LU84057A1 - PROCESS FOR THE EXTRACTION OF JUICE FROM TUBERS, ESPECIALLY TOPINAMBOURS AND INSTALLATION IMPLEMENTING THE PROCESS - Google Patents

Description

r 4 k ç Claim of the priority of a patent application filed in FRANGE, xe April 3, 1981, under N · 81 06 814. *

PATENT

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PROCESS FOR THE EXTRACTION OF JUICE FROM TUBERS, ESPECIALLY TOPINAMBOURS AND INSTALLATION IMPLEMENTING THE PROCESS Invention of Elie C0ND0LI0S and louis BERTHOD

Société Anonyme known as ALSTHOM-ATLANTIQUE

The present invention relates to a process for extracting the juice from tubers, in particular Jerusalem artichokes.

It also relates to an installation for the extraction of juice implementing the process.

5 The need for new energy to replace hydrocarbons leads us to consider the use of energy products extracted from cultivable agricultural products in France and more particularly certain tubers rich in sugar.

* 2.

Among these tubers, the easy-to-grow Jerusalem artichoke with a high yield of sugar-rich products is envisaged for the supply of energy products such as acetone butanol.

In view of the cost of producing the raw material, it is necessary to provide, at the various stages of manufacture, the lowest possible production cost and the highest possible energy product recovery efficiency.

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Processes are known for extracting the juice from the tubers comprising a tubing washing phase, a pre-grinding phase, a grinding phase and a pressing phase.

These processes do not give a good yield of energy consumed / juice production. Furthermore, these are processes whose phases are discontinuous, which increases the operating time due to the need to load and unload the mills and the presses.

An object of the present invention is to provide a process for extracting the juice from the tubers, making it possible to extract almost all of the juice with reduced energy.

Another object of the invention is to define an installation 20 for extracting the juice of tubers, in particular Jerusalem artichoke, implementing the method of the invention, and making it possible, from * soiled tubers arriving from production fields to obtain the maximum amount of clarified juice through a continuous processing chain, to provide oil cake for animal feed and to return to the 25 farmers the topsoil introduced with the tubers into the treatment plant.

3.

The subject of the invention is a process for extracting the juice of tubers, in particular Jerusalem artichokes of the type comprising the following operations: a) a washing phase of the tubers, b) a pre-grinding making it possible to reduce the tubers to particles of dimensions close to the cubic centimeter, b) grinding of a mixture consisting of the preceding elements and of an additional liquid chosen from tuber juice, depleted tuber juice, residue from distillation of tuber juice, washing water tubers, water or a mixture of these liquids, which provides a liquid pulp, c) a pressing of said pulp which provides a primary juice and a primary cake, d) a re-pulping of the primary cake by addition of a liquid, e) a pressing of the preceding pulp which provides a secondary juice and a secondary cake, characterized in that the pre-grinding, grinding, pressing and reshaping of the pulp are carried out continuously .

Advantageously, at least one of the pressing phases c and e 20 is carried out at a temperature between 30 and 50 degrees.

For this, the additional liquid of the mixture of phase b) is brought before its introduction into the mixture at a temperature between 25 and 60 degrees.

The invention also relates to an installation for the ex-traction of the juice of tubers, in particular Jerusalem artichokes, characterized in that it comprises: 4.

- a member for washing the tubers and for storing the washed tubers, - a grinding member of the type chosen from cylinder mills using in particular as grinding filler balls or bars, receiving the washed tubers and providing a pulp, 5 - at least a first pressing device of the helical screw and pressing grid type, and supplying, separately, a primary juice and a primary cake, - a mixing member for receiving the primary cake from the first pressing device and mixing it with a liquid so as to obtain a secondary pulp and at least one second pressing apparatus of the helical screw type and pressing grid receiving said pulp and supplying, separately, a secondary juice and a secondary cake.

The invention will be better understood from the description given below of a preferred embodiment of the invention with reference to the drawing in which FIGS. 1A and 1B represent a schematic view of an installation according to the invention.

In the figure, reference 1 designates a storage yard for tubers which have been harvested and which are surrounded by a tare of earth and stones.

The tubers are taken up by a machine, preferably hydraulic, fed by a basin 13 and a pump 23. The tubers are sent into a channel 3 which feeds a rotary washer 4. The washing operation is important because it must allow to rid the tubers of the earth in order to make them clean without, however, breaking or injuring them, and thus limiting as much as possible the transfer of sugar into the primary washing waters.

At the outlet of the rotating washer 4, the tubers and the dirty water are sent to a cleanser 5 which extracts the gravel and gravels from the ground.

5.

After stone removal, the tubers will be sent on a screen 5 separator-washer 6 which separates the tubers from the primary dirty water and which receives from the basin 13 a certain amount of clear water by the pump 23 to rinse the washed tubers and drain them .

The washed and drained tubers are sent to a feed silo 15 for the grinding part.

The earth-laden water leaving the washing screen 6 is sent to a desanding apparatus 7 which removes, on the one hand, the sands of dimensions less than 0.1 mm as well as the rootlets and other floating materials coming with the tubers.

After desilting, the primary washing water is clarified in a clarifier 8 with the addition of flootant from a station 10.

The earth sludge obtained is compacted to be put in the form of clods of soil by a compactor 9 with the addition of flocculant and additive from stations 10 and 11.

The clods of earth coming from the compactor 9, the sands coming from the sand separator 7 and the gravel coming from the destoner 5 are stored on the earth yard 12 and returned by the trucks which transport the tubers to the producers.

The whole scheme allows operation with practically negligible water consumption.

