US 2419365 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
April 22, 1947. T. NAGEL METHOD OF ATOMIZING LIQUIDS Filed June 8, 1944 INVENTOR llll! m IHMIIIIH ATTORNEY Patented Apr. 22, 1947 I METHOD OF ATOMIZING LIQUIDS Theodore Nagel, Brooklyn, N. Y. i
Application June 8, 1944, Serial No. 539,281
' 3 Claims. (Cl. 299-120) 1' My invention relates to an improved method or and apparatus for the atomization of liquids.
In the combustion of oil, for example rapidity of combustion depends upon the minuteness of the globules of the oil, and in atomizing the oil to produce these minute oil globules two methods are conventionally employed.
In one conventional method, the oil, supplied at high pressure, is forced to flow at high velocity and rapidly .whirled within the atomizer, the whirling 011 being elected from the atomizer through a relatively small diameter orifice. The rapidity of the whirling motion of the ejected oil stream forces the oil to spread out into a diverging stream of minute oil globules.
For this pressure-type atomizer, reliable test data permit the calculation of the rapidity of whirling necessary to produce the oil globule minuteness of atomization desired for rapid com bustion.
For example, Bureau of Engineering, U. S. Navy Fuel Oil Testing Plant, Test #1056, using Navy atomizer type #1 with four 1*," x 1%" tangential slots, 1%" diameter whirling chamber having /64" diameter orifice and atomizingl8.6 B. fuel 25 oil heated to 183 F. for lowering the oil viscosity to 150 S. S. U.
' Oil Oil Ejection whirling Pressure Capacity Velocity Velocity P. a. i. Gal/hr. FL/mln. R. p. m.
This test shows that for producing the desired globule minuteness a minimum oil whirling velocity of 27,000 R. P. M. with an ejection velocity of at least approximately 3000 ft. per minute is necessary, requiring an oil pressure of approximately 150 lbs. per square inch.
Oil atomizlng capacities of these variable pressure-type atomizers vary as a function of the stant oil pressure of 300 lbs. per square inch, with oil return line from the burner for wide-range atomizers, the capacity ranges from 1 to approximately 5.
Another conventional type of atomizer is the steam-pressure fuel-oil type. This atomizer uses relatively high steam pressures, ranging from approximately 100 lbs. to 140 lbs. per square inch and oil pressures ranging from approximately 10 20 to 100 lbs. per square inch, producing a capacity range from 1 to 7.
It will be seen, therefore, that in the oil pressure type of atomizer, the first type cited above, it is necessary to use oil pressures ranging from a minimum of 100 lbs, per square inch up to as high as 300 lbs. per square inch. In the second type atomizer cited above, using lower oil pressures ranging from to 100 lbs. per square inch, it is also necessary to use steam at pressures 20 ranging from 100 lbs. to 140 lbs. per square inch.
In these cited types ofatomizer, the oil pressure is relied upon, to introduce the oil into the whirl chamber in the first-cited type or atomizer,
' the oil is introduced tangentially into the whirl chamber under the high pressures mentioned above and caused to whirl therein; while in the steam-oil type 01 atomizer, cited above, the oil is injected by reason of oil pressure directly into the whirl chamber and caused to whirl therein by high pressure steam tangentially flowing into the chamber.
In the conventional pressure type atomizer, cited first above, radiant heat from the furnace will carbonize the oil residue and form solid carbon in the atomizer after the oil is turned off.
This necessitates removing, cleaning and replacing the atomizer, which operations require the service of burner attendants.
Th present invention provides a new and novel method of and apparatus for atomizing liquids,
such as oil for example, wherein I effect the production of oil globules of the desired minuteness much more economically than by the conventional methods above briefly referred to, and
whereby the capacity range of the atomizer is very materially increased.
I employ the principle of the whirling action for producing atomization and obtain the necessary whirling velocity by a different method than heretofore employed, which permits me to use air or steam as the whirling medium at substantially lower pressures than heretofore used, because in my improved method the oil pressure used is merely a function of the quantity of oil feed into the low-pressure stream of air or steam,
and the capacity range of this new type atomizer ranges from 1 to 20, without requiring the changing of atomizer sizes or the turning on or ofi of burners.
