EP0248868A1

EP0248868A1 - Apparatus for the fermentation of liquid products

Info

Publication number: EP0248868A1
Application number: EP19870900163
Authority: EP
Inventors: Lucien Lagrost
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-12-09
Filing date: 1986-12-09
Publication date: 1987-12-16
Also published as: AU6774687A; WO1987003614A1; FR2591230A1

Abstract

Fermenteur comportant au moins une enceinte verticale de fermentation de section sensiblement constante, des moyens pour alimenter la partie inférieure de cette enceinte en jus à fermenter et des moyens pour évacuer le jus fermenté à la partie supérieure. L'alimentation de l'enceinte de fermentation (2) est effectuée sur toute sa section et l'intérieur de ladite enceinte est libre de tout corps pouvant modifier l'écoulement du jus en fermentation.Fermenter comprising at least one vertical fermentation enclosure of substantially constant cross section, means for supplying the lower part of this enclosure with juice to be fermented and means for discharging the fermented juice at the upper part. The fermentation enclosure (2) is supplied over its entire section and the interior of said enclosure is free of any body which can modify the flow of the fermentation juice.

Description

Apparatus for fermentation of liquid products.

The invention relates to an apparatus for the fermentation of liquid products and in particular for alcoholic fermentation.

In this text, the word "fermentation" means any transformation of an organic substance into another organic substance involving ferments or enzymes produced by microorganisms and the word "fermenter" means an apparatus in which s operates a fermentation alco lic or otherwise, that this fermentation is complete or party ^"" and, in the latter case, it corresponds to what _is,;. in fermentation devices called today pre fermenters, fermentors or drop fermenters, that is to say it is located at the beginning, during or at the end of the fermentation process. Among the various known fermentations, alcoholic fermentation is one of the most used. most often done discontinuously in fairly large tanks since they have a capacity of the order of several cubic meters These tanks are filled and emptied periodically, the settled impurities being eliminated at the time o the tanks are emptied.

Since fermentation is a phenomenon involving thermal energy, such tanks must be kept at a suitable temperature. In fact, each ferment used has a very strict temperature range outside of which either the ferment is paralyzed or parasitic ferments, favored. The tanks used in bare discont are therefore generally maintained at temperature by an external watering of the walls or by a partial recycling of the mass in fermentation on an external heat exchanger. The main disadvantage of these tanks is their low yield compared to the large volumes they occupy and the handling they require, the main reasons for the low yield being the impossibility of supplying the tanks with product to be fermented at temperature. optimum closure and the difficulty of maintaining this temperature during fermentation.

There are also tanks in which the fermenta- tion is carried out continuously. They are generally cylindrical tanks, the lower part of which is sometimes conical, in which the juice to be fermented arrives at the upper part, the fermented juice being evacuated at the lower part.

An essential drawback of known tanks with continuous fermentation is the dispersion of the residence time of the particles of the juice to be fermented with respect to the optimum average time. Indeed, taking into account the volumes involved and the great differences in friction that undergo the different particles and the conditions to which they are subjected, and in particular the local currents created by the arrival of the juice to be fermented and the departure of the fermented juice, there are always preferential passages that will be taken by particles which have not dyes the desired degree of fermentation while fermented particles will stagnate at the risk of deteriorating or being victims of parasitic fermentations.

In addition, the solid impurities present in the juice to be fermented and which decant during fermentation can cause, by their accumulation, obstructions of the circuits and, in any case, are a favorite place for parasitic fermentations.

The object of the present invention is to remedy these disadvantages by proposing a fermenter operating continuously in which the passage time is practically identical for all the particles constituting the juice to be fermented, from which the temperature regulation of the mass in fermenta¬ tion can be. very strict and in which all non-fermentable impurities can be removed without the need to stop the fermenter.

