Apparatus for manufacturing rapidly cooled solidified slag

An improved apparatus for manufacturing a rapidly cooled solidified slag, the improvement relating to the use of pairs of weirs having an annular shape and a hollow portion therein; each of said pair of weirs being fixed to each edge of the peripheral surface of one of a pair of cooling drums so as to form a circular flange at right angles to the axial line of the one cooling drum around the entire circumference thereof.

FIELD OF THE INVENTION 
The present invention relates to an apparatus for manufacturing a rapidly 
cooled solidified slag, which permits a high cooling rate sufficient to 
convert a molten slag into a rapidly cooled solidified slag particularly 
adapted to serve as a cement material. 
BACKGROUND OF THE INVENTION 
Molten slags include, for example, molten blast furnace slag, molten 
converter slag, and molten electric furnace slag. It has been known that 
it is possible to obtain a rapidly cooled solidified slag by cooling a 
molten slag at a high cooling rate for solidification. 
As an apparatus for obtaining a rapidly cooled solidified slag by rapidly 
cooling and solidifying a molten slag as mentioned above, the following 
apparatus for manufacturing a rapidly cooled solidified slag is known. 
FIG. 1 shows the apparatus for manufacturing a rapidly cooled solidified 
slag, which is substantially the same as the apparatus for manufacturing a 
rapidly cooled solidified slag disclosed in the U.S. Pat. No. 4,050,884 
dated Sept. 27, 1977. The above-mentioned conventional apparatus for 
manufacturing a rapidly cooled solidified slag is described below with 
reference to FIG. 1. 
In FIG. 1, the housing 1 is an enclosed-structure having an opening 1a at 
the top thereof for passing a molten slag, and a discharge port 1b at the 
lower end thereof, for discharging a crushed rapidly cooled solidified 
slag 7'. In the housing 1, a pair of cooling drums 2 each having the same 
diameter and the same length are arranged so that the axial directions 
thereof are parallel to each other in the same horizontal plane and the 
peripheral surfaces thereof are in contact with each other. Each of the 
pair of cooling drums 2 is rotated by a suitable driving means (not shown) 
in directions opposite to each other at the same peripheral speed as shown 
by the arrows "a" and "a'" in FIG. 1, in the rising direction of the 
peripheral surface of each of the pair of cooling drums 2 at the contact 
portion thereof. A plurality of cooling through-holes (not shown) are 
pierced in the peripheral wall of each of the pair of cooling drums 2 in 
the axial direction thereof. One end of each of the plurality of cooling 
through-holes communicates with a hollow portion (not shown) of one end of 
the center axle of the cooling drum 2, and the other end of the cooling 
through-holes communicates with a hollow portion (not shown) of the other 
end of the center axle of the cooling drum 2. The hollow portion of the 
above-mentioned one end of the center axle of the cooling drum 2 is 
liquid-tightly connected to one end of a pipe 3 through a swivel joint 
(not shown). The other end of the pipe 3 is connected to the inlet of a 
heat exchanger 4 through another swivel joint (not shown). An end of 
another pipe 5 is provided with a pump 6 on the way is connected to the 
outlet of the heat exchanger 4. The other end of the pipe 5 is 
liquid-tightly connected to one of the hollow portion of the center axle 
of the cooling drum 2 through a swivel joint (not shown). In FIG. 1, one 
heat exchanger 4 is shown to be connected to one of the cooling drums 2, 
however another heat exchanger (not shown) is also connected to the other 
cooling drum 2 in the same way as mentioned above. Therefore, cooling 
water for cooling the cooling drum 2 is supplied to the plurality of 
cooling through-holes of the peripheral wall of the cooling drum 2 through 
the pipe 5 and the center axle of the cooling drum 2 by means of the pump 
6. The cooling water supplied to the plurality of cooling through-holes is 
heated as described later by means of the heat contained in the molten 
slag 7 which is adhered to the peripheral surface of the cooling drum 2, 
and supplied to the heat exchanger 4 through the center axle of the 
cooling drums 2 and the pipe 3 while partially generating steam. The 
pressurized steam supplied to the heat exchanger 4 is subjected to heat 
exchange in the heat exchanger 4 to become a cooling water which is 
supplied again to the plurality of cooling through-holes of the peripheral 
wall of the cooling drum 2 by means of the pump 6. Thus, the cooling water 
circulates through the cooling drum 2 and the heat exchanger 4. On the 
other hand, the high-pressure steam obtained through heat exchange with 
the pressurized steam in the heat exchanger 4 drives a turbine 8 which in 
turn drives an electric power generator 9. The high-pressure steam is 
cooled by a condenser 10 which is provided in the turbine 9, and 
thereafter supplied again in liquid state to the heat exchanger 4 by means 
of a pump 11. Cooling water is supplied in circulation to the condenser 10 
from a cooling tower 12 by a pump 13. 
