US2147192A - Nozzle - Google Patents

Description

Feb. 14, 1939.

w. E. CARSON 2,147,192

NOZZLE Filed Sept. 25, 1937 3 Sheets-Sheet l Feb; 14, 1939. w E. CARSON ZMZWZ NOZZLE Feb. 14, 1939. w E CARSON 2,147,192

NOZZLE Filed Sept. 25, 1937 3 Sheets-Sheet 3 NR 73 7 A20 22 2 3mm ECZLrG 0 71/ NITED STATES PATENT This invention or discovery relates to nozzles; and it comprises a plane faced. chambered nozzle useful in the manufacture of rock wool and adapt ed for connection to a source of steam or cormair, the face being orlfioed to provide olow open topped jet and there being an ausorifioe, within the jet orifice, of suhstantialu: the so. is outer contour es the jet orifice but separated therefrom by walls, and so constructed and arranged as to supply air within let and thereby to relieve local negative thin the hollow jet; all as more fully *ozth and as claimed.

y practice of making tool-z wool, reel: is melted in cuoola furnace with of appropriate fl 35 and coke. There delivery of molten roclt a temperature 1488' 8.; the drops falling into on top hollow jet of high pressure steam or coming from the orificed iace of chambered. We steel nozzle adapted for connection to source of steam or air. Steam is generally used. The point .where the drops enter the jet is spaced somewhat away from the face of the 25 nozzle. Ordinarily the hollow jet is formed by a multiplicity of small sub-jets coming from orifices in the face of the nozzle arranged to describe a i. In nozzles of a type much used, there maybe 20 or 30 -inch perforations comrnunicating with the inner chamber of the nozzle and describing a V about two inches high. Be cause of the high temperature of the molten rock it is common to face a steel nozzle with a plate of copper or, better, silver to aid in distributing heat. line steam in the chamber acts as e. cool== ing agent.

With a J jet such as described, drops of molten rock enter the top and are carried forward until they disappear, with production of loose fiber. The initial temperature of a drop is perhaps 1400 C. and it must maintain a temperature of at least 1400 C. until it vanishes. Drops cooling below the temperature of free liquidity produce shot. The operation is quite different from that in making glass wool and slag wool where drops are projected as such with a formation of a long attached trailing fiber. In making rock wool the production of shot is minimized as far as possible.

50 The drop of molten rock passes forward with the steam until it is converted into loose fiber and the steam and loose fiber are passed into a.

large quleting and settling chamber. Wool fibers in aerial suspension settle quietly to the bottom 5 of the chamber and are there collected on a. travpressure jet is an important factor.

cling conveyor and taken away a layer or blanket.

In this practice the use of a hollow open-topped It custom ary to have this jet more or less f shaped in. cross section. But a U shape or a #3 shape will serve. Instead of using a multiplicity" of small orifices forming parallel sub-jets, there he a. continuous slit in the face of the nozzle: the claims, the term orifice refers to either a single continuous slit orifice arranged as described, or an orifice made up of a number of small ortfices arranged in. the same pattern.

The great dinlculty in the operation. as so described is the short life of the nozzle. it our out quickly. With a plane laced massive ste nozzle, the eflectiye life may he only an hOJ-J." or two. By facing the nozzle with copper or silver the life may be prolonged several times; the noszle may last for a number of hours before replacement becomes necessary. Another dlfiiculty is the accumulation of slag, that is solidified roots, on the face of the nozzle as a sort of crust. Solid. accumulations of coarse matter are apt to go. forward with the wool into the settling cham= 2 her, and these are a nuisance.

Really the two troubles are the same since it is the collection of high temperature molten material in the bottom of the v next the metal face that causes burning out and accumulations oi crust. The temperature of the molten rock is several hundred degrees above the melting point of iron and of copper. Copper melts at about i106 and on an ordinary burnt out copper laced nozzle there are mdleatlons of the trans" 5 new of copper in e. molten form. In such a case the temperature of the face must, at least locally and occasionally, exceed llllll C.

The hollow jet of high pressure steam has an injector action, and. I find that because-oi its n shape negative pressure or suction develops wlth== in the jet, and particularly at the bottom of the jet next the nozzle face. Although the lncandes cent drops are delivered into the rapidly moving jet at a point spaced away from the face or" the so nozzle, hot molten material occasionally travels backward, so to speak, and reaches this point. The point of delivery of molten rock represents a compromise: if it is spaced too far away from the nozzle face there is a production of shot and if it is too near the nozzle burns out quicker.

I have discovered that by providing means for relieving negative pressure within the hollow jet at this point the stated difiiculties disappear. An ordinary massive chambered, plane faced steel nozzle, orificed to give a hollow jet, may be used for weeks without burning out. It is advantageous to provide it with a copper or silver face but not Wholly necessary.