It relates to a fermenter comprising at least one vertical fermentation enclosure of substantially equal cross section, means for supplying the lower part of this enclosure with juice to be fermented and means for discharging the fermented juice at the upper part, characterized in that that the fermentation enclosure is supplied on any section and that the interior of said enclosure is. free of bodies that can modify the flow of juice during fermentation. According to a second characteristic of the invention, the the proposed fermenter comprises means ensuring regular cyclic agitation, in the lower part of the enclosure, of the fermenting juice, this agitation being obtainable by cyclic feeding of said enclosure. According to another characteristic, the fermentation chamber is surrounded by at least one chamber in which circulates a liquid serving as a heat exchanger, one or more thermostats which may be provided in the said chamber or chambers. According to another characteristic, the The juice to be fermented is supplied in a box located under the fermentation chamber, the bottom of the box being equipped with means for removing, possibly continuously, the impurities settled during the fermentation process.

In an interesting variant of the invention, several vertical fermentation chambers are arranged, partially to me, in a single chamber in which circulates a liquid intended for regulating the temperature in the fermentation chambers. In this case, a single box can be provided for feeding all the fermentation chambers _; and an advantageous embodiment of the alimenta¬ tion then consists of a mobile distributor with several ties supplying successively all of the fermentation chambers.

Other characteristics and advantages will become apparent from the following description of an example of embodiment, given by way of non-limiting example, of the present invention.

Figure 1 is a vertical section of a fermenter according to the invention. Figure 2 is a horizontal section along II-II of Figure 1.

Figure 3 is a horizontal section along III-II of Figure 1.

The fermenter comprises a closed chamber 1, inside which are arranged thirty vertical cylindrical tubes 2 and arranged in three circular series concentric about an axis 38: a central series of five tubes, a peripheral series of fifteen tubes and a median series of ten tubes.

These tubes 2 are open at their two ends and are braced by three horizontal partitions 3, 4 and 5, the partition 3 being at a certain distance from the upper end, the partition 5, at a certain distance from the end lower and the partition 4 delimiting in the chamber 1 two compartments 40 and 41.

The chamber 1 is surmounted by a box 7 comprising a circular bottom 12 which extends around the chamber 1 and which is inclined towards an outlet chute 6. Furthermore, the said box 7 comprises, laterally and in height, a opening 8 for the evacuation of any foam as well as a pipe 9 connected to a source of anti-foam product. Finally said box 7 is covered by a cover 10 comprising a bent nozzle 11 connected either to the atmosphere or to an apparatus for storing carbon dioxide and a transparent dome 37 provided with lighting.

Chamber 1 carries at its periphery three nozzles 13 arranged at 120 ° under the partition 3, three nozzles 14 also arranged at 120 ° under the partition 4 and two pipes 15 and 16, both opening out in the center of chamber 1, the first above the partition 4, and the second above the partition 5.

A box 17, of frustoconical section, is disposed under the chamber 1, its small base being at the bottom. This small base carries a conical dead body 18 which serves as a support for a rotary feed distributor 39 whose axis of rotation merges with axis 38 around which the concentric series of tubes 2 are arranged.

The rotary feed distributor 39 consists of a vertical pipe 19 rotating in a sealed bearing 20, an enclosure 21 into which the pipe 19 opens and onto which it is welded, and six distribution pipes 22, 23, 24, 25, 26, and 27.

The distance from the axis of rotation of the distributor 39 to the axis of the outlet of the pipe 22 is the same as that of the axis 38 to the central series of tubes 2.

The outlets of the pipes 23 and 24 are diametrically opposite with respect to the axis of rotation of the distributor 29 and the distance from the axes of their outputs to this axis is the same as that from axis 38 to the middle series of tubes 2.

The outlets of the pipes 25, 26 and 27 have an angular spacing of 120 ° over a circumference having for a point situated on the axis of rotation of the distributor 39, the distance from the axes of their outlets to this latter axis is the same as that of the axis 38 to the peripheral tube series In addition, the distributor 39 is designed to be able to occ five angular positions, each of these positions being spaced from its neighbor by 72 ° and being such that the outlet of each pipe 22-27 is located in front of a fermentation tube.

The lower end of the piping 19 is provided with a watertight rotary joint 28 also covering the end of the fixed piping 29 for supplying the fermented juice onto which is stuck a small piping annex 30 re to a source. sterilized air not shown.

The pipework 19 carries a toothed wheel 31 connected by c to the pinion of a geared motor group 32 fixed to an inclined wall of the lower box 17.

A squeegee 33 whose profile corresponds to the internal section of the box 17 is welded to the pipe 27.

