DE2057410A1 - Flammable mixture for welding torches and other burners - Google Patents

Description

Dr Hans-Heinrich Willrath d - ₆₂ Wiesbaden October 2, 1970

Ul. J- / 1VIV » Gustav-Freytag-Strasse 25 I / Wh

PATENTANWÄLTE ® (oem) 372720

Telegram address: WIIXPATENT

Postal check: Frankfurt / Main 07 «3 Qp v» ·? O 1

Bank: Dresdner Bank AG. Wiesbaden series 1.

Account No. 876 807

L'Air Liquide, Ste. Ame. pour I'Etude et! 'Exploitation of the Procedes Georges Claude, 75 ,. Quai d'Orsay, 75 Paris, France

Combustible mixture for welding torches and other torches

Priority: No. EN 69 40730 of November 26, 1969 in France

It has been common practice for welding torches, i.e. torches such as those used for welding, oxygen cutting for more than half a century or bake hardening are needed to use acetylene. The heating properties of this gas are to the great Partly due to its high endothermic heat of formation. It was found that the classification of the various Hydrocarbons, which are used as fuels in welding torches or the like. tried to be the same as when she entered

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Order according to their calorific value or according to the value of their heat of formation. This naturally results in the use of methyl acetylene or propadiene or mixtures of these two substances for the industrial activities mentioned above; because these gases have endothermic heats of formation, which is that of acetylene be very close. Substances with a high endothermic heat of formation are now often unstable and this is the case with acetylene, Methyl acetylene and propadiene. The storage of these gases in a liquid state is therefore dangerous. One stabilizes the stored product by diluting these substances with permanent liquids or liquefied gases, like this has long been suggested for acetylene, e.g. by dissolving in acetone or diluting with ammonia. One stabilizes also methylacetylene or propadiene by dilution with stable hydrocarbons such as propane, propylene, Butane, butylene, etc.

When one gets such permanent liquefied mixture, the whole is endothermic heat of formation of these mixtures is smaller than that of pure methylacetylene or propadiene. This diminished endothermic heat of formation affects the calorific value of the mixture. As a result, it is appropriate to use methylacetylene or Not to dilute propadiene too much in order to keep the heat of formation of the mixture close to that of the stability limit corresponds to, i.e. a heat of formation in the order of magnitude of 30 kcal for the molar volume of the gas mixture. Mixtures whose endothermic heat of formation would be less than 10 kcal for the gaseous molar volume, would have much less interest in

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the industrial uses outlined above and would approach the properties of the diluent too closely, in order to practically differ from it. So that the finished mixture has an endothermic heat of formation for the molar volume of at least It has 10 kcal, it is enough to make up the composition of the mixture of saturated ethylenic, diethylenic and acetylenic Set connections taking into account the heat of formation of each of these connections. To have good flame properties To achieve, one preferably chooses the nature and the proportions of the saturated ethylenic, diethylenic and acetylenic constituents such that the mixture has an endothermic total heat of formation based on the molar volume of at least Has 20 kcal.

On the other hand, in separation systems for hydrocarbons intended for the production of methylacetylene or propadiene or their mixture, in order to avoid any risk of explosion, the liquid phase does not contain these substances in such contents on each tray of the distillation columns that the stabilization threshold is exceeded . As a result of this mandatory safety condition, the products obtained contain, in addition to methylacetylene and propadiene, at least kO% C, hydrocarbons, such as propane, propylene or mixtures thereof, as diluents. In order to increase manufacturing safety, the flammable mixture should preferably contain at least 50 % propane and / or propylene based on methylacetylene and propadiene at all times during manufacture or storage.

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2057-10

On the other hand, if one wishes to dilute it in a storage bottle with methylacetylene or propadiene or a mixture thereof stable hydrocarbons emptying the bottle allows a gas with an approximately constant calorific value to be withdrawn and As a result, to store an always stable liquid, it is necessary that in the course of this emptying the gas phase and the liquid phase itself will maintain its total diluent contents approximately constant. Because there are no stable hydrocarbons which have the same vapor tension as methylacetylene or propadiene, one must therefore use it as a diluent use two types of stable hydrocarbons, namely one with higher vapor tensions than those of the two main ingredients and a variety with lower vapor tensions. The first type consists of CU hydrocarbons, like propane or propylene, and the second from (^ -hydrocarbons, such as butane, butenes, butadienes, butyne. The relationship between these two types of hydrocarbons is intended in the present Limits are:.

