WO2006024410A1

WO2006024410A1 - Method and device for vaporizing liquid fuels

Info

Publication number: WO2006024410A1
Application number: PCT/EP2005/009016
Authority: WO
Inventors: Jochen Volkert; Ernst Keim; Conchita Encinas Bermudez
Original assignee: Gvp Gesellschaft Zur Vermarktung Der Porenbrennertechnik Mbh
Priority date: 2004-08-30
Filing date: 2005-08-20
Publication date: 2006-03-09
Also published as: DE102004041815A1; EP1784253A1

Abstract

The invention relates to a method for vaporizing liquid fuels (O), which comprises the following steps: a) providing a reactor (8) with means (1) disposed therein for increasing the inner surface, b) supplying liquid fuel (O) and oxygen-containing gas (L) to the reactor (8), c) carrying out an exothermic reaction between the oxygen-containing gas (L) and the vaporizing liquid fuel (O), the liquid fuel (O) being only partially oxidized, and d) removing the product formed during exothermic reaction from the reactor (8).

Description

Process and apparatus for the evaporation of liquid fuels

The invention relates to a method and a device for the evaporation of liquid fuel.

According to the prior art, WO 00/06948 discloses a method for evaporating liquid fuel according to the "cold flame principle". By the "principle of the cold flame" is meant a partially exothermic oxidation of hydrocarbons at atmospheric pressure at a temperature in the range of 300 to 500 ° C. In this exothermic reaction about 10 to 15% of the stored chemical energy is released. The reaction according to the "principle of the cold flame" does not lead to the formation of a visible flame.

In the process known from WO 00/06948, liquid fuel and air are passed into a reactor, which is heated electrically or by recirculation of hot gases. The implementation of the proposed method has proven to be problematic in practice in many respects.

In order to keep the reaction volume enclosed by the reactor uniformly at a temperature suitable for carrying out the exothermic reaction, a high expenditure in terms of apparatus and control is required. In practice, it has been shown that the temperature is not homogeneously distributed over the reaction volume due to flows forming in the reaction volume. To counteract this, according to the prior art, the energy released in a reaction zone is returned to regions in which the fuel is still in liquid form. Apart from this, local overheating and thus ignition of the mixture and explosion of the reactor can occur in the reaction volume.

The object of the invention is to eliminate the disadvantages of the prior art. In particular, a method and a device are to be specified with which a vaporization and exothermic reaction according to the principle of the cold flame can be carried out in as simple, safe and cost-effective manner as possible. In addition, the device should also make it possible to carry out the "partial oxidation" process.

This object is solved by the features of claims 1 and 19. Advantageous embodiments emerge from the features of claims 2 to 18 and 20 to 45.

According to the invention, a method for the evaporation of liquid fuel is provided with the following steps:

a) providing a reactor having a means for increasing the internal surface contained therein,

b) supplying liquid fuel and oxygen-containing gas into the reactor,

c) carrying out an exothermic reaction between the oxygen-containing gas and the evaporating liquid fuel, wherein the liquid fuel is only partially oxidized and

d) removing the product formed during the exothermic reaction from the reactor.

For the purposes of the present invention, a "reactor" is understood to mean a container which encloses a free volume. It may be, for example, a cylindrical tube.

According to an essential aspect of the invention, a means for increasing the internal surface is included in the reactor. The inventively provided means for increasing the inner surface contributes to an increase in the effective heat conductivity and / or the volumetric heat exchange coefficient in the reactor. As a result, a reactor surrounded and heated to a predetermined temperature

Reaction volume in the reactor everywhere, i. also transversely to a flow direction, almost homogeneously kept at a suitable Tempe¬ temperature for carrying out the exothermic reaction wer¬. The resulting in the exothermic reaction in addition to the energy released product, eg. As a mixture of evaporated th and partially chemically converted liquid fuel and air, is particularly homogeneous.

The exothermic reaction of the present invention is a reaction that proceeds without ignition and formation of a visible, open flame. In this case, the liquid fuel is only partially oxidized. It may be that a pre-reacted mixture is already fed to the reactor or a partially reacted mixture is removed from the reactor. For this purpose, suitable means for producing a prereacted mixture or for continuing the reaction of a partially reacted mixture may be upstream or downstream of the reactor. The heat generated in the exothermic reaction is z. T. transferred to the reactor. This is u.a. as a heat storage. In a suitable process procedure, it is only necessary to start the exothermic reaction.

In the context of the present invention, the exothermic reaction may be an exothermic reaction according to the "principle of the cold flame". According to an advantageous Aus¬ design of the method, the temperature in the reactor is so regulated that a lower temperature limit of 22O ⁰ C is not undershot and an upper temperature limit of 600 ⁰ C is not exceeded. The air ratio λ of a mixture formed from the liquid fuel and the oxygen-containing gas can assume any desired values. The air ratio λ is the ratio between the actual amount of air and the amount of air theoretically required for complete combustion. Using the proposed control, an exothermic reaction according to the "cold flame principle" can be carried out continuously.

