DE2006185A1 - Gaseous fuel mixture - Google Patents

Description

DR. W. SCHALK DIPL.-ING. P.WIRTH; Dl PL.-I NG. G. DAN N EN BERG DR.V.SCHMIED-KOWARZIK -DR. P. WE IN HOLD DR. D. GUDEL

6 FRANKFURT AM MAIN vir / ntr

OR. ESCHENHEIMER STRASSE 39 kjlV / uK.

. 'BA-15U9

Air Products and Chemicals, Inc. Widener Building 1339 Chestnut Street Philadelphia, Pa. / UNITED STATES

• Gaseous fuel mixture

The present invention relates to oxy fuel mixtures ") as used on a large industrial scale for heating, joining and cutting metals. Large amounts of oxy-fuel gas mixtures are used in used in all phases of the metal industry, and especially in such areas the metalworking industry, who bit themselves with cutting,

A common mixture is the well-known acetylene / oxygen mixture, the is used as a heating, cutting and welding fuel gas mixture. acetylene has the disadvantage that it cannot be transported in copper pipes and becomes explosively unstable at pressures above 1 «05 AtU.

Another known fuel used in an oxy fuel gas mixture is described in U.S. Patent 3,226,213. The mixture given there consists of methylacetylene and / or propadiene, propane, propylene and a hydrocarbon with k carbon atoms; it is referred to below as methylacetylene-like gas or methylacetylene gas. Although this mixture is satisfactory as a fuel for an oxy-fuel mixture, like acetylene, it cannot be carried in copper pipes. "Since this fuel gas is a mixture, it continues to show

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an evaporation differential so that the composition of the mixture varies, when withdrawn as vapor from a pressurized storage vessel. It has also been shown that one or more components of the mixture subject to polymerization under certain conditions so that harmful solid particles are formed in the storage container, regulator or burner will.

To avoid the problems mentioned above, it has now been found that after Mixing propylene with a purity of at least 9 ^ # in the form of a gas with oxygen they can use as an effective substitute for any of the fuels listed above. The present invention relates to the creation the propylene / oxygen mixture to achieve the desired heating, Cutting and connecting capacity as previously found in acetylene or the gas of the patent mentioned.

The main object of the present invention is therefore to provide an improved one Fuel for an oxy-fuel mixture.

Another aim is to provide an improved oxyfuel misuse for use in heating, joining and cutting metals.

It has now been found that after mixing at least 9 ^ # pure propylene with oxygen in an oxy fuel burner, these mixtures can be used for most purposes where acetylene is used, and for all purposes where the fuel gas of the above-mentioned patent is used , can use. The ratio of oxygen to fuel in use of propylene and less should 4.5 * u 1 · vary tests have shown that the aböohiometri eohe ratio when using k of oxygen, 5 »u 1 'Further, as between 2

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- 3 -
found that for most cutting processes less than stoichiometric ratios should be used in order to prevent oxidation of the material to be machined. For cutting and brazing, a range of 3 to 1 to less than 1.5 to 1 is satisfactory, depending on the oxy-fuel torch used. For welding, the ratio should be below 3 to 1, preferably around 2.5 to!, ■> ·

The propylene should be technically pure, ie have a purity of at least 9 * 4 % . Up to about 6 # hydrocarbon impurities can be tolerated with no adverse effect on the oxy fuel mixture.

The oxy fuel burner can be provided with the flat standard tip ("standard flat faced tip") or a slightly cup-shaped tip ("slightly cup or dish faced tip"). The flat tips are commonly used for acetylene, while the flat or slightly curved tips are used for ethyl acetylene gas. The pressure in the burner can be over 1.05 Atü. Burner pressures above 1.05 atmospheres are tough as the higher exit velocity improves the overall effectiveness of the burner. It is inexpedient to use acetylene at pressures above 1.05 atmospheres since acetylene becomes explosively unstable above 1.05 atmospheres. The propylene used in accordance with the invention can be stored in cylinders or tanks and transported to remote locations using conventional copper or copper alloy pipes without any reaction with the pipe. or silver compounds react with the formation of harmful and explosive aoetylides

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2Q0G185 - * -

There. Propylene, which is almost pure and has a higher vapor pressure, manages it significantly higher pressures than methylacetylene gas or other known fuels, Ethyl acetylene gas or another common fuel, namely propane Insufficient working pressures at temperatures of -18 C. or below- * Due to the higher vapor pressure of propylene is at these temperatures still sufficient pressure, which is why propylene at these temperatures can be used as fuel. This is the transportation of propylene possible in unheated environments in most parts of the country.

