ADJUSTABLE POSITIONING APPARATUS FOR COOLING MEMBERS AND METHOD
An apparatus for adjusting the cooling members located beneath fiberizing bushings is disclosed having the capability of moving each cooling member, or one portion of each cooling member, in a generally vertical direction, and/or in a lateral and/or tilting direction. Also disclosed is a process of using the apparatus to make fibers from molten material including molten glass.
The invention involves adjustable apparatus for positioning cooling members beneath a fiberizing bushing, and a method for making fiber from a molten material such as molten glass using this apparatus. More particularly, the present invention involves a bushing apparatus and a method for making fiber that reduces investment while providing a more uniform temperature profile across the orifice plate of the bushing and a better temperature control capability for the operators.
BACKGROUNDIn the manufacture of fiber from molten material, such as molten glass, it has been common practice to use a bushing made of precious metals including platinum, rhodium, palladium, ruthenium, iridium and alloys thereof. The bushings are electrically heated by their own resistance and are box-like, open on the top and comprise an orifice plate containing hundreds or thousands of nozzles or tips welded or punched thereon as shown by U.S. Pat. Nos. 4,207,086 and 4,078,413, which disclosures are hereby incorporated by reference.
As the molten material emerges from the orifices or nozzles, a meniscus of molten material is formed below each orifice or tip from which a fiber is pulled continuously. This is the objective, but if the temperature of the meniscus is not carefully controlled, one or more fibers break, requiring a costly stoppage of fiberization from that bushing and a restart of the bushing. To remove the heat that must be removed to cool the molten fiber so that it will have integrity and strength to pull the formed fiber behind, cooling members are located close to the orifices or nozzle tips to remove heat from the meniscus and newly formed fiber. These cooling members can be either cooling tubes like shown in U.S. Pat. Nos. 4,397,665, 5,244,483 and 6,196,029, the disclosures of which are hereby incorporated by reference, or cooling fins as are well known in the fiber industry.
Because it is not possible to maintain a uniform temperature across all of the nozzles or orifices using only the bushing, it is conventional to adjust the cooling tubes or fins individually and as a group to address hot spots, cold corners, and other fiber forming temperature problems. Bushings continue to get larger with thousands of nozzles or orifices creating or exaggerating temperature non-uniformities versus smaller bushings of the past. Past apparatus for adjusting the cooling members has been cumbersome and difficult to position the cooling members precisely to maintain the desired spacing between the cooling members and the tip plate or orifice plate, the tips, the molten glass meniscuses beneath the tips or orifices and the just formed fibers. This spacing is extremely important because at the temperatures the tips and meniscuses are at during fiberization, the heat transfer is dependent upon the square of the separation distance. It is very hot and uncomfortable around the bottom bushing and bushing mounting frame that holds the bushing in place. To insure that the cooling members are optimally positioned, it is important that the adjusting means is easy to use and to quickly and precisely position the cooling members. To achieve accurate positioning in this hot corrosive environment it is also important for the adjusting apparatus to be simple with none or few moving parts. Current adjustable support apparatus exists for adjusting the cooling members vertically, but is severely lacking in the these requirements and in enabling adjustment of the each tube laterally towards or away from the exit end of the tips and the meniscus.
SUMMARYThe invention comprises an apparatus for supporting and permitting adjustment of the position of cooling members mounted close to the tips or orifice plate of a fiberizing bushing to enable the desired spacing between the cooling members and the tips, meniscuses and/or fibers to be achieved and maintained. The apparatus comprises a bushing having cooling members that can be adjusted vertically, laterally and by tilt angle wherein each cooling member is supported by one or more generally vertical rods (generally vertical when the bushing assembly is first assembled) that can be moved to adjust the cooling member generally vertically and that can be moved laterally and/or easily bent to move the cooling member generally laterally and/or to give the cooling member a tilt angle or to change the tilt angle. By generally vertical means at an angle of no more than about 10 degrees, more typically no more than about 7 degrees and most typically no more than about 3-5 degrees off of true vertical. It is desirable to mount the rods as vertical as practical. The rods are adjustably mounted on a support member that usually runs perpendicular to the direction of the cooling members, but that can run parallel or at an angle with the cooling members. The support member is located at an elevation that is substantially lower than a tip plate of the bushing. By substantially lower is meant low enough to provide a length of rod that allows the rod to be easily bent or that allows the cooling member to be tilted the desired amount. Typically, each cooling member is supported by two generally vertical rods, but can also be supported by a single rod. By generally laterally is meant laterally even though the top of the cooling member may be moved a greater distance laterally than the bottom of the cooling member. The cooling members are designed to carry a cooling liquid or gas. Air is a gas and water is a liquid, but other gases and other liquids can be used.
