Process for the Production of Compressed Artificial Sandstones and Apparatus therefor.
Year: 1899

page_text: Date of Application, 24th May, 1899
Complete Specification Left, 26th Feb., 1900-Accepted, 24th May, 1900
PROVISIONAL SPECIFICATION.
Process for the Production of Compressed Artificial Sandstones
and Apparatus therefor.
1, DR. WALTER SCHULTHESS, of Tunnelstrasse 7, Zurich, Switzerland, Chemist,
do hereby declare the nature of this invention to be as follows: —
This invention relates to a steaming process and to apparatus for use in the
production of compressed artificial sandstones from sand containing silicic acid
and slaked lime in the form of powder. This process consists in making use,
for effecting the chemical reaction between sand and lime with a view to the
production of stone, of superheated yet pressureless steam at a temperature of
over 100° C. By treating the formed pieces with superheated steam the forma-
tion of calcium silicate, according to the degree of superheating, is effected in
a short time, say from 8 to 48 hours.
In carrying out the above-mentioned process, there may be used with advan-
tage the steaming chamber illustrated in Figs. 1 to 4 of the accompanying
drawing of which Fig. 1 represents a vertical longitudinal section corresponding
to the line A-A of Fig. 3, Fig. 2 a cross section corresponding to the line B--B
of Fig. 3, and Fig. 3, a horizontal section, whilst Fig. 4 is a detail of the
interior arrangement corresponding to the section line C-C of Fig. 3.
This steaming-chamber has a superheating device founded on the fact that
steam of about 97° C., when passed through metal pipes that are in a medium
warmer than 100° C., is heated to the temperature of this medium without
experiencing a rise of pressure when the issuing superheated steam enters a
vessel at ordinary atmospheric pressure. This is on the supposition that the
pipes that are in the hot medium and through which the steam is passed, are
given a surface of a size corresponding to the velocity with which the steam
passes through.
The steaming-chamber has a containing-vessel 1 which is preferably made of
thin sheet-iron and open at the top, and the upper compartment 11 of which
receives the shaped blocks that are to be steamed. The said blocks are placed
on a perforated intermediate floor 2, which, in the example shown, consists of
longitudinal beams, preferably of iron, which form a grid or grate. In order
to facilitate the introduction of the articles to be steamed the perforated inter-
mediate floor 2 rests on an underframe made like a carriage the wheels 12 of
which can run on a rail track 15 arranged on the floor 13 of the receiver 1.
The means for superheating the steam consist of boilers 16, carried by the
truck-frame, and passed through a number of coils of metal pipes 17, the ends
of which are respectively connected steam-tight with the upper and lower boiler-
wall.
These boilers 16, on which the intermediate floor 2 rests, are carried by trans-
verse beams 24 which are themselves fastened to longitudinal beams 25 located

page_text: between the boilers; to the said longitudinal beams the
wheels 12 are fixed.
bearings for the
The middle boiler 16 has an inlet-pipe 18 and is in communication through
the pipes 19 with the outer boilers 16, each of which is provided with a dis-
charge pipe 20. In addition all three boilers are in communication with
another supply 21.
In the space 23 under the boilers a steam-pipe 22 is arranged; this has a
serpentine shape and is provided inside the containing-vessel 1 on both sides
with suitably sized holes to permit the steam to sweep as uniformly as possible
over the entire interior of the lower compartment 23
The connection between the compartments 11 and 23 should, as far as possible,
be only through the worms 17. To this end the spaces between the boilers 16
are closed at the top by a plate 26 and the part of the wheels 12 that rises
above this is covered with a cap 27. Further, in each of these interspaces,
the space between the two longitudinal beams 25 on the one hand and between
the two wheels 12 on the other, is formed into a boiler 30 by the upper plate 26,
a lower plate 28, and two sides plates 29 which boilers 30 are also traversed
by a number of coiled metal pipes 17, the ends of which are each joined steam-
tight to the upper and lower plate. These boilers 30, serve, as do the boilers 16,
to superbeat the steam coming from the pipe 22 and are for this purpose in
connection with the inlet pipe 21, and on one hand by the pipes 31 with the
middle boilers 16 and on the other by pipes 32 with the outer boilers 16.
