CH636023A5 - Pipe for injecting and spraying liquid waste (residues) - Google Patents

Description

The present invention relates to an injection and spraying rod for liquid residues, usable either for the production of a simple injector, in the case where good spraying is required, or for the production of a burner rod, within heating equipment placed, for example, on an incineration oven.

The injection pipes or burner pipes commonly used for this function are in fact materials derived from those which are conventionally used for spraying water or fuel oil.

The presence of impurities prohibits so-called mechanical spraying, in which the fluid to be sprayed must pass through calibrated orifices of small diameter.

So-called assisted or auxiliary fluid spraying 5 is therefore used according to which the residue is sprayed by a high-speed injection of another fluid, generally gaseous, for example steam, compressed air, compressed gas, or other.

The injection of the spraying fluid is generally carried out either by direct expansion or by stepped expansion, the injection of the spraying fluid then taking place in an emulsion chamber maintained at low pressure, and the mixture obtained between the residue and the spraying fluid then expanding between the emulsion chamber and the outside.

Some manufacturers have adopted a compromise consisting in ef-15 carrying out the injection of the spraying fluid at the rear of the spraying nozzle, the mixture thus obtained relaxing in the conical part forming the front of the spraying nozzle.

In all cases, the injections of spraying fluid can be either radial, the injection taking place, in fact, in directions concurrent with the axis of the cane, or tangential, the injection then taking place , in directions tangent to an average circle of diameter smaller than that of the nozzle.

Whichever solution is used, the results obtained by this material are very average, especially when the viscosity of the residue is high. The main shortcomings that are encountered are:

- Poor spraying, especially when the auxiliary fluid injections are tangential: the auxiliary fluid jet does not sufficiently penetrate the residue jet and the center of the latter is not sprayed. The consequences of this bad spraying are

.w many: presence of solid and gaseous unburnt matter at the outlet of the oven, that is to say emission of smoke, formation of lava in the ovens, sticking of particles on the walls with agglomeration of these particles, flame instability, possibility of mini-explosions or re-ignition in or downstream of ovens, and other disadvantages.

- Bad flame divergence, especially when the auxiliary fluid injections are radial. The interpenetration of the jets is better but, the assembly does not rotate, the resulting jet does not flare at the outlet of the nozzle. The consequences are: instability of

40 flame, flame drifts, induction of vibrations both in the combustion gas circuit and in the burner rod supply circuits, and other disadvantages.

- Clogging of the nozzle orifices, especially in the case of staged spraying. To maintain a certain pressure in the

45 emulsion chamber, it is indeed necessary to have relatively limited orifices in section, which leads to blockages in the case of charged residues.

- Pulsation at the spray fluid injection nozzles. These pulsations are essentially due to variations in the su penetration of the auxiliary fluid into the residue to be sprayed.

The pulsations propagate downstream in the form of flame beats which can go as far as triggering by flame safety and, upstream, in the form of pressure vibrations in the pipe which can go as far as damage to the material in the case where 55 a phenomenon of resonance appears.

The object of the present invention is to produce a rod meeting the following three criteria:

- Good spraying of the residue even if the viscosity of the residue is high.

6 (i - Good divergence of the spray jet.

- Pressure stability in the supply lines, even if slight pulsations appear sporadically at the injection of the spray fluid.

For this purpose, the injection and spraying rod according to Fin-fi.5 vention has the characteristics specified in claim 1.

According to one embodiment of the cane according to the invention,

this rod comprises, immediately downstream of the balance sleeve

brage, an emulsifier, the emulsion chamber of which includes an inlet diaphragm through which the residue is supplied, an outlet diaphragm and, in the side wall which extends between the two diaphragms, spray nozzles by means of which the arrival of spraying fluid takes place.

The emulsifier spray nozzles can be arranged so as to introduce a rotation of the emulsion produced.