The advantages of my process and apparatus will be appreciated by those skilled in this art; my invention provides for wide-range capacity without change of atomizer size, a range which may be as high as 20 to 1,. which makes the atomizer ideal for full automatic control. For a fluctuating wide-range power demand, full automatie control is impossible with the conventional oil burning methods above outlined, where it is necessary manually to change atomizer sizes or manually to turn on or off burners in order to obtain a capacity range produced by a single atomizer of the applicants type.
My invention also provides another advantageous feature which will be appreciated by those skilled in this art. Inasmuch as I employ air or steam only at low pressure, it is economically sound to allow this medium to flow through the atomizer after the oil is turned oil, so that the atomizer is automatically purged of oil and continually cooled, thereby eliminating the manual operation necessary for removal and cleaning of the atomizers.
More specifically, my invention provides a method and apparatus wherein the low-pressure air or steam acts as a carrying medium for the oil, the oil being introduced continuously into this medium prior to entry of either the oil or the carrying medium into the whirl chamber. The oil is introduced into the air or steam as the air or steam is flowing at high velocity through converging channels which enter the whirl chamber substantially tangentially thereto. This imparts the desired velocity to the oil before flowing into the whirl chamber, from which the whirling oil is continuously ejected to form a diverging stream of minute oil globules.
The stream velocity of the oil-carrying mediumair or steam-is a function of the pressure used as shown by data in the following tabulation:
Discharge of Air Through an Orifice," Table 17, Kents Mechanical Engineers Handbook, th Ed., p. 667, shows pressure capacity data for rates of flow as follows:
Discharge of Free Air I Air Pressure Orifice .Dia. Orifice 54 Die.
CF/Min. Ft./Min. CF/Min. FtJMin.
l Extrapolated data.
duces a whirling velocity in the chamber exceeding 210,000 R. P. M. and an ejection velocity of 27,800 it. per minute. It is appreciated, of course, that, while the introduction of the oil into the air or steam flowing toward the whirl chamber decreases the free area of flow of the air or steam, the maximum quantity of oil feed which can be atomized to the desired globule minuteness reaches an optimum quantity when the oil-laden carrying medium has been slowed down within the whirl chamber to a minimum whirling velocity of 20,000 R. P. M.
In the accompanying drawing:
Fig. 1 is a sectional view of an atomizer housing assembly, an embodiment of my invention;
Figs. 2 and 3 are sections on the lines 2-2 and 3-3, respectivel of Fig. 1; and
Fig. 4 is a view of the atomizer.
Referring to the drawing in detail: i
2 designates the atomizer casing or tube. Mounted within this tube and spaced from the sidewalls thereof is liquid conducting member 4 through which the liquid to be atomized, such as oil, for example, is conducted toward the dis- .charge end of the atomizer.
Inserted into the discharge end of the liquid conducting member 4 is the atomizer 6 of Fig. 4. This atomizer is provided with an enlarged head 8 and an enlarged base ill, the two being spaced from each other so as to provide a circumferential groove l2 between them. Liquid-conducting or feed channels I4 extend lengthwise oi the nib through the base ill.
The head 8 of the atomizer is provided in its face with whirl chamber l6 and in its periphery and face with a plurality of channels or slots l8 and entering the whirl chamber substantially tangentially thereto.
It will be noted from Fig. 3 that the liquidconducting channels M connect into the feed channel [2, providing an annulus feed of the width of the annulus and the width of each one of the tangential channels or slots I 8, to' provide for the continuous flow of the oil or other liquid to be atomized into the rapidly flowing air or steam carrying medium prior to the entry 01 either into the whirl chamber H5.
The ejection outlet is in the atomizer tube cap 20 and in alignment-with the whirl chamber ii.
In operation, low-pressuresteam or air is supplied continuously to the tube along the exterior of the liquid-conducting member 4, this space communicating directly with the tangential channels l8.