The containing vessel 1 is provided with a door 36 at one side, to permit
of the introduction and withdrawal of the truck, and is covered with a casing 8
made of a poor conductor of heat; wood has been found to be a practical
material for this purpose, and this is provided on the side facing the containing
vessel with a covering of thin sheet zinc. The sheet-zinc forming the inner
covering is preferably laid, as shown, not directly on the wooden-wall but fixed
at a certain distance from the same; the air-space which is thus formed between
the sheet-zinc and the wooden wall increases the insulating power of the latter
considerably.
The dimensions of the casing 8 are so chosen that its side walls are every-
where at a certain distance from the containing vessel 1; in this way a free
space is formed which is closed at the bottom by the laterally-projecting
edge 10 of floor 13 of the containing vessel 1. The free space can be closed
steam-tight inasmuch as the projecting rim 10 is made like a channel for the
reception of water into which the walls of the casing 8 plunge after filling.
The lid of the casing is formed like a roof so that the water arising from
condensation, which deposits itself on the lid, does not drop back into the con-
taining-vessel 1, but runs along the interior walls into the free space 9.
The walls of the casing may be fastened by hooks to the containing-vessel
and be connected together and with the roof in steam tight fashion by soldering
the zine coverings. Rather large pipes 33 are arranged to take the overflow
from the channel 10. Similarly a siphon pipe 34 is arranged at the floor 13
of the containing vessel 1 for the escape of the condensation water.
Finally the casing 8 is provided with a door 35 corresponding to that of the
containing-vessel 1.
:-
The starting and mode of operation of the steaming chamber is as follows:-
The stones to be steamed are placed on the intermediate floors 2 in such a
manner that between every two pieces in the horizontal direction there remains
a free space (about 1-1 cm.), whilst the separate layers are laid directly on
one another. After the doors 32 and 35 have been closed, a medium warmer
than 100° C. is allowed to enter the boilers 16 and 30 through the inlet pipes 18
and 21 and to circulate in the same and at the same time steam at about 97° C.
is allowed to pass out through the pipe 22. This steam is compelled to pass
through the tube-coils 17, which are surrounded by the medium warmer than
100° C., and is thereby heated to the temperature of this medium with a simul

page_text: taneous corresponding increase of its volume. From what has been said above
an increase of its pressure is avoided, because the space 11, into which it goes
on leaving the tube-coils, is at ordinary atmospheric pressure.
The heated steam is compelled to fill the spaces left between the stones before
it can reach the free space 9 after being deflected by the roof of the casing.
The steam filled casing space permits of as high and as uniform a heating of
all parts of the containing-vessel 1 as is possible and also of a complete utiliza-
tion of the heat contained in the steam; the consumption of steam is by this
arrangement reduced to a minimum.
The intermediate floor 2 and the superheating arrangement might, instead of
being on a truck, be fixed in the containing vessel 1, or to carry out the process
any simple box fitted with suitable steam inlet and outlet pipes may be used.
But these constructions are less advantageous.
For carrying out the chemical re-action use could also be made of the steam-
ing-chamber represented in Figs. 5 and 6 in vertical and horizontal section.
This steaming-chamber is constructed in a similar way to that previously
described the intermediate floor may be rigidly fixed in the containing vessel 1.
The lower compartment 23 contains, for direct and indirect heating, tubes 3
and 5 which are in communication with the steam pipe 6.
The tube 3, intended for heating by means of direct steam, is of serpentine
shape and is provided inside the containing-vessel 1 with suitably sized holes
on both sides, to enable the steam to sweep the entire interior of the lower
compartment 23 as uniformly as possible. Cocks 4 are fixed for regulating the
steam supply.
A second winding tube 5. preferably formed as a ribbed heating tube, serves
for the indirect heating. The steam supply for this tube 5 can be regulated
by a cock 7 fixed to the end joining the steam pipe 6; the tube 5 is open
at its other end which discharges outside the containing vessel 1.
The containing vessel 1, as well as the casing 8, should each be provided on
one side with a door (not shown).
In addition, the steaming-chamber is provided with two thermometers 37
and 38 which indicate the temperature in the containing-vessel 1 and in the
free space 9.
