DE1237725B - Device for generating a turbulent, hot gas flow at high speed in the manufacture of fibers from materials which can be softened in the heat - Google Patents

Description

O UINJJtOKJIl 'U BLIK DJi U TSCJiLAIN D

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

DOId

German KL: 29 a-6/30

Number: 1237725

File number: P 26560 VI b / 29 a

Filing date: February 11, 1961

Open date: March 30, 1967

The invention relates to a device for generating a swirled hot gas stream from high speed that occurs when brought into contact with materials which can be softened in the heat Production of fibers is made possible, essentially consisting of a chamber in which fuels introduced, burned there and from which the combustion gases are blown out at high speed are, characterized in that in the flow path of the fuel gases within the Chamber an elongated baffle, for example a rod, is arranged and also an ignition device is provided that ignite the combustion gases in front of or on the impact body. With this device can be z. B. produce glass fibers, including very fine fibers.

U.S. Patents 2,489,242 and 2,489,243 describe a method and apparatus for the production of very fine individual (discontinuous) glass fibers. In this process, »ο a very fast and hot gas stream at a certain angle, preferably in right angle, meet a solid glass thread (pre-thread) or a stream of glass, whereby the The thread or stream warms up again to such an extent that it becomes soft and by the speed of the Gas stream can be divided. The gas flow arises in the burner of a combustion chamber, in the one a combustible gas mixture with a relatively low flow rate and below relatively low pressure, d. H. from 0.14 to 0.7 atmospheres and these gases in the chamber burns completely. The burned gases pass through an outlet opening of limited Cross-section at one end of the chamber in the form of a hot (1650 ° C) gas flow at high speed (150 to 215 m / sec.). The narrowing of the gas flow on its way through the opening accelerates it strongly. Generally lies the ratio of the cross section of the chamber to that of the outlet opening between 4: 1 and 8: 1.

A feature of the gas flow produced in this way is that the vortex which forms during the combustion of the gases in the chamber is significantly reduced by the narrowing of the gas flow as it flows through the narrow opening. This reduction in turbulence significantly reduces the effectiveness of the gas flow for heating the solid glass thread up to the softening temperature and for breaking up the softened thread. A strongly swirling hot gas stream transfers its heat much more quickly to the device for generating a swirled one
hot gas flow of high speed in the manufacture of fibers from in the heat
softenable materials

Applicant:

Pittsburgh Plate Glass Company, Pittsburgh, Pa.

(V. St. A.)

Representative:

Dr. W. Beil, A. Hoeppener

and Dr. H. J. Wolff, lawyers,

Frankfurt / M.-Höchst, Adelonstr. 58

Named as inventor:

Donald William Denniston, Pittsburgh, Pa.

(V. St. A.)

Claimed priority:

V. St. v. America February 15, 1960 (8651)

Glass thread and also breaks up the softened threads or streams much better.

The present invention relates to a device for generating the swirled hot gas flow of high speed. The special thing about it is that the in the stream of this Gases switched on elongated baffle causes that after ignition of the combustion gases Flame is thereby fixed in its position in the chamber and from then on extends further in the direction of flow of the gases.

In addition to the United States patents mentioned above, there are already pulling and burner devices for the production of glass fibers by the USA.-Patent 2 841213 became known with which very high blowing speeds are achieved. However, this latter patent is not yet the Rod-shaped impact body of the type shown here in the combustion chamber became known.

With reference to the drawing, the invention is described below for some particular embodiments described in more detail. In the drawing is

F i g. 1 a cross-section through the chamber in which the fuels are burned,

F i g. 2 the section along the line III-III in Fig.l;

709 547/330

3 4

F i g. 3 to 6 are isometric views of various sections of the in FIG. 6 shown rod 74 is

Dener rod forms as impact body, which in the U-shaped, with the Mittelteil.des U in general

F i g. 1 and 2 are inserted transversely to the direction of flow of the gases. In the-

the can; Small holes can also be made in this cross-section.

F i g. 7 is a section showing another negotiation. The rods 70 and 74 also meet

management form of the in F i g. 1 chamber shown serves its purpose better if the webs or middle parts

shows. a certain angle, namely from 45 to 89 °,

The burner contains a long narrow chamber 45, for the general direction of flow of gases through which are partly made of silicon carbide or other fire- forming chambers. Of course, you can also attach them Building materials 48 consists. The refractory lining has more rod shapes and more than one rod in front of it is surrounded by fire-resistant insulating bricks 49. For example, you take a number of jacks enter, and the whole thing is vertical, across the width of the chamber, in by a metal jacket 52 held together. The insulating blocks can be spaced apart from bars Aluminum silicate or other insulating compounds as just a single continuous horizontal stand, the metal jacket made of steel. The metal 15 rod. The purpose of the rods is explained below jacket is on an end or expansion plate 56 in connection with the course of the process fastened with screws 58, which are described in more detail from the jacket 52.