A pair of weirs 14 are provided in the upper halves of the both ends of 
each of the pair of cooling drums 2 so as to be in contact with the both 
ends of each of the pair of cooling drums 2. In FIG. 1, one of the pair of 
weirs 14 is shown. The pair of weirs 14 are supported on the housing 1 by 
means of a suitable supporting means (not shown). A slag sump 15 is formed 
by the peripheral surface of each of the pair of cooling drums 2 and the 
pair of weirs 14. The molten slag 7 discharged from the slag runner 16 is 
poured, through the opening 1a of the housing 1, into the slag sump 15 
where a slag pool is formed. The molten slag 7 poured into the slag sump 
15 adheres to the peripheral surfaces of the cooling drums during 
rotation, rapidly cooled and solidified into a rapidly cooled solidified 
slag. The cooling water supplied to the plurality of cooling through-holes 
of the peripheral wall of the cooling drum 2 is heated by the molten slag 
7 deposited on the peripheral surface of the cooling drum 2 to become a 
pressurized steam. When the rapidly cooled solidified slag 7' reaches the 
lower half of the cooling drum 2 along with the rotation of the cooling 
drum 2, the rapidly cooled solidified slag 7' adhering to the peripheral 
surface of the cooling drum 2 is peeled off therefrom, while being crushed 
by a scraper 17 supported on the housing 1 by means of a suitable 
supporting means (not shown), and drops into the lower part of the housing 
1. An opening and closing means (not shown) is provided in the discharge 
port 1b of the lower part of the housing 1. The peripheral surface of the 
cooling drum 2 from which the rapidly cooled solidified slag 7' has been 
peeled off by the scraper 17 comes again into contact with the molten slag 
7 of the slag sump 15 along with the rotation of the cooling drum 2, 
whereby a rapidly cooled solidified slag is continuously manufactured. 
According to the above-mentioned apparatus for manufacturing a rapidly 
cooled solidified slag by using the cooling drum, it is possible to 
continuously manufacture a rapidly cooled solidified slag, and to recover 
the heat at a high temperature gained by the cooling drums through the 
heat exchange with the molten slag. 
However, the above-mentioned apparatus for manufacturing a rapidly cooled 
solidified slag has the following problems. Being always in contact with 
the both ends of each of the pair of cooling drums 2, the pair of weirs 14 
are also cooled. When a molten slag 7 comes into contact with the pair of 
weirs 14, therefore, the molten slag 7 adheres to the surface of each of 
the pair of weirs 14, resulting in formation of a solidified slag thereon. 
Formation of the solidified slag on the slag pool causes decrease in the 
slag pool temperature and further growth of the solidified slag. As a 
result, smooth rotation of each of the pair of cooling drums 2 is 
impaired, and this finally leads to stoppage of the rotation thereof. 
Also, due to the difference in thermal expansion between the pair of weirs 
14 and the pair of cooling drums 2, the contact resistance between the 
pair of weirs 14 and the pair of cooling drums 2 increases, and this 
impairs smooth rotation of each of the pair of cooling drums 2. 
SUMMARY OF THE INVENTION 
A principal object of the present invention is therefore to provide an 
apparatus for manufacturing a rapidly cooled solidified slag, which 
permits achievement of a high cooling rate sufficient to convert a molten 
slag into a rapidly cooled solidified slag. 