This steaming chamber is set to work as follows:-
The stones to be steamed are placed on the intermediate floor 2 and the doors
are then closed. A current of steam is next sent through the heating-tube 5:
in a short time the containing-vessel 1 as well as the casing space 9 is warmed
up and this warmth is communicated to the stones to be steamed. When the
temperature inside 1 has become constant (which is shown by reading the ther-
mometer 37 after turning the handle 7 a current of steam is allowed to enter
the containing vessel 1 through the steam worm 3 until the steam leaves the
tubes 33 in large quantity. As soon as the steam leaves the tubes 33 in
streams, the corresponding cock 4 of the coil 3 is turned until on one hand
only water comes out of the tubes 33 and on the other hand the thermometer 38
shows a temperature of about 97° C.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
Process for the Production of Compressed Artificial Sandstones
and Apparatus therefor.
I, DR. WALTER SCHULTHESS, of Tunnelstrasse 7, Zurich, Switzerland, Chemist,
do hereby declare the nature of this invention and in what manner the same

page_text: is to be performed to be particularly described and ascertained in and by the
following statement:-
This invention relates to a steaming process and to apparatus for use in the
production of compressed artificial sandstones from sand containing silicic acid
and slaked lime in the form of powder. This process consists in making use,
for effecting the chemical reaction between sand and lime with a view to the
production of stone, of superheated yet pressureless steam at a temperature of
over 100° (
By treating the formed pieces with superheated steam the forma
tion of calcium silicate is effected in a short time, say from 8 to 48 hours
according to the degree of superheating.
In carrying out the above-mentioned process, there may be used with advan-
tage the steaming chamber illustrated in Figs. 1 to 4 of the drawings filed with
my Provisional Specification, of which Fig. 1 represents a vertical longitudinal
section corresponding to the line A-A of Fig. 3, Fig. 2 a cross section corre-
sponding to the line B-B of Fig. 3, and Fig. 3 a horizontal section, whilst
Fig. 4 is a detail of the interior arrangement corresponding to the section
line C-C of Fig. 3.
This steaming-chamber has a superheating device founded on the fact that
steam of about 97° C., when passed through metal pipes that are in a medium
warmer than 100° C., is heated to the temperature of this medium without
experiencing a rise of pressure when the issuing superheated steam enters a
vessel at ordinary atmospheric pressure. This is on the supposition that the
pipes that are in the hot medium and through which the steam is passed, are
given a surface of a size corresponding to the velocity with which the steam
passes through.
The steaming-chamber has a containing-vessel 1 which is preferably made of
thin sheet-iron and open at the top, and the upper compartment 11 of which
receives the shaped blocks that are to be steamed. The said blocks are placed
on a perforated intermediate floor 2, which, in the example shown, consists of
longitudinal beams, preferably of iron, which form a grid or grate. In order
to facilitate the introduction of the articles to be steamed the perforated inter-
mediate floor 2 rests on an underframe made like a carriage the wheels 12 of
which can run on a rail track 15 arranged on the floor 13 of the receiver 1.
The means for superheating the steam consist of chambers or vessels (herein-
after called chambers) 16, carried by the truck-frame, and having passing
through them a number of coils of metal pipes 17, the ends of which are respec-
tively connected steam-tight with the upper and lower chamber wall.
These chambers 16, on which the intermediate floor 2 rests, are carried by
transverse beams 24 which are themselves fastened to longitudinal beams 25
located between the chambers; to the said longitudinal beams the bearings for
the wheels 12 are fixed.
The middle chamber 16 has an inlet-pipe 18 and is in communication through
the pipes 19 with the outer chambers 16, each of which is provided with a
discharge pipe 20. In addition all three chambers are in communication with
another supply 21.
In the space 23 under the chambers a steam pipe 22 is arranged; this has a
serpentine shape and is provided inside the containing-vessel 1 on both sides
with suitably sized holes to permit the steam to sweep as uniformly as possible
over the entire interior of the lower compartment 23.
