FI60384C - SAETTING OVER ANORDING TO A MINERAL FUEL TRANSPORT - Google Patents

Description

F5Br * l ΓβΙ advertisement publication «Bä W (11) UTLÄGGNINGSSKRIPT 6U0Ö4 C Patent issued II 01 1982 W Patent oeddelat ^ * - / (51) K» .ik.Vct3 C 03 B 37/10 // C 04 B 43/02 ENGLISH —FINLAND (21) p «* nttih * k # mM« —p »*« K * n. <Muw »,« 763 ^ 96 (22) Hakwnitpllvt —Ameknln | * d «g 03-12.76 '' (23) Alkupliv · —GHtighaadaf 03.12.76 (41) Translators] ulktoufc * l - Bllvlt offvntllj 20.07.77

Patent and Registration Office ............. , . , -. . (44) Date of entry into force of this Regulation. -

Patents and Registration of AmMun uttafd odi wi. * Krift.n pubikund 30.09.81 (32) (33) (31) ^ yH «** y« boHmu · —8 «glrd prforttct 19.01.76

Sweden-Sweden (SE) 7600U63 ~ 9 (71) Rockwool Aktiebolaget, Skaravägen, S-5 ^ 1 00 Skövde, Sweden-Sweden (SE) (72) Rolf Lennart Alenrot, Skövde, Ulf Aberg, Skövde, Sven Torbjörn Lundh, Skövde , Sweden-Sweden (SE) (7 * 0 Oy Kolster Ab (5U) Mineral fiber transport method and equipment - Sätt och anordning för att transportera mineralfiber

The present invention relates to a method and apparatus for transporting mineral fibers according to the species definition of claims 1 and 7.

In the production of mineral wool in a conventional manner, a mixture of coke, diabetes and a flux, such as limestone, is melted in an oven and the resulting melt stream is spun into fibers by means of a fiber-forming device. The fiber-forming device is formed by a series of closely spaced, rapidly rotating rollers with horizontal axes, and the fibers are formed so that when the melt stream encounters, the rollers disintegrate into droplets which are centrifuged by the centrifugal force and simultaneously stretched into fibers. The fibers are taken from the spinner to a spinning chamber where they are assembled on a collection belt. To control the transport of the fibers from the fiber forming device to the spinning room, the spinning device is provided with a nozzle, preferably formed by slits, which direct a strong gas flow towards the newly formed fibers and force them towards the other end of the spinning room. At the same time, a binder solution and a lubricant are applied to the fibers to reduce dust formation. There are nozzles in the fiber forming device for this application. Behind the assembly belt is still a fan device which creates a vacuum in the spinning room and thus contributes to directing the fibers from the spinner to the assembly belt. Since the melt is not completely stretched into fibers during spinning, some particulate matter is also formed, the so-called beads which are undesirable in the finished product and which are therefore attempted to be separated from the fibers.

This separation is achieved, for example, by fitting a threshold in the fiber flow path, by means of which the direction of the fiber flow is changed and some of the beads are separated and fall down into the waste shaft. However, due to the strong gas flow, especially due to the use of annular blow nozzles, some of the beads are trapped indiscriminately and will be included in the finished product. In addition, as the gas flow rate in the spinning chamber gradually decreases, starting from the spinning device at the inlet end of the chamber and counting toward the assembly belt at the outlet end of the chamber, the fibers formed later reach the previously formed fibers during transport through the spinning chamber. In addition, the decrease in the velocity of the gas flow creates a strong vortex in the spinning chamber, which is an additional cause of clumping and flocculation. The fibrous flakes thus formed are the cause of the uneven deposition of the fibers on the assembly belt, which in turn means that the final product has a less desirable, uneven fiber distribution. Flocculation in the spinning chamber is a further disadvantage, as it causes the application of the binder to become uneven because the binder solution is unable to penetrate the flocs.

It is an object of the present invention to obviate the disadvantages described above in connection with the conventional production of mineral fibers and to create a fluff-free fiber stream in a substantially vortex-free gas stream in the spinning chamber. In short, this is achieved by creating an accelerating gas flow with a gradually increasing speed in the spinning chamber, in addition to making the inlet end of the spinning chamber as open as possible in order to reduce the vortexing to a minimum.

It is already known from Swedish Offenlegungsschrift 386 887 to adjust the decreasing flow rate in the manufacture of nonwoven mats between the fiber-forming member and the conveyor belt on which the fibers land. However, in contrast to the present invention, the gas flow is not accelerated, followed by an increased gas velocity, but on the contrary, the chamber where the flow takes place has a gradually increasing cross-sectional area which is 1-2 times larger at the outlet end than at the inlet end. This increase in cross-sectional area is counteracted by the supply of additional air so that the amount of liquid flowing and thus the velocity of the gas remains essentially constant along the entire flow path.

The essential features of the method and device according to the invention become clear from claims 1 and 7.

In the following, the invention will be explained in more detail with reference to the accompanying drawings. In these, Figure 1 shows a strongly schematic side sectional view of a preferred device for carrying out the method according to the invention. Figure 2 shows a horizontal projection of the device according to Figure 1 along section II-II in Figure 1.

