US2351697A - Atomizer - Google Patents

Description

June 20, 1944. P, D. NIELSEN ATOMIZER Filed July 5 1940 Patented June 20, 1944 ATOMIZEB Peer I). Nielsen, Lorain, Ohio, assignor to National Tube Company, a corporation of New Jersey Application July 3, 1940, Serial N0. 348,887 2 Claims. (Cl. 299-118) This invention relates to atomizers and is particularly concerned with the problem of thoroughly atomizing liquid fuels such as heavy oil or tar, whereby to condition such fuels for burning in industrial furnaces.

A specific example of the invention is illustrated by the accompanying drawing, in which:

Figure 1 is a top view;

Figure 2 is a section from the line 11-11 in Figure 1; and

Figures 3 and 4 are cross sections from the lines III-III and IV-IV, respectively, in Figure 1.

More specifically, the atomizer illustrated by these drawings comprises a body I providing a chamber having an inside 2 of cylindrical contour terminating with a Venturi throat 3, the chamber having an entrance 4 at the end of the inside 2 opposite the throat 3 and which points tangentially respecting the cylindrical inside. This entrance 4 connects with a pipe 5 carrying an atomizing fluid under pressure, this fluid ejecting at the entrance 4 and swirling forwardly along the inside 2, its velocity being greatly increased at the throat 3 while its pressure is decreased. The fluid leaves the chamber by way of an outlet 8, it going to a suitable burner.

A liquid fuel supply tube I extends longitudinally of the above described chamber concentrically respecting its cylindrical inside 2, the tube being cylindrical throughout its length inside the chamber and passing through the end of the chamber by way'of a stufllng box 8 which permits the tube to slide longitudinally without leakage of the atomizing fluid, the tube being in threaded engagement with a nut 8 turned by a handwheel ill and rotatively fixed against longitudinal movement by a bracket ii fixed to the body I. With this arrangement, the inside end of the tube 1 can be adjustably positioned respecting the throat 3, this being done by turning the handwheel Ill.

The end of th tube 1 has a flaring opening i2, and a flaring head l3 cooperates with this opening to form a flaring annular orifice. This annular orifice is adjustable by reason of the flaring head l8 being positioned through the medium of a rod 14 passing longitudinally through the tube 1, the rod I 4 being itself positioned by being in screw-threaded engagement with a nut I! mounted by a pipe fitting T It screwed onto the end of the tube 1. The nut I5 is screwed into the fitting sufllciently tightly to be nonrotative, the rod I 4 having a squared end [4 to which a wrench may be applied and a stuillng box I! serving to seal the rod against leakage. The fuelis introduced by way of a pipe i 8 screwed into the fitting ii, the fuel traveling along through the tube and ejecting as a flaring annular film through the orifice between th hole I! and the head I I, this film ejecting concentrically into the swirling atomizing fluid at the throat 3 where the atomizing fluid is at high velocity and low pressure.

The method of using the atomizer consists in heating the liquid iuel'introduced to the atomizer through the pipe ll, to a temperature that is sufflciently high to cause the fuel to vaporize at atmospheric pressure. The fuel is maintained liquid by applying a suitable pressure to it, and it therefore ejects as a flaring annular liquid film into the throat 3. Here the atomizing fluid, which may be steam or air, is moving at its highest velocity but is at a relatively low pressure, the result being that the annular liquid film is mechanically atomized with great violence by the rapidly whirling atomizing fluid and, at the same time, vaporized due to the pressure reduction of the atomizing fluid caused by the increase in its velocity resulting from its constriction by the Venturi throat 3. The result is a very complete atomization of the liquid fuel, this greatly increasing its heating efllciency when it is burnt by a burner of proper design. a

Different types of fuels may be accommodated by working the handwheel I! to adjust the point where the flaring annular fllm of liquid fuel is ejected respecting the throat I, to the end of producing the best results. The proper position is best determined experimentally, observation of the flame produced being the best guide. Furthermore, the thickness of the flaring annular film of fuel may be varied by turning the rod l4, this being another adjustment that can be most exactly made by observation of the results produced. Since the liquid fuels sometimes tend to clog orifices, it may happen that the annular orifice provided by the hole [2 and head I! becomes clogged, but this is easily remedied by turning the rod l 4 so as to move the head l3 forward, this opening the orifice so as to permit it to clear.

I claim:

1. An atomizer for liquid fuel, including a chamber having a cylindrical inside contour terminating with a Venturi throat and provided with a tangential inlet spaced from said throat with means for supplying said inlet with atomizing fluid under pressure, and a cylindrical liquid fuel supply tube extending longitudinally of said chamber concentrically therewith with a flaring annular orifice adjacent said throat and pointing theretowards, said orifice being positioned to elect a flaring annular fllm of liquid fuel into said throat at a position where the velocity of the whirling atomizing fluid passing theretlircugh is relatively high.

2. A method of atomizing liquid fuel, comprising creating a whirling flow of atomizing fluid under pressure, constricting said flow-to Produce a 5 high-velocity, low-pressure zone of whirling fluid, heating the liquid fuel to above its atmospheric

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