Another object of the present invention is to provide an apparatus for 
manufacturing a rapidly cooled solidified slag, which permits effective 
recovery of high-temperature heat contained in a molten slag. 
A further another object of the present invention is to provide an 
apparatus for manufacturing a rapidly cooled solidified slag, which 
permits prevention of formation of a solidified slag in a slag pool. 
In accordance with one of the features of the present invention, there is 
provided an apparatus for manufacturing a rapidly cooled solidified slag, 
which comprises: 
a pair of cooling drums each having the same diameter and the same length, 
the axial lines of said pair of cooling drums being arranged in parallel 
with each other in the same horizontal plane, the peripheral surfaces of 
said pair of cooling drums being contact with each other; a driving means 
for rotating said pair of cooling drums, said driving means being adapted 
to rotate said pair of cooling drums in directions opposite to each other 
at the same peripheral speed in the rising direction of the peripheral 
surface of each of said pair of cooling drums at the contact portion of 
said pair of weirs provided at the both ends of said pair of cooling 
drums, said pair of weirs forming a slag sump in cooperation with the 
upper half of the peripheral surface of each of said pair of cooling 
drums; a slag feeding means arranged above said pair of cooling means, for 
pouring a molten slag into said slag sump; a scraper provided so as to be 
in contact with the lower half of the peripheral surface of each said pair 
of cooling drums; a cooling water for cooling said pair of cooling drums, 
said cooling water being supplied into each of said pair of cooling drums 
through the center axle of each of said pair of cooling drums, said 
cooling water exchanging heat with said molten slag in said slag sump, 
which has adhered to the peripheral surface of each of said pair of 
cooling drums, along with the rotation of each of said pair of cooling 
drums, and, said cooling water which has exchanged heat with said molten 
slag being discharged through said center axle of each of said pair of 
cooling drums for heat recovery, whereby said molten slag adheres to the 
peripheral surfaces of said pair of cooling drums is converted into a 
rapidly cooled solidified slag through heat exchange with said cooling 
water and is then peeled off from the peripheral surfaces of said pair of 
cooling drums by means of said scraper, along with the rotation of said 
pair of cooling drums; said apparatus being characterized in that: each of 
said pair of weirs has an annular shape and has a hollow portion therein, 
and, each of said pair of weirs being fixed to each edge of the peripheral 
surface of one of said pair of cooling drums so as to form a circular 
flange at right angles to the axial line of said one cooling drum over the 
entire circumference thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
With a view to solving the above-mentioned problems involved in the 
conventional apparatus using a pair of cooling drums for manufacturing a 
rapidly cooled solidified slag, we carried out extensive studies. As a 
result, we obtained the following findings: 
A solidified slag adheres to the pair of weirs because the same molten slag 
is in contact with the pair of weirs for a long period of time. By 
constantly moving the pair of weirs, therefore, the pair of weirs become 
always in contact with a fresh molten slag, and it is thus possible to 
prevent the solidified slag from adhering to the pair of weirs. 
The present invention was made on the basis of the above-mentioned finding, 
and the apparatus for manufacturing a rapidly cooled solidified slag of 
the present invention comprises: 
a pair of cooling drums each having the same diameter and the same length, 
the axial lines of the pair of cooling drums being arranged in parallel 
with each other in the same horizontal plane, the peripheral surfaces of 
the pair of cooling drums being in contact with each other; a driving 
means for rotating the pair of cooling drums, the driving means being 
adapted to rotate the pair of cooling drums in directions opposite to each 
other at the same peripheral speed in the rising direction of the 
peripheral surface of each of the pair of cooling drums at the contact 
portion of the pair of cooling drums; a pair of weirs provided at the both 
ends of the pair of cooling drums, the pair of weirs forming a slag sump 
in cooperation with the upper half of the peripheral surface of each of 
the pair of cooling drums; a slag feeding means arranged above the pair of 
cooling drums, for pouring a molten slag into the slag sump; a scraper 
provided so as to be in contact with the lower half of the peripheral 
surface of each of the pair of cooling drums; a cooling water for cooling 
the pair of cooling drums, the cooling water being supplied into each of 
the pair of cooling drums through the center axle of each of the pair of 
cooling drums, the cooling water exchanging heat with the molten slag in 
the slag sump, which has adhered to the peripheral surface of each of the 
pair of cooling drums, along with the rotation of each of the pair of 
cooling drums, and, the cooling water which has exchanged heat with the 
molten slag being discharged through the center axle of each of the pair 
of cooling drums for heat recovery, whereby the molten slag adhering to 
the peripheral surfaces of the pair of cooling drums is converted into a 
rapidly cooled solidified slag through heat exchange with the cooling 
water and is then peeled off from the peripheral surfaces of the pair of 
cooling drums by means of the scraper, along with the rotation of the pair 
of cooling drums; the apparatus being characterized in that: each of the 
pair of weirs has an annular shape and has a hollow portion therein, and, 
each of the pair of weirs being fixed to each edge of the peripheral 
surface of one of the pair of cooling drums so as to form a circular 
flange at right angles to the axial line of the one cooling drum over the 
entire circumference thereof. 
