Improvements in Gas Generators.
Year: 1895

page_text: Improvements in Gas Generators.
I, FREDERIC. THUMAN, of 9 Victoria Street, in the County of London, Gas
Engineer, do hereby declare the nature of this invention to be as follows:-
--
My invention relates to gas generators of the kind in which gas is generated by
passing air or steam through a previously heated mass of carbonaceous fuel, and it
has particular reference to the construction of the grates upon which the fuel
mass is supported in the generator, and to the combination of the grates with the
generator.
As heretofore constructed, generators of the kind referred to have been provided
with cleaning doors extending through the walls above the level of the grate
surface. Usually these doors open both above and below the grate surface so as to
give access at the same time to the ash chamber and to the top of the grate, access
to the grate being necessary for the introduction of the cleaning tools and the
extraction of the clinker and ash. Much trouble has been found to ensue from
this construction, particularly in water gas generators, in which steam is from time
to time reversed in its direction of passage through the fuel. The principal
mischief is due to the tendency that exists to fuse away the firebrick lining of the
generator immediately above the cleaning doors, caused by unequal distribution of
the air blast and steam, and by the lodgment of fuel in the fire door openings.
The object of my invention is to avoid the mischief and mischievous tendencies
mentioned, and this I accomplish by supporting my grate normally substantially at
the level of the top of the cleaning doors, and at the same time so constructing the
grate that it can be retracted or removed in such a manner as to give passage
through the cleaning doors for the tools and clinker. It is obviously not necessary
to move the entire grate for this purpose, and I therefore, preferably, construct
the grate in sections, some of which, registering with the cleaning doors, can be
moved in such a way as to give the necessary opening through the doors to the top
of the grate.
The further purpose of my invention is to provide a means of removing all the
clinker and ash from the fuel bed with the removal of the least possible amount
of valuable fuel from the generator. As grates have heretofore been constructed,
large quantities of valuable fuel have been allowed to fall through the spaces of
the grate bars into the ash chamber during the process of cleaning the fire and
sul.sequently withdrawn with the ash, thus decreasing the fuel economy. To avoid
this, I have, by my invention, provided a means of closing at will the spaces
between the grate bars of the fixed portions of the grate. This I accomplish by
means of a secondary movable grate or grid so constructed that its bars can be
made to close the spaces of the upper primary grate during the period of cleaning
the fire, and can be retracted during the time that the generator is in action.
According to oue mode of carrying my invention into effect, the cleaning doors
leading into the ash chamber below the normal working position of the grate extends
for some distance above the grate to give passage to cleaning tools and for the
removal of clinker and ash. The grate is made up of a fixed part or section, and
one two or more movable sections. The normal level of the grate, at least when
it registers with the cleaning doors, and preferably throughout, should in all cases
be substantially that of the top of the cleaning doors, so that in operation the fuel
D

page_text: charge nes above the level of the tops of these doors, and in order to permit of
the insertion of cleaning tools and the extraction of clinker and ash the grate must
be retractable to such an extent as will secure an opening of the required size for
this purpose through the doors and on to the upper surface of the grate. I provide
supporting bars extending across and below the stationary grate surface and on
these bars I rest the inner ends of the movable grate sections, the outer ends of
which extend into the cleaning doors and are supported on cross bars resting on
ledges formed in the sides of the door openings. Of course any convenient means
may be employed for supporting the outer ends of the movable sections, but the
use of removable cross bars is desirable, because by drawing these bars backward
the outer ends of the movable sections are allowed to fall down, giving at once
access to the fire above the grate over the top of the said movable sections through
the door openings. The portions of the movable grate sections which extend within
the generator chamber are made up of grate bars, while the outer portion which
normally lies in the door opening should consist of a flat plate.
When I make the movable grate section removable, it is advisable to supply
supplemental means for sustaining the portion of the charge normally lying above
the removable sections when they are withdrawn. I sometimes provide pockets
for this purpose. These pockets rest at their inner ends upon the supporting bars
above mentioned and at their outer ends on cross bars supported on ledges formed
or fixed to the sides of the cleaning doors. The bottoms of the pockets slope downward
and are preferably provided with slots and side walls. These pockets support the
fuel when the movable sections are withdrawn and allow of the cleaning tools being
readily passed through the door over the tops of the pockets, to effect the removal
of the clinker and ash from the grate. After the grate has been properly cleaned,
the bars are replaced in position and the movable sections can then be passed over
the bars to their normal operative position. The portion of the fuel lying in the
pocket below the removable section being withdrawn before the doors are secured
over the openings, it will be seen that the sloping bottoms of the pockets will guide
the front ends of the movable sections into position while the side walls of the
pockets will also serve as guides preventing a lateral displacement of the movable
sections. Moreover since the air has free access to the back of the pocket and
thence to the under side of the movable sections the draught will be evenly
distributed over the entire grate surface even if slots are not provided in the bottom
of the pockets.
