Distillation device by direct heating at the heart of the liquid to be distilled, energy-efficient and with low GHG emissions

Abstract

Distillation device by direct heating at the heart of the liquid to be distilled, energy-efficient and with low GHG emissions. Double distillation of alcohols is very energy-intensive. The subject of the invention is a distillation heating device by direct heating for a boiler 10 containing a liquid 23 comprising, depending on the size and use of the boiler 10, a certain number of tappings 26 made through the walls of the boiler and distributed around its periphery and on several horizontal levels, for example between levels 30 and 40, 40 and 40, 50 and the bottom of the boiler, electric immersion heaters, for example 31.1, 31.2, 41.1, 41.2, 51.1, 51.2, mounted in each tapping 26 and electrically connected to a power and control cabinet controlling the individual electrical supply of each immersion heater according to a defined heating program. Figure to be published for the abstract: [Fig 3]

Description

Title of the invention: Distillation device by direct heating at the heart of the liquid to be distilled, energy-saving and with low GHG emissions

[0001] The technical sector of the present invention is that of the distillation of alcohols.

[0002] State of the prior art: The distillation of spirits has existed since the Middle Ages. The tools and processes have gradually improved empirically over time to arrive at the so-called Charentais stills used today, among other places, in the Charentes region of France, Scotland and Ireland. All the stills used throughout the world to distill alcohols are entirely made of copper because this material is easy to form, an excellent heat conductor and, as demonstrated empirically over time, this material, in contact with the alcohol vapors during the flows, reflux in the boiler and then condensation in the coil, transforms and / or eliminates the sulfur and oil components which are undesirable from an organoleptic point of view.

[0003] As described in patent FR3117042A1 among others, the general principle of making a Charentais still is visible in [Fig.l] and comprises a boiler 10 configured to contain a liquid to be distilled 23, a gas burner 11 arranged under the boiler 10, a fire tower 12 integrated into the block 18 surrounding the boiler and configured to evacuate the burnt gases resulting from the combustion towards an evacuation conduit 13, a capital 14 surmounting the boiler 10 at the level of which condensation and reflux phenomena take place, a swan neck 15 collecting the alcohol vapors leaving the capital 14 and conveying them towards a coil 17 positioned in a cooling pipe 16 containing water 22 to condense the alcohol vapors into distillate 24 collected in the alcohol meter holder 20.The widely used device for preheating wines recovering calories around the piping connecting the swan neck 15 to the refrigeration system 16 allowing the wines to be preheated to 45-50°C upstream of the boiler load is not shown.

[0004] In simplified terms, for the production of Cognac brandy known as double distillation, the first pass distills wines containing 8 to 12% ethanol (TAV - Alcoholic Strength by Volume) to produce a brouillis containing 28 to 32% ethanol. This brouillis distilled during the second pass will become a brandy with a TAV of around 70% ethanol.

[0005] This is the very significant difference in the latent heat of vaporization of ethanol (843 KJ / Kg at 78.3°C) with that of water (2,257 KJ / Kg at 100°C, therefore higher than this value at 78.3°C) which makes distillation particularly effective for distilling alcohols.

[0006] In simplified terms, the heating curve begins with heating at maximum intensity for 1h30 to 2 hours (depending on whether heating wine preheated to 45°C or cold brouillis), then, when the first alcohol vapors pass through the swan neck, the heating intensity is reduced to 25% until the cut (brouillis tails at 8% TAV which will be mixed with the following wine batches, seconds at 30% TAV which will be mixed with the following brouillis batches and eau de vie tails at 8% TAV which will be mixed with the following wine or brouillis batches) to return to 100% heating intensity to finish extracting as much as possible the remaining ethanol present in the tails and the seconds which will be redistilled with the next batches of wine or brouillis according to the protocol followed.The vinasse remaining at the bottom of the boiler (65% of the initial wine charge, 45% of the initial brouillis charge) containing less than 2% ethanol is emptied to be cooled and treated.

[0007] Cutting is the term used to designate the action of changing the destination of the distillate from one container to another according to its ethanol TAV read on the alcoholometer of the alcoholometer holder 20.