According to an alternative procedure, the temperature is suitably regulated in the reactor, that a lower temperature limit of 600 ⁰ C range and an upper temperature limit of 1500 ⁰ C is not exceeded. According to a further embodiment, the air ratio λ of a mixture formed from the liquid fuel and the oxygen-containing gas is <1. Using the proposed control, an exothermic reaction according to the principle of "partial oxidation" can be carried out continuously.

The two aforementioned alternative variants of the method can advantageously be carried out in one and the same device. In addition, it is possible to modulate the performance of the device in a wide range. - The aforementioned temperature ranges apply to atmospheric pressure. When changing the pressure parameters, the indicated temperature window is to be adapted accordingly.

Advantageously, the liquid fuel is at most to

90%, preferably at most 50%, oxidized. This allows z. B. a subsequent combustion of the vaporized Ge mix.

According to a further embodiment feature, the liquid fuel is atomized on entering the reactor. For this purpose, the reactor may have a mixing section upstream, in which one from the. atomized liquid fuel and the oxygen-containing gas formed mixture is produced. In the mixing section, means for fluid mechanical stabilization can be included. These may be flow baffles and the like. This ensures that a homogeneous Gemischbil¬ tion is guaranteed in the mixing section in a large modulation range. The mixture is always generated and homogenized by the proposed means for stabilizing the flow in the mixing section.

The means taken in the reactor to increase the inner surface also serves to keep the reaction zones in the reactor over a wide modulation range away relative to the axial extent of the reactor in a predetermined area. Thus, an evaporation product with given properties can always be produced across the entire modulation range.

By way of example, an air nozzle for introducing the air into the mixing section can be provided with a swirl generator as a means for stabilizing the flow. It can thus be generated with a twisted or untwisted free jet. Further, an exit diameter of the air nozzle and a distance of the air nozzle to the means for increasing the inner surface can be varied. The free jet causes recirculation of the energy and the chemical radicals within the mixing section. As a result, the reactions occurring in the mixing section can be kept stationary in a wide modulation range. The means for increasing the inner surface thus causes a determination of certain reaction zones within the reactor. The boundaries of the reaction zones depend on the power with which the device is operated. Depending on the modulation range, they vary within a given axial range. However, the means for increasing the internal surface ensures that the reactor Onszonen as such over the entire modulation range er¬ hold and thus always the given Verdampfungs¬ product is generated.

According to a further embodiment, the reactor before the step lit. heated b. Preheating the reactor serves to start and / or maintain the exothermic reaction. For this purpose, the reactor can be preheated, for example, by combustion of a mixture formed from the liquid fuel and the oxygen-containing oxidant. In this case, the mixture is adjusted so that combustion can take place. Once the reactor is at operating temperature, combustion is stopped. Subsequently, a mixture of liquid fuel and oxygen-containing gas without the formation of a visible flame in the reactor exo¬ therm partially oxidized and thus evaporated. The heat released in the exothermic reaction expediently heats the means for increasing the inner surface.

According to a further embodiment feature, the reactor is heated with an electric heating element. Such a heating element is used in particular for starting the reactor to start the exothermic reaction. If, during operation of the reactor, excessive cooling of the reactor occurs, then heat can be supplied again by means of the electrical heating element. However, it is also possible, for example, to recirculate the hot product leaving the reactor and to use it for heating the reactor. Of course, instead of the product, hot exhaust gases can also be recirculated, which are formed, for example, by combustion of the product. For this purpose, a chamber can be provided downstream of the reactor, from which a recirculation line branches off to recirculate the product. Similarly, the reactor can also be a burner with a

Downstream combustion chamber, from which a recirculation line for recirculation of hot exhaust gases branches off. such Recirculation lines can be connected, for example, to the above-mentioned mixing section. The oxygen-containing gas can also be heated indirectly via a heat exchanger, which is heated with the hot exhaust gases or the hot product.

According to a further embodiment, it may also be that the means for increasing the inner surface is used as the heating element. In this case, the means for increasing the inner surface is expediently designed as a resistance heating element. For example, it may be made of metal, silicon carbide or the like.

According to a further embodiment, it is also possible to heat the reactor by hot gas. Such gas can be a waste product of another process.

The temperature of the reactor can be conveniently controlled by increasing or decreasing the temperature of the oxygen-containing gas supplied. It is also possible to control the temperature of the reactor by increasing or decreasing the mass flow of the oxygen-containing gas through the reactor. In these cases u. U. be dispensed with a heating element for heating the reactor.

Air can be used as the oxygen-containing gas and hydrocarbons as the liquid fuel, preferably light heating oil or diesel. In principle, any oxygen-containing gas in conjunction with all oxidizable hydrocarbon-containing fuels is suitable for carrying out the exothermic reaction according to the "cold flame" principle and / or the "partial oxidation".