I provide a grid-like device for closing the openings through the grate while the
latter is being cleaned; the said device has openings corresponding to those of
the grate and is movable by means of a screw and handle upon slides. By this
means I prevent the loss of valuable fuel through the grate.
In a modification of my invention a single transverse supporting bar extends
across the middle of the generator, and to it are clamped hinge rods. The inner
ends of the movable sections are hinged to the said rods, while their outer ends
extend into the cleaning openings. In operative position the outer ends of the
movable sections are thrust upward against the top of the cleaning door openings
and retained by suitable wedge blocks. On the withdrawal of these wedge blocks,
or other supporting devices, the outer ends of the movable sections will fall down
to the bottom of the openings, thus permitting the entry of tools and the
withdrawal of clinker. The entire section of grate on each side of the supporting
bar may be hinged, but it will be sufficient to hinge only those portions which
register with the cleaning doors. I provide a movable cross bar in the upper
portion of the cleaning door to afford a rest to the cleaning tools.
According to a further modification the stationary portion of the grate is
supported upon two cross bars and the movable portions of the grate are
substantially like the ones last described but rather shorter, being hinged to rods
secured to the two cross bars. An advantage of this construction is that it permits
of the use of the grate closing device hereinabove referred to.
In a further modification the stationary grate sections are constructed and

page_text: placed with regard to the cleaning bars, substantially as is usual with the grates.
heretofore used, the grate bars being supported on a central cross bar upon a flange
extending out from the body of the generator, while the portions extending into
the cleaning bars are supported on other cross bars. The advantage of my
invention is imparted to this construction of grate by the use in connection with
it of retractable portions, which are thrust in through the openings over the top of
the grate bars forming in themselves, at their outer ends a supplemental series of
grate bars which incline upward from the level of the stationary portion of the
grate to the top of the cleaning bars. While I much prefer to raise the whole
level of the grate to the top of the cleaning bars the use of these retractable grate
sections permits the advantage of my invention to be secured in great measure
without changing existing apparatus.
Obviously the use of the unbroken stationary grate surface permits of extended
use of the grate closing device, which, in this construction, can practically close the
entire grate.
According to a still further modification embodying my invention, the grate
surface is divided into two sections each supported upon cross bars which in turn
rest upon the top of vertically movable supports constituting piston rods extending
into cylinders and provided with pistons situated inside of the cylinders. Conduits
are provided through which fluid under pressure is introduced into the cylinders or
permitted to flow out therefrom with the result of either raising or lowering the
grate section resting on the rod belonging to the cylinder which is in operation.
In the lower position the grate section is lowered to the bottom of the cleaning bar
and a cross bar may be conveniently supplied for sustaining the weight of the
grate bar section at that point. In order to support the grate bar section in its
elevated position independently of the pressure in the cylinder, I provide cross bars
resting at one end of the bottom of the cleaning bar and at the other end in slots
formed in a cross bar which lies across the centre of the generator between the
two grate sections.
Any other suitable means can be employed for lowering or lifting the movable
portions, such as steam power, screws, or combination of levers.
In this modification of my invention, the closing device previously referred to
will not be necessary as the grate or portions of the grate lowered to be cleaned
will rest substantially upon the bottom of the ash chamber thus making it
impossible for any of the fuel to fall through the bars. It offers the advantage of.
allowing one section of the grate to be lowered at a time; thus the inner portion
of the lowered section is as accessible for the purpose of removing clinker as the
outer portion adjacent to the cleaning doors.
Dated this 3rd day of December 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings,' London, W.C., Agents for the Applicant.
Improvements in Gas Generators.
I, FREDERIC THUMAN, of 9 Victoria Street, in the County of London, Gas
Engineer, 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 :-
My invention relates to gas generators of the kind in which gas is generated by
passing air or steam through a previously heated mass of carbonaceous fuel, and it
has particular reference to the construction of the grates upon which the fuel:
mass is supported in the generator, and to the combination of the grates with the
generator.