[0008] Instead of a constant level of low heating intensity until the cut, some distilleries choose to gradually increase the heating intensity, for example from 25% to 60% just before the cut since, although the volume in the boiler decreases gradually, the latent heat of vaporization of the binary in the boiler increases over time with the progressive reduction of the TAV linked to the distillation process.

[0009] Problems related to heating wines and brouillis:

[0010] The energy-intensive nature of double Charentaise distillation is therefore explained by the principle of discontinuity of distillation which intrinsically generates significant losses of calories due to the need to heat and then cool each load.

[0011] Furthermore, the only insulation of the boilers is carried out in a suboptimal manner on the lower two thirds of the boiler by the refractory or non-refractory components surrounding the walls and making up the block 18, the upper third of the boiler 10, the capital 14, the swan neck 15 and the piping connecting it to the coil 17 of the cooling pipe 16 not being insulated.

[0012] At the same time, as almost all of the Charente stills in the Cognac AOC are mainly heated by propane gas, each annual distillation campaign emits some 170,000 tonnes of CO2 to produce approximately 1 million HLAP (hectolitres of pure alcohol).

[0013] Existing solutions:

[0014] Addressing the first two issues cited, various improvements have been thought of and some tested over the years as in the following significant but non-exhaustive list of patents:

[0015] FR2620729A1, lateral chamber for circulation of hot burnt gases in contact with the boiler walls.

[0016] FR3033026A1, improved gas burner.

[0017] FR3033025A1, 2-stage fire tower to better recirculate burnt gases around the boiler.

[0018] FR3033027A1, fire tower with reinforced insulation.

[0019] FR3073524A1, improved fire tower.

[0020] FR3096902A1 distillation boiler equipped with at least one bi-material wall.

[0021] FR3117042A1 and EP3747522A1, distillation device with reduced energy consumption.

[0022] FR2970479A1, Energy transfer apparatus for distillation stills of alcohol.

[0023] US2017312649A1 and WO2016066622A3, Distillation System.

[0024] Concerning the third problem cited, in order to take into account the obligations linked to the objectives of reducing GHG (Greenhouse Gas) emissions by 2050, the BNIC (National Interprofessional Cognac Bureau) associated with the INAO and two major AOC Cognac houses has been interested in finding an alternative heating method to gas, a net emitter of GHG, from 2018. The heating method chosen for this exploratory work is a device operating by external steam loop in a heat exchanger. Schematically, the liquid to be brought to a boil (wine or brouillis depending on the pass) is put into continuous circulation and adjustable in flow from the bottom of the boiler to a liquid / saturated steam exchanger (from a steam generator) before returning to the boiler.

[0025] Several test campaigns were thus conducted in order to demonstrate that the heating of the stills, mainly with gas over an open flame, could be replaced by external heating, for example by a saturated steam loop without modifying the organoleptic qualities of the eaux-de-vie produced (experiments conducted in the laboratory and in two distilleries for the scale 1 tests during the 2020-2022 distillation campaigns). The favorable results of this experiment thus open the way to the replacement of gas by electrical energy (to heat the steam plant) by authorizing the next modification of the specifications of the AOC Cognac removing the obligation of heating the boilers over an open flame.

[0026] Note that this device does not appear to have been the subject of a patent application, this technique, in this form or another, being used very widely more or less identical in Scotland for the double distillation of whiskies since the sixties.

[0027] Given that the electricity supplied in France is highly decarbonized, converting the heating of the entire fleet to electric to supply steam power plants would only generate 6,000 tonnes of CO2 per year (according to ADEME data based on an onshore wind / nuclear mix), i.e. a 27-fold reduction in GHG emissions compared to heating open-fire gas boilers.

[0028] This device (external heating loop by steam generator) does not, however, offer any reduction in the energy consumed in KWh per hectolitre of pure alcohol (KWh / HLAP) produced since, even if this device allows insulation to be applied to the external walls of the boiler to avoid heat losses in the surrounding mass, the efficiency of the steam generator and the additional energy required for the continuous circulation of the water / ethanol binary between the boiler and the heat exchanger compensates for this gain.

