted to escape at the

page_text: chimneys J, J, or by closing the dampers K, K, may be turned through the diving
flues L to the boiler H.
By the means and appliances above described an air blast of any desired velocity
and pressure is produced by a jet of superheated steam generated by the wasto
heat from the hot-blast oven, and the entire cost of establishing and maintaining
the steam motors and blowing engines with the immense and costly foundation and
coverings, as well as the maintenance of costly superintendence, is saved. And in
addition to this great economy the results attained are superior, because any
desirable pressure can be produced and maintained with perfect uniformity and
with complete control directly by the furnace men.
This hot blast may be conducted directly to the tuyeres as usual, and, if desired,
it may be employed to draw the hot gases down from the top of the cupelo, as
shewn in Fig. 9; or it may be utilized in other ways, as herein-after set forth.
The second part of this Invention relates from the manufacture of gas from mineral
or other oils for either heating or illuminating purposes by means of a hot blast.
The practical difficulties, both mechanical and chemical, encountered in handling
or treating liquid hydrocarbons have heretofore been so great that the production
upon a large scale of a fixed gas from these sources have not been practicable; but
these difficulties are by the new method of my present Invention overcome or so
reduced in magnitude that they become insignificant.
The great volatility of liquid hydrocarbon has rendered it impossible to introduco
it into hot retorts, except in minute quantities, without the production of incom-
bustible compounds of free carbon, and the treatment of the hydrocarbon with an
insufficient degree of heat fails to produce a fixed gas. Various methods have been
suggested proposing to overcome these difficulties, but without producing practical
results, except upon a limited scale.
I am aware that there have been many devices proposing to feed liquid hydro-
carbon and its vapors to fire chambers, and that steam has been employed with
such vapors in a variety of ways; and also that it has been proposed to carburett
the blast air by forcing it to pass over a surface of liquid hydrocarbon; but I am
not aware that a blast of air has ever been employed as a vehicle to convey an
arbitary quantity of vaporous hydrocarbon with greater velocity and pressure into
and through hot retorts; nor am I aware that a jet of superheated steam at a high
pressure has been employed with an injector to automize and force an arbitrary
quantity of vaporous hydrocarbon into a blast of hot air as a vehicle to convey
said vapor to hot retorts; nor am I aware that in connection with a hot blast and
an injector using superheated steam, liquid hydrocarbon has been introduced in
company with a supplemental blast of hot air, whereby said hydrocarbon has been
warmed and prepared for the action of the superheated steam; and I am not aware
that carburetted hydrocarbon gas has ever been produced by a continuous process
without residuum.
The products of this Invention must not be confounded with carburetted air pro-
duced by the passage of the blast through a carburetter whereby the blast will
become more or less charged with hydrocarbon vapor. These are very essential
differences.
First, as to the method of feed; the quantity of vapour taken up will vary
with the heat of the blast and the vilatility of the hydrocarbon exposed,
because the process will depend upon evaporation, and in the carburetter there will
be a consequently increasing quantity of involatile residuum and a corresponding
deficiency in uniformity and control.
By the present Invention the feed is positive, and under perfect control, and there
is no residuum whatever.
Second, as to the quality of result. By the carburetter method inore hydrocarbon
vapor is taken up than the air blast will absorbed, and the product cannot be more
than a carburetted air entirely insufficient to replace solid carbonaceous fuel.
By the present Invention the blast of air is employed as a vehicle to convey an
arbitrary quantity of hydrocarbon vapor to the retorts, wherein its conversion into

page_text: a gas associated with but irrespective of the prosence of the atmospheric air is
completed, whereby I am enabled to produce a fuel gas from liquid hydrocarbon
competent to replace solid fuel much superior to it, at much cheaper rates, and by a
continuous process under a high pressure.
The elements of my Invention are,-
First. A continuous series of retort pipes through which to pass the hydrocarbon
vapors for convertion into gas.
