LU84450A1 - PROCESS AND INSTALLATION FOR OBTAINING A HOMOGENEOUS GAS MIXTURE, IN DETERMINED PROPORTIONS, FROM A CARRIER GAS AND A LIQUID ENRICHING ADDITIVE - Google Patents

Description

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Process and installation for obtaining a homogeneous gas mixture, in predetermined proportions, from a carrier gas and a liquid enriching additive /

The present invention relates to a method and an installation making it possible to obtain a homogeneous gas mixture, in predetermined proportions, from a carrier gas and a liquid enriching additive, said gas mixture 5 being able to be used in particular as industrial fuel, as domestic fuel or as fuel.

In order to obtain the desired enriched gas mixture, an attempt has already been made to spray liquid enriching additive into a stream of carrier gas, the proportions of the components in the mixture being determined by adjusting the quantity of sprayed additive and / or by adjusting the gas flow rate. However, this known method has proved to be of little interest in practice: on the one hand, the device for injecting the liquid additive in spray form 15 is costly both to purchase and to service maintenance current; on the other hand, the entire installation (reservoir for the carrier gas, reservoir for the liquid additive, injection device) is relatively bulky and must be placed at the place of use, which poses problems for some applications where space is limited.

In an attempt to remedy these drawbacks, it has also been proposed to prepare the desired gas mixture, for example by bubbling the carrier gas into the liqui-25 additive, and to take the gas phase for the intended use. If this known process had the advantage of simplicity, it nevertheless had a serious drawback: although the liquid additive was introduced in proportions s * 2 perfectly determined within the mixture, it was however impossible to be sure that the additive would be present in the same proportions, and stably, in the gas mixture which is withdrawn; in application of the generalized Raoult and Dalton laws on the vaporization of mixtures with total miscibility, the concentrations of the different gaseous bodies of the mixture indeed vary as a function of pressure and temperature.

10 However, in certain applications, the mixture that it is desired to use is a combustible mixture stored in a tank, the filling of which varies in significant proportions as the fuel is consumed: therefore, the composition of the vapor phase overhanging the liquid phase is subject to considerable variations.

In addition, for example if the fuel is a fuel for an internal combustion engine of a motor vehicle, the temperature can also vary in large proportions depending on the atmospheric conditions of use of the vehicle.

Therefore, it was impossible to ensure, by direct extraction of the mixture in the gas phase, the stability of the pressure and temperature j and therefore it was impossible to ensure the consistency of the proportions of the mixed products within this gas phase.

The object of the invention is therefore essentially to remedy the above-mentioned drawbacks of previous methods and to propose a method and an installation which satisfy, better than current methods and installations, the various requirements of the practice, in particular by making so that one can obtain, with simple and inexpensive means, an enriched gas mixture which is homogeneous and stable.

According to a first aspect of the invention which relates to a process for obtaining a homogeneous gas mixture, 3 usable in particular as industrial fuel, as domestic fuel or as fuel, from a carrier gas and an additive liquid enricher, the following steps are carried out: 5 - the carrier gas is liquefied, - the liquefied carrier gas is mixed, in required proportions, with the liquid enrichment additive so as to obtain a homogeneous liquid mixture, - the homogeneous liquid mixture in a vaporizing apparatus, and a gaseous mixture containing carrier gas and the enriching additive in gaseous form is collected at the outlet of the vaporizing apparatus.

It has been found during experiments that the gaseous mixture obtained in accordance with the invention is perfectly homogeneous and exhibits great stability in the required proportions of the constituents "

Of course, it may be advantageous to carry out mixing of the mixture of the carrier gas and the liquid additive 20 to improve, if necessary, the homogeneity of the mixture.

It will be noted, as another advantage, that the implementation of the method of the invention presents no technical difficulty and can be carried out with simple and inexpensive means.

In addition, another advantage of the process of the invention lies in the ease of separating the stages of manufacture of the liquid mixture and the stages of vaporization of said liquid mixture to obtain the desired enriched gaseous mixture: the latter can easily take place 30 at the place of use of the enriched gas mixture, even if the space available is reduced, since a large part of the equipment is permanently confined to the places of manufacture of the liquid mixture.

Depending on the applications envisaged for the gas mixture, the carrier gas can be either a combustible gas or a combustible gas. Likewise, the liquid additive 4 serving to increase and / or improve at least one of the characteristics of the carrier gas can be, for example, but not exclusively, a circulating additive in the case of a carrier gas used as fuel and an ameliorative additive -5 rant the characteristics and performances of the carrier gas used as fuel (for example the octane number for a fuel for internal combustion engine, the septane number for a fuel for diesel engine, density, viscosity, etc. ), 10 According to a second aspect of the invention which relates to an installation for obtaining a homogeneous gas mixture, usable in particular as industrial fuel, as domestic fuel or as fuel, from a carrier gas and an enriching additive liquid, said installation comprises in combination: - a source of carrier gas in the gaseous state, - means for liquefying the carrier gas supplied by the said source, - a source of liquid enriching additive, 20 - a mixing device for mixing, according to the required proportions, the liquefied carrier gas and the liquid enriching additive, - and vaporizing means linked to said mixing device for receiving liquid mixture and arranged to supply a gaseous mixture containing, stably and homogeneous, the required proportions of the carrier gas and of the gaseous enriching additive.