The invention also comprises a process of making fiber from a molten material by flowing the molten material into a fiberizing bushing having at least one generally vertical side wall, an orifice plate having holes therein or a tip plate having a plurality of tips thereon, each tip having an orifice therethrough that communicates with the molten glass in the bushing and with the environment external of the bushing, causing the molten material to flow through the orifices in the orifice plate or in the tips whereby a meniscus is formed below each operative orifice or tip and pulling a fiber from each meniscus, cooling the molten glass meniscus and just formed fibers using a plurality of cooling members held in place below the orifice plate or tip plate with a mounting apparatus for mounting the plurality of cooling members, the improvement comprising one or more mechanisms on the mounting apparatus to allow vertical adjustment of each cooling member with respect to the orifice or nozzle plate independently from other cooling members, each cooling member being supported with one or more generally vertical and bendable rods, and adjusting the temperature profile of the orifice plate or tip plate by adjusting the vertical spacing between each end portion of each cooling member and the bottom of the orifice plate or tip plate and/or by bending one or more of the bendable rods to adjust the one or more cooling members laterally. The support rods can have any reasonable cross sectional shape, at least in the unthreaded portion, and are made from a metal that is easy to bend in the hot atmosphere below the fiberizing bushing and are made of a metal that resists corrosion in this very corrosive environment.
When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond that stated so long as the advantages of the invention are realized. Practically, there is rarely the time or resources available to very precisely determine the limits of all the parameters of ones invention because to do would require an effort far greater than can be justified at the time the invention is being developed to a commercial reality. The skilled artisan understands this and expects that the disclosed results of the invention might extend, at least somewhat, beyond one or more of the limits disclosed. Later, having the benefit of the inventors disclosure and understanding the inventive concept, the objectives of the invention and embodiments disclosed, including the best mode known to the inventor, the inventor and others can, without inventive effort, explore beyond the limits disclosed using only ordinary skill to determine if the invention is realized beyond those limits, and when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein. It is not difficult for the artisan or others to determine whether such an embodiment is either as expected or, because of either a break in the continuity of results or one or more features that are significantly better than reported by the inventor, is surprising and thus an unobvious teaching leading to a further advance in the art.
The upper portions of the sidewalls 4 can be bent out to form flanges 6. When the bushing is installed, the upper surface of the flange 6, which extends uninterrupted entirely around the upper periphery of the bushing, will contact, and be held against, with a well known mounting frame 38 shown in
A space is left on the bottom of the orifice plate in between each double row of tips to allow cooling members such as cooling tubes 24, each with or without a heat removing fin 26 attached to their top surface. A tremendous amount of heat must be removed from the molten glass extruding from the tips 14 at over 2000 degrees F. very quickly and the water cooled tubes 24 with their fins 26 perform this function, supplemented by a flow of air pulled into the area of the tips and fibers by the glass fibers moving rapidly away from the tips 14. Although cooling tubes are not shown on the outside of the outer double rows of tips, it is sometimes preferred to use cooling tubes with single fins in those positions also such that each row of tips is adjacent to a fin and cooling tube and adjacent, but staggered, to another row of tips.
The center cooling tube differs from the other cooling tubes in that it has two fins 28 on its top surface. Fitted between the two fins 28, as will be shown later in more detail, is a ceramic support 11 that contacts the bottom of the orifice plate 8 beneath the weld and runs down the entire length of the bushing to further support the orifice plate 8. The cooling tubes are supported in a well known manner, such as disclosed in U.S. Pat. No. 5,244,483. While the cooling tubes shown here are rectangular in cross-section, they can be oval, round, square, rectangular with radiused ends, etc. as is well known.
During several months of continuous operation, the orifice plate or tip plate 8 becomes deformed, sags with the maximum sag being in the center portion of the tip plate 8, due to hot creep of the precious metal. When that happens one or more rows of tips 14 often become cocked towards one side of the bushing 3. The above conventional cooling tube 24 and cooling tube fin 26 adjusting system does not allow optimum compensation for these orifice plate or tip plate 8 deformations. Since the deformation is not uniform across the tip plate 8, adjusting the cooling members 24 as a group does not address the problems caused by the sagging and uneven sagging problem. This often is the reason for the end of the effective life of the bushing.
One end of each TAR 34 is attached, such as being brazed, welded or silver soldered to the underneath side of each cooling tube 24 at a location that is usually laterally outboard of, but near, each end of the bushing 3. If the tips 14 do not extend all the way to the end of the bushing, the area where the TAR 34 is soldered to the bottom of the cooling member 24 can be inboard of the end of the bushing 3, but not such as to interfere with fibers coming from the tips 14. By near is meant within about 1 inch of the end of the bushing 3. In the embodiment of
To assemble the cooling member assembly normally the first step is to insert the adjustor ferrules 100 into the support bars 85 and lock them into place with the snap rings (89). The cooling tubes 24 (all) are then installed in the bars by inserting the TARs 34 in the ferrules 100. The cooling member assembly is then turned over and the end portion 93 of each ferrule 100 is screwed onto the TAR by turning them with a nut driver or electric screw driver, until the end of each TAR extends below the bottom of the end portion 93 of the ferrule, typically up to about one inch.