2rd. For a hot-air blast for a vehicle to convey an arbitrary quantity of hydro-
carbon vapor to the furnace or fixed retorts.
3rd. A jet of superheated steam under high pressure, say, from 90 to 100 lbs. per
square inch to automize and disintrigate said vapors.
4th. A hydrocarbon supply pipe and a supplemental current of hot air to receive
the liquid hydrocarbon warm and discharge it into the jet of superheated steam and
hot blast whereby the vapor of liquid hydrocarbon is, in company with hot
atmospheric air and superheated steam under great pressure, subjected to a tem-
perature competent to decompose said vapors, and produce therefrom carburetted
hydrogen gas, the value of which will be proportionate to the quantity of liquid
hydrocarbon employed.
The chemical reactions which take place or their order I do not undertake to
explain, but the results produced are as herein set forth.
Associated with this gas will be the oxygen desired from the atmospheric air and
from the decomposition of the watery vapour of the superheated steain. For some
purposes the fixing retorts may be dispensed with, but their use ensures the most
perfect results.
For all purposes requiring the production of high degrees of heat, as in metalurgis
furnaces, puddling, welding, potteries, glass works, steam generators, and domestic
heaters, the gas is designed to be consumed as fast as produced. For purposes of
illumination it may be purified as stored in gas holders as usual.
K is my tank or reservoir for liquid hydrocarbon, and this tank may be located
at any convenient or desirable distance from the oven, but when properly protected
there is no objection to placing it in the position represented, or in close proximity
to the oven. A gauge indicates to the eye at any moment the quantity of liquid
in the tank, and by knowing the caliber of the tank the quantity discharged during
any given time may be easily determined by inspecting the gauge. The tank K is
connected with the blast pipe D by means of the pipe M, which is provided with
check and stop valves m, n, and discharges into the blast or injector nozzle, so that
by exhaustion liquid is drawn from the pipe M and carried with the blast into the.
oven retorts B, B, where its decomposition and transformation without residuum
into a carburetted hydrogen gas associated with the constituents of the atmosphere
and superheated steam. However in the production of heat for any purpose the
presence of the oxygen derived from the atmosphere is of advantage irrespective of
the nature of the union between it and the carburetted hydrogen because of its
immediate influence as a supporter of combustion.
It is desirable to heat the liquid hydrocarbon before it encounters the superheated
steam, and in that way facilitate its vaporization and decomposition, and I therefore
place an air pipe P in the oven, coiled back and forth, so that the air passing through
it shall become highly heated and insert the end of said pipe into the chamber p
surrounding the nozzle of the pipe M. The hot air issuing from the pipe P and
sucking the liquid hydrocarbon from the pipe N, vaporizes it almost instantly, and
as it passes into the blast pipe it is subjected to the action of the jet of superheated
steam, and from thence to the retorts the temperature is continuously rising until
decomposition has been effected, and the hydrocarbon vapor associated with the
constituents of atmospheric air and the superheated steam has been resolved into a
highly combustible gas which when fed to and fired in the furnace produces an
intense heat and deposits no residuum. The quality of this gas is determined by
the quantity of liquid hydrocarbon fed to the blast, and this quantity is perfectly
under control by means of the valve n,

page_text: The practical effect of this Invention is the production of a continuous process of
gaseous fuel from liquid bydrocarbon at a cost of less than half the cost of coal,
and this fuel is produced without risk, and in quantity and quality as desired, and
under perfect control. It leaves no residuum; it imparts no impurities to the sub-
stance under treatment, and in the working of iron the product is not only superior
in quality, but there is also an increased yield due to the absence of impurities and
the diminished formation of slugs. In practico this gas is fed to the furnace at the
temperature of the fixing retorts, and its combustion is correspondingly intensified,
with a corresponding economy in consumption.
The third part of my Invention relates to a new and improved method of
utilizing hot air for generating steam and other purposes.