protrude and through holes in the plates 56 to operate the procedure described in FIGS and with. This screwed by nuts 60 direction one leads into the chamber a combustible are. 20 Gas mixture below 0.035 atm and higher pressure

A combustible gas mixture, e.g. B. of natural gas and and with a flow rate that is short

Air, is passed through line 62 to burner 38 in front of the rod in the chamber about 6 to 60 m / sec.

fed. A mixture of propane can also be achieved. The cross-sectional dimensions of the chamber

and air or from very finely sprayed liquid fuel 45 in the first section 65 and that of the

use substances and air. At its end carries 25 refractory linings 48 surrounding the section

the line 62 is a transition piece 63 that has the shape., for example 19 X 127 to 19 X 380 mm. These

a Mache Hebra nozzle can have, the flow dimensions are chosen so that they have a gas

flow cross-section to that in the chamber 45 flow of approximately the same dimensions in one Ent '

adapt. Sieves 64 with clear mesh widths at a distance of about 25 to 50 mm from the burner

from 0.25 to 0.42 mm can result across the flow mouth. The width of the burner

mungsbahn lying at the inlet and outlet points and the gas flow is different and directed

of the transition piece 63 attached to all rigidly according to the number of pre-threads and the

to break down no eddies and all the speed with which these are frayed. the

To compensate for differences in gas flows, the length of chamber 45 from its inlet to the

as a result of the curvature of the feed line 62, for example, or the rods is 10 cm or more and from

can stand. It is recommended that the speed. the rod or rods to the chamber outlet 25 cm

speed profile of the gases in the first section 65 of the supply or more.

Combustion chamber 45 in front of the impact rod practically right. The overall dimensions of these rods, for example angled and the swirling of the gases evenly in relation to the rod 66, are 0.75 to 13 mm in hold. The transition piece 63 and the sieve 64 can have a diameter of 19 mm for a chamber of 19 mm height, by the way, but it must be possible. Its shape is chosen so that it assumes the swirling of the gases, which enter the section 65 about 4 to 67% of the cross-sectional area of the chamber, practically evenly in front of the rod and to keep an additional swirling in the moderate. 45 fast flowing gases are generated.

In the first section 65 of the chamber 45. B. the rod 66, attached, the cut 65 of the chamber up to the rod 66 under through the entire chamber through from a side relatively low pressure of. 22 until the wall goes to the other. This rod can, as shown in FIG. 3 50 88 g / cm ² , preferably 35 g / cm ² and with one shown, have a circular cross-section or a speed of about 6 to 28 m / sec., Preferably, as in FIGS. 4 to 6 show another cross-section about 12 m / sec. You can form a for this, for example. The cross section of the rod 67 in FIG. Figure 4 shows the stoichiometric mixture of 10 parts of air in the shape of a V, with the tip of the V taking 1 part of natural gas. A spark igniter 80, e.g. B. the unburned gases is directed. A Tesla coil, inserted through an opening 81, has been found in that the rod 67 fulfills its purpose better, the chamber 45 incorporates or builds it in and, if the tip of the V under a certain angle, generates an ignition spark on the rear side of the rod (in kel, namely from 1 to 45 °, viewed from the all-direction of flow). The spark jumps from the normal flow direction of the gases through the chamber igniter onto the rod and ignites so that the mer 45 is directed at an angle. The rod 67 can also have small holes in the gas mixture, the flame adhering to the rod, so that a small part of the gas mixture can of course also be ignited in a mixture of the combustible gases and in this way.

Stick as well as around it. · The flame strides along the side of the stick

The cross section of the in F i g. 5 Sta- fort shown; so a stabilized flame runs through the

bes 70 shows the shape of a double T-beam, 65 entire chamber 45 starting from the rod. Are

whose web is generally transverse to the flow. as in a preferred embodiment, several

direction of the gases. The rod 70 can also have rods, so the gases must be present on each of these

have small holes in this bridge. The cross bars are ignited. When operating the in F i g. 2

Claims (1)