The next step is to level all of the cooling tubes. This is done by placing the entire assembly on a flat surface with the cooling tubes 25 resting on the flat surface. A spacer, normally about 1⅞ inch thick is placed under each end of each adjuster bar 85, lifting the cooling tubes off the flat surface. Each cooling tube 24 is then lowered by adjusting each ferrule 100 until the cooling tube, 24 or fin 26, just touches the flat plate. After repeating on all of the cooling tubes 24, all of the top surfaces of the tubes 24, or fins 26, in the same plane.
The entire cooling member assembly is then attached to the bushing frame 13 with using the threaded rods 21 and the nuts as shown in
The adjustor nuts 32 or 61 remain tight against the support bars 19 or 85 during installation to prevent the cooling member assembly from moving while the bushing assembly 9 is being installed in a fiber forming position. After installation, the adjustor nuts 32 or 61 are loosened to a light snug and then locked in place with the locking nuts 68 before heating up the bushing 2. This arrangement allows the cooling tube assembly to float longitudinally while the bushing 2 and bushing frame 13 undergo thermal expansion due to the large temperature increase to about 1900 degrees F. or higher.
After this the adjustor nuts 32 or 64 and the locking nuts 31 or 61 are normally not changed further during the life of the bushing 2, and the cooling member assembly is allowed to move with any thermal changes. The reason for this is the bushing frame heats up with the bushing but the cooling tubes stay relatively cool and do not expand because they remain at or near the temperature of the cooling water or other fluid. Without this movement, a stress would be put on the cooling member supports causing the cooling members to warp and cause fiberizing problems.
After the bushing 2 is up to temperature, a final check of cooling member alignments is made and the TARs 34 are bent with the tool 80 where required. No further cooling member 24 vertical adjustments are made until the tip plate 8 has begun to sag or a hot spot develops in an area of the tip plate 8. Desirably, the TARs have a 10-24UNC threads (90) which means one turn of the ferrule 100 will move the cooling tube 1/24 inch or approximately 0.041 inches. Using this relationship allows making fine adjustments of the cooling members 24. Most vertical adjustments are made using ⅛ turn increments of the bottom portion 93, but lesser to greater magnitude of turn increments can be used. Being able to adjust the cooling members easily, quickly and from a comfortable distance away from the furnace, compared to prior equipment and practice, results in more timely and more effective adjustment and significantly increased fiberizing efficiency and product productivity.
Different embodiments employing the concept and teachings of the invention will be apparent and obvious to those of ordinary skill in this art and these embodiments are likewise intended to be within the scope of the claims. The inventor does not intend to abandon any disclosed inventions that are reasonably disclosed but do not appear to be literally claimed below, but rather intends those embodiments to be included in the broad claims either literally or as equivalents to the embodiments that are literally included.
Claims
1-37. (canceled)
38. A process of making fiber from a molten material by flowing the molten material into a fiberizing bushing having at least one generally vertical side wall, an orifice plate having holes therein or a tip plate having a plurality of fiberizing tips thereon, each tip having an orifice therethrough that communicates with the molten glass in the bushing and with the environment external of the bushing, causing the molten material to flow through the orifices in the orifice plate or in the tips whereby a meniscus is formed below each operative orifice or tip and pulling one or more fibers from each meniscus, cooling the molten glass meniscus and just formed fibers using a plurality of cooling members held in place below the orifice plate or tip plate with a mounting apparatus for mounting the plurality of cooling members, the improvement comprising one or more mechanisms on the mounting apparatus to allow vertical adjustment of each cooling member with respect to the orifice or nozzle plate independently from other cooling members.
39. The process of claim 38 wherein each cooling member is supported with one or more generally vertical and bendable or rotatable items.
40. The process of claim 38 further comprising adjusting the temperature profile of the orifice plate or tip plate by adjusting one or more of the vertical spacings between each end portion of each cooling member and a row of orifices or row of fiberizing tips closest to each cooling member and/or by bending or rotating one or more of said rods to adjust the one or more cooling members laterally.
Type: Application
Filed: Apr 12, 2011
Publication Date: Aug 4, 2011
Inventors: Thomas Kent Thompson (Granville, OH), Terry Joe Hanna (Millersport, OH), Russell D. Arterburn (Athens, TN)
Application Number: 13/084,872
International Classification: C03B 37/083 (20060101);