JPH0710736B2 - Taphole for mineral wool fiber manufacturing equipment. - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to the production of mineral wool fibre for thermal insulation, and more particularly to a taphole for a mineral wool fibre production apparatus and a method for effectively cooling the taphole.

PRIOR ART In the manufacture of mineral wool fibers, molten material from a furnace enters a truss through a taphole and is directed to the face of a fiberizing spinner. It is known that due to the significant heat generated by the molten material flowing through the taphole, it is sometimes necessary to provide a taphole cooling system. This is usually accomplished by constructing the taphole out of steel and cooling the steel with water. However, this approach is ineffective, as a crust of solidified material accumulates on the working surface of the cooled metal in unpredictable and variable amounts, resulting in uneven discharge of the molten material.

Troughs for molten material delivery have been a source of headache for designers for many years. Refractory construction is expensive, has a short life in air, and can cause unpredictable buildup before the system reaches thermal steady state, making steady delivery impossible and resulting in unstable, undulating flow. The same problems occur with water-cooled metal troughs, especially since the troughs must be water-cooled, typically made of carbon steel or stainless steel. Until now, no trough has been manufactured that provides consistent, even material flow from the trough discharge end.

The function of a fiberizing spinner is to impart kinetic energy to a stream of molten material, whereby high velocity air, steam or other vapor impinges on the rapidly moving stream of molten material, causing the stream to be transformed into a multiplicity of small diameter, long fibers.

Long fiber, low density mineral wool is typically used for roof insulation in the United States and has proven effective with single wheel spinners. High density fiber for cavity wall retrofit or industrial pipe jacketing, ceiling tiles, etc. typically uses four wheel spinners worldwide.

The four-wheel spinner has four parallel drive spindles with water-cooled wheels at the end of each, each wheel having a diameter of approximately
250-350mm (10-14 inches), rim width approx. 100-130mm (4
The four wheels are mounted on the same plane, and the molten material dripping onto the top wheel is given a velocity to move in the second direction.
The wheels collide with each other and move in sequence, the lowest one being the third,
As it passes the fourth wheel, high velocity air or steam pushes the high energy molten material laterally with great force, separating it into fibers.

These four-wheel spinners have traditionally been made of steel and are usually water-cooled, resulting in wheels that wear out after about a week of use and require refinishing, which is extremely expensive.

As detailed in Applicant's U.S. Pat. No. 4,032,705 (which reference is hereby cited as prior invention), Applicant has discovered that rapid, continuous removal of large amounts of energy, on the order of IBTU/ ⁱⁿ² /s, through a water-cooled metal wall requires that the metal have good thermal conductivity and a practically high melting point to avoid damage to the wall, and that forced cooling to a constant temperature is achieved by the generation and effective removal of steam at the backside.

To steam 1 pound (0.454 kg) of water, you need 212°F.
967 BTU (536 calories per gram at 100°C). By continuously supplying water to the area to be cooled, turning it into steam, and then immediately removing the steam to make the water accessible, a significantly more efficient and predictable cooling system is obtained. The area to be cooled must be free of additives that would create film effects that would adversely affect effective heat transfer.

Experiments have shown that the best way to remove the steam film immediately after it is formed is to apply a very high velocity of cooling water to the back of the metal wall. The required cooling water velocity is at least 3.05 m/s (10 f
t/s), and this velocity must occur on a metal surface.
This is not the velocity in the center of a cooling passage with one wall facing the metal. A preferred water cooling velocity is at least 20 ft/s (6.1 m/s). As is readily apparent, this velocity requires a high flow rate through the narrow passages, which results in a pressure drop of approximately 1.4 to 4.2 kg/cm, depending on the surface, shape, and length of the part to be cooled.
² (approximately 20 to 60 psi).

To highlight the effectiveness of this cooling, the available price,
A processable metal with a high melting point and high thermal conductivity is required. From the physical properties of the device, it is easy to process, relatively inexpensive, and
The following table lists materials with melting points of approximately 1000°C and good thermal conductivity.