Heretofore, when air has been employed as a vehicle for the conveyance of heat.
from the furnace to the subject to be acted on, the air current so einployed has
been dissipated and lost in the surrounding atmosphere as soon as it had passed the
point or object upon which it was designed or expected to act, and the heat which
it holds at the time of such dissipation is lost. Thus, as an illustration, at the
lowest calculation the hot air escaping at the top of the funnel of a steam gene-
rator furnace carries with it 75 per cent. of the effective power of the fuel
consumed, so that work represents not more than 25 per cent., and loss not
less than seventy-five per cent. This vast percent is utterly waste and loss. A
certain portion of it consists of gaseous compounds, combustable and non-com-
bustable, but with a well constructed furnace by far the larger portion is simply air
bearing with it the effective force of the fuel in the form of heat.
To supply the above-named loss of hot air through the funnel, cold air is being
constantly drawn in at the draft, and the heat lost with the escaping air must bo
constantly replaced by a consumption of fuel in proportionate excess of the con-
sumption due to the work performed.
I propose to remedy to a great extent this obvious and well known loss, by
causing the hot air to move in a closed circuit, constantly returning to the source of
heat, and only requiring the consumption of sufficient fuel to make good the loss of
caloric expended in work, and the slight loss by radiation.
I am aware that in blast furnaces the waste gases have been collected at the top
of the cupelo and returned to the tuyeres there to be burnt; but this is not a closed
circuit, because the necessity for the constant fresh air to support combustion is the
same as before.
The waste gases are returned for the purpose of being themselves burnt, and
not for the purpose of aiding combustion, or of being utilized as conveyors of heat
from the furnace to some other point. I am also aware that steam and hot water
have been employed to convey heat from the generator to distant points, and con-
stantly return in a closed circuit, but in these cases entirely different, and minor
results are obtained, the effective difference between these practices and my
present Invention being sufficient to constitute the basis of an entirely independent
Invention.
By way of explanation to clearly show the difference between my Invention and
the previous discoveries alluded to, as the law directs, I will mention, 1st, neither
steain nor water possesses the capacity of air to receive and transmit heat. Steam
is decomposed by high temperature, and its elements possess very different properties
and capacities from a gaseous vapour.
For heating purposes, steam is only available practically to a temperature
ranging from 212° to 250°; at a higher temperature its expansive force and its de-
composition renders its use dangerous; water cannot be employed at a temperature
exceeding 212°, at which point it is converted into steam. These vehicles are
therefore useless for the purposes of my Invention, which demands a temperature
ranging from 600° to 1000° Fahrenheit, as will more fully appear herein-after.
To render my meaning clear in this particular, any device whereby the heat of
the blast is withdrawn. therefrom and utilized I denominate a convertion of heat

page_text: into work, whether the saine be a steam generator, or a simple radiator for heating
the surrounding air in a room.
My Invention therefore consists in a hot blast having a high temperature, say of
800° or 1000° Fahrenheit, and caused to move in a circuit from heater to radiator,
or place of work and back to heater, said circuit being closed, or nearly so, against
the admission of fresh or cold air, so that when the hot air has passed the surface
to be acted on, it is returned to the heater instead of being permitted to escape into
the surrounding atmosphere, whereby it follows that it is only necessary to replace
the heat lost in work and unpreventable radiation at each return to the heater,
and the expenditure of fuel is the quantity necessary to so replace this expended
heat to raise the temperature from, say, 700° to 800°, instead of a quantity sufficient
to raise the same volume from 70° to 800°.
800° may represent the effective temperature before work, and 700° the tem-
perature after work, showing an expenditure of 100°. In ordinary practice this
residue of 700° will be lost, and must be constantly inade good by the heating of
cold air to the effective temperature.
It will appear evident that this Invention is applicable to all purposes where the
required temperature does not exceed that to which atmospheric air may be raised,
say, for instance, 800° to 1000° Fahrenheit, and without attempting to renumerate
all such uses I will only designate the heating of boilers for the generation of steam
and domestic use for heating and cooking.