As shown in Fig. 1, mineral wool is formed at the other end of the spinning chamber 1, at the inlet end 2, so that the molten mineral 3 is fed from one or more nozzles towards a fiber forming device 5 consisting of at least one and preferably two or more rapidly rotating cylinders 6 having substantially horizontal axes. From the cylinder 6, a centrifugal force is centrifuged out of the mineral melt as thin fibers 7 as well as beads in which no fiber formation has taken place. The gas flow entrains the formed mineral wool material into the spinning chamber 1 and further towards the other end of the spinning chamber, the outlet end 8. The gas flow through the spinning chamber 1 is provided by a ventilation member 9 located behind the spinning chamber outlet end and sucking air through the spinning chamber 1. In this connection, it is of course possible instead to fit the ventilation element 9 in front of the inlet end 2 and to blow air through the spinning chamber. It is essential to provide a pressure difference between the inlet end 2 and the outlet end 8 so that a gas flow is obtained from the inlet end 2 and towards the outlet end 8. It should be noted that blow nozzles are not used in the preferred embodiment of the device according to the invention. according to the beads, entanglement in the fiber stream. In order to further create the conditions for the vortex-free gas flow through the spinning chamber, as mentioned earlier, the inlet end 2 has been made as open as possible in order to prevent the ingress of gas into the spinning chamber 1 as little as possible. In this connection, it is also advantageous to round the corners and edges in the path of the gas flow. The open shape of the inlet head 2 also makes it possible to simply place additional fiber forming devices, whereby the production efficiency is increased.

In order to separate the beads and other waste material, there is a gap 18 in connection with the inlet end 2, into which the waste material falls and from which it is transported. The waste falling into the shaft 10 originates in part from particulate matter which, immediately during fiber formation by the fiber forming apparatus, falls down into the shaft, in part from particulate matter entrained in the spinning chamber 1 but separated therefrom 7 and dropped down into the chamber. formed by a conveyor belt 11 which feeds the recovered particulate matter into the shaft 10. The conveyor belt should be arranged substantially horizontally in order to also prevent fibers from accumulating on the belt.

As previously mentioned, according to the invention, in order to avoid turbulence and flocculation, the gas flow through the spinning chamber 1 must be accelerated along a significant part of its path through the spinning chamber, whereby the velocity of the gas flow gradually increases. This acceleration of the gas flow and the increase in velocity is preferably achieved in the device according to the invention so that the cross-sectional area of the spinning chamber 1 decreases towards its outlet end 8. This surface reduction can be achieved by tapering one or more of the spinning chamber walls towards the outlet end 8. the vertical walls 17,18 converge, as shown in Figure 2.

An accelerated, fibrous gas stream substantially free of particulate waste material eventually encounters a gas permeable assembly belt 12 at the spin chamber outlet 8, with the gas stream passing through the assembly belt, the fibers 7 landing on the belt and forming a mat 14, the assembly belt 12 1 is shown used clockwise, the formed fibrous mat 13 is fed gradually upwards and out of the spinning chamber 1, after which it is transferred to a second conveyor belt 16 for further processing.

In order to achieve the power referred to in the invention, the gas flow rate must be increased by an average of 5-65%, preferably about 25%, during acceleration through chamber 60. In this case, the acceleration should be greatest closest to the fiber forming device 5, i.e. at the inlet end 2. Furthermore, the gas flow should be accelerated along as much of the distance between the fiber forming device 5 and the assembly belt 12 as possible and along at least 50% of this distance. In practice, a suitable value is that the gas flow is accelerated along about 70% of the distance between the fiber forming device and the collecting belt 12. Acceleration over the entire distance is difficult to achieve in practice, because the spinning chamber must expand at the discharge end 8 immediately before the collecting belt 12, among other things, to allow space for the formed nonwoven 13 to be fed out.

The invention has been described and explained in more detail above with reference to a particularly advantageous device, but it is clear that the invention is not limited to the device shown and specifically described, but also includes other devices and methods for accelerating the gas flow through the spinning chamber.

Claims (12)

A method of transporting mineral wool fibers by means of a stream of a gaseous medium, preferably air, from the fibrating assembly (5), wherein the fibers (7) are formed by slurrying molten mineral from the outside of at least one rotating cylinder (6) with substantially horizontal axis, to a gas-permeable collecting band (12), wherein the fibers (7) are deposited into a mat (13) while simultaneously separating the gaseous medium, characterized in that the gas stream is accelerated along a significant portion of the distance between the fibrating assembly (5). ) and the collection band (12) beginning at the fibrating assembly (5). 2. A method according to claim 1, characterized in that the velocity of the gas stream during the acceleration is increased by an average of 5-65%, preferably about 25%. 3. A method according to claim 1 or 2, characterized in that the acceleration of the gas stream is greatest closest to the fibrating unit (5). in +. Method according to any of the preceding claims, characterized in that the velocity of the gas stream is reduced immediately before the collection belt (12). 5. A method according to any of the preceding claims, characterized in that the gas stream is accelerated along at least 50% of the distance between the fibrating unit (5) and the collecting band (12). 6. A method according to claim 5, characterized in that the gas stream is accelerated along about 70% of the distance between the fibrating assembly (5) and the collecting band (12). Apparatus for carrying out the method according to any of the preceding claims, comprising a substantially horizontal spinning chamber (1) of rectangular cross-section where two of the walls (17, 18) are vertical, a fibrating assembly (5) comprising at least one rotatable cylinder (6) having a substantially horizontal axis is provided at one end of the spinning chamber, the input end (2), while a gas-permeable collecting band (12) is provided at the other end of the spinning chamber, the output end (8), and the spinning chamber (1) is connected fan means (9) for effecting a pressure difference between the input end (2) and the output end (8), characterized in that the cross section of the spinning chamber (1) decreases in direction from the input end (2) and towards the output end (8) along a significant portion of the distance between these two ends.