Patent GB-488732-A (GB)
Title: Method and apparatus for producing artificial fogs
IPC: F41H9/06
Filed: 1937-02-09
Abstract: 488,732. Smoke-producing apparatus. WESSTROM, N., and LUNDIN, G. Feb. 9, 1937, No. 3839. Convention date, Feb. 10, 1936. Addition to 458,202, [Group I]. [Class 81 (i)] [Also in Groups I and XXIX] A pump of the rotary type is used for spraying fog-producing liquid in the method of producing artificial fogs claimed in the parent Specification. Water, steam, or colouring substances may be mixed with the fog-producing liquid before or after atomization. Fig. 1 shows an apparatus comprising three containers 1a holding different fog-producing liquids such as oleum, stannic or titanium tetrachloride, and chlorsulphonic acid, and a container 1b for an additional liquid such as a hydrocarbon. The containers are provided with air inlets and may be mounted on the deck 12 of a ship. Pipes 6 connect the containers 1a with a header 13 provided with a number of cocks 14 and connected to the suction side of a rotary pump 7a. The pressure side of the pump is connected by a pipe 16 to conduits 9a, 9b carrying atomizing nozzles 10a, 10b, the supply of liquid to the nozzles being controlled by a threeway cock 20. The container 1b is connected to the suction side of a rotary pump 7b the pressure side of which is connected through a pipe 18 to the conduits 9a, 9b. The pumps are driven by electric motors 8 controlled by a controller 15 on the deck of the ship. Additional nozzles 21 may be placed near the nozzles 10a, 10b for spraying water, colouring liquid, or another fog-producing liquid or for blowing pulverized colouring matter into the spray projected from the nozzles, 10a, 10b. Separate pumps and containers may be provided for the additional nozzles 21. Additional containers may be connected by pipes to the cocks 14 which may be opened and closed by the controller 15. The fogs produced by the apparatus may be used for concealing objects and as protective fogs for agricultural purposes. The Specification as open to inspection under Sect. 91 describes a spray nozzle 10 as shown in Fig. 2 (Cancelled) which is enclosed in a container 22 holding lime or other substance which reacts with the fog-producing liquid to produce a vapour. The container is normally closed by a thin cover 24. When the pumps are started drops of liquid fall from the nozzle 10 and act on the lime &c. to form a vapour which breaks the cover 24. The pipe 9a with its nozzle may project through the cover 24 which is then broken by drops of liquid falling upon it when the pumps are started. The pumps may be run slowly so that the liquid is not atomized by the nozzle, the fog being produced entirely by the reaction between the liquid and lime &c. Fig. 4 (Cancelled) shows another type of nozzle in which the discharge aperture 42 is formed in a removable cap 26 and is closed by a disc 25 of waxed paper or other fragile material. The cap may be exchanged for another having an aperture of different size. In order to prevent the fog-producing liquid from creeping along the shaft 29 of the pump shown in Fig. 5 (Cancelled); the inlet 38 of the pump is connected by a passage 27 to an annular passage 28 surrounding the shaft. To equalize the pressure on the rotor of the pump the inlet 38 is also connected by a passage 40 with a chamber 39. Fig. 6 (Cancelled) shows a part of an aircraft in which a pump 7 withdraws liquid from a container 1 and forces it through an atomizing nozzle projecting into the air. To fill the container 1 the nozzle is removed and replaced by a screw connection 30 which joins the pipe 9 to a pipe 31 leading to a barrel 36 filled with fog-producing liquid. An air pipe 35 connects the upper part of the container 1 with the upper part of the barrel 36. To fill the container the direction of rotation of the pump is reversed. This subject-matter does not appear in the Specification as accepted.