12 «^" content of CU-thinners ^ content of (^

12 ^ ^

30 ^ content of (^ - thinners ^ 5

As a result, a large part of the C, hydrocarbons initially escapes with a large part in the course of emptying Methylacetylene and propadiene, and then the rest of the (^ hydrocarbons and most of the C ^ hydrocarbons escape with the remainder of methylacetylene and propadiene. Under these conditions the gases and the liquid become in the course of the Emptying always a fairly constant ratio between methylacetylene and propadiene on the one hand and C 1 - and C ^ -hydrocarbons on the other hand have.

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Although it is for achieving the withdrawal of a mixture with constantly constant ratio of methylacetylene, propadiene or their mixture is sufficient, the proportions of C, - Ch-hydrocarbons and Ch-hydrocarbons, as just mentioned, should be preferred the ratio between the C, - and Ch-hydrocarbons in the diluent lie between the following limits:

85 ^ content of C , diluent ^ -92 15 ^. Content of CjJ diluents ^ * ~~ 8

Some compositions of the gas mixtures based on methylacetylene or propadiene are given below by way of example communicated according to the invention.

example 1

The fuel gas mixture for welding torches has the following composition in volume-1:

Methyl acetylene and propadiene 45 %

Propene 50%

l-butene '5 Jf

Its total endothermic heat of formation based on the molar volume is 20.9 kcal.

Example 2

The fuel gas mixture for welding torches or other torches has the following composition:

Methylene acetylene 20 %

Propadien '25 %

Propene 50 %

i-butene 5

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INSPECTED

Its endothermic heat of formation is based on 21.8 kcal the molar volume.

Example 3

The fuel gas mixture has the following composition:

Methyl acetylene 9 %

Propadiene 31 %

Propene 54 %

1-butene 6 %

Its heat of formation is 19.90 kcal.

Example 4

The fuel gas mixture has the following composition:

Methyl acetylene 9.5 %

Propadiene 34 %

Propene 50 %

Butane 5.5 %

Its heat of formation is 19.80 kcal.

Example 5

The fuel gas mixture according to the invention has the following composition:

Methyl acetylene 20 %

Propadien '''25 %

Propylene 40 %

Propane 10 %

1-butene 5 %

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_; , ORIGINAL INSPECTED

205-74 TO

Its heat of formation is 18 ₃ 90 kcal.

Example 6

The fuel gas according to s. Ch for welding torches according to the invention the following composition:

Methyl acetylene 10 %

Propadiene 3 ^ %

Propylene 50 %

1-butene 6 % Λ

Its heat of formation is 21.6 kcal.

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Claims (9)

Claims . characterized in that the diluent contains at least 40% C, -Kohlenwasser- W substances, the endothermic heat of formation of the mixture based on the molar volume of at least 10 kcal and the ratio between the CU and Cn hydrocarbons in the diluent is between 70: 30 and 95 '5 lies. 2. Fuel gas mixture according to claim 1, characterized in that the ratio between the C, hydrocarbons of the diluent (propane and / or propylene) and methylacetylene and propylene is preferably below 50 % . 3. fuel gas mixture according to claim 1 or 2, characterized in that ™ that the ratio of the contents of C, -hydrocarbons and (^ -Hydrocarbons in the diluent is between 85:15 and 92: 8. k. Fuel gas mixture according to one of Claims 1 to 3, characterized in that the total endothermic heat of formation, based on molar volume, is at least in the order of magnitude of 20 kcal. 5. fuel gas mixture according to claim H, characterized by a content of H5% methylacetylene propadiene, 50 % propylene and 5 % 1-butene. 1 09823/1227 6. fuel gas mixture according to claim 4, characterized by a content of 10 % methylacetylene, 34 % propadiene, 50 % propylene and 6 % 1-butene. 7. fuel gas mixture according to claim 4, characterized by a content of 9 % methylacetylene, 31 % propadiene, 5 ^ % propylene and 6 % 1-butene. 8. fuel gas mixture according to claim 4, characterized by a content of 9.5 % methylacetylene, 3 ^ % propadiene, 50 % propylene and 5.5 % butane. \ 9. fuel gas mixture according to claim 4, characterized by a content of 20 % methylacetylene, 25 % propadiene, 40 % propylene, 5 % 1-butene and 10 % propane. 109823/12 27