A description of a practicable method of applying my Invention to these purposes
will render the utility and method of the Invention so plain that any further
Invention required in working it will be merely in minor details of the structure of
appliances to be used in connection therewith.
Having now set forth the general features and scope of this part of my Invention,
I will for convenience confine any particular description to methods of applying it
to the purposes indicated above.
It will be understood that Fig. 1 represents merely a typical apparatus, and not
a structure necessarily to be followed in any of its details.
A represents a hot blast oven which may be constructed in any approved manner,
but a common structure is shown in the Drawings.
The pipes B are constructed of refractory material, and when in full operation im-
parts to the air passing through them a temperature ranging from, say, 700° to 1000°
Fahrenheit; a blast of this character has never been heretofore employed except in
metalurgic furnaces for the purpose of intensifying the combustion of the fuel
by a copious supply of oxygen already heated to or nearly to the temperature of
ignition, and as above stated none of the air once passing through the heater and
for these purposes is returned thereto again, so that the supply is constantly
cold air.
The motor employed to move this air current may be similar to those now
employed, only adapted to withstand the high temperature to which it will be
subjected.
I make no claim herein to any method of forcing the blast, but the method I
prefer to employ, because of its simplicity and efficiency, is steam injection, which I
have fully tested in connection with my hot blast for metalurgic furnaces, and
herein before described.
In the Drawings hereto attached G represents an injector, as referred to. The
current of air forced by the blast engine, of whatever description, moves through
the oven A, and is heated therein, as set forth, and escapes through the flux
pipe Q, whereby it is conveyed to the steam generator R, around which it is caused
to circulate by suitably disposed breachings and jackets of non-conducting and
refractory materials; after circulating about the generator R, as described, the blast
returns through a reflux pipe S to the blower, and is again driven through the
heater A.
Now it is evident that this hot blast will speedily raise the temperature of the

page_text: generator and the contained water to a temperature equal to the temperature of said
blast, and that if steam is not withdrawn from said generator the temperature will
remain at that point, and the consumption of fuel in the fire-box a will only bo
sufficient to replace the loss by unpreventable radiation, and the loss in tempera-
ture will only be in proportion to the volume of steam escaping and the constant
absorbtion of heat in the conversion of water into steam to supply the loss of said
escape.
The efficiency of the injector depends upon a difference in temperature between
the steam injector and the air or fluid drawn in, and it is therefore necessary to
employ a jet of superheated steam at a very high temperature, or to admit a little
cold air, provided the loss of temperature at the boiler R is not sufficient to suitably
cool the return draft. I therefore place at ra cold-air valve, which may be opened
or closed by the attendant as circumstances may at the time require.
In Fig. 10 is represented broadly my plan of applying my hot-air circulation to
domestic uses, that is, for the heating of apartments, cooking, and other purposes. A
is the hot-blast oven, as herein-before described, and G is the injector to force the
blast through the flux pipe Q, from which it passes into lateral pipes t, and to the
u represents the
several buildings, apartments, or places to be supplied with heat.
heat radiator, whereby the heat of the air blast is converted and utilized, whether the
same be for the purposes of warming merely, or for cooking food, or any one of
the many domestic or industrial purposes which require heat. After passing through
the radiator u the current of hot air returns by the pipe i to the reflux pipe S, and
again to the injector G and furnace A.
It will sometimes happen in a range of buildings supplied from the same inain, as
shewn in Fig. 10 for instance, that a greater or lesser number of them will be out of
use some one moment of time, and in that event it appears evident the equilibrium
of pressure would be disturbed. I therefore place between said pipes Q and Sa
connecting pipe or passage T, having with it an automatic pressure valve, which will
open when the pressure in pipe Q exceeds the proper limit of excess. For this pur-
pose a simple weighted valve of some refractory material will answer efficiently.