The foaming spray nozzles can be arranged so that the axes of the jets are tangent to an imaginary cone, the top of which is at the entrance of the foam concentrate and the base of which is located anywhere along of the foam concentrate.

The emulsifier spray nozzles can be arranged so that the axes of the jets are tangent to a cone coaxial with the emulsion chamber.

The foaming spray nozzles are preferably arranged in three successive rows, each row being arranged along the same circumference, the jets of the first row being tangent to the cone in the vicinity of its top, the jets of the second row being tangent to an imaginary circle whose diameter is equal to approximately half the diameter of the emulsion chamber, and the jets of the third row being almost tangent to the side wall of the emulsion chamber.

The rod may comprise, downstream of the foam concentrate, a final spray nozzle provided with a series of injection nozzles arranged so that the corresponding jets induce, at the level of the emulsion, a rotational movement in opposite directions of the rotational movement induced by the foaming spray nozzles.

According to a variant of the invention, the rod comprises, downstream of the foam concentrate, a final spray nozzle provided with a series of injection nozzles arranged so that the corresponding jets induce, at the level of the emulsion, a rotational movement in the same direction as the rotational movement induced by the spray nozzles of the foam concentrate.

The direction of rotation chosen depends on the characteristics of the products to be sprayed, and on the use made of the equipment.

The appended drawing, given by way of nonlimiting example, will allow a better understanding of the characteristics of the invention.

The flg. 1 to 3 are views showing, in section along a longitudinal plane passing through the axis, three known spray nozzles.

Fig. 4 is a view of an injection and spraying cane according to the invention, in section along a longitudinal plane passing through the axis.

Fig. 5 is a perspective view in section of the emulsion chamber of the cane foam concentrate shown in FIG. 4.

Figs. 1 to 3 show the circuits of spray product 1 and spray fluid 2, respectively, in the case of a direct expansion spray nozzle, in the case of a stepped spray spray nozzle of the spray fluid, and in the case of a so-called rear injection spray nozzle of the spray fluid.

In all three cases, the various drawbacks already described above are noted in use.

There is shown in FIG. 4 an injection and spraying rod which essentially consists of a balancing sleeve 3, an foam concentrate 4 and a final nozzle 5.

636,023

The balancing sleeve 3 receives the residue to be sprayed and the spraying fluid by respective tubes 1 and 2. A straight length of calibrated section 6 is provided inside the balancing sleeve, on the residue circuit. The diameter of this straight length is calculated according to the residue flow and the size of the particles which can circulate. The length is defined as a function of the viscosity, so that the pressure drop thus created is, in all cases, greater than the pressure variations induced by the pulsations which could occur at the injection of the auxiliary spraying fluid. . Under these conditions, even if such pulsations occur, the corresponding disturbance cannot go back upstream of the balancing sleeve, which makes it possible to avoid a conventional phenomenon of resonance and to lead, on the contrary, to an auto- vibration damping.

The emulsifier 4 contains an emulsion chamber 7 delimited inside a tubular wall 8, between an upstream axial diaphragm 9 and a downstream axial diaphragm 10. The straight length of calibrated section 6 of the balancing sleeve 3 opens out on the diaphragm 9, while the spray fluid circuit ends in the foam concentrate 4 at an annular chamber 11 delimited around the wall 8. Three rows of spray nozzles 12, 13 and 14 are arranged through the wall 8. Each row extends along a circumference of the wall 8, the jets of the spray nozzles being directed so as to be tangent to an imaginary cone 15 shown in FIG. 5. The top of the cone 15 is located in the middle of the diaphragm 9, and its base is located approximately three-quarters of the length of the emulsion chamber 7, in the direction of the diaphragm 10, this cone 15 being coaxial with the chamber d emulsion 7.

We see in fig. 5 that the jets corresponding to the first row of spray nozzles 12 are located in the vicinity of the top of the cone 15. The jets associated with the second row 12 are tangent to an imaginary circle 16, the diameter of which is equal to approximately half the diameter of the emulsion chamber 7. The jets associated with the third row 13 have almost a tangential orientation relative to the emulsion chamber 7.

