US2926456A

US2926456A - Device for projecting pulverulent substances such as fire-extinguishing products or insect-powders

Info

Publication number: US2926456A
Application number: US485958A
Authority: US
Inventors: Biro Guillaume
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-02-05
Filing date: 1955-02-03
Publication date: 1960-03-01
Anticipated expiration: 1977-03-01

Description

2,926,456 SUCH DERS '9 Ill/111% G. BIRO DEVICE FOR PROJECTING PULVERULENT SUBSTANCES AS FIRE-EXTINGUISHING PRODUCTS OR INSECT-POW Filed Feb. 3, 1955 March 1, 1960 DEVICE FOR PROJECTING PULVERULENT SUB- STANCES SUCH AS FIRE EXTINGUISHING PRODUCTS OR INSECT POWDERS Guillaume Biro, Chaville, France Application February 3, 1955, Serial No. 485,958 Claims priority, application France February 5, 1954 2 Claims. (Cl. 43147) I a A device for projecting a heavy pulverulent product a relatively great distance according to the present invention, comprises a straight cylindrical ejector tube having a uniform bore of a length materially greater than the diameter of the bore, the front end portion of the tube being open, a first valve mounted at the rear end of the tube and including a chamber communicating at its front end with the ejector tube through a passage of relatively 30 small cross-sectional area with respect to the tube bore,

a duct leading from the chamber, asource of supply of the pulverulent product comprising a container therefor provided with a low pressure gas supply, the duct connecting the chamber and the container. In this manner 35 a gaseous stream from the container carrying the pulverulent material in suspension may be led into the chamher, the first valve being adapted to adjustably release the gaseous stream and pulverulent material forwardly into the ejector tube. Also provided is a nozzle having a throttle disposed axially at an intermediate location along the ejector tube and directed forwardly in the ejector tube, means for supplying gas under relatively high pressure to the nozzle and a second valve mounted in the ejector tube adapted to adjust the flow of the high pressure gas into the tube, the two valves being adapted to be adjusted and controlled whereby the pulverulent'material may be projectedfrom the ejector tube at a relatively high speed.

The pulverulent product is stored in a tank under a relatively low pressure which is connected through a fiex- O ible connection to the rear portion of the nozzle.

Other objects and features of the invention will appear as the following description proceeds with reference to the attached drawing forming part of this specification and illustrating diagrammatically by way of example a 55 preferred form of embodiment of the device.

In the drawing:

Figure l is a longitudinal axial and fragmentary section of the device;

Figure 2 is a cross-section taken upon the line II-Il of Fig. 1;

Figure 3 is a diagrammatical view showing the ejector tube'of the device connected through a first flexible hose to a stationary tank and through another flexible hose to a compressedgas cylinder. 65

The device illustrated in Fig. l of the drawing comprises a body 1 having formed therein a cylindrical chamher 2 into which leads a duct 3 connected to pipe 5. To this inlet pipe 5 is attached a flexible hose 6 (see Fig. 3) connected at its other end to the lower portion of a reservoir 7 containing a pulverulent product 8 subjected to aired gtates Patent- ICC the action of a low-pressure gas it). The body 1 of the device has mounted 'at its rear portion a handle 12 of a first valve, and having pivotally attached thereon through a pivot pin 13 a hollow and curved actuating lever 15. The curved shape of the upper portion of this actuating lever is designed to facilitate the gripping of the lever with the palm of the hand, the fingers engaging the lower surface of the handle 12; a spring 16 is interposed between the handle 12 and the lever urging the latter away from the former and against the rear end of the tube 1.

The first valve includes in the front portion of the chamber 2 of body 1 a ring 18 secured by three set screws 20 engaging a groove 21 formed in the ring 18. In the rear portion of the body 1 a sliding rod 22 is mounted co-axially with the chamber 2 and formed with a frusto conical, valve-forming front end 23 adapted to be seated against the rear edge of the passage 25 formed with a relatively small cross-sectional area with respect to the bore of tube 28 in the ring 18 when the sliding rod 22 is allowed to move to the left in chamber 2 (Fig. 1). The rear end portion of the rod 22 extends through a slot 26 formed in the front portion 17 of the lever 15 and is formed with a rear annular enlargement 27 of a diameter greater than the width of the slot 26.

The front portion of the body 1 has fitted thereon a cylindrical, straight rigid and relatively large ejector tube.