page_text: As heretofore constructed, generators of the kind referred to have been provided
with cleaning door ways or openings extending through the walls above the level
of the grate surface. Usually the cleaning doors open both above and below the
grate surface so as to give access at the same time to the ash pit and to the top of
the grate, access to the grate being necessary for the introduction of the cleaning
tools and the extraction of the clinker and ash. Much trouble has been found to
ensue from this construction, particularly in water gas generators, in which steam
is from time to time reversed in its direction of passage through the fuel. The
principal objection is the tendency that exists for the firebrick lining of the
generator immediately above the cleaning door ways or openings to fuse by reason
of unequal distribution of the air blast and steam, and by the lodgment of fuel
in the fire door openings. According to my invention this objection is avoided
by normally supporting the grate substantially at the level of the top of the
cleaning door ways and at the same time so constructing the grate that it can be
retracted or removed in such a manner as to give passage through the cleaning
door ways for the tools and clinker. It is obviously not necessary to remove the
entire grate for this purpose, and I therefore, preferably construct the grate in
sections, some of which, registering with the cleaning door openings can be moved
in such a way as to give the necessary opening through the said door ways to the
top of the grate.
The further purpose of my invention is to provide a means of removing all the
clinker and ash from the fuel bed with the removal of the least possible amount
of valuable fuel from the generator. As grates have heretofore been constructed,
large quantities of valuable fuel have been allowed to fall through the spaces of
the grate bars into the ash chamber during the process of cleaning the fire and
to be subsequently withdrawn from the ash, thus decreasing the fuel economy.
To avoid this wastefulness I have, by my invention, provided a means of closing
at will the spaces between the grate bars of the fixed portions of the grate. This
I accomplish by means of a secondary movable grate or grid so constructed that its
bars can be made to close the spaces of the upper primary grate during the period
of cleaning the fire, and can be retracted during the time when the generator is
in action.
Reference will now be had to the drawings, which illustrate convenient and
practicable constructions embodying my invention.
Figure 1 is a sectional plan of the lower part of a water gas generator embodying
my invention in what I believe to be its most convenient form the section being
taken on the line 2-2 of Figure 2; and
Figure 2 is a sectional elevation of the same part of the apparatus, taken on the
line 1-1 of Figure 1.
Figure 3 is a perspective view of one of the pockets B¹ shown in Figures 1
and 2 ;
Figure 4 is an elevation on a small scale of a water gas generator having
connections for the reversal of the steam;
Figure 5 is a sectional plan on the line 3-3 of Figure 6, showing the bottom of
a modified form of apparatus, and
Figure 6 is a sectional elevation on the line 4-4 of Figure 5.
Figure 7 is a sectional plan on the line 6-6 of Figure 8 showing a modified
construction.
Figure 8 is a sectional elevation on the line 5-5 of Figure 7, and
Figure 9 is a sectional elevation on the line 7-7 of Figure 7.
Figure 10 is a sectional plan on the line 9-9 of Figure 11 showing another
modification,
Figure 11 is a sectional elevation on the line 8-8 of Figure 10, and
Figures 12 and 13 show details of construction.
Figure 1 is a sectional plan on the line 11-11 of Figure 15 showing still
another modification, and
Figure 15 is a sectional elevation on line 10-10 of Figure 14.

page_text: A indicates the generator, which in Figure 4 is shown provided with an air
blast. inlet G situated below the grate indicated at B. Gas take-off pipes lead
from both the bottom and top of the generator, and are indicated at J and J¹.
Valves K and K¹ are provided in each pipe and both pipes connect with a common
take-off J. H and H indicate steam pipes connecting respectively with the
conduits J and J' and by which steam can be introduced at the bottom or top of
the generator. This is the type of apparatus to which my improvements are
peculiarly applicable, but it will be understood that my invention is also adapted
for use, and can be advantageously used, with water gas generators in which the
air and steam are passed through the fuel in only one direction, and also with
fuel gas generators.