The means for increasing the inner surface is expediently a permeable, porous medium and can be selected from the following group: Porous bodies, eg. For example, with a foam structure made of ceramic or metal, static shear, wire or Fasergewirk, tube assembly, bed, arrangement of perforated plates. Conveniently, the means for increasing the inner surface of a ceramic, a glass, a binder or made of metal. In any case, the means for increasing the inner surface is an agent which is temperature resistant. It may be that the means for increasing the inner surface is provided with a catalytic coating.

The means for increasing the inner surface is expediently received in a cylindrical reactor housing. It is in any case designed such that a flow through the reactor from an inlet to an outlet is possible and at the same time the heat released during the exothermic reaction is stored in an effective manner by the means for increasing the internal surface for its further maintenance.

According to another aspect of the invention, a device for the evaporation of liquid fuel is provided, with a Reak¬ tor, in which a means for increasing the inner surface is added, a means for supplying Flüssigbrenn¬ material and oxygen-containing gas in the reactor, and a Means for controlling the temperature of the reactor such that an exothermic reaction between the oxygen-containing gas and the evaporating liquid fuel is feasible such that the liquid fuel is only partially oxidized.

The proposed device is simple and inexpensive to produce. By carrying out the reaction in a reactor in which a means for increasing the internal surface area is provided, it is possible to more safely and reliably avoid undesired ignition of the mixture while forming a free, visible flame in the reactor. Apart from this, by the additional heat capacity created by the means for increasing the inner surface, sufficient heat can be stored in the reactor, so that the exothermic reaction can be easily maintained.

Expediently, the temperature in the reactor can be regulated with the means for controlling so that a lower temperature limit of 220 ^° C. is not undershot and an upper temperature limit of 1500 ^° C. is not exceeded. Thus, the temperature in the reactor, on the one hand, can be kept constant, for example in a temperature range from 22O ⁰ C to 600 ⁰ C, so that in this temperature range an exothermic reaction according to the principle of the "cold flame" can be carried out. On the other hand, it is also possible to maintain the reactor at a temperature in Be¬ ranging from 600 to 1500 ⁰ C, so that in this Tempe¬ raturbereich takes place a "partial oxidation" of the supplied overall premix. Thus, with the proposed control, the performance of the device can be modulated in a wide range. With the control it is possible to operate the device either in accordance with the principle of the "cold flame" in a first temperature range or according to the principle of "partial oxidation" in a second temperature range. For this purpose, only a single structural design of the device is necessary. It is suitable for carrying out both of the above-mentioned process variants.

Advantageously, a means for atomizing the Flüssig¬ fuel is provided. Thus, a particularly homogeneous mixture can be produced. The vaporized product made therefrom is also particularly homogeneous.

The sputtering means may comprise at least one nozzle. The nozzle in turn may be surrounded by an annular nozzle for supplying oxygen-containing gas. Advantageously, the annular nozzle is provided with a swirling element. Thus, the oxygen-containing gas can be added, for example, in a rotating about the axis of the annular nozzle flow. The annular nozzle and possibly the swirling element can open in a mixing section of the reactor, which upstream the means for increasing the inner surface is arranged. In the mixing section, a homogeneous mixture of the oxygen-containing gas and the finely atomized liquid fuel is formed. In the mixing section, an ignition device for igniting the mixture can be provided. By Ver¬ combustion of the mixture, a preheating of the device can be achieved in a simple manner.

According to a further embodiment, a means for supplying hot gases to the reactor is provided. This may be the product discharged from the reactor or also exhaust gases from a downstream combustion process or other hot exhaust gases.

According to an advantageous embodiment, a device for injecting the liquid fuel may be provided under a pressure in the range of 3 to 100 bar. A variation of the pressure allows operation of the device with a predetermined power. In particular, in the field of low power, it has proved expedient that a means for injecting the liquid fuel is provided at a predetermined clock frequency. The agent may be fast closing valves. Such valves can be operated with a frequency in the range of 5 to 70 Hz. The amount of liquid fuel to be injected can be controlled by the closing time of such valves.

According to a further embodiment, an electrical heating element is provided for heating the reactor. It may be a heating coil or the like surrounding the reactor. Furthermore, a means for heating the supplied oxygen-containing gas can be provided. The means for supplying may further comprise a fan for supplying the oxygen-containing gas into the reactor. The means for heating the supplied oxygen-containing gas can spielsweise be integrated into the blower and also from Heating coils exist, through which the oxygen-containing gas is passed.

The heating element is expediently accommodated in the annular nozzle or in a space upstream of the ring nozzle, preferably an annular space. In this case, the annular nozzle at least partially pass through the room. The nozzle can be surrounded at least in sections by a thermal shielding device in a section which passes through the space. It may be, for example, one or more protective tubes.