[0029] The additional (but marginal) advantage of heating by external steam loop is to extend the life of the boilers which is conditioned among other things by the progressive reduction in the thickness of its bottom due to gas heating by naked flame directly under the boiler and the frequency and intensity of internal cleaning of residues from Maillard reactions (in particular for the distillation of wines with lees).

[0030] On average in the AOC Cognac, it is still necessary to consume some 600 KWh of heating energy to produce 1 hectolitre of pure alcohol (HLAP) despite the material and process developments made over many years, mainly in terms of insulation of hearths, optimisation of gas burners, improvement of fire towers, preheating of wines, optimisation of heating curves.

[0031] The energy cost of heating represents 35 to 45% of the production cost depending on the distillery.

[0032] Criticism of the prior art:

[0033] The improvements described in patents FR2620729A1, FR3033026A1, FR3033025A1, FR3033027A1, FR3073524A1 were able to bring about consumption gains of the order of 15% maximum according to our assessment when applied jointly on a new installation. Considering the entire existing fleet, the implementation of one or more of these improvements, however, involves carrying out significant work to rework the blocks surrounding the boilers, which has a significant impact on costs and thus proportionally increases the return on investment, hence the low number of conversions.

[0034] Proposing to go further, patents FR3117042A1 and EP3747522A1 together with the techniques described in patent FR3096902A1 propose various solutions for heating either the external walls of the boiler or by circulating the liquid to be heated in an external loop through a heat exchanger, each type of solution being able to operate together, independently or alternately during a complete heating cycle. Furthermore and in a similar manner, US2017312649A1 and WO2016066622A3 propose recovering the energy available from the water leaving the condenser in the form of steam by means of a liquid / steam separator and one or more heat exchangers to use it to heat the boiler load and reinject the water thus cooled into the condensation system.

[0035] The solutions for heating the external walls of the boiler are achieved either by means of the circulation of a heat transfer fluid from a heat exchanger within pipes fixed to the outside of the walls or by electromagnetic induction using a solenoid fixed to the outside of the walls surrounding the boiler, each of these two solutions being able to operate together, independently or alternately depending on the availability of the primary heat sources throughout each cycle and according to requirements.

[0036] The heating solutions by external circulation of the liquid to be heated are those validated by the experiments conducted during the test campaigns conducted by the BNIC described in

[0024] and

[0025] improved mainly in that the heat exchanger can be a very high temperature heat pump on the one hand and that the second heat transfer fluid used in the heat pump can be the hot water 22 coming from the cooling pipe 16, thus recovering the unused thermal energy.

[0037] The solutions for heating the external walls of the boiler involve, in their implementation, profound structural modifications to the boiler which are difficult to envisage on an existing boiler and can therefore only reasonably be envisaged on new boilers, greatly reducing its scope of application in consideration of the real need for renewal of the fleet (boiler lifespan greater than 50 / 60 years) and the obstacle linked to the very high price of new boilers.

[0038] More generally, achieving a significant reduction in energy consumption targeted by patents FR3117042A1 and EP3747522A1 involves a long development and complex operational control of the heating process according to the need and the availability of the various primary heat sources.

[0039] Finally, patent FR2970479A1 claims a very significant reduction in heating energy consumption but is based, among other things, on the principle of cascade operation of a boiler operating under pressure with a boiler operating under vacuum, principles inapplicable to existing boilers in due to their structural construction in terms of wall thickness versus the pressure and vacuum constraints inherent in the patent.

[0040] None of the listed heating solutions, applied separately or jointly, responds quickly, validly and effectively to the need for a significant joint reduction in energy consumption and GHG emissions within the framework of a rapid return on investment for distillers on the existing fleet of stills.

[0041] Description of the invention: The present invention relates to a distillation device by direct heating of the liquid to be distilled inside the boiler with the aim of significantly reducing both greenhouse gas emissions and energy consumption during the distillation process while retaining at least the organoleptic qualities of the distillate sought and specific to each Cognac house thanks to fine control of the heating curves.