At the same time, the oil or other liquid to be atomized is fed through the member [and flows through the grooves or channels H in the atomizer base It! into an annulus chamber provided by 12, which connects with each one of the tangential slots I 8, where the liquid is picked up by the rapidly flowing steam or air stream and conveyed by it to the whirl chamber l6 at high velocity, instead of being charged directly into the whirl chamber, as in conventional steam-oil atomizers. In the applicant's method, the oil or other liquid has attained the velocity necessary to effect whirlin of the liquid at the desired R. P. M. before the liquid flows into the whirl chamber.
In tests run on my improved atomizer, in which I employed eight tangential slots or channels I8, each 1 8" wide by 1%" deep, a whirl chamber i6, which was /2 in diameter and an annular chamber or groove l2, so dimensioned as to provide a 1 s x 1%" area oil feed orifice into each aeraecs Oil Air Steam Pres- Capacity Pres- Pros- A Sum Gal/Hr. Range Sure Us M Sum Lbs/Hr.
390 208 20 60 20 130 i O, 75 10. 4 l 3 3 E 55 It will be seen from these test that I obtained a capacity range of 20 to 1, which is far beyond the range possible with conventional atomizers such as those above referred to; it will be seen, also, that even when operating at 208 gallons of oil per hour, I used air or steam pressure of only 20 lbs. per square inch, while at the low capacity of 10.4 gallons of oil per hour, the air or steam pressure used was only 3 lbs. per square inch.
It will be seen, furthermore, that the quantity of steam consumed is extremely low in comparison with oil consumed and hence steam generated, establishing, as above pointed out, the soundness, economically, of permitting the steam or air, as the case may be, to flow so as automatically to purge and to cool the atomizer when the oil is shut ofl.
It is to be understood that changes may be made in the details of construction and arrangement 01 parts hereinabove described without departing from the spirit and scope of my invention.
It is to be understood also that the pressures, dimensions, etc., set out hereinabo've are not em- :ployed in a limiting sense, but may :be varied within the purview of the invention.
What I claim is:
1. The method of atomizing a liquid to pro duce a diverging conical stream of minute globe ules, which method comprises releasing a pinrality of gaseous streams under pressure into a cylindrical chamber substantially tangentially thereto, and" prior to expansion of the gaseous streams introducing the liquid to be atomized thereinto, so that the gas and liquid enter the chamber intermixed, and contacting the charm ber wall will be caused to whirl at the rapidity required for producing the desired globule minuteness, and continuously electing the whirling mixture axially of the chamber from about the edge of the end of the same continuously to produce a diverging conical stream of minute globules.
2. The method of atomizing a liquid to pro duce a diverging conical stream of minute globules, which method comprises continuously converging a plurality of gaseous streams upon a cylindrical chamber from without the pe riphery thereof, effecting passage of these gaseous streams through the side Wall of the chamher into chamber substantially tangentially thereto, and flowing the liquid to be atomized into the said gaseous streams transversely thereof and sufiiciently remote from the chamber so that the gas and liquid flowim, through the chamber Wall enter the chamber as streams of intermixed liquid and gas whereby the mixture upon its contact with the walls of the chamber will be caused to whirl at the rapidity required for producing the desired giobule minuteness, and continuously ejecting the whirling mixture from the end of the chamber about the edge of the same continuously to produce a diverging conical stream of minute globules.
3. The method of atomizing oil to produce a diverging conical stream of minute globules, which method comprises continuously converg ing a plurality of gaseous streams upon a cylindrical chamber from without the ohmic-er periphery, effecting passage of these gaseous streams under pressure through the side wall of the chamber into the chamber substantially tangentially thereto, and introducing the oil to be atomized into the said gaseous streams as the latter are passing through the chamber wall so that the gas and oil enter the chamber as streams of intermixed gas and oil and are projected against the chamber walls and caused to whirl at the rapidity required for producing the desired globule minuteness, and continuously eject ing the whirling mixture axially of the chamber from about the edge of the end of the chamber continuously to produce a diverging conical stream of minute globules.
TEEQDGRE REFERENCES @KTEEB The following references are of record in the file of this patent:
UNITED STATES PATEl'iTS