It is not necessary that I should give any detailed description of the apparatus to
be employed in the various domestic or industrial uses alluded to above, as it will
be understood no special structure is required. It is only necessary that the object
or vessel to be subjected to heat shall be placed in a proper receptacle, which is itself
surrounded by the current of hot air.
The fourth part of my Invention relates to apparatus for making gas for fuel, and
especially adapted to steam generators on board ship, whereby practically perfect
and complete combustion can be secured, and the great per-centage of waste up the
stack saved. The only problem in the case is the cost of the gas product in relation
to the waste under ordinary methods. By my method, as herein shewn and
describe, the cost of converting liquid hydrocarbon into gas is almost nominal,
being only between three and four pence per thousand cubic feet.
The following additional Drawings relate to this part of my Invention :—
Fig. 12 is a transverse section of retort; Fig. 13 is a longitudinal section of the
same.
Fig. 14 is a front elevation of retorts and marine boiler.
Fig. 15 is a longitudinal section of furnace.
Fig. 16 is a longitudinal section of injector.
Fig. 17 is a front elevation of three benches of gas retorts.
Fig. 18 is a longitudinal section of gas retort; and Fig. 19 a transverse section of
the same.
A is a boiler, say, of a steamship, arranged with the furnaces B1, B¹¹, in the
usual way; C is a bench of ovens or retorts for heating the blast air and super-
heating the steam; D" is the blast injector, and Ell is the blast pipe. Steam is
taken from the boiler in the pipe F", and conducted thereby to the superheater G",
and then to the blast injector D" H" is a tank for liquid hydrocarbon, which may
be. located at any convenient and desirable place at a sufficient elevation to give it

page_text: free discharge, and sufficiently far from the furnace to render it secure against fire.
I, I, are the hydrocarbon injectors, whereby the liquid hydrocarbon is injected
into the furnace in the form of gas, or, if the feed is excessive, in gas and spray, and
complete combustion is secured without reference to artificial draft produced by
smoke stacks.
The bench of retorts C¹¹ has its own fire for the heating of the retorts I", and
said fire may consist as usual of a coal fire upon the grate, or a gas flame, or a
combination of the two. It will perhaps be necessary to use coal or other similar
fuel staring up, but after the parts are once hot, gas may entirely be substituted.
The retorts G consist of cylindrical vessels divided longitudinally by partitions
into four passages, as shewn; this is the manner which at present I prefer. The
same end may be attained less advantageously by means of pipes placed one within
the other. The connection from one division to the next may be formed by means
of the pipes K", or by making the partitions i alternately short at one end.
The retort G contains coils of steam pipes, shewn in Fig. 18, through which
steam passes from the boiler, and is superheated before it reaches the injector D".
The air blast from the injector D" is forced through the retorts J" successively,
and is thereby heated nearly or quite to the point of ignition, and from the last of
said retorts it is conducted in pipe L" in front of the furnace B¹¹, and by a branchi
opposite each furnace it is conducted to the fire space above the grate. The
nozzle of the pipe " constitutes a second injector, as shewn in Fig. 15, receiving
superheated steam by the pipe m", hot air through the branch 1, and liquid hydro-
carbon through the pipe 1. The separate supplemental injector I" at each furnace
is necessary to give efficient control over each furnace separately.
The liquid hydrocarbon is drawn in by the jet of steam and hot air in such
quantity as may be desired and permitted by the adjustment of the controlling
valve, and by the heat of the air and steam jet it is instantly volatilized and pro-
jected into the fire chamber in the form of gas already heated nearly to the point of
ignition, and in company with the blast of hot air sufficient to supply nearly or
quite all the oxygen required for its combustion. Little or no extraneous draft will
be required.