Chromium, molybdenum, and nickel are not very easy to process and are relatively expensive. Furthermore, the thermal conductivity of these materials is three to five times lower than that of copper.

The relatively low melting point of copper and the high melting point of iron have made steel the automatic choice in the past for water-cooled tapholes, troughs, and spinners, but this is completely unreasonable. This was despite the fact that iron has less than one-fifth the thermal conductivity of copper. Furthermore, for a number of reasons, water-cooled steel tends to form a highly insulating film on its surface.

Compounding this technical drawback, to the applicant's knowledge,
No attempt has been made to effectively remove heat energy from the tap orifice, trough, or back of the spinner by generating steam on a clean surface and removing it directly with new cooling water moving at very high speeds. It should be noted that the use of stainless steel only makes matters worse, since its thermal conductivity is 1/16 to 1/24 that of copper.

SUMMARY OF THE INVENTION The present invention overcomes the known problems described above by allowing a solid material or shell of predictable and consistent thickness to solidify on a working surface.

(Means for solving the problem) In the present invention, the above problem is solved by constructing a tap outlet for molten material from a melting furnace used in a mineral wool fiber manufacturing apparatus from a metal member having an inner working surface which forms an orifice through which molten material from the furnace passes, and by forming an extremely narrow passage for flowing coolant around the orifice, which is located close to the inner working surface.

Furthermore, in the present invention, at such a tap outlet,
This problem is solved by cooling the taphole by flowing a coolant at a velocity of at least about 3.05 m/s (10 ft/s) adjacent to the surface forming the orifice through which the molten material passes.

1 shows a longitudinal cross-section of an ultra-high velocity, water-cooled copper taphole constructed in accordance with the principles of the present invention, generally designated 10. The front end of taphole 10, i.e., the left side of the drawing, is secured to a known graphite nozzle 12. Nozzle 12 does not form a part of the present invention and is shown in phantom to represent its exterior only. Nozzle 12 is attached to the crucible wall of a melting furnace in a manner well known in the art.

The taphole 10 consists of three main parts: an inner copper member;
The elements 14, 16, and 18 are relatively thin-walled tubular, preferably cylindrical or circular in cross section, with the exception of the front copper member 14, the intermediate coolant guide 16, and the outer jacket 18 being coaxial with one another.

The inner surface 20 of the copper member 14 is the working surface of the taphole 10 and defines the opening through which the molten material from the furnace passes from left to right in the figure.
The wall thickness of the valve increases at the forward end 22 to a small diameter inner portion forming an orifice 24. The orifice 24 is formed by the inner working surface
26 and is continuous with the inner working surface 20 of the copper member.

To effectively cool the working surface of the orifice, a plurality of passages 28 are drilled into the thick wall portion 22. Each passage is formed by drilling from the exterior of the copper member 14 toward the working surface 26 of the orifice 24. A second hole 32 is drilled axially offset from the first hole 30 and inward toward the working surface 26 of the orifice 24, intersecting the inner end of the first hole 30.

Thus, each passageway 28 is generally V-shaped, with a wall surface 34 aft of the offset working surface 26. The surface 34 is relatively close to, but spaced from, the working surface 26. Each hole 3 forming a passageway 28
The 0.32 is approximately 4 mm (5/32 in) in diameter, thus forming a narrow passage for the coolant. Although only two passages 28 are shown in the figure, any number of passages may be used, and in the preferred embodiment, offset
The passages are equally spaced about the axis of 24. In the preferred embodiment, 12 passages are used.

As described above, the coolant guide 16 is disposed coaxially around the copper member 14. The front end of the coolant guide 16 is fixed to the outer surface of the copper member 14 by welding or the like, and the fixing position 36 is between the openings 30 and 32. A narrow annular space 38 is formed between the inner copper member 14 and the coolant guide
16 and extends for nearly the entire length of the taphole 10. The space 38 forms part of a narrow, restricted passageway, and the passageway passes through the hole 32.
It is connected to 28.