[0042] This device in all its embodiments only involves minor modifications to the existing boilers without major structural modification, thus providing a concrete solution with a rapid return on investment applicable to the entire existing still fleet.

[0043] This device in all of its embodiments is also directly applicable to the manufacture of new boilers.

[0044] Other features and advantages will appear in the detailed description which follows the five non-limiting examples of embodiments of the invention illustrated by [Fig.2] to [Fig.9] placed in the appendix and in which:

[0045] [Fig. 1] is a schematic representation of a distillation device illustrating an embodiment of the prior art.

[0046] [Fig.2] is a vertical section of part of the boiler with its insulation thermal diagram illustrating the detail of an embodiment of the present invention of a tapping and the mounting of an immersion heater in this tapping.

[0047] [Fig.3] is a schematic representation (vertical section and horizontal section) of the general principle of installation of immersion heaters on a boiler which illustrates a first embodiment of the present invention.

[0048] [Fig.4] is a schematic representation (vertical section and horizontal section) of the installation of immersion heaters on a mixed boiler (distillation of wines and brouillis) which illustrates a second embodiment of the present invention.

[0049] [Fig.5] is a schematic representation (vertical section and horizontal section) of the installation of immersion heaters on a boiler dedicated to the distillation of wines which illustrates a third embodiment of the present invention.

[0050] [Fig.6] is a schematic representation (vertical section and horizontal section) of the installation of immersion heaters on a boiler dedicated to the distillation of brouillis which illustrates a fourth embodiment of the present invention.

[0051] [Fig.7] is a schematic representation (vertical section and horizontal section) of the installation of immersion heaters on a boiler dedicated to the distillation of brouillis which illustrates a fifth embodiment of the present invention.

[0052] [Fig.8] is a representation of an example of heating sequences for each immersion heater on a combination boiler during a complete distillation cycle of a wine batch preheated to 45°C which illustrates an embodiment of the second embodiment of the present invention.

[0053] [Fig.9] is a representation of an example of heating sequences for each immersion heater on a combination boiler during a complete distillation cycle of a 10°C mash feedstock which illustrates one mode of use of the second embodiment of the present invention.

[0054] The present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment or any other mode of use in an advantageous manner.

[0055] The general principle of the present invention is based, firstly, on the observation that heating a liquid such as water to boiling point using an immersion heater at the heart of the liquid is on average up to 2.5 times faster and consumes up to 2.75 times less energy than heating the container at its base depending on the shape and materials of the container.

[0056] In the case of distillation, the liquid to be heated is mainly a binary water-ethanol mixture, which we will retain in the thermodynamic sense since distillation is fundamentally based on this physical principle. Note that the other constituents which are present in very small quantities are essential because they are what make up the bouquet of eaux-de-vie.

[0057] The physicochemical characteristics of the water-ethanol binary have been studied many times on a theoretical level and tested in the laboratory due to the simplicity of access and implementation of this mixture, hence a profusion of theses and reports of work available in the literature.

[0058] In summary, water and ethanol are two solvents that come together by mixing with a strong bond between the two molecules (1 volume of water mixed with 1 volume of ethanol gives 1.92 volumes instead of 2 volumes), hence a particular liquid-vapor phase diagram that allows the ethanol to be efficiently split from the water.

[0059] Furthermore, another unique feature of the water-ethanol binary is that its thermodiffusion coefficient (Ludwig-Soret effect) changes sign around 14% ethanol concentration. The consequence of this change of sign is that with an increase in the temperature of the binary, the heavier solute will migrate towards the hotter regions when the coefficient is negative (below 14% ethanol concentration) and conversely towards the colder regions when the coefficient becomes positive (above 14% ethanol). This Soret effect, combined with the effects of natural convection (thermoconvection) linked to heating, allows for even better separation of the constituents of the binary.

[0060] As a reminder, the double distillation known as Charentaise consists of:

[0061] A first pass distilling wines containing 8 to 12% ethanol to produce a brewing process containing 28 to 32% ethanol. During this cycle, the wine in the boiler will gradually go from a TAV of 8-12% to a TAV of 1.5% (vinasse). The Ludwig-Soret coefficient of the water-ethanol binary is therefore negative throughout the cycle.