According to a particularly advantageous embodiment, it is provided that a reactor housing is part of a heat exchanger, through which the oxygen-containing gas is fed to the reactor zu¬. This makes it possible in a simple and cost-effective manner to preheat the supplied oxygen-containing gas through the heat released in the reactor during combustion according to the "cold flame" principle. This allows an autothermal operation of the device, in particular, no energy must be supplied to heat the reactor. At the same time, the reactor can be operated in a wide power dynamic range. The oxygen-containing gas can be preheated with the heat exchanger to a temperature of up to 300 ° C. The preheating advantageously causes avoidance of condensation.

The heat exchanger expediently has a first annular channel formed between a first inner housing and the reactor housing, through which the oxygen-containing gas is passed. The circulation of the reactor with the oxygen-containing gas avoids unwanted cooling of the reactor by the emission of heat. The first ring channel may be connected to the ring nozzle. Between a second inner housing and the first inner housing, a second annular gap for discharging a thilde formed in the reactor, the partially vaporized liquid fuel containing Product be provided. The proposed structural design of the device allows a particularly simple and efficient implementation of the reaction according to the prin¬ zip the "cold flame".

Conveniently, at least one sensor is provided for measuring the temperature prevailing in the reactor. It may be a conventional thermocouple. Of course, it is also possible to provide several sensors for measuring the temperature along the flow path. This makes possible a refined control of the temperature prevailing in the reactor and / or the setting of a given temperature profile along the flow path in the reactor.

According to a further embodiment, the means for regulating the temperature as a function of the temperature measured by the sensor on the basis of a predetermined algorithm controls the power of the electric heating element and / or the means for heating the supplied oxygen-containing gas and / or of the blower. For this purpose, the means for regulating the temperature may include a conventional control with a microprocessor which effects the regulation of the temperature according to a predetermined control algorithm.

The means for increasing the inner surface is expediently produced from one of the following materials: ceramic, glass, binder, metal. Furthermore, the agent for increasing the inner surface may be selected from the following group: Porous bodies, eg. B. foam or

Sponge, wire or Fasergewirk or knitted or -flecht, tube arrangement, bed, arrangement of perforated plates and the like.

An embodiment of the invention will be explained in more detail with reference to the drawing. Herein show: 1 is a schematic view of a device according to the invention,

2 shows the pore body according to FIG. 1 and the temperature profile prevailing in the pore body during the exothermic reaction, FIG.

3 shows a sectional view of a first reactor and the temperature profile prevailing in the reactor in the case of an exothermic reaction,

4 is a sectional view of a second reactor,

5 is a cross-sectional view according to the section line A- A 'in Fig. 4,

6 is a sectional view of a third reactor,

7 is a sectional view of a fourth reactor,

8 is a sectional view of a heating element,

9 is a side view of the heating element of FIG. 8,

10 is a schematic partial sectional view through a fourth reactor,

11 is a sectional view of a fifth reactor,

12 is an enlarged partial sectional view of FIG. 11,

13 is a sectional view of a first heater,

14 is a plan view of FIG. 13,

15 is a sectional view of a sixth reactor, 16 is an enlarged partial sectional view of FIG. 15,

17 is a sectional view of a second heater,

18 is a side view of FIG. 17,

19 is a plan view of FIG. 17,

20 is a sectional view of a seventh reactor,

21 is a schematic view of another device according to the invention,

Fig. 22 is a partial sectional view of the seventh reactor with a first ignition device received therein and

Fig. 23 is a partial sectional view of the seventh reactor with a second igniter received therein.

In Fig. 1, a porous body 1 is shown, which is made of, for example, a porous ceramic, a porous metal, a Draht¬ braid or the like. The porous body 1 has a communicating pore space, so that a mixture consisting of air L and vaporized or partially vaporized liquid fuel 0 can flow through. For example, as shown in FIG. 1, the porous body 1 can be made cylindrical and accommodated in a correspondingly designed housing or reactor (not shown here). The reactor can conventionally have in each case an inlet for the air L and the liquid fuel O or else a common inlet for a premixture formed from the air L and the liquid fuel O. For discharging the product formed in the porous body 1, the reactor has an outlet in a conventional manner (not shown here). To generate a suitable flow rate through the pore body 1, a blower 2 is provided, which is provided with a heater 3. 4 designates a pump with which liquid fuel O can be sprayed in an atomized form through the nozzle provided thereon (not shown here) into the free volume in front of the pore body 1.

The air L can by a suitably designed feeder, z. B. by means of an air nozzle, are guided in the free volume such that forms a free jet. By appropriate measures and installations in the Luftzufüh¬ tion, it is also possible to form this free jet as a twisted free jet. The fuel is supplied in the vicinity of the axis of the free jet by atomizing the flüssi¬ gen fuel by means of a centrally disposed nozzle, whereby a very large surface area of the fuel is generated and intensive mixing of the fuel with the air L takes place. In the upstream free volume wer¬ caused by the free jet recirculation flows whose size u. a. is determined by the ratio of reactor diameter to the diameter of the air outlet and by the distance between the air outlet and the pore body 1. By means of these measures, a virtually stationary stabilization of the evaporation process and of possible chemical reactions between the liquid fuel O and the air L is achieved.