An annular space 40 also remains between the coolant guide 16 and the outer jacket 18. This annular space extends from a point near the front end of the taphole 10 to a point near the discharge end of the taphole, and is spaced from the taphole. Near the front end of the taphole 10, the jacket 18 is secured to the copper member 14 by a mounting portion 42. The front end of an O-ring 44 communicates with the passage 28 via the hole 30.

The annular space 46 at the rear of the tap 10 between the coolant guide 16 and the jacket 18 is isolated from the main portion of the annular space 40 by an O-ring seal 48 and communicates with the annular space 38 through a number of openings 50 at the rear end of the coolant guide 16. The openings 50 can be formed by battlementing the end of the coolant guide 16 or by drilling a number of holes in the end. An inlet port 52 communicates with the annular space 40 and an outlet port 54
communicates with the annular space 46.

The function of the taphole 10 is as follows: molten material, e.g., molten slag, flows from the furnace into the nozzle 12, through the offset 24,
The molten material flows through the taphole, along with the working slug 20 of the copper member 14, and out the discharge end of the taphole. As the molten material flows through the taphole, a significant amount of heat is transferred to the copper member 14. The desired coolant, such as water, is forced into the inlet port 52, passes through the annular space 40, and enters the passages 28 through openings 30. The coolant flows out of the passages 28 through openings 32 and into the annular space 38. At the rear end of the taphole 10, the coolant enters the annular space 46 through openings 50 and exits the outlet port 54. Because the passages 28 and the annular space 38 are very narrow, the coolant, combined with the pressure of the incoming coolant, is forced against the surface 34.
and the outer surface of the copper member 14 is subjected to an ultra-high speed of at least 3.05 m/s (approximately 1
The steam generated on this surface flows without stagnating, effectively cooling the copper parts.

As a result of the effective cooling provided by the present invention, a coating or shell of solid slag material of predictable and consistent thickness is deposited on the orifice and taphole working surfaces 26, 20, resulting in smooth and consistent drainage of molten material. Furthermore, this shell is thermally insulating and
The shell also protects the copper from overheating and prevents physical wear on the copper working surfaces.

(Reference Example) Fig. 2 shows a vertical cross section of an ultra-high speed water-cooled copper trough, designated by the reference numeral 110, which is constructed according to the same principle as the tap outlet of the present invention. The trough 110 is located below the tap outlet 10, and therefore,
Molten material, such as molten slag 114, flows from the taphole 10 and is guided along the top surface of the trough to the spin station or other desired location.

The entire trough 110, except for the end wall 116, is generally semi-cylindrical, as best seen in Figure 3. The trough has an elongated, generally cylindrical upper copper member 118. An upper working surface 120 of the copper member 118 is adapted to receive the molten material 118.
14. A complementary coolant guide 122 is mounted below the lower surface 124 of the copper member 118 and is closely spaced therebetween to form an extremely narrow passage 126. The passage 126 extends substantially the entire length of the trough 110.

Below the coolant guide 122 is a return passage or space 1
28 is formed by a lower jacket 130. The jacket 130 has a shape similar to that of the upper copper member 118 and the coolant guide 122. As shown in FIG.
The side edges of the holes 13 are closed by closing portions 132 and 134.
6 is formed in the coolant guide near the discharge end of the trough 110, and the second
As shown on the right side of the figure, communication is provided between the passage 126 and the return passage 128 .

The end wall 116 of the trough 110 includes an inlet port 138 and an outlet port 140.
A channel 142 communicating with the inlet port 138 extends substantially the full width of the trough and communicates with the passage 126.
Similarly, a channel 142 communicating with the outlet port 140 communicates with the return location 128 .