There are various ways of relieving negative pressure within the jet possible under the present invention. In one way of operating I supply a small down jet of steam within the hollow jet, contouring the face of the nozzle so this down jet reaches the point where negative pressure is apt to develop. There may be a spoon shaped recess inthe face of the nozzle with the point of the spoon coming to the plane at the bottom of the V. In another way of operating I provide an air inlet within the hollow jet from a conduit leading to a point back to the nozzle and arranged to supply heated air to the inter-jet space. Passage of air to the hollow jet depends on the development of negative pressure therein and is, therefore, more or less self regulating. Sometimes, however, provision is made for introducing the air under pressure, rather than deheated air.

pending on the jet suction alone. In all embodiments the face of the nozzle has an opening, separated from the V-orifice by narrow walls, and substantially coextensive with the interior oi theV; and the additional steam or air is supplied through this opening. In all embodiments, development of negative pressure at the danger point is precluded.

In detail, in the first way of operating using a V jet comingfrom a multi-perforated or slitted fiat faced steel nozzle, I hollow out the face within the V to a sort of spoon shaped recess, the depth of the recess being the greatest at the top and coming nearly to plane at the point. Within this hollow Lproduce a couple of down jets of steam from special orifices communicating with the steam chamber. This releases the suction on the interior of the basket of steam jets and produces a plenum. In the other way of achieving the same result, I also use a recess and provide a conduit extending through the nozzle fitting into communication with the air. With this arrangement, negative pressure is relieved by inflow of With a conduit extending through the hot massive fitting, the air reaching the hollow jet is hot. If desired, the air can be supplied under some positive pressure.

Using either modification, there is no longer a collection of molten rock at the point of the V and the nozzle is not eroded. There is no accumulation of slag lumps to pass forward with the wool. Molten matter does 'not reach and contact with the metal and there is neither an accumulation of frozen stufi nor local burning out. Whatever the explanation, the difiiculties are removed and substantial advantages accrue.

The length of life of a nozzle in operation becomes indefinitely long. Nozzles of naked steel, according to this invention, have been in daily use over a, period of weeks without needing replacement. However, following the usual practice, I generally face the nozzle with copper or silver in an ordinary way.

In the accompanying drawings I have shown more or less diagrammatically four embodiments of apparatus within the purview of the invention. In the showings, I

Fig. 1 is a perspective view of one form of nozzle fitting;

, Fig. 2 is a front elevation corresponding to Fig. 1;

Fig. 3 is a vertical section of the fitting, taken along line 3-3 of Fig. 2 and including a showing of the molten rock supply means;

Fig. 4 is a section taken along line 4-4 of Fig.

Fig. 5 is a rear elevation of the device of Fig. 1;

Fig. 6 is a front elevation of a modification having a U-jet;

Fig. '7 is a side elevation of a modified form in which air is admitted to the inter-jet space;

Figs. 8 and 9 are front and rear elevations corresponding to Fig. 7;

Fig. 10 is a view taken along line |0l0 of Fig.

Fig. 11 is a view taken along line ll-ll of Fig. 7;

Fig. 12 is aview in vertical section of a modification of the apparatus of Fig. 7, having means for supplying the air under positive pressure;

Fig. 13 is a view taken along line l3 |3 of Fig. 12; and

Fig. 14 is a perspective view of one element of Fig. 12.

Referring to Fig. 1, the nozzle takes the form of a cap 10, threaded at H for attachment to a steam or air pipe, not shown. A plurality of small holes i2 are bored through the plane front face i3 of the cap, and the arrangement thus provides a substantially V-shaped jet system projecting steam at a high velocity outwardly. In use, the cap is arranged about as shown in Fig. 3 with respect to a pipe i5 from which fiows a stream of molten rock, not shown. The jets project the molten rock to the right in Fig. 3, forming filaments. cessed as indicated at IS, the recess having a triangular shape with beveled walls and being deeper at the top than at the bottom. The recess is separate from the series of jet orifices as shown. Steam is supplied downwardly to this recess through orifices H. The quantity of steam supplied to the recess is ordinarily smaller than the quantity issuing through the V Jets.

In operation, steam or air at high pressure escapes from the V jets and an auxiliary supply flows from the recess, and rock wool is projected outwardly in the formof fine fibers. The advantages described ante are realized. The nozzle lasts indefinitely even when embodied in ordinary steel.

While the invention has been described with r reference to a jet arrangement composed of a plurality of. small circular orifices in V configuration, the stated advantages result when this exact shape is not used. Sometimes it is I desirable to employ a single continuous slot instead of a plurality of separate orifices.

Referring to Fig. 6, a U-shaped slot I8 is made in cap l0 and forms the primary nozzle for projection of the fibers. A cavity I9 is provided within the space defined by the slot and of shape corresponding generally to the slot. Steam is supplied to the cavity through holes 11.

The entire fitting, or the face thereof, can be embodied in or faced with copper, silver or other suitable metal if desired.