The connection between the compartments 11 and 23 should, as far as possible,
be only through the coils 17. To this end the spaces between the chambers 16
are closed at the top by a plate 26 and the part of the wheels 12 that rises
above this is covered with a cap 27. Further, in each of these interspaces, the
space between the two longitudinal beams 25 on the one hand and between the
two wheels 12 on the other, is formed into a chamber 30 by the upper plate 26,
a lower plate 28, and two side plates 29 which chambers 30 are also traversed
by a number of coiled metal pipes 17, the ends of each of which are joined

page_text: steam-tight to the upper and lower plates. These chambers 30, serve, as do
the chambers 16, to superheat the steam coming from the pipe 22 and are for
this purpose in connection with the inlet pipe 21, and on one hand by the
pipes 31 with the middle chambers 16 and on the other by pipes 32 with the
outer chambers 16.
The containing vessel 1 is provided with a door 36 at one side, to permit of
the introduction and withdrawal of the truck, and is covered with a casing 8
made of a poor conductor of heat; wood has been found to be a practical
material for this purpose, and this is provided on the side facing the containing
vessel with a covering of thin sheet zinc. The sheet-zinc forming the inner
covering is preferably laid, as shown, not directly on the wooden-wall but fixed
at a certain distance from the same; the air-space which is thus formed be-
tween the sheet-zinc and the wooden wall increases the insulating power of the
latter considerably.
The dimensions of the casing 8 are so chosen that its side walls are every-
where at a certain distance from the containing vessel 1; in this way a free
space 9 is formed which is closed at the bottom by the laterally-projecting
edge 10 of floor 13 of the containing vessel 1. The free space can be closed
steam-tight inasmuch as the projecting rim 10 is made like a channel for the
reception of water into which the walls of the casing 8 plunge after filling.
The lid of the casing is formed like a roof so that the water arising from
condensation, which deposits itself on the lid, does not drop back into the con-
taining-vessel 1, but runs along the interior walls into the free space 9.
The walls of the casing 8 may be fastened by hooks to the containing-vessel 1
and be connected together and with the roof in steam tight fashion by soldering
the zinc coverings. Rather large pipes 33 are arranged to take the overflow
from the channel 10. Similarly a siphon pipe 34 is arranged at the floor 13
of the containing vessel 1 for the escape of the condensation water.
Finally the casing 8 is provided with a door 35 corresponding to that of the
containing-vessel 1.
:--
The starting and mode of operation of the steaming chamber is as follows:-
The blocks to be steamed are placed on the intermediate floors 2 in such a
manner that between every two pieces in the horizontal direction there remains a
free space (about 1-1 cm.), whilst the separate layers are laid directly on one
another. After the doors 36 and 35 have been closed, a medium warmer than
100° C. is allowed to enter the chambers 16 and 30 through the inlet pipes 18
and 21 and to circulate in the same and at the same time steam at about 97° C. is
allowed to pass out through the pipe 22. This steam is compelled to pass through
the tube-coils 17, which are surrounded by the medium warmer than 100° C., and
is thereby heated to the temperature of this medium with a simultaneous corre-
sponding increase of its volume. From what has been said above an increase of
its pressure is avoided, because the space 11, into which it goes on leaving the
tube-coils, is at ordinary atmospheric pressure.
The heated steam is compelled to fill the spaces left between the stones before
it can reach the free space 9 after being deflected by the roof of the casing.
The steam filled space enclosed by the casing permits of as high and as uniform
a heating of all parts of the containing-vessel 1 as is possible and also of a com-
plete utilization of the heat contained in the steam: the consumption of steam
is by this arrangement reduced to a minimum.
The intermediate floor 2 and the superheating arrangement might, instead of
being on a truck, be fixed in the containing vessel 1, or to carry out the process
any simple box fitted with suitable steam inlet and outlet pipes may be used.
But these constructions are less advantageous.
For carrying out the chemical reaction use could also be made of the steaming-
chamber represented in Figs. 5 and 6 in vertical and horizontal section.
This steaming-chamber is constructed in a similar way to that previously
described the intermediate floor may be rigidly fixed in the containing vessel 1.

page_text: The lower compartment 23 contains, for direct and indirect heating, tubes 3
and 5 which are in communication with the steam pipe 6.
The tube 3, intended for heating by means of direct steam, is of serpentine
shape and is provided inside the containing-vessel 1 with suitably sized holes on
both sides, to enable the steam to sweep the entire interior of the lower com-
partment 23 as uniformly as possible. Cocks 4 are fixed for regulating the steam
supply.