A heating element 5, shown schematically here, can surround the pore body 1. Of course, the heating element 5 can also surround the reactor. It may also be that the means for increasing the inner surface itself is designed as a resistance heating element.

The porous body 1 is further provided with a thermocouple 6 for measuring the temperature prevailing therein. The thermoelement 6 is connected to a control unit 7. The control unit 7 serves to control the temperature of the pore body 1. The control unit 7 can do this with the blower 2, the Heating device 3, the pump 4 and the heating element 5 ver¬ be connected. With the control unit 7, one or more of the aforementioned components for controlling the temperature can be controlled ge according to a predetermined algorithm, so that the temperature of the pore body 1, for example, in a range from 360 to 400 ° C is kept constant. In this case, the temperature of the porous body 1 can be influenced by the temperature of the supplied air L, which is adjustable by means of the heating device 3. It can also be influenced by the flow velocity of the air L flowing through the pore body 1, which can be influenced by means of the blower 2. Finally, it is possible to increase the temperature of the porous body 1 by means of the heating element 5. By means of the pump 4, the amount of liquid fuel O supplied and thus advantageously the mixture composition and the temperature in the pore body 1 or reactor can be adjusted.

FIG. 2 again shows the pore body 1 shown in FIG. 1 and an example of a temperature profile formed along this pore body 1 during the execution of the exothermic reaction.

FIG. 3 shows a reactor 8 produced, for example, from a metal or ceramic tube, in which the porous body 1 is accommodated. Upstream of the porous body 1 is a mixing section 9, in which an air nozzle 10 and a liquid fuel nozzle 11 open. A distance of an outlet cross-section of the air nozzle 10 to the downstream downstream porous body 1 is denoted by S and a Austritts¬ cross-section of the air nozzle 10 with d. Instead of the air nozzle 10 and the liquid fuel nozzle 11 also two-fluid nozzles and the like. Can be used.

To carry out the process of the invention spielsweise air L is upstream of a first temperature Tl of 300 ⁰ C and liquid fuel O in the pores of the body 1 Mixing section 9 out. As a result, vaporization of the liquid fuel O in the air L and at a sufficiently high temperature results in the use of chemical reactions causing partial oxidation of the liquid fuel O. In this case, a temperature profile is formed in the free volume of the mixing section 9, which permits a local assignment of the processes of evaporation and of the energy release by partially exothermic oxidation. The local fixation is primarily determined by the characteristics of recirculation and fuel injection. The energy released in the partial oxidation supports the evaporation process, so that the air inlet temperature can be lowered significantly after the starting process. Depending on the residence times in the reactor 8, a temperature increase over the axial extent of the reactor 8 is determined, but the gradient of the temperature rise is markedly reduced after entry into the pore body 1. At the same time, the porous body 1 causes temperature deviations to be maintained transversely to the flow direction within a relatively narrow range. The maximum temperature is limited at the position indicated as cold flame oxidation of kohlenwasserstoffhal- term fuels to about 500 ⁰ C. In principle, however, it is possible to carry out in the reactor 8 or a subsequent reaction space the chemical reaction generally described as partial oxidation of fuels and thus to achieve temperatures which are above the cold flame temperature and limited at λ <1 in their maximum by the oxygen supply become.

By means of the chemical reactions taking place before, in and after the pore body 1, energy is released, which leads to an annealing of the reactor 8 and of the enclosed volume. Due to the material properties of the pore body 1, inhomogeneities in the temperature field are rapidly compensated for and, overall, a homogeneous temperature in the pore body 1 occurs. This also happens in interaction with the pore body 13

Homogenization of the flow in the reactor 8 caused by the pore body 1.

The product formed in the exothermic reaction, z. As a consisting of air L and liquid fuel O steam and product gases is discharged at the exit of the pore body 1.

As can be seen from FIGS. 2 and 3, a homogeneous temperature distribution predominates over the entire volume of the pore body 1, essentially. As a result, the exothermic reaction according to the "principle of the cold flame" or the "partial oxidation" can be performed particularly homogeneous. The product leaving the porous body 1 has hardly any concentration fluctuations. The pore body 1 acts like a heating element 5, which generates a constant reaction temperature in the entire reaction volume. Local overheating or undesired cooling in the reaction volume is avoided by the use of the porous body 1 proposed according to the invention.

In the second reactor shown in FIG. 4, a reactor housing 12, preferably cylindrical in shape, is provided with an inlet 12a for supplying air L. In the reactor housing 12, a first annular gap 14 is formed between a first inner housing 13 received therein and the reactor housing 12. The inner housing has a baffle plate 12b opposite the inlet 12a, at which the air L supplied through the inlet 12a is deflected and guided in the first annular gap 14. The first annular gap 14 connects the inlet 12a with an annular space 15 surrounding the liquid fuel nozzle 11. The annular space 15 is connected to the mixing section 9 via the air nozzle 10. The mixing section 9 and the pore body 1 provided downstream are accommodated in a second inner housing 16, which is surrounded by the first inner housing 13 with the formation of a second annular gap 17. The first inner housing 13 and the second inner housing 16 may be cylindrical as well as the reactor housing 12 and arranged coaxially.