Figs. 7 to 11 show a modification in which the cuneiform inter-jet space is put in direct communication with the atmosphere, so that air is drawn in to relieve the subatmospheric pressure. As shown, the nozzle comprises a hollow cylindrical housing 20, capped at each end at 2| and 22, and having a pipe connection 23for admission of steam into the housing. At the front end of the housing is mounted a plate 24, having a V-shaped slot orifice 25 extending through the The face of the cap is re- In use, steam under.

plate and the cap 22. pressure issues from this slot-like jet. The plate also has a large sector-shaped orifice 26 spaced from slot by a thin wall 21. A V-shaped trough-like member 30 is provided in the housing, defining a passage extending clear through the housing from front to rear. Cap 2i has an orifice 3i registering with the end of member 30, so that air can flow freely through the fitting, as indicated by arrows in Fig. 7. A swinging damper 32 pivotally attached at 33 to a bracket 32 on the housing, is provided for adjusting the air flow. I usually provide a series of small steam orifices 35 near the apex of the V; though these can be omitted without substantial change in the characteristics of the nozzle.

In operation steam at high pressure flows in through pipe 23, fills the interior of the housing, and escapes through 25 and 35. Air is drawn through passage 26, relieving pressure in the inter-jet space. The air is heated in its passage, since element 30 is kept hot by the steam.

This nozzle gives excellent results. The rock wool produced is of exceptional uniformity and is free from shot, and the nozzle is very durable.

It is sometimes advantageous to supply hot air under some positive pressure, and Figs. 12, 13 and 14 show a convenient way of doing this. As shown, there is provided a face plate 24 similar to that of Figs. 7 to 11 and having a triangular orifice 2E and a V-shaped orifice 25. The plate is attached to a cylindrical housing E29 with a steam connection 23 as in Fig. 7. Within the housing is a hollow member 10 (shown by itself in Fig. 14), generally tubular in shape and merging into the orifice 26. Member 68 is advantageously, though not necessarily, made of copper. A cap 48 closes the end of housing I20 as shown. A steam-jet blower ll of known type is provided, comprising a Venturi-like chamber 42, a steam jet 43, and a steam pipe 44 screened at 45 and controlled by a valve 46. The pipe is connected to the housing I20 at 47 and takes steam therefrom. With this arrangement, air is blown through orifice 25 under some superatmospheric pressure and at relatively low velocity with respect to the steam jets from slot 25. The air is heated directly by the steam as well as by passage through the steam-heated member 40.

The apparatus of Figs. 12 to 14 is economical of steam, employing only about half as much steam as the apparatus of Figs. 7 to 11 for a given output and the product is good.

What I claim is:

1. A nozzle useful in making rock wool comprising a chambered metal member adapted for engagement with a steam pipe and having a plane face orificed in V configuration to provide a substantially V-shape jet for steam, the plane face being recessed between the arms of the V, throughout substantially the entire area included between the V-shaped orifice to form a cavity separate from the V orifice, and means for delivering steam downwardly to the recess, whereby the nozzle is capable of forming rock wool fibers without substantial destruction of the nozzle.

2. A nozzle for making mineral fibers, comprising a chambered metal body adapted for engagement with a steam pipe and having a face orificed in V configuration to provide a jet for steam, a triangular recess within the V, deep near the top of the V and becoming shallower near the bottom, walls separating the recess from the jet, and means for supplying steam into the recess near the top thereof.

3. A nozzle useful in making rock wool, of the type having a massive, chambered metal member adapted for engagement with a source of steam or air under pressure, and a face member having an orifice extending therethrough into communication with the chamber, the orifice being defined by wall portions of the face member and so constructed and arranged as to produce a hollow, open topped jet receiving molten rock from above; said nozzle being characterized by having an opening in the face of the face member, separated from the orifice by wall portions of the face member and extending substantially across the area outlined by the orifice, and means for introducing a flow of steam or air into said opening for relieving lower pressures within the hollow jet.

4. The matter of claim 3 wherein the means for introducing air within the opening is a conduit extending therefrom back through the chambered member to the atmosphere.

5. The matter of claim 3 wherein the opening is a hollowed-out cavity in the face member, and steam is introduced downwardly thereinto to flow out from the cavity within the hollow jet.

6. A nozzle useful in making rock wool comprising a chambered massive metal member adapted for engagement with a source of steam or air under pressure and having an orificed face so constructed and arranged as to produce a steam or air jet of hollow open topped configuration adapted for the reception of molten rock through the top, the member further having an opening in said orificed face within the hollowjet orifice and separated therefrom by narrow walls, and means for introducing additional steam or heated air through said opening, into the interior of the hollow jet, to relieve low pressures existing therein. 7

7. The nozzle of claim 6 wherein the opening in said orificed face is a shallow cavity, and the chambered metal member is provided with a passage for steam or air extending from the cavity to the interior of the chambered metal member,

8. A nozzle useful in making rock wool comprising a chambered massive metal member adapted for engagement with a source of steam or air under pressure and having an orificed face so constructed and arranged as to produce an open topped hollow steam or air jet adapted for the reception of molten rock through the top, an elongated air conduit extending from the portion of the orificed face lying within the hollow jet, to the atmosphere, and means for heating the air in said conduit.

WILLIAM E. CARSON.

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