GB617239A - A method of and apparatus for atomising liquid fuel and mixing it with air to form acombustible mixture for use in internal combustion engines - Google Patents

Abstract

617,239. Surface carburetters; direct injection engines. ROSENTHAL, A. H. Nov. 8, 1944, No. 22008. Convention date, Aug. 27, 1943. [Class 7 (iii)] The invention relates to forming a combustible mixture or improving the mixing of the fuel and air thereof by supplying liquid fuel to form a film upon a surface of an electrically excitable vibrator and exciting the vibrator by electric oscillations of supersonic frequency. Means for producing the vibrations using a piezo electric element or alternatively using an electromagnet are described. In Fig. 5, fuel is fed on to a piezo-electric element 22 which is situated in an induction pipe 103, the fuel being atomized by supersonic vibrations caused by electric oscillations supplied to the element. An insulator 114 is held in a casing 126 by screwed portions 118, 117, the two portions forming a unit which is screwed into the casing. The element may consist of two steel members with a number of small square-shaped plates of piezo-electric crystal between them, the steel members having holes through them so that the petrol can be fed beneath the element and flow through the holes to just cover its surface. In an alternative, an electrode may have holes bored in the top surface and adjacent region and the fuel be fed to these. It is stated that a similar arrangement could be fitted in an engine combustion chamber, the fuel being injected on to it. Porous substances, fine wire meshes, &c. can be arranged on top of the element 22. Various ways are mentioned of forming electrodes on the element by coating it with aluminium or copper &c. If the engine is to be operated with different kinds of fuels or at greatly varying loads, a set of devices of different resonance frequencies &c. may be arranged in the combustion air, one, some, or all of the devices being switched in to obtain optimum effects. An electromagnetic means for causing the vibrations for atomizing the petrol is shown in Fig. 3, an electromagnet receiving the electric oscillations actuating a diaphragm 53. Alternatively, a rod mounted at one end may be vibrated longitudinally by varying impulses supplied by an electromagnet at the natural frequency of vibration of the rod. The energy of the electric oscillations may be controlled by an operator or automatically in dependence on the speed or load independently of or in conjunction with means regulating the volume of combustion air admitted to the engine. A speedometer or governor may control both the admission of air and the energy of the oscillations. The Specification as open to inspection under Sect. 91 comprises also a further construction in which a hollow tube forming a nozzle projecting into a combustion chamber is vibrated in the direction of its axis by an electromagnet so as to atomize the petrol as it issues from the nozzle. This subject-matter does not appear in the Specification as accepted.