The open to the porous body 1 second annular gap 17 opens through the annular space 15 sweeping transfer channels (not shown here) in a plenum 18 and from there into an outlet 19th

The reference numeral 20 denotes a protective tube which shields the liquid fuel nozzle 11 against thermal influences.

FIG. 5 shows a schematic sectional view according to the section line A-A 'in FIG. 4. In particular, the overflow channels 21 penetrating the annular space 15 and a swirl generator 22 arranged in the air nozzle 10 can be seen here.

Fig. 6 shows a sectional view through a third reactor. The third reactor differs from the second reactor in particular in that the protective tube 20 extends to the mouth of the air nozzle 10. Thus, a particularly good thermal shielding of the liquid fuel nozzle 11 is achieved.

In the illustrated fourth reactor shown in Fig. 7, two possible arrangements of the heating elements 5 are shown. The heating elements 5 can each extend within the annular space 15 either parallel to its longitudinal axis to the longitudinal axis of the liquid fuel nozzle 11 or also perpendicular thereto.

8 and 9 show a possible embodiment of a heating element 5. A resistance wire 23 may be wound separately by an insulation 24 in the manner of a helix on a ceramic rod 25. Reference numeral 26 designates electrical connections which correspond to the resistance standing wire 23, which may for example consist of ISA chrome 60, are connected.

Fig. 10 shows a possible arrangement of the in Figs. 8 and. In this case, the heating elements 5 are arranged with their axis perpendicular to the axis of the liquid fuel nozzle 11 and project into the annular space 15. They can surround the liquid fuel nozzle 11 in a star shape, so that the air L preheated by the annulus 15 and then through the Air nozzle 10 is ejected.

In the fifth reactor shown in FIGS. 11 to 14, heating elements 5 designed in the manner of a heating coil are arranged in a third annular gap 27, which connects the annular space 15 to the air nozzle 10. As can be seen in particular from FIG. 24, a multiplicity of heating elements 5 are provided which surround the protective tube 20 radially in the third annular gap 27. In a rear space bounding the annulus 15, a thermal insulation 28 may be included.

Figs. 15 to 19 show a sixth reactor. The heating elements 5, which in turn are designed in the form of a helix, are arranged with their axes parallel to the liquid fuel nozzle 11. A carrier element 29 accommodating the heating elements 5 is designed such that it extends over the entire length of the annular space 15. The guided through the annular space 15 air L is preferably guided by the heating elements 5 to the air nozzle 10 necessarily.

In the seventh reactor shown in FIG. 20, cooling air L1 can be passed through a further inlet 30 into the protective tube 20 for additional cooling of the liquid fuel nozzle 11. For improved thermal shielding, a thermal shielding device 31, for example a further protective tube, which surrounds the protective tube 20 may be provided in the annular space 15. Fig. 21 shows schematically a device with a seventh reactor. In this case, downstream of the blower 2, an adjusting element 32 downstream of which the proportion of air L supplied to the inlet 12a and the proportion of cooling air L1 fed to the further inlet 30 can be adjusted.

In the case of the further seventh actuators shown in FIGS. 22 and 23, an ignition device 33 projects into the mixing section 9 in each case. It can be a device for generating a spark (see FIG. 22) or else an ignition device Glü¬ heinrichtung (see Fig. 23) act.

The function of the reactors shown in Figs. 4 to 23 is as follows:

Air L supplied by the blower 2 passes through the first annular gap 14 into the annular space 15. The air L is preheated by the hot product discharged from the reactor 8 in the second annular gap 17.

As can be seen in particular from FIG. 4, a circulating air flow is generated by means of the swirl generator 22, with which the air L exits the air nozzle 10. In the mixing section 9, the air L mixes with finely atomized liquid fuel emerging from the liquid fuel nozzle 11, for example light oil. The homogeneous mixture produced enters the porous body 1, which is located on a suitable for carrying out the reaction according to the principle of "kal¬ tem flame" temperature. It comes in particular in the pore body 1 to the reaction according to the principle of the "cold flame". The hot, partially oxidized product formed is deflected at the baffle plate 12b by approximately 140 degrees and exits the reactor 8 in the opposite flow direction through the second annular gap 17, the overflow channels 21 and the outlet 19. By the product emerging from the pore body 1 is deflected by 180 ° and guided along the second inner housing 16, is the mixing chamber 9 preheated and / or kept at a suitable Tem¬ temperature. The product emerging from the pore body 1 is therefore used both to maintain a suitable temperature in the mixing section 9 and to preheat the air L supplied through the first annular gap 14. The baffle plate 12b may be made of a thermally insulating material. Depending on the thermal insulation capacity of the baffle plate 12b, it is thus possible to set a temperature in the reactor 8 or to stabilize a temperature distribution in the device. A further stabilization of the temperature conditions can be achieved by a suitable choice of the ratio between length and diameter of the reactor.