Now, an embodiment of the apparatus for manufacturing a rapidly cooled 
solidified slag of the present invention is described with reference to 
the drawings. 
FIG. 2 is a schematic sectional view showing an embodiment of the apparatus 
for manufacturing a rapidly cooled solidified slag of the present 
invention. In FIG. 2, 1 is an enclosed-structure housing. The housing 1 
has an opening 1a at the top thereof for passing a molten slag, and a 
discharge port 1b at the lower end thereof for discharging a crushed 
rapidly cooled solidified slag. A suitable opening and closing means (not 
shown) is provided in the discharge port 1b. In the housing 1, a pair of 
cooling drums 2' each having the same diameter and the same length are 
arranged so that the axial lines thereof are parallel with each other in 
the same horizontal plane and the peripheral surfaces thereof are in 
contact with each other. Each of the pair of cooling drums 2' is rotated 
by a suitable driving means as described later, in directions opposite to 
each other at the same peripheral speed as shown by the arrows "a" and 
"a'" in FIG. 2, in the rising direction of the peripheral surface of each 
of the pair of cooling drums 2' at the contact portion thereof. 
In FIG. 2, 4 is a heat exchanger. Cooling water circulates through the 
cooling drums 2', the pipe 3, the heat exchanger 4 and the pipe 5. A pump 
6 for supplying cooling water to the cooling drums 2' is provided in the 
pipe 5 connecting the exit side of the radiation section of the heat 
exchanger 4 and the cooling drums 2'. In FIG. 2, one heat exchanger 4 is 
shown to be connected to one of the cooling drums 2', however another heat 
exchanger (not shown) is also connected to the other cooling drum 2' in 
the same way as mentioned above. 
A pair of hollow weirs 18 as described later are fixed to the both ends of 
the peripheral surface of one of the pair of cooling drums 2'. Only one of 
the pair of weirs 18 is shown in FIG. 2. A slag sump 15 is formed by the 
peripheral surface of each of the pair of cooling drums 2' and the pair of 
weirs 18. Above the pair of cooling drums 2', there is arranged an end of 
a slag runner 16 as a slag feeding means for pouring a molten slag into 
the slag sump 15. The molten slag 7 discharged from the slag runner 16 is 
therefore poured, through the opening 1a of the housing 1, into the slag 
sump 15 where a slag pool is formed. The molten slag 7 poured into the 
slag sump 15 adheres in a substantially uniform thickness onto the 
peripheral surface of each of the cooling drums 2' during the rotation 
thereof, rapidly cooled and solidified into a rapidly cooled solidified 
slag by means of the peripheral surface of each of the cooling drums 2'. 
As shown in FIG. 2, a scraper 17 is provided on as to be in contact with 
the lower half of the peripheral surface of each of the pair of cooling 
drums 2'. The scraper 17 is supported on the housing 1 by means of a 
suitable supporting means (not shown). When the rapidly cooled solidified 
slag 7' adhering to on the peripheral surface of each of the cooling drums 
2' reaches the lower half of each of the cooling drums 2' along with the 
rotation of the cooling drums 2', the rapidly cooled solidified slag 7' is 
peeled off therefrom by the scraper 17, and drops, while being crushed, 
into the lower part of the housing 1. 