The box 17 comprises, at the foot of the conical dead body 1, a circular path 34 onto which opens a pipe 35 comprising a valve 36.

Under these conditions, the operation is established as described below.

The juice to be fermented, previously mixed with suitable microorganisms, in devices which are not designed because they are not part of the invention, arrives in the enclosure 21 of the rotary distributor 39 through the pipes 29 and 19 and is then distributed between distribution pipes

22 to 27.

The juice distributed by each of these pipes passes, for the most part, into the tube 2 opposite which each pipe opens, the rest being diffused in the juice already contained in the box 17.

This results in a slight upward movement and agitation of the fermenting juice in the 2-cons tubes while the part of the juice to be fermented diffused in the box causes only a very reduced upward movement of the mass in fermentation in the other tubes 2, without γ causing agitation. The agitation due to this preferential feeding of certain tubes does not create true turbulence in the masses of juice in fermentation, taking into account that the upward speed of these masses is very low since it is between 0.01 and 0 .07 centimeters per second. After a certain time and according to a pre-established cycle, the geared motor group 32 drives the toothed wheel the rotary distributor 39 in rotation through 72 ° so as to unblock each of the pipes 22 to 27 opposite the neighboring tube , in the direction of rotation of the distributor, of the tube opposite which it previously opened. It is therefore in another series of tubes that the fermenting juice is agitated by a preferential supply from the pipes 22 to 27.

Given that the central series of tubes 2 comprises five for a single distribution pipe 22, that the middle circular series has ten for two distribution pipes 23 and 24 and that the peripheral circular series that includes fifteen for three distribution pipes distribution 25, 26 and 27, after five displacements of 72 °, all the tubes 2 of the chamber 1 received a preferential supply for a certain time, which means that each mass in fermentation was subjected to some agitation. On the contrary, outside this period of agitation, each farmhouse in fermentation undergoes only the very slight upward push due to the part of the food diffusing throughout the box.

The movement towards the upper part of the 2 juice fermentation tubes is not only thanks to the supply at the bottom of the device, but also thanks to the fact that the juice to be fermented which feeds the device has a density stronger than that of the fermented juice discharged at the top, also thanks to the fact that the rise in temperature due to the exothermic nature of the fermenta¬ tion is greater at the beginning than at the end of the fermenta- tion and thanks, finally, to the fact that the bubbles of carbon dioxide gas released during fermentation, rise towards the case 7 to be evacuated by the nozzle 11 and thus promote the upward movement of the juice inside said tubes. The fermented liquid which overflows at the upper part of the tubes 2 in the box 7 flows on the partition 3 at the ends of the tubes 2, before being collected by the inclined f 12 on which it flows to the chute 6 from where i is evacuated. In the event of foam formation, these are evacuated automatically by the nozzle 8, unless they are destroyed by anti-foam product which would have been sent by the line 9.

Depending on requirements, an injection of oxygen in the form of sterilized air can be carried out via the pipe 30 so as to revive the fermentation. At the same time, it increases, lo-rs preferential supplies, gas agitatio and promotes the upward movement in the tubes 2 concerned. Between the periods of preferential feeding, it produces a settling of solid impurities thanks to a certain number of factors, including, the relative tranquility of the medium combined with the decrease in viscosity and density of the juice during fermentation. There is therefore a cyclical alternation between an agitation inside each tube 2 for one fifth of the temp and a rest time for four fifths of the time, making it possible to achieve a balance between a certain beneficial stimulation and a stability necessary for good settling of solid impurities.

Because these tubes are open over their entire section at the bottom, all the impurities fall into the box 17 where they are deposited on its inclined wall or on the wall of the conical dead body 18. The squeegee 33, integral with the piping 27 moves with the latter discontinuously and at very low speed, gathering in the circular path 34 the decanted solid impurities. Each time the squeegee 33 arrives near the nozzle 35 the valve 36 opens so as to evacuate the decanted solid products repelled by the squeegee 33.

At the same time, a temperature regulation system for the tubes 2 operates. For this, a liquid at the desired temperature is sent through the pipes 15 and 16 into the two compartments 40 and 41 of the chamber 1. The liquid entered from the compartment 40 through the piping 15, circulates around the tubes 2 and exits through the outlet nozzles 13 to pass through to a heat exchanger not shown and return to the piping 15 at the desired temperature.