To support the air preheating, the heating elements 5 shown in FIGS. 7 to 19 can be used. However, it is also possible to produce a suitable preheating of the reactor 8 by ignition of the mixture by means of the ignition device 33. After a predetermined temperature has been reached, the flame can be extinguished again and then a reaction according to the principle of the "cold flame" can be performed. In particular, in the embodiments shown in FIGS. 20 and 21, it is possible to regulate or control a temperature in the mixing section 9 by supplying a suitable amount of cooling air L 1 through the further inlet 30.

The proposed method and the device are easy to handle. They are available at low cost. The proposed device can be used with conventional components, eg. As burners, chemical plants, engines and the like. Combine readily.

The device can be operated not only in the aforementioned mode of operation according to the principle of the "cold flame", but also in the further mode of operation of the "partial oxidation". For this it is only necessary to adjust the tempera- in the reactor 8 in a range of 600 to 1500 ⁰ C to rule. The "partial oxidation" reaction is different from the "cold flame" reaction. The "partial oxidation" involves oxidation reactions with complete decomposition of the CH chains to produce hydrogen (H ₂ ) and carbon monoxide (CO). On the other hand, the reaction according to the "cold flame" principle only leads to a disintegration of the long CH chains.

The inventively proposed device can be operated without kon¬ structural change in both modes. For a particularly high modulation of the performance of the device is possible. The device according to the invention is particularly suitable for operating burners with a high power modulation.

Reference sign list

1 pore body

2 blowers

3 heating device

4 pump

5 heating element

6 thermocouple

7 control unit

8 reactor

9 mixing section

10 air nozzle

11 liquid fuel nozzle

12 reactor housing

12a inlet

12b baffle plate

13 first inner housing

14 first annular gap

15 annulus

16 second inner housing

17 second annular gap

18 collection room

19 outlet

20 protective tube

21 overflow channel

22 swirl generator

23 resistance wire

24 insulation

25 ceramic rod

26 electrical connection

27 third annular gap

28 thermal insulation

29 carrier element

30 more entries

31 thermal shielding device

32 control element

33 ignition device d diameter of the outlet section

L air

Ll cooling air

O LPG

S distance

Tl first temperature

T2 second temperature

Claims

claims

1. Process for the evaporation of liquid fuel (F) with the following steps:

a) providing a reactor (8) with a means (1) received therein for increasing the internal surface,

b) supplying liquid fuel (O) and oxygen-containing gas (L) into the reactor (8),

c) carrying out an exothermic reaction between the oxygen-containing gas (L) and the evaporating Flüssigbrenn¬ substance (O), wherein the liquid fuel (0) is only partially oxidized and

d) discharging the product formed in the exothermic reaction from the reactor (8).

2. The method of claim 1, wherein the temperature in Reak¬ gate is controlled so that a lower temperature limit of 220 ⁰ C not lower and an upper temperature limit of 600 ⁰ C is not exceeded.

3. The method of claim 1, wherein the temperature in Reak¬ gate is controlled so that a lower temperature limit of 600 ⁰ C not lower and an upper temperature limit of 1500 ⁰ C is not exceeded.

4. The method according to any one of the preceding claims, wherein the air ratio λ is one of the liquid fuel (O) and the oxygen-containing gas (L) formed mixture <1.

5. The method according to any one of the preceding claims, wherein the liquid fuel (O) at most 90%, preferably at most 50%, is oxidized.

6. The method according to any one of the preceding claims, wherein the liquid fuel (0) is atomized on entering the reactor (8).

7. The method according to any one of the preceding claims, wherein the reactor (8) before the step lit. b is heated.

8. The method according to any one of the preceding claims, wherein the reactor (8) is preheated by combustion of a mixture formed from the liquid fuel (0) and the oxygen-containing gas (L).

9. The method according to any one of the preceding claims, wherein the reactor (8) is heated by the heat released in the exothermic reaction.

10. The method according to any one of the preceding claims, wherein the reactor (8) with an electric heating element (5) is heated be¬.

11. The method according to any one of the preceding claims, wherein as the heating element (5) the means for increasing the inner surface Ober¬ is used.

12. The method according to any one of the preceding claims, wherein the reactor (8) is heated by supplying a hot gas.

13. The method according to any one of the preceding claims, wherein the temperature of the reactor (8) by an increase or decrease in the temperature of the supplied oxygen-containing gas (L) is controlled.

14. The method according to any one of the preceding claims, wherein the temperature of the reactor (8) by an increase or decrease in the mass flow of the oxygen-containing gas (L) is controlled.

15. The method according to any one of the preceding claims, wherein as the oxygen-containing gas is used air (L) and as a liquid fuel (O) hydrocarbons, preferably light fuel oil or diesel.

16. The method according to any one of the preceding claims, wherein the liquid fuel (0) is injected in response to a predetermined power at a pressure in the range of 3 to 100 bar.