28. The ejector tube 28 is secured on the body 1 by means of the same screws 20 employed for securing the ring 18 in the chamber 2. Ejector tube 28 has a uniform bore of a length materially greater than the diameter of the bore and its front end is open.

At an intermediate location along the tube 28 (see Fig. 2) a device for adjustably controlling the inlet of compressed gas is mounted. This device, a second valve, comprises essentially a body 30 formed integrally with a handle 31, a needle valve 32, a gas-expanding nozzle 33 also formed integrally with the body 30, and a detent 34 adapted to control the needle valve 32. The body 30 is secured on the outer surface of the ejector tube 28 intermediate of its ends by means of a pair of threaded bolts 35 having screwed thereon blind nuts 36. Nozzle 33 projects into the ejector tube 28 through an aperture provided for this purpose. A suitable gasket surrounding the nozzle 33 is interposed between the body 30 and tube 28. A hard-soldering is effected after assembling the parts to preserve the fluid-tightness of the tube 28. The nozzle 33 located within the tube 28 is formed with an elbow-like passage and the outlet throttle 38 of the terminal part of this passage is directed forwardly towards the open end of ejector tube 28.

The stem 40 of the needle-valve 32 is slidably mounted in a socket 41 screwed in the body 3%, a suitable sealing gasket being interposed therebetween. A rubber packing is also provided between the sliding stem 49 and the socket 41. The stem 40 is formed externally of the body 39 with a head 42 adapted to be lifted wten the lever 34 is actuated; this lever is pivotally mounted on a pivot pin 43 fixed on the handle 31. A compression spring 45 constantly urges the needle-valve 32 to its seated position.

The compressed gas under high pressure enters an inner chamber formed in the body 36 which contains the-spring 45 through a passage (not shown) provided at its inlet end with a fitting (also not shown) to which is attached one end of a flexible hose 46 (Fig. 3) having its other end attached to the outlet of a compressed-gas cylinder '47.

The operation of the device described hereinabove' is" very simple. The'operator grips the handle 12 and de--' presses the control lever 15 of the first valve with the, palm of the hand. The other hand grips the handle 31 of the second valve controlling the flow of high pressure gas from the cylinder 47 and the lever 34 is depressed for this purpose. At the same time the outlet of the projection device is pointed toward the area to be sprayed with pulverulent product.

As the control lever 15 is depressed, the return spring 16 is stressed and the valve stem or rod 22 is pulled to the right (Figs. 1 and 3) as its enlarged portion 27 is engaged by the slotted portion of lever 15. The frustoconical valve 23 is moved into chamber 2 and opensthe axial passage 25 in ring 18. The low-pressure gas 19 in the reservoir '7 escapes through the flexible hose 6 and carries along in suspension a stream of pulverulent product particles 8. This stream passes through the hose 6, pipe and duct 3 into chamber 2, is expanded a first time as it flows out from the passage 25 of ring 18, then another time at the outlet of the body 1 as it enters the larger ejector tube 28. Therefore, it circulates throng-h the entire width of the ejector tube 2.3 but at a relatively moderate speed due to the low pressure in the reservoir 7.

- Immediately upon depressing the lever 34, the compressed gas from the cylinder 47 penetrates into the nozzle 33 and is ejected at a relatively high velocity from the throttle 38 forwardly toward the open outlet end of ejector tube 28 as indicated by the arrow F in Fig. l. A suction is thus produced in the rear portion of the ejector tube 2'8 and consequently the pulverulent product is sucked forwardly. Immediately upon clearing the nozzle 33 this product is projected at relatively high speed in the direction of the ejector tube outlet by the compressed gas expanding through the throttle 38.

From the foregoing it is apparent that the nozzle device 33 acts as an accelerator designed to accelerate the flow. of pulverulent product in the ejector tube 28 and to increase its speed to a substantial extent. The operational range of the device range is therefore very much increased. The elastic force of the gas is utilized much more efficiently than if this gas were fed under a very high pressure to the reservoir 7, because there would be very substantial pressure drop between the reservoir 7 and the passage. On the contrary, with the arrangement provided by this invention the reservoir 7 is under a relatively low pressure, i.e. a value :just sufficient to carry along the pulverulent product to the body 1. As a result, the pressure drop is very small. It is the gas fed under a relatively high pressure through the nozzle 33 which sucks downwardly the pulverulent productentering the body and ejector tube 28 projects same without any appreciable pressure loss from the rectilinear ejector tube 28. In other words, the efficiency of the device is improvedwhile reducing the gas consumption.