Table 1 provides comparative data for known oxy fuel mixtures that were tested in a series of controlled cutting tests. In the tests, the fuel and oxygen were consuming and Sohneidegeschwindigkeit in the production of "drop-cuts" of 1.25 cm thick wrought iron plates accurately measured · The industry knows the quality Tate default values for products manufactured by Oxybrennstoffmiechungen ^ff drop-cuts ".,

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Table 1

Fuel fuel preheat. Schneidegeschwind., Brenstof f consumption consumption of vorherhitzt.

flow; 1 oxygen cm / min 28.3 1 / 30.4 m oxygen; 28.3 1/30.4 m 1 . Cutting length cutting length .

propane
Propylene

147 263

Propylene 190

50:50 propylene & ₉₇₉ propane * ^f *

50:50 propylene & ₂ - ₂

· "Propane
co ^

J ^ methyl acetylene gas "249 ο '■

-> ^ acetylene

68.5 78.5 68.5

76.0

71.0

73.5 61.0

3.85 6.00 4.96

6.41

6.07 10.00 '

24.6 26.4 18.9

26.0

22.2

24.3 11.0

O O CD

From the table above it can be seen that the oxy fuel mixtures the use of propylene as a fuel component are at least as good as known fuels for oxy fuel mixtures.

Table 2 gives the results of Durchlöcherungstests to 2.5 cm thick Schtledeasenplatten with the fuels from Table 1. When Durchlöcherungstest a burner at a predetermined distance from the plate will go-old, and it mii3t the time for heating the plate with eil he given Oxybrennstoffmischung to a temperature at which a jet of pure oxygen reaches full penetration.

Table 2

Fuel 1 Perforation
since; lake Distance from
Burner tip closed
Plate mm propane 229 22nd 3.2 Propylene 241 7th 3.2 Propylene 399 5 3.2 Propylene & Propane (50:50)
* Me thy lace tylengas " 252
297 10
6th 3.2
3.2 acetylene 385 16 3.2

From Table 2 it can be seen that the oxy-propylene mixture is at least as good or better than the known oxy-propylene mixture.

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Claims (7)

1.- Gaseous fuel mixture to heat, bonding and cutting of metals consisting of propylene having a purity of at least 94 j> and oxygen in a Mischr-ungsverhältnis between 2 biö less than 4.5 parts oxygen to 1 part propylene. 2.- mixture according to claim 1, characterized in that the propylene is a Has purity of at least 95 # and has lower levels of carbon pollution; contains cleaning. ■■ -.-, 3. Mixture according to claim 1 and 2, characterized in that the ratio of oxygen to propylene is between 3 and less than 4.5 parts of oxygen to 1 part of propylene. - 4.- A method for heating, joining and cutting metals using an oxy fuel mixture, characterized in that one is connected to a Oxy fuel burners have a source of oxygen and a source of propylene a purity of at least 94 # followed, with oxygen and propylene present in gaseous form under pressure, the burner supplies fuel and ignites the fuel, supplies the burner with oxygen and and adjusts propylene flow until the ratio of oxygen to propylene in the burner is between 3 and less than 4.5 to 1 and the adjusted oxy-fuel flame adjusts to the metals. 5.- The method according to claim 4, characterized in that propylene of a purity of 95 i> is used. 6.- The method according to claim 4 and 5, characterized in that one Burner with a slightly cup-shaped tip is used. 7.- The method according to claim 4 to 6, characterized in that the Druok la Brenner is between 1.05 and 2.10 AtU. The patent attorney: 00 9840/1223