25 To ensure a controlled process of continuous grinding of the pulp, it is planned to store the tubers in a storage silo 15 6.

with a limited buffer volume in order to obtain the regularity of the flow extracted from this silo and which feeds a pre-grinding member 16, preferably of the cylinder mill type, with splines or pins. After pre-grinding the tubers, the particles are sent to a grinder 17.

5 The grinder is designed to ensure the complete bursting of the pulp of the tubers in order to allow the most complete possible extrusion of the juices. This crusher is preferably of the cylinder crusher type with a grinding charge, in particular balls or bars. This type of mill is chosen because it operates continuously, thanks to the extraction of the ground material with an additional liquid. It receives as indicated below, sweet juice, preferably hot, and possibly a small amount of secondary water moderately loaded with sugar from the secondary pressing from the tank 26 which will be described later.

The ground pulp coming from the mill is optionally reheated in an exchanger 31 and then sent to a stirred buffer tank 19 which feeds, by positive displacement pumps 20, continuous pressing devices 21.

These pressing devices are preferably of the helical screw and pressing grid type. Such an apparatus is described in French Patent No. 8,100,282 of January 9, 1981. This type of apparatus is chosen because of the fact that it operates continuously and has an excellent yield (ratio of the quantity of juice extracted to energy consumed).

25 They allow the hot crushed pulp to be pressed continuously in order to obtain the maximum of clear sweet juice, ie around 70% of the weight in tubers and a primary cake at a dryness of around 70%.

Given the unit flow treated by each device, the number of devices in operation will depend on the solid flow rate of crushed pulp.

7.

The most ooncen-5 very pressing primary sweet juices are sent to a tank 18 and then transferred by the pump 29 to a fermentation-distillation workshop 50. A portion of these juices is optionally returned to the grinder 17.

The cakes leaving the primary presses 21 still contain a certain amount of sweet juice.

10 In order to improve the overall recovery yield, it will be beneficial to process them and, more specifically, to put them back in the form of pulp before subjecting them to a pressing operation.

For this it is planned to take up by the pump 30 a low flow of primary clarified water coming from the tank 13 and to transfer it 15 to a tank 22 in order to re-inflate the primary cake coming from the presses 21 after having reheated it in an exchanger 32.

After rewashing the cake in the mixing tank 22, the pulp is taken up by the positive displacement pumps 24 and sent to pressing devices 25 preferably of the same type as the devices 21.

The second pressing cake is sent by handling means 27 to a drying member for the manufacture, for example, of animal feed.

The secondary sweet juice leaving the presses 25 is collected in a tank 26 and sent either to the mill 17 to be mixed with the pulp of the tubers during the milling after reheating, or to distillation. A pump 33 is arranged for this purpose at the outlet of the tank 26.

, * 8.

This recovery allows an overall juice recovery yield of 92? with a flow rate of primary juices of 10? only.

In order to improve the quality of the secondary meal, the liquid pulp supplying the pressing devices 25 is mixed, by a feed member 40, with the addition of a few? of vegetable fibers. (alfalfa, cellulose fiber, straw, haulm, sawdust).

This addition makes it possible to have a better filterability of the »pulp and to avoid losses of dried material through the grid of the pressing device; moreover, the addition of these fibers improves the quality of the residual meal which is used for animal feed.

The process and the installation which have just been described offer the main advantages: - to offer the best yield (ratio of the quantity of juice extracted to the energy consumed) in particular due to the continuous operation.

15 - to obtain continuously clear sweet juices which will greatly accelerate the fermentation in a production line of acetone butanol or ethyl alcohol at the lowest price with a minimum of manpower exploitation.

- to obtain the best juice recovery yield since with 20 a dilution of the primary juices of the order of 10? the overall sugar recovery yield may reach 92 ?.

- to reduce as much as possible the maintenance costs of production equipment by thorough washing of the tubers before treatment and to return to the operators the soil arriving at the treatment plant.

Claims (5)

* i 9. 1 / Method for extracting the juice of tubers, in particular Jerusalem artichokes, of the type comprising the following operations: a) a washing phase of the tubers, b) a pre-grinding allowing the tubers to be reduced to particles of dimensions close to the cubic centimeter, b) grinding of a mixture made up of the above elements and of an * additional liquid chosen from tuber juice, depleted tuber juice, distillation residue from tuber juice, washing water tubers, water or a mixture of these liquids, which provides a liquid pulp, c) a pressing of said pulp which provides a primary juice and a primary cake, d) a reshaping in the form of cake pulp primary, preferably with addition of a liquid and heating, e) pressing the previous pulp which provides a secondary juice and a secondary cake, characterized in that the pre-grinding, grinding, pressing and reshaping of the pulp are effe ctues continuously. 2 / A method according to claim 1, characterized in that at least one of the pressing phases c and e is carried out at a temperature between 30 and 50 degrees. 3 / A method according to claim 2, characterized in that the additional liquid of the mixture of phase b) is brought before its introduction into the mixture at a temperature between 25 and 60 degrees. 10. t. v 4 / Installation for the extraction of juice from tubers, in particular Jerusalem artichokes, characterized in that it comprises: - a member for washing (4) tubers and for storing washed tubers, - a member for pre-grinding ( 16) receiving the tubers washed and oven-. grinding particles - a grinding member (17) of the type chosen from U ball mills and bar mills, receiving the particles and supplying a pulp, - at least one first pressing device (21) of the helical screw type -. dales and pressing grid, and supplying, separately, a primary juice and a primary cake, - a mixing member (22) for receiving the primary cake from the first pressing device and obtaining a secondary pulp and at least a second pressing device (25) of the helical screw type and pressing grid receiving said pulp and supplying, separately, a secondary juice and a secondary cake. 5 / Installation according to claim 4, characterized in that it comprises a distribution member (40) of plant fibers connected to the inlet of the mixer member. Is