The final nozzle 5 is of a conventional type with direct expansion. It receives the emulsion produced in the foam concentrate 4 between the residue and the spraying fluid via the downstream diaphragm 10, while the annular chamber 11 of the foam concentrate 4 opens into an annular chamber 17 of the final nozzle 5 , from which a series of jets 18 start. The axes of these jets are oriented so as to form generators of the same hyperboloid with a single layer, and to induce a rotation occurring in the opposite direction within the emulsion. rotation induced by the spray nozzles of the foam concentrate 4. This feature has the effect of breaking the effects of centrifugation, and thus improving the spraying result. Indeed, the emulsified mixture being in rotation, there is produced by centrifugation a vacuum in the central part of the flow. Under these conditions, even if the jets 18 of the final nozzle 5 lack penetration force to penetrate the flow, this has no unfavorable consequences. In addition, the reversal of the direction of rotation, associated with the venturi effect of the outlet diaphragm 10 of the foam concentrate, has the effect of achieving a very fine fragmentation of the particles.

As can be seen in fig. 4, the flow obtained at the outlet of the injection and spraying rod according to the invention itself has roughly the shape of a hyperboloid with a ply.

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2 sheets of drawings

Claims (8)

636,023 CLAIMS 1. A nozzle for injecting and spraying liquid residues comprising means for spraying a mixture of liquid residue to be sprayed and of auxiliary spraying fluid, pulsations caused by variations in the penetration of the spraying fluid into the residue to be sprayed being likely to occur during the mixing of this fluid with this residue, characterized in that it comprises a balancing sleeve placed upstream of these spraying means, this sleeve being traversed by the supply lines of the residue to spraying and spraying fluid to the spraying means and comprising, on the supply line of the residue to be sprayed, a calibrated section of length allowing a pressure drop sufficient to absorb said pulsations to be obtained. 2. Rod according to claim 1, characterized in that it comprises, immediately downstream of the balancing sleeve, an emulsifier, the emulsion chamber of which comprises an axial inlet diaphragm, by which the arrival of residue, an axial outlet diaphragm and, in the side wall which extends between the two diaphragms, spray nozzles through which the spray fluid is supplied. 3. Rod according to claim 2, characterized in that the spray nozzles of the foam concentrate are arranged so as to induce rotation of the emulsion produced. 4. Rod according to claim 3, characterized in that the spray nozzles of the foam concentrate are arranged so that the axes of the jets are tangent to an imaginary cone, the apex of which is at the entrance to the foam concentrate and the base of which is located anywhere along the foam concentrate. 5. Rod according to claim 3, characterized in that the spray nozzles of the foam concentrate are arranged so that the axes of the jets are tangent to a cone coaxial with the emulsion chamber. 6. Rod according to one of claims 4 or 5, characterized in that the spray nozzles of the foam concentrate are arranged in three successive rows, each row being disposed along the same circumference, the jets of the first row being tangent to the cone in the vicinity of its top, the jets of the second row being tangent to an imaginary circle whose diameter is equal to approximately half the diameter of the emulsion chamber, and the jets of the third row being almost tangent to the side wall of the emulsion chamber. 7. Cane according to one of claims 3 to 6, characterized in that it comprises, downstream of the foam concentrate, a final spray nozzle provided with a series of injection nozzles arranged so that the corresponding jets induce, at the level of the emulsion, a rotational movement in the opposite direction to the rotational movement induced by the spray nozzles of the emulsifier. 8. Cane according to one of claims 3 to 6, characterized in that it comprises, downstream of the foam concentrate, a final spray nozzle provided with a series of injection nozzles arranged so that the corresponding jets induce, at the level of the emulsion, a rotational movement in the same direction as the rotational movement induced by the spray nozzles of the emulsifier.