US2612405A - Spraying nozzle - Google Patents

Description

p 1952 E. KIRSCHBAUM 2612405 SPRAYING NOZZLE Fi1ed Juno 5, 1950 INVENTOR EMIL KIRSCHBAUM by ATTORNEYS Patented Sept. 30, 1952 UNITED SPRAY ING NOZZIE Emil Kirschbaum, Grotzingian, near Karlsruhe/Baden, Germany,'as signor to Industriewerke -Karlsruhe Akt iengesellschaft,

Baden, Gexmany Apiiliciation Ju'n'e 5, 1950, Serial In Gex:many June 2, 1949 This invention relates to an atomising nozzle. In the atomisation of liquids, arrangements workingon various-physioal principles are"em-' ployed. In .atomising liquids for the purpose 'of drying, particular care must be taken that;solid substances separating from the liquid do not obstruct'the atomising device, and that vis cous so- 1 lutions can also be dealt with.

Of the devices employed for the atomisation of liquids by means-of compressed gases, particular practioal importance .attaches to that in which the liquid is introduced laterally into the rapidly flowing gas; In the case of. spraying for drying purposesthe gas and the atomisedliquid flow at great velocity into a drying chamber which almost always has the form of a vertical oylinde3r, which must be of very great length becaus e the two aforesaid substances are cnveyed parallel to the axis of the oylinder at one end thereof and because the droplets mustremmin therein ior not less than a certain period of time. The

' great length of the drying chamber is a fundamental disadvantage because it entails high cost of production, oc cupies a great amount of spaoe and causes considerable heat losses.

This invention has for its object both 130 av oid the formation of deposits at the point of discharge of the liquid and to red'uc'e the kinetic energy after the discharge of the liquid from the atomising device, in order that the arrange ments in which the atomising device is employed;v for (example drying towers, may be constructed in simpler forms, and to this end the atomising device according to this invention operates with two gas streams, between which the sprayed liquid particles move after leaving the nozzle mouth, and is characterised by the fact that at least one of the two air streams is set in circular motion before it leaves the nozzle mouth. The arrangement may be such that both gas streams rotate in opposite directions. The rotation of the gas streams can be obtained by guiding devices provided in the atomising device in front of the point of discharge of the gas streams, the said guiding devices having either equal or different pitches. Moreover, the gas streams themselves may have either equal or different velocities in order to influence the whirling eiiect.

It is preferable to employ the rotation of the gas streams in atomising devioes in which, in

accordance with a particular feature of the in- 2 When employing the atomising device in liquid driers, it is preferable to introduce part of the drying air into the drying arrangement through a central nozzle tube. I The=invention is illustrated by way of example in the accompanying drawings, in which:

Figure 1 is a diagrammatic longitudinal section through an atomising nozzle ofthe type to which the present invention is applicable.

Figure 2 is a diagrammatic longitudinal sec tion through a constructional form comprising guide deviees according to this invention, and

Figure 3 is a horizontal section through the device shown in Figure 2.

In the atomising nozzle shown in Figure l,'the k liquid fed through the annular channel I is guided along a wall 2 and.is atomised at the.

nozzle mouth 5 by means of the streams of atomising gas delivered through the ducts 3, 4

the stream of atomising gas coming from the duct 3 flowirig parallel to the wall 2.

Owing to the surface friction between the gas and the liquid on the wall 2, the liquid is disintegrated and thus atomised. The stream of gas gu ided" directly to the liiouth 5 b'y the charinel 4 serv'es to effecteflicient atbmisation such as is Tequired mainly for the operatioh of spray driers, in which deposits may form at the point of distzharge 5 of the liquid mist. The gas and liquiddroplets leave the discharge a1 eas in the directioh of the axis of the nozzle with, such kinetic energy that the liquid mist contin ugs to move at considerable velocity at-a great distanoe from the nozzle, for example at 5 m. This phe- .nomenon, however, necessitates a considerable overall length of the arrangements in which the atomising device is employed, such as drying towers. In order to counteract this, special arrangements of the type hereinafter described may be employed.

In the atomising device shown in Figures 2 and 3, the compressed air at an absolute pressure of, for example, 0.4 atmosphere is delivered special oompression by means of a noimal Ian

Images