Moreover, the re-acceleration of the stream of pulverulent product by the action exerted by the gas expanded in the nozzle 33 will ensure a perfect diffusion of the particles of pulverulent product. In fact, immediately upon clearing the nozzle 33 the solid particles forming the pulverulent product are stirred by the expanded gas and distributed uniformly through the gaseous stream. The stream projected from the tube outlet is characterized not only by a very long range but also by a perfect, uniform distribution of solid particles of pulverulent product therethrough.

Of course, many non-essential constructional details may be altered and modified in the form of embodiment shown and described herein, without departing however from the spirit and scope of the invention.

The device according to this invention may be used for projecting any desired pulverulent'material or products to a relatively remote location. Thus, this device may be employed successfully for projecting either insectpowcier over agricultural areas, or a special anti-freeze powder over a water pool or channel in order to make the water surface non-freezing. The gas employed for reeaccelerating and, projecting the pulverulent productmay be of any desired character, such as compressed air or nitrogen.

The device according to this invention is also applicable to the projection of fire-extinguishing products in pulverulent form in case of fire. In this case, of course, the compressed gas will be an inert gas, preferably carbon dioxide, so that the device described and illustrated herein may be employed for carrying out the method described in a co-pending patent application Serial No. 485,959 filed by the applicant on February 3, 1955 for ivfethods of and Devices for Fighting Fires which has matured into US. Patent 2,853,139, granted September In fact, this patent relates to a method consisting essentially in projecting onto the seat of a fire a pulverulent product of which each particle is coated with a layer of frozen carbon dioxide, this coating being obtained by causing a strong expansion of the carbon dioxide in a nozzle fed with the pulverulent product.

The device of this invention is particularly adapted for implementing the above-mentioned method by causing the carbon dioxide ot expand through the nozzle 33. As already explained in the general description of the operation of the device, the carbon dioxide expanded by the.

nozzle 33 ensures the rte-acceleration of the pulverulent product and the perfect diffusion of the particles thereof.

However, the strong expansion of the gas, in this case carbon dioxide, causes the latter to freeze around each particle of pulverulent product. Before issuingfrom the bore each particle is thus coated with a layer of frozen carbon dioxide and the particles of pulverulent product are thus projected onto the seat of the fire. Nevertheless, the freezing of the carbon dioxide does not occur immediately as it is ejected from the nozzle 33; due to the carbon dioxide impinging against the particles of pulverulent product, the carbon dioxide will freeze only at some distance from the nozzle 33, i.e. in the front end portion of the ejector tube 28. Therefore, before freezing the carbon dioxide will also in this specific case accelerate the stream of pulverulent product to permit the long-range projection thereof as well as the diffusion of the particles for an optimum dispersion thereof in the blast issuing from the device.

What I claim as new is:

l. A device for projecting a heavy pulverulent prodmaterially greater than the diameter of said bore, the

front end of said tube being open, a first valve mounted at the rear end of said tube and comprising a chamber communicating at its front end with said ejector. tube through a passage of relatively small cross-sectional area with respect to said tube bore and a duct leading from said chamber, a source of supply ofsaid pulverulent product comprising a container therefor provided with a low pressure gas supply, said duct connecting said chamber and said container, whereby a gaseous stream from said container carrying said pulverulent material in suspension may lead into said chamber, said first valve being adapted to adjustably release said gaseous stream and said pulverulent material forwardly into said ejector tube, a nozzle having a throttle disposed axially at an intermediate location along said ejector tube and directed forwardly in said ejector tube, means for supplying gas under a relatively high pressure to said nozzle, and a second valve mounted on said ejector tube adapted to adjust the flow of said high-pressure gas into said tube, said two valves being adapted to be adjusted and controlled whereby said pulverulent material may be projected from said ejector tube at a relatively high speed.

2. The device as set forth in claim 1, wherein said chamber is of cylindrical shape as well as coaxial with said tube, and said duct is disposed laterally of said chamber.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Schanz June 7, 1938 Bramsen et a1. Apr. 2, 1240 Clipson Apr. 18, 1950 Grifiin July 24, 1951 Mueller Jan. 13, 1953 6 FOREIGN PATENTS Switzerland Nov. 1, 1927 Switzerland Mar. 16, 1939 Great Britain July 13, 1949 Great Britain Dec. 31, 1952