In an advantageous embodiment, the installation according to the invention further comprises, on the one hand, pumping means and single counter means, the output of which is connected to the mixing device and, on the other hand, switching means arranged upstream of said pumping means, arranged to allow the arrival at the inlet of the pumping means either of liquefied carrier gas, or of liquid enriching additive.

5

Preferably, the installation further comprises primary storage means for storing the liquid mixture which has just been manufactured and secondary storage means distributed respectively on the places of use and to which the medium vaporizers.

Thus, thanks to the invention, only are present at the place of use the secondary storage means (for example a simple bottle or a tank of vehicle) and the vaporizing means: the operation is is greatly facilitated, especially when the enriched gas mixture is used for domestic purposes, such as space heating, or as fuel for the supply of an internal combustion engine.

In addition, since the liquid mixture is produced in equipment that can be separated from the use equipment, this equipment for manufacturing the liquid mixture can be permanently installed, in any suitable location, for example in the vicinity of a place of production of the porous gas. -.20 tor, and above all they can be arranged with all the desirable improvements, without concern for space, to maximize the manufacturing yield of the liquid mixture; the manufacturing cost of this mixture can thus be lowered in significant proportions compared to the previous processes.

the invention will be better understood on reading the detailed description which follows of certain embodiments given solely by way of nonlimiting examples; in this description, reference is made to the appended drawings 30 in which î - Figure 1 is a schematic view of an installation arranged in accordance with the invention, and - Figure 2 is a schematic view of a variant of the installation of figure 1.

35 Firstly referring to FIG. 1, the installation according to the invention comprises an inlet 1 for a carrier gas, fuel or fuel, which it is desired to enrich.

6

A liquefier device 2, connected to the inlet 1, makes it possible to liquefy the carrier gas in any desirable manner known to those skilled in the art, either by compression at constant temperature (in particular ambient temperature), 5 or by pressure cooling constant (including atmospheric pressure).

the liquefied carrier gas is discharged, still in the liquid state, into a buffer tank 3.

Another tank 4 contains the liquid additive which must serve to enrich the carrier gas. Although the invention is not limited to this single case, it will however be noted that its advantage is greatest when the additive is liquid under normal conditions of temperature (room temperature) and pressure (atmospheric pressure). "

Evacuation conduits 5 "6 are connected respectively to the tanks 3" 4 so that only the liquid phases are removed therefrom. For these purposes, the conduits 5, 6 open at the bottom (as shown in .20 in FIG. 1), or even in the bottom of the tanks 3 »4o

Two pumping and measuring groups (for example volumetric) 7, 8 ensure the transfer, in predetermined proportions, of the respective liquids in a mixing tank 9 · Although the discharge of the two liquids in the tank 9 can alone ensure obtaining a homogeneous mixture, it may be advantageous for certain liquid products which are more difficult to mix with using auxiliary means, such as mechanical stirring means (pumping in a closed circuit for example), to perfect the homogeneity of the liquid mixture contained in the tank 9 (these auxiliary means are not shown in Figure 1). the liquid mixture thus obtained contains the required proportions of the liquefied carrier gas and of the liquid additive; it is homogeneous and stable.

A discharge pipe 10 opens in the tank 9 so that only the liquid phase of the mixture can be discharged, under pressure or with pumping means 7 (not shown) as the case may be: the pipe 10 opens the lower part, or even in the bottom of the tank 9 ·

The conduit 10 brings the liquid mixture to the inlet of a vaporizing device 11 capable of producing at the outlet a gaseous mixture containing the required proportions of carrier gas and vaporizing enriching additive; this gas mixture is perfectly homogeneous and stable. The vaporizer device can be of any type known to those skilled in the art for the applications specifically envisaged.

10 The gaseous mixture available at the outlet of the vaporizer device 11 can then be directed (at 12) to the desired user member, with the interposition of an expansion and regulation valve 13.

FIG. 2 represents a more detailed diagram of a variant of the installation of FIG. 1, and this in an application which seems particularly interesting.

the carrier gas is available from a reservoir 21, which can be, for example, either a buffer reservoir in an assembly producing said gas continuously, or a reservoir for storing and transporting said gas between the producing assembly and the installation for manufacturing the mixture according to the invention.

The carrier gas, possibly sucked in by a pump 22, is sent into a liquefier device 23 ”which operates under the same conditions as above. On leaving the liquefying device, the liquefied carrier gas is stored in a buffer tank 24.

The liquid enriching additive is stored in a tank 25, under the same conditions as above.