[0062] The brew distilled during the second pass will become a brandy with a TAV of around 70% ethanol. At the start of the second pass cycle, the brew contains 28-32% ethanol and ends at the end of the cycle with a TAV of 1-1.5% ethanol (vinasse). During this cycle, the Ludwig-Soret coefficient is therefore positive up to approximately the cut (TAV distillate 60%) and then becomes negative until the end of the cycle.

[0063] It is these particular characteristics of the Ludwig-Soret effect (thermodiffusion) that the present invention exploits in combination with a modularity of installation and operation of the heating points at the heart of the volume of liquid to be heated in the boiler which makes it possible to optimize energy consumption and to control convection phenomena within the mass of liquid to be heated.

[0064] The combination of thermodiffusion and thermoconvection phenomena exploited by the present invention is called thermogravitational diffusion in the scientific literature. The optimization of thermogravitational diffusion aims to improve the separation of species (ethanol and water) in order to favor the evaporation of ethanol during each part of each distillation cycle of wines (first pass) and brouillis (second pass).

[0065] The first advantage of the present invention is to divide by up to 2 the energy consumption necessary for the production of eau de vie by direct heating at the heart of the liquid to be distilled inside a correctly thermally insulated boiler 10 and to reduce by a factor of 25 to 30 the emission of GHGs by using electricity as primary heating energy.

[0066] The second advantage of the present invention, beyond the energy saving provided by the direct heating at the heart of the liquid to be distilled, is either to optimize the energy devoted to the evaporation of the ethanol (separation of the species) by increasing the ethanol TAV of the distillates or to shorten the cycle times in order to further reduce the energy required for the entire distillation process or to combine the two according to the characteristics desired by the distiller.

[0067] According to a first embodiment illustrated in [Fig. 3], the boiler 10 is fixed on a metal supporting structure 35 with a walkway (not shown) around the perimeter and its means of access from the ground for maintenance and servicing operations for example. Illustrated in the partial section [Fig. 2], the boiler 10 is entirely equipped with thermal insulation 27 on its bottom and its external walls up to the lower part of the top in order to reduce heat loss as much as possible.

[0068] As illustrated in [Fig. 3], the tappings 26 are located around the perimeter of the boiler 10 on at least 2 levels or even at least 3 levels depending on the capacity of the boiler. The upper level 31 of the tappings is located between level 30 (boiler load level, for example 13H1 for a 15H1 boiler) and level 40 (wine stillage level at the end of the first pass), the intermediate level 41 of the tappings is located between level 40 (wine stillage level at the end of the first pass) and level 50 (broiled stillage level at the end of the second pass) and the lower level 51 of the tappings is located between level 50 (broiled stillage level at the end of the second pass) and the bottom of the boiler.

[0069] The reason for the existence of at least 2 or even at least 3 implantation levels is the progressive drop in the level of liquid to be distilled (up to 60% of the initial height for the first pass, 45% for the second pass) during the distillation cycle. Preferably, the lower level or even the 2 lower implantation levels are located below the lowest level line of residual vinasse (that of the second heating for a boiler which successively distills wines and brouillis).

[0070] [Fig.2] illustrates an embodiment of the installation of a tapping 26 through the wall of the boiler 10 which receives an immersion heater 25. The immersion heater 25 is for example a screw-on model or, preferably, a flanged model in order to allow rapid disassembly and reassembly during cleaning operations of the boiler and the immersion heaters.

[0071] [Fig.3] illustrates the general principle of installation of immersion heaters according to an embodiment of the present invention on a boiler 10 with 6 immersion heaters on the 3 levels distributed as follows:

[0072] The upper level 31 receives the immersion heaters 31.1 and 31.2 in opposition, the intermediate level 41 receives the immersion heaters 41.1 and 41.2 in opposition and offset by 90° with respect to 31.1 and 31.2, the lower level 51 receives the immersion heaters 51.1 and 51.2 in opposition and offset by 90° with respect to 41.1 and 41.2.