The function of the trough 110 is as follows: the molten material, e.g., molten slag 114, flows from the taphole 10 onto the working surface 120 of the copper member 118, and from there onto the spinner or the like.
A large amount of heat is transferred to the copper member 118 as it flows along the copper member 118. A selected coolant, such as water, is forced into the inlet port 138,
The coolant flows through the channel 142 into the passage 126.
The coolant flows through the return passage 128 into the channel 142 and out the outlet port 140. The combination of the extremely narrow restrictor passage 126 and the incoming coolant pressure forces the coolant against the underside 124 of the copper member 118.
flowing at very high speeds, i.e. at least 3.05 m/s (approximately 10 ft/s),
The steam generated on this surface is allowed to flow without stagnating, and the copper member 118
Effectively cools the

As a result of the effective cooling provided by the trough, a coating or shell of solid slag material of predictable and consistent thickness solidifies on the working surface of the trough, resulting in a consistent and stable material flow from the outlet end of the trough. Additionally, the shell is thermally insulating, protecting the copper from excessive temperatures. Additionally, the shell protects the copper working surface from wear.

4 shows a cross-sectional view of an ultra-high speed water-cooled copper spinner, generally designated 210, constructed in accordance with the same principles as the tapping outlet of the present invention. The spinner 210 has a generally cylindrical copper shell 212 on the outer working surface 214 of the shell 212, on which molten material, e.g., molten slag 11, is deposited.
4 is jetted to form the kinetic energy receiving fiber. The copper shell 212 has an inner cylindrical surface 216 and an end wall 218 integrally formed with the cylindrical portion 212.

A coolant guide 222 is attached within the outer shell 212 by a plurality of bolts 220. The coolant guide 222 is generally cylindrical and has an outer cylindrical wall 224. The coolant guide 222 is coaxially disposed within the outer shell 212, and the surface 224 is closely spaced from the inner surface 216 of the outer shell 212 to form an extremely narrow throttle passage 226.

The inner conduit 23 extends axially through the central opening 228 of the guide 222.
4. The front end of the conduit 230 is rotatable relative to the guide 222, and a liquid seal is provided using an O-ring 232. The rear end of the conduit 230, the left end in FIG. 4, is a fixed inlet port 234.

The outer conduit 236 is coaxial with the inner conduit 230 and forms a return passage, which will be described later. The front end of the conduit 236 is fixed to the rear surface of the guide 222 by a plurality of bolts 240 and sealed by an O-ring 242.

The other end of the outer conduit 236 is connected to a first portion 244 of a rotary union 246.
The other stationary half 248 of the rotary union 246 is fixed to the inner conduit 230 and the inlet port 234.
The rotary union 246 has an outlet port 250 which communicates with the annular space or return passage 238 as shown.

A generally disk-shaped space 252 is formed inside the guide 222 at its rear end, i.e., near the left side in FIG. 4. The space 252 communicates with the annular space, i.e., the return passage 238. The space 252 communicates with the narrower passage 226 via a plurality of holes 254. The holes 254 extend radially through the guide 222 from the outer surface 224 to the space 252. In a preferred example, twelve holes 254 are formed at equal angular intervals around the outer periphery of the guide 222.

The front surface 256 of the guide 222 is generally dished. That is, the distance between the surface 256 and the end wall 218 decreases with increasing radius. As is well known to those skilled in the art, this provides a constant flow rate between the surface 256 and the end wall 218. The spinner is rotated via a gear or pulley secured to the outer conduit 236 in a well-known manner.

The functions of the spinner 210 are as follows: outer shell 212, guide 22
The combination of 2 and outer conduit 236 is rotated at a desired speed while molten material, e.g., molten slug 114, is fed onto working surface 214 of copper shell 212 to form fibers.
14, significant heat is transferred to the copper shell 212. The desired cooling fluid, such as water, is forced into the inlet port 234 and flows through the conduit 230.
222 and into the space between the surface 256 of the guide 222 and the end wall 218. From there, the coolant flows through the passage 226, the opening 254, and into the space
252 and flows through return passage 238 to outlet port 250. The combination of the extremely narrow throttle passage 226 and the pressure of the incoming coolant causes the coolant to flow over the inner surface 216 of the copper shell 212 at an extremely high speed, at least 3.05 m/s (approximately 10 ft/s), without allowing any vapor generated on this surface to stagnate, thereby effectively cooling the copper shell 212.