A second winding tube 5, preferably formed as a ribbed heating tube, serves
for the indirect heating. The steam supply for this tube 5 can be regulated by a
cock 7 fixed to the end joining the steam pipe 6: the tube 5 is open at its other
end which discharges outside the containing vessel 1.
The containing vessel 1, as well as the casing 8, should each be provided on
one side with a door (not shown).
In addition, the steaming-chamber is provided with two thermometers 37 and
38, which indicate the temperature in the containing-vessel 1 and in the free
space 9.
This steaming chamber is set to work as follows:-
The blocks to be steamed are placed on the intermediate floor 2 and the doors
are then closed. A current of steam is next sent through the heating-tube 5;
in a short time the containing-vessel 1 as well as the casing space 9 is warmed up
and this warmth is communicated to the blocks to be steamed. When the tem-
perature inside 1 has become constant (which is shown by reading the ther-
mometer 37) after turning the handle 7, a current of steam is allowed to enter
the containing vessel 1 through the steam worm 3 until the steam leaves the
tubes 33 in large quantity. As soon as the steam leaves the tubes 33 in streams,
the corresponding cock 4 of the coil 3 is turned until on one hand only water
comes out of the tubes 33 and on the other hand the thermometer 38 shows a
temperature of about 97° C.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In the production of compressed artificial sandstones from silicic-acid-con-
taining sand and slaked lime in the form of powder, the process of treating
the shaped pieces by submitting them to the action of superheated pressureless
steam. substantially as described.
2. For use in the process specified in Claim 1, apparatus comprising a steam-
ing-chamber provided with container for the shaped pieces, which is open at
the top, surrounded on all sides by a free space and has an intermediate floor
that is pierced (for example, by longitudinal openings or perforations), the free
space surrounding the container being enclosed and covered by a heat insulating
or badly-conducting casing, substantially as described.
3. For use in the process specified in Claim 1, apparatus comprising a steam-
ing chamber and superheating device having heated fluid containing chambers
traversed by tubular coils into which the steam to be superheated
enters at one side of the said chambers and passes out superheated at the other
side, substantially as described.
4. For use in the process specified in Claim 1. apparatus comprising a con-
tainer for the shaped pieces, which is open at the top, surrounded by a free
space and has a movable intermediate floor that is mounted on wheels and is
pierced (for example, by longitudinal openings or perforations), the free space
surrounding the container being enclosed and covered by a heat insulating
or non-conducting casing, substantially as described.
5. For use in the process specified in Claim 1 apparatus comprising a steaming
chamber provided with a container, which is open at the top, has an inter-
mediate floor pierced (for example, by longitudinal openings or perforations),
and is surrounded by a free space enclosed and covered by a heat insulating or

page_text: non-conducting casing, and a superheating device having chambers traversed
by tube coils and arranged beneath the pierced intermediate floor, substantially
as described.
6. For use in the process specified in Claim 1, apparatus comprising a steaming
chamber provided with a container, which is open at the top, surrounded by a
free space and has an intermediate floor that is pierced (for example, by longi-
tudinal openings or by perforations), the free space surrounding the container
being enclosed and covered by a heat-insulating or non-conducting casing and
the Hoor of the said container extending laterally beyond the vertical walls of
the said casing and forming the support therefor, substantially as described.
7. For use in the process specified in Claim 1, apparatus comprising a steaming
chamber provided with a container, which is open at the top, surrounded by a
free space enclosed and covered by a heat-insulating or non-conducting casing,
and has a perforated intermediate floor, the joint between the floor of the con-
tainer and the casing being luted so as to effect the steam tight separation of
the free space from the atmosphere, and the intermediate floor having combined
therewith a superheating device having one or more heating fluid containing
chambers traversed by tubular coils, the arrangement being such that the stean
to be superheated enters the coils at one side of the said chambers and passes
out at the other side, and through the perforated intermediate floor into the
container in a superheated condition, substantially as described.
8. Apparatus constructed, arranged and operating substantially as described
with reference to and shown in Figs. 1 to 4 inclusive; and figs. 5 and 6
respectively of the drawings filed with my Provisional Specification.
Thatod +1: L
1000
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.