The ordinary grate of the furnace is covered with coke or asbestus to catch the
unvolatilized liquid through an excess of feed by being involatilized. Out of the
nozzle the intense heat will immediately volatilize any such spray and cause its
combustion. By these I am enabled to apply liquid hydrocarbon to the heating of
marine boilers with the fullest control, and with all advantages which attend the
saving of about three-fourths the space now occupied by coal, the saving of
nearly all the expense of handling this solid fuel residuum of ashes, and the saving
of all the present waste fuel up the smoke stack in smoke and inconsumed carbonic
oxide.
My improvements herein shewn are equally well adapted to boilers on laud, but
as the same necessity for economy of room does not exist on land I therefore repre-
sent and describe its application to marine boilers.
The fifth part of my Invention relates to the manufacture of fixed gas for illumi-
nating purposes from liquid hydrocarbon in ordinary gas retorts.
To convert the gas formed as described above into permanent gas for illuminating
purposes it is necessary to pass it through a series of retorts, where it may be sub-
jected to the heat required to decompose the elements and constitute a compound
fixed gas. This result does not require the use of retorts of any special structure,
but it is desirable to make the best possible change in existing methods, and especially 5
to facilitate the adaption of existing plants to my new method. I therefore show
how ordinary benches of gas retorts may at a small expense be constructed to
manufacture gas from liquid hydrocarbon by my method.
Fig. 17 represents three benches of ordinary gas retorts O". Into each of said
retorts a cast-iron pipe P", six inches in diameter through the cap, and extended 5
nearly to the inner end of the retort; another pipe q" of equal diameter is likewise
inserted through the same cap, but terminates close to inner surface of said cap..

page_text: The short pipe q11 of one retort is connected by an intermediate pipe by a long
pipe 2 of the adjacent retort, so that if a blast of gas or air is forced through said
series it will be subjected successively to the heat of the several retorts, being forced
to pass through the whole length of each.
The cold air is taken in at R", and after passing through the several retorts of
the first bench, and thereby becoming heated, it enters the injector D", at which
point the liquid hydrocarbon is also received, as hereinfore set forth, through pipe u¹¹,
and the mingled hot air, superheated steam, and vaporised hydrocarbon are blown
through the several rotorts of the second and third benches successively, and the
gas becomes fixed. From the last retort of the third bend the gas passes to the
hydraulic main, and thence to the scrubbers and purifiers, as in the ordinary manu-
facture of gas.
The pipes S for superheating steam may be laid in one or more of the retorts, as
shewn.
The last part of my Invention relates to a compound liquid fuel suitable for use
with the several devices herein-before described.
It is well known that the tar refuse from the manufacture of coal gas is a very
rich hydrocarbon, but all efforts to utilize this product on a commercial scale as fuel
have heretofore failed.
I have discovered that a mixture of coal tar with the refuse of oil distillation
from petroleum, shale, and resin constitutes a very valuable and cheap liquid com-
pound capable of convertion into gas at a very cheap rate, suitable for heating or
illuminating purposes.
The proportions of the ingredients may vary, but I have found most advanta-
geous a mixture as follows:-
Coal tar
-
2 parts.
Refuse of oil distillation from petroleum, shale, and resin
1 part.
When thoroughly mixed this compound is sufficiently volatile to be fed to
proper retorts, and converted into gas, which may be consumed in furnaces while
in a crude form, or, after proper purification, as an illuminating gas.
As a fuel its advantages over coal are very important. Ten pounds of this com..
pound is equal to eighty pounds of coal, and occupies but one-eighth the space.
It also renders unnecessary most of the labor required to handle the coal and ashes.
These advantages are of great importance on shipboard, where economy of storage
is a matter of moment.
Having described the construction and manner of working my said Invention,
what I claim is,-
First. An apparatus to produce a hot blast, consisting essentially of a hot-blast.
oven, a steam generator, and a hot-blast injector taking steam from said generator
at a high pressure, in combination substantially as set forth.
Second. A hot-blast oven and a blast injector taking steam from said generator
substantially as described, combined with a hot feed pipe E laid in the wasto heat
space of said oven for the purpose set forth.