As a result of the efficient cooling provided by the spinner, a skin or shell of solid slug material of predictable and consistent thickness adheres to the spinner's working surface, allowing for fine control of the fiberization process. Additionally, the shell is thermally insulating, preventing the copper from overheating. Furthermore, the shell protects the copper working surface from physical wear.

In the above-described embodiment and reference examples, one port is the inlet port and the other port is the outlet port, but the opposite is also possible. The same cooling effect can be achieved by flowing the coolant in the opposite direction, entering through the outlet port and exiting through the inlet port. Furthermore, the coolant guide, conduit, and jacket can be made of copper, stainless steel, or other required materials.

The present invention may be embodied in other ways without changing its essence, and the scope of the present invention is defined by the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of an ultra-high speed water-cooled copper taphole according to the principles of the present invention; FIG. 2 is a longitudinal cross-sectional view of an ultra-high speed water-cooled copper trough; FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2; and FIG. 4 is a cross-sectional view of an ultra-high speed water-cooled copper spinner.

(Explanation of symbols) 10... tapping outlet, 12... graphite nozzle, 14... inner steel material, 16... intermediate coolant guide, 18... outer jacket, 24... orifice, 26... working surface, 28... passage, 30
First hole, 32, second hole, annular spaces 38, 40, 46, opening 50, inlet port 52, outlet port 54

Claims (10)

[Claims] [Claim 1] A tapping outlet for molten material from a melting furnace for use in a mineral wool fiber manufacturing apparatus, comprising a metal member having an inner working surface forming an orifice through which molten material from the furnace passes, the orifice being surrounded by an extremely narrow passage for the flow of cooling liquid located adjacent to the inner working surface. 2. The tap outlet of claim 1, wherein the passage is formed within the metal member. 3. The tap outlet according to claim 3, wherein the passage is provided so as to surround the outer periphery of the orifice. 4. The passage includes a first hole and a second hole provided in the metal member adjacent to the orifice and in an outer wall of the metal member, the first hole and the second hole being connected to each other.
a tunnel-shaped flow path that communicates with the first hole,
3. A tap outlet as claimed in claim 2, wherein said first hole is the coolant inlet and said second hole is the coolant outlet. [Claim 5] A tap outlet as described in claim 4, wherein the passage includes a plurality of tunnel-shaped flow paths, each of which includes the first hole and the second hole, and all of the first holes and all of the second holes are each connected to each other. 6. A tap outlet according to claim 5, wherein said metal member includes a hollow tubular portion extending axially from the area in which said passage is provided. [Claim 7] A tap outlet as described in claim 6, including a tubular coolant guide member that is coaxial with the tubular portion, extends axially around at least a portion of the tubular portion, and has one end connected to the portion of the metal member where the passage is provided, so as to form an extremely narrow first annular space between it and the tubular portion, and the first annular space is connected to the tunnel-shaped flow path via the second hole. 8. The cooling fluid guide member according to claim 7, further comprising a tubular outer jacket extending axially around the cooling fluid guide member, coaxially with the cooling fluid guide member, and having one end connected to a portion of the metal member where the passage is provided, to form a second annular space between the cooling fluid guide member and the tubular outer jacket, and the second annular space is connected to the tunnel-shaped flow path via the first hole.
The tap outlet described in paragraph. 9. The tap outlet according to claim 1, wherein the metal member is made of copper. [Claim 10] A method for effectively cooling the tap outlet of molten material from a melting furnace in a mineral wool fiber manufacturing apparatus, comprising: constructing said tap outlet from a metal member having an inner working surface forming an orifice through which molten material from the furnace passes; forming a very narrow passageway around said orifice adjacent said inner working surface for the flow of cooling liquid; and flowing cooling liquid adjacent to the surface forming the orifice through which the molten material passes at a velocity of at least about 3.05 m/s (10 ft/s).