17. The method according to any one of the preceding claims, wherein the liquid fuel (0) is injected at a predetermined clock frequency.

18. The method according to any one of the preceding claims, wherein the means for increasing the inner surface of the fol¬ lowing group is selected: pore body 1, static Mi¬ shear, wire or Fasergewirk or -gestrick or -geflecht, tube assembly, bed, Arrangement of perforated plates.

19. Device for evaporating liquid fuel (O) with a reactor (8), in which a means (1) for increasing the inner surface is accommodated,

a means (4, 2) for supplying liquid fuel (O) and oxygen-containing gas (L) into the reactor (8), and

a means (7) for controlling the temperature of the reactor such that an exothermic reaction between the oxygen-containing gas (L) and the evaporating liquid fuel (0) is feasible so that the liquid fuel (0) is only partially oxidized.

20. The apparatus of claim 19, wherein with the means (7) for regulating the temperature in the reactor (8) is adjustable so that a lower temperature limit of 22O ⁰ C not lower and an upper temperature limit of 1500 ⁰ C is not exceeded.

21. Device according to one of claims 19 to 20, wherein so that the air ratio λ of a liquid fuel from the (O) and the oxygen-containing gas (L) formed mixture <1.

22. Device according to one of claims 19 to 21, wherein a means for atomizing the liquid fuel (O) is hen provided.

23. The apparatus of claim 22, wherein the means for Zer¬ dusts at least one nozzle (11).

24. The apparatus of claim 23, wherein the nozzle (11) is surrounded by an annular nozzle (10) for supplying oxygen-containing gas.

25. The apparatus of claim 24, wherein the annular nozzle (10) is provided with a swirling element (22).

26. The apparatus of claim 25, wherein the annular nozzle (11) and optionally the swirling element (22) in a Mischungsab¬ section (9) of the reactor (8) open, which is arranged upstream of the means for increasing the inner surface.

27. Device according to one of claims 19 to 26, wherein in the mixing section (9) an ignition device (33) is provided for igniting the mixture.

28. Device according to one of claims 19 to 27, wherein an electrical heating element (5) for heating the reactor (8) is provided.

29. Device according to one of claims 24 to 28, wherein the heating element (5) in the annular nozzle (10) or one of Ring nozzle (10) upstream upstream space, preferably an annular space (15) is added.

30. The apparatus of claim 29, wherein the annular nozzle (10) at least partially passes through the space (30).

31. Device according to claim 30, wherein the annular nozzle (10) is surrounded by a thermal shielding device (20, 31) in a section which crosses through the space (30), at least in sections.

32. Device according to one of claims 19 to 31, wherein a reactor housing (12) Bestanteil a heat exchanger through which the oxygen-containing gas (L) is fed to the reactor (8).

33. The apparatus of claim 32, wherein the heat exchanger between a first inner housing (13) and the Re¬ actuator housing (12) formed first annular gap (14) through which the oxygen-containing gas (L) is supplied.

34. The apparatus of claim 33, wherein the first annular channel is connected to the annular nozzle (10).

35. Apparatus according to claim 33 or 34, wherein between ei¬ nem second inner housing (16) and the first inner Ge housing (13) has a second annular gap (17) for discharging a in the reactor (8) formed, the partially evaporated liquid ¬ fuel-containing product is provided.

36. Device according to one of claims 19 to 35, wherein the heating element (5) is the means for increasing the inner surface Ober¬.

37. Device according to one of claims 19 to 36, wherein a means for supplying hot gases to the reactor (8) is vorgese¬ hen.

38. Device according to one of claims 19 to 37, wherein a means (3) for heating the supplied oxygen-containing gas (L) is provided.

39. Device according to one of claims 19 to 38, wherein the means for supplying the oxygen-containing gas (L) comprises a blower (2).

40. Device according to one of claims 19 to 39, wherein at least one sensor (6) for measuring the temperature prevailing in the reactor (8) is provided.

41. Device according to one of claims 19 to 40, wherein the means (7) for regulating the temperature as a function of temperature values measured with the sensor (6) on the basis of a predetermined algorithm, the power of elektri¬'s heating element (5) and / or the means (3) for heating the supplied oxygen-containing gas (L) and / or the blower (2).

42. Device according to one of claims 19 to 41, wherein a device for injecting the Flussigbrennstoffs under a pressure in the range of 3 to 100 bar is provided.

43. Device according to one of claims 19 to 42, wherein a means for injecting the Flussigbrennstoffs is provided at a predetermined clock frequency.

44. Device according to one of claims 19 to 43, wherein the means for increasing the inner surface of one of the following materials is made: ceramic, glass, Binde¬ medium, metal.

45. Device according to one of claims 19 to 44, wherein the means for increasing the inner surface of the fol¬ lowing group is selected: pore body 1, static Mi- shear, wire or Fasergewirk or -gestrick or -geflecht, tube arrangement, bed, arrangement of perforated plates.