Third. In combination a hot-blast oven and a blast injector taking steam from a
steam generator through a superheated pipe I laid in the waste heat space of said
oven, substantially as described.
Fourth. A hot feed pipe E and rettorts B, B, combined with a blast injector G
and a jet of high-pressure superheated steam, as set forth.
Fifth. The injector G and retorts B, B, combined with the feed pipe F and
gate, for the purpose of regulating and controlling the flow of air to the blast pipe.
Sixth. An injector G provided with two steam jet pipes within it, substantially
as set forth.
Seventh. A continuous process for converting liquid hydrocarbon into gas, sub-
stantially as herein described, to wit, injecting by means of superheated steam at
high pressure a spray or automized jet of liquid hydrocarbon into a blast of hot air,
whereby it is conveyed into and through a series of hot retorts wherein it con-
vertion into inflamable gas is completed, as set forth.

page_text: Eighth. In combination to form an apparatus for the continuous manufacture of
gas from liquid hydrocarbon, consisting essentially in a series of retorts in a hot
oven, a blast injector operated by a jet of high-pressure superheated steam, and a
supply pipe to deliver liquid hydrocarbon, as set forth.
Ninth. The combination for the purpose set forth of a series of retorts B, B, set
in a hot oven, a steam injector G, a hot feed pipe F, and a supply pipe M entering
the supplementary hot-blast chamber p within the steam nozzle of said injector, and
delivering liquid hydrocarbon, as set forth.
Tenth. A blast of hot air to receive and warm a jet of liquid hydrocarbon, com-
bined with a jet of superheated steam at a high pressure to vaporize said hydro-
carbon, and force the same with the hot air into and through the fixed retorts,
substantially as set forth.
Eleventh. Combined with the injector G, steam pipe I, and hot-air pipe P, the
hydrocarbon pipe M provided with a check valve m to check back pressure from
the injector.
Twelfth. The process, substantially as herein described, for using a current of hot
air substantially in a closed circuit, as set forth, whereby said hot air is conducted
to the place of work and returned to the heater in a constantly recurring succession,
as and to the effect set forth.
Thirteenth. A blowing apparatus and a blast heater,_combined with flux and
reflux pipes or ducts, and an interposed steam generator R, or other converters of
heat into work, substantially as set forth.
Fourteenth. A hot oven A, flux and reflux pipes or ducts, and a steam generator
R, or other converters of heat into work, combined with a steam blast injector G,
substantially as set forth.
Fifteenth. A blowing apparatus, a blast heater, separate flux and reflux pipes or
ducts combined with a system of connecting pipes, substantially as shewn in Fig. 10,
whereby the hot blast is conveyed by the Aux pipe, and transmitted therefrom to
the reflux pipe for the purpose of distributing said hot blast to a large number of
intermediate points, as set forth.
Sixteenth. A blowing apparatus, a hot-blast oven, separate flux and reflux pipes
connected by lateral pipes t and v with interposed radiators u, combined with an
equalizing valve T, as and for the purpose set forth.
Seventeenth. One or more boilers A¹¹, marine or otherwise, with the furnaces B¹¹,
as set forth, combined with the bench of retorts for heating the blast and super-
heating the steam, the blast injector D" and the blast pipe E", L", in front of the
furnace B, as set forth.
Eighteenth. The benches A", B", C", of ordinary retorts combined with an
injector D and pipes 2" extending nearly to the inner ends of the several retorts,
and the pipes q" and connecting pipes for manufacturing fixed gas from liquid
hydrocarbon in ordinary gas retorts, substantially as set forth.
Nineteenth. A liquid fuel compound, consisting of a mixture of coal tar and the
refuse of oil distillation from petroleum, shale, and resin, substantially as set forth.
In witness whereof, I, the said Martin Benson, have hereunto set my hand and
seal, this Second day of April, in the year of our Lord 1878.