FF indicate cleaning openings or door ways leading into the ash chamber below
the normal working position of the grate, and as I have above explained, usually
extending for some distance above the grate to give passage to cleaning tools and
for the removal of clinker and ash. In Figures 1 and 2 the grate is shown made
up of parts or sections B, B2 and B'; in Figures 5, 6, 7, 8 and 9 as made up of
the sections B and B3; in Figures 10 and 11 of sections B and B and in Figures 14
and 15 of sections B, B in all cases indicating a fixed grate section while the
portions marked B1 B2 B3 B4 aud B are movable. The normal level of the grate
should in all cases be substantially that of the top of the cleaning door openings F,
so that in operation the fuel charge lies above the level of the tops of these door
openings and (in order to permit of the insertion of cleaning tools and the extraction
of clinker and ash) the grate must be retractable to such an extent as will secure
an opening of the required size for this purpose through the door ways and on to
the upper surface of the grate. I accomplish this in the construction shown in
Figure 1 by making the portion of the grate indicated at B fixed, while the portions
adjacent to the cleaning door openings are made retractable. As shown provide
supporting bars C C extending across and below the stationary grate surface B
and on these bars I rest indirectly the inner ends of the grate sections B², the
outer ends of which extend into the cleaning door openings and are supported on
cross bars E' resting on ledges E formed in the sides of the door openings. Of
course any convenient means may be employed for supporting the outer ends of
the sections B2, but the use of removable cross bars E' as shown, is desirable,
because by drawing these bars backward out of the lugs E the outer ends of the
sections B are allowed to fall down, giving at once access to the fire above the
grate over the top of the sections B3 through the door openings. The portions of
the grate sections B2 which extend within the generator chamber are made up of
grate bars as indicated at 6, while the outer portion which normally lies in the
door opening should consist of a flat plate as shown.
When, as in the construction shown in Figures 1 and 2, I make the movable
grate section removable, it is advisable to supply supplemental means for sustaining
the portion of the charge normally lying above the removable sections when they
are withdrawo, and what I may call the pockets B', are provided for this purpose.
These pockets rest at their inuer ends b directly upon the supporting cross bars C
and at their outer ends 62 on cross bars D₁ supported on ledges D formed or fixed
to the sides of the cleaning door openings. The bottoms of the pockets slope:
downward as shown and are preferably provided with slots as shown at 64 and
with side walls as indicated at 63. It will be obvious that these pockets will.
support the fuel when the sections B2 are withdrawn and that cleaning tools can
be readily passed through the door openings over the tops of the pockets and
clinker and ash can be removed from the grate. After the grate has been properly
cleaned, the bars El are replaced in position and the sections B2 can then be passed
over the bars to their normal operative position as indicated in Figure 2. The
portion of the fuel lying in the pocket below the removable section being withdrawn
before the doors F are secured over the openings, it will be seen that the sloping
bottoms of the pockets will guide the front ends of the movable section into.
position while the side walls will also serve as guides for preventing a. lateral.

page_text: displacement of the movable sections. Moreover since the air has free access to
the back of the pocket B₁ and thence to the under side of the movable sections B²
the draft will be evenly distributed over the entire grate surface even if the slots 64
are not provided in the bottoms of the pockets.
N indicates a device for closing the openings through the grate while it is being
cleaned, it is a grid like device having openings corresponding to those of the grate
and is movable, by means of a screw N₁ and handle N2, upon slides, here formed
on bars C so as to close the grate openings while the operation of cleaning is going
on and so prevent the loss of valuable fuel through the grate.
G in all the figures indicates the air blast opening below the grate, and H in
Figures 2 and 6, indicates a steam pipe leading below the grate.
I is an opening
in the ash chamber into which a gas take-off pipe J may lead. This take-off
would normally be higher up in the ash chamber.
Referring to Figures 5 and 6, B as in the other figures, indicates the stationary
portions of the grate, while B³ indicates the various retractable sections of the
grate. In this construction a single transverse supporting bar C' extends across
the middle of the generator, and to it are clamped hinged bars e by means of a
clamp such as shown, the inner ends of the section B3 being hinged to the bars c,
while their outer ends extend into the cleaning openings F. In operative position
the outer ends of the sections B³ are thrust upward against the top of the cleaning
door openings as shown at the right hand side of Figure 6 and are held firmly in
this position by wedge blocks L. On the withdrawal of these wedge blocks, or
other supporting devices, the outer ends of the sections B3 will fall down to the
bottom of the openings F, as indicated at the left hand side of Figure 6 permitting
the entry of tools and the withdrawal of clinker. The entire section of grate on
each side of the supporting bar C' may be hinged, but it will be sufficient to hinge
only those portions adjacent to the cleaning door openings as shown in the drawing.
M indicates a movable cross bar in the upper portion of the cleaning door
opening supported on brackets M, the function of the bar in this construction being
to afford a rest to the cleaning tools.