[0073] The offset of the immersion heaters from one level to another according to other embodiments can be 90°, 45° or 30° or any other angular offset. Each tapping 26 receiving an immersion heater 25 is located either on a horizontal axis, or on an axis perpendicular to the wall of the boiler 10 at the location of the drilling of the wall of the boiler 10, or on an axis located at any angle inside a cone of 60° angle centered on the axis of the perpendicular drilling of the wall of the boiler 10.

[0074] According to the configuration previously stated, each tap receives an electric immersion heater with a power defined according to the capacity of the boiler, the total number of immersion heaters used and its installation in each level (the nominal powers of the immersion heaters of the same level are preferably identical). Each immersion heater can be equipped with at least 1 integrated temperature sensor in the immediate vicinity of the tubular heating elements or even 2 temperature sensors, one above, the other below the tubular heating elements.

[0075] The immersion heaters are electrically connected to a power cabinet (not shown). This power cabinet is connected to the distillery's power supply and to a control cabinet (not shown) to control the distribution of power to each immersion heater according to the heating program defined as a function of the progress of the cycle, the type of cycle (first heating or second heating) and the information coming from the various temperature and level probes installed on the immersion heaters and on the boiler.

[0076] [Fig.3], [Fig.4], [Fig.5], [Fig.6] and [Fig.7] each illustrate an example of a configuration mode for installing the tappings 26 and their immersion heaters 25 on a boiler 10.

[0077] [Fig.8] and [Fig.9] each represent an example of immersion heater power supply sequences.

[0078] [Fig.8] represents an example of sequences for supplying the immersion heaters of the mixed boiler according to a second embodiment illustrated [Fig.4] during a distillation cycle of a load of wine preheated to 45°C (first heating).

[0079] [Fig.9] represents an example of sequences for supplying the immersion heaters of the mixed boiler according to the second embodiment illustrated [Fig.4] during a distillation cycle of a mash load at 10°C (second heating).

[0080] The boiler according to the second embodiment illustrated [Fig.4] is called mixed because it is configured in terms of the location of the immersion heaters to be used both for first heatings and for second heatings.

[0081] For the readability of [Fig.8] and [Fig.9], the heating step of each immersion heater is of a fixed duration of 10 minutes, the heating stop step is of a fixed duration of 10 minutes and each immersion heater heating is set at 100% of the immersion heater's rated power.

[0082] On [Fig.8] and [Fig.9], superimposed on all the power supply sequences of the 8 immersion heaters, there is the total instantaneous power curve in 10-minute steps in thin line and in bold line, the total instantaneous power curve averaged in 60-minute steps (moving average of the previous one).

[0083] The immersion heater power supply sequences of [Fig.8] and [Fig.9] describe the general principle of heating. Operationally, the optimization of the thermogravitational diffusion effects according to what the distiller wishes to obtain in order to act on the parameters, such as, for example, cycle duration, distillate flow rate, distillate TAV or even organoleptic quality of the distillate, requires at least the use of heating sequences for each immersion heater with shorter fixed or variable steps, for example 5 minutes, preferably between 3 and 9 minutes, and heating intensities that can be fixed or variable, preferably between 10% and 100% of the nominal power of each immersion heater.

[0084] At the beginning of the first heating cycle described in [Fig.8], phase 1 of boiling the wine, only the lower and intermediate level immersion heaters 41.1, 41.2, 51.1, 51.2, 51.3, 51.4 are supplied at 100% and in phase shift in order to avoid local overheating points and thus minimize Maillard reactions which are harmful from an organoleptic point of view. This way of proceeding is particularly important in the case of the distillation of wines with lees due to the presence of solid particles which are not necessarily at the bottom of the boiler after loading.

[0085] After approximately one hour of heating, the immersion heaters 31.1 and 31.2 of the upper level are powered and the power supply to the immersion heaters 51.1, 51.2, 51.3, 51.4 of the lower level is gradually cut off.

[0086] As soon as the first vapors appear at the swan neck 15 (detected by the thermocouple 29 downstream of the swan neck), phase 2 of pouring the mist distillate begins.

[0087] During this phase 2, the instantaneous power is reduced.