the burner shown, the flow rate of the unburned gases is allowed to increase gradually from 3 to 15 minutes until the gas flows. The strength of the secondary fibers can be between less than 1 and 25 μ or more shortly before the rod, depending on the desired size, and the amount of secondary fibers, about 6 to 60 m 5, is probably due to the increased cutting force. The higher the flow rate, in the present process partly on the, the finer the diameter of the ultimately stronger turbulence of the gas flow in the secondary fiber and / or the greater the same as the gas flows that were previously used in the amount of fibers produced. The pressure of the combustion equipment, of a similar type, which produces unburned gas mixtures, is about .0.035 to ^ o, the combustion chambers of which are narrowed to 0.35 atmospheres. At this time the gases burn over a manure. had. The secondary fibers obtained are a considerable part of the burner length. longer on average than those with previous gas The rod, which has no streamlined shape, is used to create a stream. The nonwovens are also to swirl the gases strongly if they are more elastic and tensile strength, both in the longitudinal as flow past, and eddy currents immediately 15 also in the transverse direction of the fiber layer, behind manufacture, in order in this way the process. Another embodiment of the invention is combustion of the fast-flowing gases behind the in F i g. 7 shown. The burner 84 is in here Hold or stabilize the rod. The comparison is built in the same way as the one according to FIG. 1 The combustion process starts immediately behind the rod, and 2, with the difference that the free transverse d. H. at most 3 mm behind it, and there is still 20 sections of the refractory section of the chamber 85 15 to 25 cm or more in the direction of flow just behind the rod a little, namely around the away. At high flow velocities, the width of the two projecting parts 86 constricts is greater the flame a few centimeters behind the rod than that of the first chamber section 65. At something and then gradually increases in height, this embodiment form the protruding so that they have a vortex surface in the vicinity of the outlet opening with the 25 parts 86 and diminish Chamber wall comes into contact. Virtually any flow rate. But this becomes the Gases are burned in the chamber. The altitude combustion process stabilizes, with the flames of the gas stream engaging the pre-filaments should adhere to the protruding parts. The previous be about 12 mm or more so that the protruding parts 86 are just behind the threads can linger in it long enough to be at 30 rod 66, z. B. about 12 to 25 mm behind. to The high passage velocities at the beginning of the combustion process are ignited will. The inclusion of the gas flow in the gas mixture at the end 88 of the first section 65 in Chamber is supposed to spark the current against the outside atmosphere the same way as it was for above shield until the gases are completely burned, the rod 66 has been written. The flame plants and leads to the fact that the current after the exit 35 is now from the rod and from the end of the first increases so much in its dimensions that a section 65 and the protruding parts 86 very strong fraying of the pre-threads is possible. off away. The advantage of this embodiment is The shielding of the gas flow also prevents more gases in it along the length of the chamber Heat losses to the surrounding atmosphere, which can be burned, which is why the chamber can arise through mixing with it, and can be prevented for a shorter period of time. also changes losses of kinetic energy, the cooling - cooling liquid, z. B. in the opposite the consequence of which is an acceleration of the surrounding electricity to the flowing mixture of the burning Atmosphere and a slowing down of the gas flow gases, makes it possible to reduce the flow velocity. were. The refractory lining 48 is not necessary if the gases are not activated when the burner is started up. to keep the gases burning. 45 and not to increase gradually. You That which emerges from the mouth 82 of the burner also extends the life of the burner. Gas stream is about 1650 ° C or more warm and another advantage of cooling is that has a speed of 150 to 305 m / sec. the guide 56 no longer bends so easily or more. Which are not replaced as often during the combustion process and therefore The vortex generated in the chamber 45 remains at 50 den. The flow velocity is there Exit largely preserved; the strength of the ver chosen so that the temperature of the metal walls vortex in the chamber emerging from the burner below the ignition temperature of the Gas flow is between 10 and 50%. flammable gases remains. Used preferably The drawing speed exerted by the gas produced in this way, water at room temperature, is therefore greater than the coolant, so that its flow speed is sufficient for the drawing speeds of all gas flows previously used for this purpose to reduce the temperature of this water. This certain to only allow 12 to 22 ° C to rise. The cooling of the chamber achieved at this drawing speed is the length of the produced way improves the fiber from a single thread per second. It has been observed that the stability and uniformity of the combustion is that the gas flow acts in that the process in the chamber, in that additional deaerators than the gaseous ignition points previously used for this purpose, are the desired ignitions and gas flows, as it causes a greater part of the pre-uneven combustion to unravel each unit of the gas used to be switched to shredded,
able. It has been observed in comparative tests that its splitting power or fiberization 65 patent claims:
effect was greater than it was with the same Hourly output a finer secondary fiber or with the 1st device for generating a vortex Generation of a secondary fiber of the same fineness, hot gas flow at high speed The speed of production when it is brought into contact with materials that can be softened under heat of fibers made possible, essentially consisting of a chamber in which fuels introduced, burned there and from which the combustion gases at high speed are blown out, characterized in that in the flow path of the Fuel gases within the chamber an elongated baffle, e.g. B. a rod arranged and an ignition device can be seen that ignite the combustion gases in front of or on the impact body. 2. Apparatus according to claim 1, characterized in that the chamber has a plurality of rods (66, 67, 70 or 74) as an impact body. 3. Apparatus according to claim 2, characterized in that the chamber is just behind the rod or rods expanded. Considered publications:
U.S. Patent Nos. 2,681,696, 2,841,213. 1 sheet of drawings 709 547/330 3.67 © Bundesdruckerei Berlin