In FIG. 2, 8 is a turbine driven by a high-pressure steam from the exit 
side of the heat absorbing section of the heat exchanger 4; 9 is an 
electric power generator driven by the turbine 8; 10 is a condenser 
connected to the turbine 8; 11 is a pump for feeding water from the 
condenser 10 to the entry side of the heat absorbing section of the heat 
exchanger 4; 12 is a cooling tower of cooling water for the condenser 10; 
and, 13 is a pump for feeding the cooling water from the cooling tower 12 
to the condenser 10. 
In FIGS. 3 to 5, 2'a is the inner wall of one of the cooling drums 2', 
which has a pair of weirs 18; 2'b is an outer wall fixed concentrically 
relative to the peripheral of the inner wall 2'a; 19 is a space formed 
between the inner wall 2'a and the outer wall 2'b; 18 are a pair of hollow 
weirs each of which is fixed to each end of the outer wall 2'b over the 
entire periphery thereof so as to form a circular flange at right angle to 
the axis of the cooling drum 2'; 22 are a pair of center axles each of 
which is horizontally fixed to the axial center portion of each end of the 
cooling drum 2' through each of a pair of side walls 20 each of which is 
fixed to each end of the cooling drum 2', each of the center axles 22 
having a hollow portion 24, and having an end closed by a closing plate 
25; and, 26 are at least two connecting pipes which connect the pair of 
hollow weirs 18 to each of the pair of center axles 22 through at least 
two mouth pieces 21. 
The above-mentioned space 19 is divided into at least two compartments 23 
by at least two partitions 27 provided along the axial line of one of the 
cooling drums 2'. In each of at least two compartments 23, a zigzag 
passage 29 for cooling water parallel to the axial line of the cooling 
drum 2' is formed by providing a plurality of current plates 28 in 
parallel with the axial line of the cooling drum 2'. Therefore, cooling 
water flows from the hollow portion 24 of one of the center axles 22, 
through one of the connecting pipes 26 and one of the mouth pieces 21, 
into one of the weirs 18, and after passing through the zigzag passage 
running through the compartments 23, enters into the other weir 18. 
Cooling water then flows from the other mouth piece 21 and the other 
connecting pipe 26 into the hollow portion 24 of the other center axle 22. 
Thus, the peripheral surface of each of the cooling drums 2' and each of 
the weirs 18 are efficiently cooled by cooling water. In addition, since 
the weir 18 is always in rotation in a vertical plane, it is hard for a 
molten slag to adhere to the surface of the weir 18. As a result, a 
solidified slag is not formed on the slag pool, so that rotation of the 
pair of cooling drums 2' is never impaired by solidified slag, and the 
cooling drums 2' rotate always smoothly. 
The pair of center axles 22 of each of the pair of cooling drums 2' are 
rotatably supported at the both ends thereof in the housing 1 by means of 
a pair of bearings 30. A driven gear 31 is fixed to one of the center 
axles 22 and engages with a suitable driving means (not shown). Thus, the 
cooling drum 2' is rotated by the driving means. 
The other drum of the pair of the cooling drums 2' has the same structure 
as the above-mentioned former cooling drum 2' except for the lack of the 
provision of the pair of weirs 18. 
In the heat exchanger 4, the pressurized steam obtained through heat 
exchange between the cooling water and steam may be used, in place of 
driving the turbine 8, for the other applications such as heating the work 
space in a plant. 
According to the present invention, as described above, it is possible to 
manufacture, from a molten slag, a rapidly cooled solidified slag easily 
and continuously, to very efficiently recover the heat produced when 
cooling and solidifying a molten slag into a rapidly cooled solidified 
slag, and furthermore, to eliminate the risk of stoppage of the cooling 
drums by a solidified slag adhering to the surface of the weir, because 
the molten slag hardly adheres to the weir surface, thus always allowing 
smooth rotation of the cooling drums, and providing industrially useful 
effects.