[0088] Then, throughout phase 2, the total instantaneous power is very gradually increased to take into account the increase in the proportion of water in the liquid to be distilled (decrease in the ethanol TAV) and when the liquid level approaches the upper part of the upper level immersion heaters 31, the immersion heaters 31.1 and 31.2 cease to be supplied. The final instantaneous power required of 100% to complete the cycle is delivered by the immersion heaters 41.1, 41.2, 51.1, 51.2, 51.3, 51.4 still in the liquid.

[0089] Phase 2 ends when the distillate TAV falls below 6 to 8% ethanol with the cutting of the mash. During phase 3 of pouring the tails, the supply of immersion heaters 41.1, 41.2, 51.1, 51.2, 51.3, 51.4 is maintained.

[0090] Phase 3 ends when the TAV of the distillate falls below 2% ethanol and the power supply to the immersion heaters 41.1, 41.2, 51.1, 51.2, 51.3, 51.4 is then cut off.

[0091] The wine stillage is then discharged from the boiler.

[0092] At the start of the second heating cycle described in [Fig.9], phase 1 of boiling the brouillis, the immersion heaters of the lower level and the intermediate level 41.1, 41.2, 51.1, 51.2, 51.3, 51.4 are supplied at 100% and in phase shift, then the immersion heaters of the upper level 31.1 and 31.2 are gradually supplied. The supply of all the immersion heaters is necessary in this phase because, although the sensible heat of the brouillis is lower than that of the wine, the brouillis is loaded into the boiler at a temperature of 10°C (pouring and storage temperature).

[0093] As soon as the first vapors appear at the swan neck 15 (detected by the thermocouple 29 downstream of the swan neck), phase 2 of pouring the brandy distillate begins.

[0094] At the start of this phase of pouring the brandy, the instantaneous power is reduced to approximately 25% of the instantaneous power of the previous phase by cutting off the power supply to the immersion heaters 51.1, 51.2, 51.3, 51.4 of the lower level of the boiler 10.

[0095] Throughout this phase 2, the total instantaneous power is kept approximately constant in order to favor the regularity of the distillate flow rate, a critical factor in the organoleptic qualities of the brandy. When the level of the mash in the boiler approaches the upper part of the immersion heaters 31.1 and 31.2, the latter cease to be supplied and the total instantaneous power is kept constant by increasing the use of the immersion heaters 41.1 and 41.2 increased according to the need for the supply sequence of the immersion heaters of level 4L

[0096] When the TAV of the distillate passes the 60% mark, the cut occurs which switches the destination of the distillate from the brandy tank to the steam tank for the seconds.

[0097] As soon as the cut is made, phase 3 of casting the seconds begins. The total instantaneous power is increased to take into account the increase in the proportion of water in the liquid to be distilled (drop in the ethanol TAV) and, quickly, when the liquid level approaches the upper part of the immersion heaters of the upper level 41, the immersion heaters 41.1 and 41.2 cease to be supplied. The power final instantaneous heat of 100% required to complete the cycle is delivered by immersion heaters 51.1, 51.2, 51.3, 51.4 still in the liquid.

[0098] Phase 3 ends when the distillate TAV falls below 6 to 8% ethanol with the second cut. During phase 4 of pouring the tails, the supply of immersion heaters 51.1, 51.2, 51.3, 51.4 is maintained.

[0099] Phase 4 ends when the TAV of the distillate falls below 2% ethanol and the power supply to immersion heaters 51.1, 51.2, 51.3, 51.4 is then cut off.

[0100] The brewed vinasse is then discharged from the boiler.

[0101] Some home-made distilleries (distillers who only distill their own wine harvest) have only one still which operates according to the following sequence: 2 or 3 first heatings then 1 second heating and so on. This so-called mixed boiler therefore has two separate immersion heater supply curves, one for the first heatings and another for the second heatings without any other modification. This configuration is illustrated in [Fig.8] and [Fig.9] in a second embodiment of the heating sequences.

[0102] In this embodiment, the boiler has a capacity of 15H1 and is equipped with 8 immersion heaters of 12 KW of unit nominal power distributed over the 3 levels 31, 41 and 51 according to an installation mode illustrated in [Fig.4].