It is envisaged to use only a single pumping and measuring device (for example volumetric) 26, in order to keep the cost of the installation at a minimum level. It is therefore expected that two conduits 27, 28 open in the tanks 24 and 25 respectively and are equipped with valves 29, 30 respectively before joining at the single inlet of the pumping and measuring device 26. The two valves 29 and 30 are slaved to each other (as symbolized by the dashed line 31), so that it is possible, in association with the operation of the pumping and measuring device 26, to take samples required proportions (for example by volume) of the two liquid constituents. By way of example, the mu-tual control of the taps 29, 30 can be such that only one is open at a time, the other then being closed; by changing the opening of these valves, the proportions of the components of the mixture to be obtained can be adjusted by acting on the flow rate and / or the operating time of the pump 10 26.

The products alternately sucked by the pump 26 are poured into a single storage tank 32, in which one can optionally provide suitable mixing means for perfecting, if necessary, the homogeneity of the liquid mixture liquefied carrier gas / liquid enrichment additive.

the part which has just been described of the installation of the invention (part situated to the left of the vertical dashed line 33 in FIG. 2) can be produced in the form of a fixed unit, permanently installed with all the organs desirable auxiliaries to improve its efficiency and therefore its yield, without worrying about a search for reduced bulk. In other words, it may be an industrial size unit producing the desired mixture in liquid form, a mixture which is kept in storage tanks 32 (primary storage) for subsequent distribution in fractional form.

This distribution (shown diagrammatically in FIG. 2 by the dashed arrow 34) is intended to bring the mixture, still in liquid form, into individual storage tanks (secondary storage) 35 available to the user. The distribution can be of any type appropriate either to the nature of the product distributed, or to the nature of the individual storage tank (liquid fuel distribution station for filling tanks placed on board motor vehicles equipped with combustion engines. internal working with an enriched gas mixture î bottles or tanks filled with * 9 main tank 32 transported to the user for industrial use - cutting of sheets with a blowtorch - or domestic - space heating; transport by tanker truck for filling dual individual tanks).

IF

From the individual storage tank 35 "the liquid mixture is directed onto a vaporizer 36 which delivers an enriched gas mixture conveyed, by means of an expansion and regulation valve 37" to the intended use 38 .

This part of the installation of the invention (part located to the right of the dashed line 33 in FIG. 2) can be produced in a sufficiently compact form to be accommodable in locations where the available space is counted (equipment motor vehicles running on gaseous fuel, for example).

Ultimately, an installation arranged in accordance with the invention is, in addition to its great flexibility of use, made up of simple and common elements, and is therefore relatively inexpensive while allowing the formation of a homogeneous gas mixture and stable which provides superior advantages (same performances or superior performances, more economical, safer to use) than the mixtures obtained by the previous processes.

25 As it goes without saying and as it already follows from the foregoing, the invention is in no way limited to those of its modes of application and embodiments which have been more especially envisaged; on the contrary, it embraces all its variants.

Claims (7)

1. Method for obtaining a homogeneous gas mixture, usable in particular as industrial fuel, as domestic fuel or as fuel, from a carrier gas and a liquid enriching additive, characterized in that it comprises the succession of steps following; - the carrier gas is liquefied, - the liquefied carrier gas 10 is mixed in required proportions with the liquid enriching additive so as to obtain a homogeneous liquid mixture, - the homogeneous liquid mixture is brought into a vaporizing apparatus, - and there is collected, at the outlet of the vaporizing apparatus, a gaseous mixture containing carrier gas and the enriching additive in gaseous form, and this with great stability of the required proportions, in a perfectly homogeneous form, and with simple and inexpensive means to achieve. 20 2 - Method according to claim 1, characterized in that the mixture of the liquefied carrier gas and the liquid enriching additive is mixed, 3. Method according to claim 1 or 2, characterized in that the carrier gas is a fuel and in that the liquid additive is a circulating additive. 4. Method according to claim 1 or 2, characterized in that the carrier gas is a fuel and in that the liquid additive is an enhancer of characteristics and performance of the carrier gas. 30 5 - Installation for obtaining a homogeneous gaseous mixture, usable in particular as industrial fuel, as household fuel or as fuel, from a carrier gas and a liquid enriching additive, characterized in that it comprises in combination: 35 a source (1) of carrier gas in the gaseous state, - means (2) for liquefying the carrier gas supplied by the said source, - a source (3) of liquid enriching additive, "r '11 - a mixing device (4) for mixing in the required proportions the liquefied carrier gas and the liquid enriching additive, - and vaporizing means (5) linked to said mixing device (4) for receiving the liquid mixture and arranged to supply ( in 6) a gaseous mixture containing, in a stable and homogeneous manner, the required proportions of the carrier gas and of the gaseous enriching additive. 6. Installation according to claim 5, character-10 in that it further comprises, on the one hand, pumping means and single counter means whose output is connected to the mixing device, and, on the other hand , switching means arranged upstream of said pumping means, arranged to authorize the arrival at the inlet 15 of the pumping means either of liquefied carrier gas, or of liquid enriching additive. 7. Installation according to claim 5 or 6, characterized in that it further comprises means. / primary storage for the storage of the liquid mixture which has just been manufactured and secondary storage means distributed respectively at the places of use and to which the vaporizing means are respectively connected.