It is the same for the liquid in compartment 41 which circulates around the tubes 2 and leaves through the outlet nozzles 14 to pass through a heat exchanger and return to the piping 16 at the desired temperature.

Given the design in the form of constant section tubes of the fermentation chambers, maintaining temperature is facilitated by the high ratio between the external surface of the chamber and the volume of the latter. For example, for a volume of fermenting juice of 50 m3, one could have a device according to the invention comprising 30 tubes of 0.6 m in diameter / 6 m in height. The exchange surface would be 339 m2, i.e. a surface / volume ratio in m2 / m3 of 6.7. By way of comparison, a conventional cylindrical fermenter of 50 m3 _} 3.50 m in diameter and 5.20 m high would only have an exchange surface of 57.2 m2, ie a surface / volume ratio of 1 , 1.

One sees all the interest for exothermic fermentations of the proposed apparatus: a surface / volume ratio of 1.1 is then insufficient to cool the whole mass in fermentation properly. '

It is understood that it is possible, without departing from the invention, to modify such or such a construction detail or to adopt such an alternative embodiment making it possible to obtain the same results.

For example, the fermentation chambers, instead of being of circular section, could be of polygonal section.

They could also be arranged, no longer in circular series, but in parallel lines and, in this case, the cyclic supply could be carried out with a distributor with linear displacement, alternating or not. A chamber containing the fermentation chambers could be divided into several compartments, each compartment then being able to have its temperature regulated from one or more thermostats arranged in said compartment, possibly on one or the other of the fermentation chambers. . The device for collecting settled solid impurities could be independent of the feed distributor and have its own control.

The cyclic agitation of the fermentation chambers could be obtained by a continuous movement of the rotary distributor 39. It would then be enough a slow rotational speed so that the pipes 22 to 27 can, in their pass in front of the tubes 2, achieve a preferential feeding of these.

Claims

CLAIMS 1) - Fermenter comprising at least one vertical fermentation enclosure of substantially constant cross section, means p supply the lower part of this enclosure with juice to fe ment and means for discharging the fermented juice at the upper part, characterized in that the fermentation chamber (2) is fed over its entire section and the interior of said enclosure is free of any body being able to modify the flow of the fermentation juice. 2) - Fermenter according to claim 1 characterized in that it comprises means (29-19-39,30) for ensuring, in the lower part of the fermentation chamber (Z), intermittent agitation of the fermentation juice .

3) - Fermenter according to claim 2 characterized in that the means ensuring the intermittent stirring of the juice in fermation, are constituted by the means (29-19-39,30) ensuring the supply of juice to ferment.

4) - Fermenter according to claims 2 or 3 characterized in that it comprises means (32-39) ^' ensuring, in the lower part of the enclosure (2) fermentation cyclic agitation of the juice in fermentation.

5) - Fermenter according to one of the preceding claims, characterized in that the fermentation enclosure (2) is open, over its entire section at its lower part. 6) - Fermenter according to one of the preceding claims, characterized in that it comprises several fermentation chambers (2) grouped, surrounded, at least over part of their height, by at least one chamber (40,41) receiving a l the heat exchanger. 7) - Fermenter according to claim 6 characterized in that q the fermentation chambers (2) are arranged in concentric circular series in a cylindrical chamber (40,41) for temperature regulation.

8) - Fermenter according to claim 7 characterized in that it comprises several distribution pipes (22 to 2 ensuring the supply of juice to be fermented, these pipes being rotatably mounted on an axis coincident with the axis around which are arranged the series of fermentate speakers (2) 9) - Fermenter according to claim 8 characterized in that each circular series of fermentation chambers (2) beyond the central series comprises a number of fermentation chambers constituting a multiple of the number of fermentation chambers of the series central, the number of distribution pipes (22 to 27) serving each of these ser being equal to this multiple number.

10) - Fermenter according to one of claims 6 to 9 characterized in that it comprises a lower box (17) of inverted frustoconical profile with a conical central dead body (18) and a scraper (33) driven in rotation by the distribution system for supplying (39) juice to be fermented, the said box comprising at its lower part means (36) for discharging the sludge which accumulates therein.