[0103] Those skilled in the art will easily understand the multiple possibilities offered by the present invention concerning both the extreme diversity of choices in the installation of the immersion heaters in a boiler, their nominal power and in the organization of the heating sequences according to the size of the boiler, its mode of use and the performances desired by the distiller constituting as many other embodiments. [Fig.5], [Fig.6] and [Fig.7] present some examples of other embodiments of the installation of the immersion heaters which illustrate the potential extent of the possibilities offered by the present invention.

[0104] As a reminder, the way in which the feed sequences are defined can also be advantageously linked to the ideal combination of thermodiffusion (Ludwig-Soret effect) and the induction of natural convection in the volume of liquid to be distilled, a combination called the thermogravitational process. Optimizing the effects of the thermogravitational process in order to increase either the TAV of the distillate or to reduce the duration of certain phases of the cycle, or a combination of both, is obtained by acting on the relative feed sequences of the immersion heaters per level and per immersion heater. This spatial and temporal modulation of the power delivered to the liquid to be distilled is usefully and mainly applied during phase 2 of the first heating and during phases 2 and 3 of the second heating, as are many other embodiments.

[0105] Each immersion heater feed sequence is therefore defined in relation to the others mainly as a function of the architecture and dimensions of the boiler, the nature of the liquid to be distilled (wine without lees, with lees, brouillis), the organoleptic qualities of the distillate, the flow rate of the distillate and the desired cycle durations. Each boiler can therefore operate with its own feed sequences predefined and programmed in the control device.

[0106] Furthermore, if the distiller who distils on a contract basis (distillation on behalf of a client winegrower) distils for clients with different expectations, he can use specific families of feed sequences for each.

[0107] Finally, those skilled in the art will appreciate that the technical characteristics of the present invention and the flexibility of its operating modes are directly and simply applicable to any device for distilling wines, beers, molasses or any other more or less alcoholic liquid, whatever the shape or size of the container used for heating the distillation of these liquids, both for double distillation and for continuous column distillation or even for vacuum distillation.

Claims

Claims

1. Distillation heating device for a boiler 10 containing a liquid to be distilled 23 comprising, depending on the size, capacity, shape and use of the boiler 10, a certain number of tappings 26 made through the walls of the boiler 10 and distributed around its periphery and on several horizontal levels, identical or different immersion heaters 25, of the screw-in or flange type, mounted in each tapping 26, a power cabinet and a control cabinet connected to each of the temperature and level probes installed on the immersion heaters and on the boiler controlling the individual power supply of each immersion heater 25 according to a heating program defined as a function, among other things, of the evolution of the heating cycle, the type of cycle (for example, first or second heating), the duration of the cycle, the type of liquid to be distilled, the flow rate of the distillate,the desired organoleptic qualities of the distillate and according to the information coming from the temperature and level probes installed on the immersion heaters and on the boiler.,

2. Distillation heating device according to claim 1, characterized in that each tapping 26 is located either on a horizontal axis, or on an axis perpendicular to the wall of the boiler 10 at the location of the drilling of the wall of the boiler 10, or on an axis located at any angle inside a cone of 60° angle centered on the axis of the perpendicular drilling of the wall of the boiler 10.

3. Distillation heating device according to claim 1 or claim 2 characterized in that the energy supplying the immersion heaters is electric.

4. Distillation heating device according to claim 1 or claim 2 characterized in that the immersion heaters are of the tubular exchanger type and the energy supplying the immersion heaters is a flow of heat transfer fluid.

5. Distillation heating device according to any one of the preceding claims characterized in that the external walls of the boiler 10 are externally equipped with thermal insulation plates up to the area directly below the base of the capital 14.

6. Method of operating the distillation heating device according to any one of the preceding claims, characterized in that, depending on the progress of the heating cycle and the need to optimize the thermogravitational diffusion effects at each stage of the progression of the cycle, the immersion heaters 25 are supplied with energy individually, together or sequentially with respect to each other for supply durations which are fixed or variable and with supply intensities which can be modulated up to 100% of their nominal capacity.

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