Referring next to the modification shown in Figures 7, 8 and 9, it will be seen
that the stationary portion B of the grate is supported upon two cross bars C, C,
as in Figures 1 and 2. The movable portions of the grate, indicated at B³ B³, are
substantially like the similar portions indicated in Figures 5 and 6 by the same
letter of reference but rather shorter, being hinged to rods c secured to the two
cross bars C C. An advantage of this construction is that it permits of the use
of the grate closing device N, described in connection with Figures 1 and 2, such
a use being obviously inconvenient, if not impracticable, with the construction
indicated in Figures 5 and 6.
I will now refer to the construction shown in Figures 10 to 13. In this
modification I have indicated stationary grate sections B B constructed and placed
with regard to the cleaning door openings F substantially as is usual with the
grates heretofore used, the grate bars being supported by a central cross bar C³
which rests upon a flange extending out from the body of the generator and
indicated at C, while the portions extending into the cleaning openings are supported
on cross bars C. The advantage of my invention is imparted to this construction
of grate by the use in connection with it of retractable portions B B, which are
thrust in through the openings F over the top of the grate bars forming in
themselves, at their outer ends a supplemental series of grate bars which incline
upward from the level of the stationary portion of the grate to the top of the
cleaning openings as shown in the drawing. While I much prefer to raise the
whole level of the grate to the top of the cleaning openings the use of these
retractable grate sections B4 permits the advantage of my invention to be secured
in great measure without changing existing apparatus.
Obviously the use of the unbroken stationary grate surface permits of extended
use of the grate closing device N ; which, in this construction, can practically close
the entire grate, the sliding grid being here shown as supported on cross bars C³ C³.

page_text: In Figures 14 and 15 I have shown still another modification embodying my
invention, the grate surface being here divided into two sections B5 B' each sup-
ported upon cross bars C+ which in turn rest upon the top of vertically movable
supports indicated at OO and here constituting piston rods extending into the
cylinders P and provided with pistons situated inside the cylinders, P' indicating
conduits through which fluid under pressure is introduced into the cylinders or
permitted to How out therefrom with the result of either raising or lowering
the grate section resting on the rod O belonging to the cylinder which is in
operation. In the lower position as shown at the right hand side of Figure 15
the grate section is lowered to the bottom of the cleaning door opening F and
a cross bar S may be conveniently supplied for sustaining the weight of the grate
bar section at that point. On the left hand side of Figure 15 the grate bar
section B is shown as elevated to the top of the cleaning opening and in order
to support it there independently of the pressure in the cylinder P, I have shown
cross bars R resting at one end on the bottom of the cleaning opening F and at
the other end in slots Q' formed in a cross bar Q which lies across the centre of
the generator between the two grate sections B, B. Any other suitable means
can be employed for lowering or lifting the portions of the grate, such as steam
power, screws, or combinations of levers.
In this modification of my invention, it is obvious that the closing device
previously referred to as N will not be necessary as the grate or portions of the
grate lowered to be cleaned will rest substantially upon the bottom of the ash
chamber thus making it impossible for any of the fuel to fall through the bars.
It offers the advantage of allowing one section of the grate to be lowered at a
time; thus the inner portion of the lowered section is as accessible for the purpose
of removing clinker as the outer portion adjacent to the cleaning door openings.
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 :-
1. In combination with a gas generator having cleaning door openings such as F,
a grate situated in said generator and having the portions of its surface which
correspond with the cleaning openings normally flush with the tops thereof but
retractable therefrom below the level of the tops of the door openings or otherwise
in order to give access to the top of the grate through said cleaning openings,
substantially as described.
2. The construction of the grate in sections which are retractable, the inner ends
of said sections being sustained by fixed supports, and the outer ends by removable
supports whereby said outer ends can be dropped at will to a lower level, substantially
as, and for the purpose, specified.
3. The combination with the movable grate sections of pockets B' having inclined
bottoms extending up to or near the level of the fixed grate section, and with
or without side walls & extending to or about the same level, situated below said
Sections B2 and adapted to support the fuel when said sections are withdrawn,
ubstantially as described.
4. The movable grid situated below the grate and adapted to open or close the
rate openings at will, substantially as described.
5. The improvements in gas generators, substantially as described with reference
o one or other of the constructions illustrated in the accompanying drawings, for
he purposes specified.
Data L
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.