US2513768A - Gaseous fuel - Google Patents

Description

Patented July 4, 1950 osrieca A GiisEoUs SamueLHL-White, Detroit; Mich.

"No-Drawing: Application July 15, 1947, Serial No 761,156 In Great BritainApril 24., 19.47- i 2 Claims. (01. 48-197) This invention relates to gaseous fuel mixtures and more particularly to such fuel mixtures that have a high calorific value and a low ignition point.

Fuel mixtures of this type are in demand for use in metallurgical and other industrial operations in which an intense local heat is required, as for instance in cutting metals, hardening and annealing, scarfing, melting and welding metals and the working of lead, hard glass and silica. For these purposes the oxy-acetylene and oxyhydrogen flames have been widely used, but both are comparatively expensive, and in the case of acetylene, because of high carbon content and critical nature of the flame, unless great precautions in use are observed, it is liable to be dangerous and costly and work may be spoiled.

It is an object of the present invention to provide a cheap gas mixture by raising the calorific value and lowering the ignition point of propane. B'y propane is meant, not necessarily the chemically pure propane but also the commercial propane as produced in the refining of crude petroleum and containing a proportion of butane and traces of other hydrocarbons.

The gas mixture can be made in the first instance and compressed in cylinders and used direct from the cylinders to the burner. Alternatively, the supplementary gaseous material required to raise the calorific value and lower the ignition point of the propane may be obtained from material compressed in cylinders and where a pipe line supply of propane is available, the supplementary material may be supplied from the cylinder to such pipe lines by means of suitable flow meters.

As the materials for addition to the propane are necessarily of an easily condensable character compared with the propane, such substances may be expected to condense under pressure in the cylinders and when the cylinder is opened to supply a burner direct or when the added material is introduced into factory pipe lines, imperfect diffusion of the constituent gases may occur, unless the proportions and the nature of the added material have been properly selected. In such a case a homogeneous gas such as acetylene will not be supplied to the burner and, moreover, when the rapidly moving stream of gas meets the oxygen supply there may be again imperfect dififusion with consequent deleterious effects upon the intensity of the flame and its resulting temperature.

It has now been found possible to make a selection of the added material and the propor- 2 tions in which it is to be used to produce a gas mixture which, whether used from cylinder or formed in a pipe line by introducing compressed material from a cylinder, will give a homogeneous mixture at the point at which ignition occurs, and which may be used with oxygen in the same way as acetylene and produce comparable results, and in some respects even improved results.

According to the present invention a gaseous fuel mixture consists in propane as above defined or a mixture of propane and butane with petroleum ether, the proportion of the two ingredients being 5-9 parts by weight of propane or mixture of propane and butane to one part of petroleum ether. The petroleum ether referred to is the petroleum fraction having boiling ranges extending over approximately 40 C.- C. at atmospheric pressure, such, for example, as benzin. Other petroleum ethers with high boiling points may be used in the proportions stated, provided means are employed to vapourize the material sufiiciently for proper diffusion with the propane before ignition occurs. The petroleum ether may be mixed with the propane in liquid or gaseous form.

If the mixed gases or the mixed liquified gases are in the proportions above stated, when the mixture is evaporated and burned with oxygen, a homogeneous mixture is obtained and the flame temperature of the propane or mixture of propane and butane is increased, the flame propagation is reduced and the high ignition point is lowered resulting in a flame of great intensity.

When burned with oxygen the gas mixture according to the invention, compared with untreated propane or mixture of propane and butane when mixed with oxygen, gives a flame which permits a material saving in time for a given work and the mixture can be used in the same manner and for the same purpose as acetylene or hydrogen.

It has been found that smaller proportions of the petroleum ether than given above are inefiective for the purposes mentioned, while larger proportions than the maximum specified above provide no additional advantages. It should be noted that the proportions given by volume and the proportions given by weight have as a resultant mixture approximately the same proportions of the constituent gases.

Although a certain specific embodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the said petroleum ether being a petroleum fraction boiling over the range of 40 C. to 60 0., at atmospheric pressure, said mixture being in the proportion of 5-9 parts of propane to one part 5 of petroleum ether. SAMUEL H. WHITE.

10 2,411,759 mixture comprises propane and petroleum ether,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,565,935 Harris Dec. 15, 1925 1,637,187 Harris July 26, 1927 2,305,753 White Dec. 22, 1942 Seley Nov. 26, 1946 OTHER REFERENCES "The Science of Petroleum, Dunstan, Editor, Oxford University Press, London 1938, vol. I, pages 7 and 12.

Hackhs Chemical Dictionary, by Hackh, 2nd edition, published by Blakistons Son Inc., Philadelphia 1937, page 698.

Claims (1)

1. A GASEOUS FUEL MIXTURE HAVING A HIGH CALORIFIC VALUE AND A LOW IGNITION POINT, WHICH MIXTURE COMPRISES PROPANE AND PETROLEUM ETHER, SAID PETROLEUM ETHER BEING A PETROLEUM FRACTION BOILING OVER THE RANGE OF 40*C. TO 60*C., AT ATMOSPHERIC PRESSURE.