EP0952229B1 - Process and apparatus for producing beet marc - Google Patents

Abstract

In the production of sugar beet juice, slices of washed sugar beet are continuously fed into a mashing station (24) in which a first constant temperature is maintained in the range 75 to 95 degrees C. The beet slices pass through the mashing station (24) forming a pumpable mass which is then discharged to a cooking tank (30) maintained at a second higher temperature of preferably 105-106 degrees C. Following cooking, liquid is drained from the mashed sugar beet. The liquid is then thickened to preferably 78 Brix. Also claimed is a suitable assembly.

Description

The invention relates to a method for producing beet weed starting from washed sugar beet pulp and to a device therefor.

Beet herb is a product made from fresh, boiled and pressed sugar beet. The dry content is typically around 78 Brix. The pH is between 4.6 and 4.7. According to the prior art, beet herb is produced in batches. The beets, which are roughly finger-thick slices, are cooked in so-called beet steamers. A number of such dampers are usually available. By adding water, the spaces between the chips are filled, and by adding water, the density of the juice that runs off after cooking is also influenced. The beet pulp and the water in the beet steamer are heated by introducing superheated steam. After about an hour and the cooking temperature has been reached, the steam supply is reduced. If the temperature remains the same, the cutlets remain in the cooking container for about ten hours.

The cells are broken down by the cooking temperatures. Sugar and not sugar substances and water are released. Sugar beets usually have a sugar content of about 16% to 18% sucrose. This would crystallize into granulated sugar in the later finished product. However, temperature and time split part of the sucrose into glucose and fructose, fructose is also called invert sugar. With equal parts of sucrose and invert sugar, no sugar crystals can form. Achieving this balance is therefore also the aim of the method according to the invention.

After completing the cooking process in the individual beet steamers, they are emptied. Part of the juice obtained is drained through a sieve in the ground. The so-called mash, the beet pulp, is drained through an opening and fed into a mash container. In discontinuous operation, the mash is pressed out in filter presses. The resulting pressed chips are dried in a drying drum from 35% dry content to approximately 90% dry content. You will e.g. used as animal feed. The raw juice emerging from the filter cloths is cleaned of fine particles in separators and then gradually thickened until a dry content of about 78 Brix is reached.

This discontinuous process according to the prior art is labor-intensive and requires considerable energy. The invention has for its object to provide a continuous process for the production of beet herb, which eliminates the disadvantages of batch production according to the prior art.

In terms of method, this object is achieved by a method for producing beet herb, in which washed sugar beet pulp is filled into a pulp mashing station essentially continuously, in which a temperature of 75 to 95 ° C., preferably 80 to 90 ° C. and in particular of about 85 ° C. is maintained, and pass through this pulp mash station until there is a pumpable mass at the exit of the pulp mash station, then this pumpable mash is placed in a cooking vessel in which a higher temperature than in the pulp mash station is maintained, which is in the range from 95 to 115 ° C., preferably 100 to 110 ° C and in particular at about 105 to 106 ° C and finally the mash is pressed and the raw juice obtained is thickened to about 78 Brix.

In terms of the device, the object is achieved by the devices according to claims 9 or 10. Accordingly, the pulp mashing station is either a substantially vertically arranged container which has an upper inlet for the essentially continuous supply of sugar beet pulp and which has an outlet in its lower region for the has pumpable mash, or the schnitzel mashing station is a countercurrent mash which has a drum which has an in has a substantially horizontal axis and has rotatable blades in the drum about this axis and which has an inlet for sugar beet pulp near a first end region, an outlet for the pumpable mash near the other end region and a sieve near the first end region, through the circulation juice can be removed from the drum.

According to the invention, a container does not have to be heated up batch-wise or a large number of containers have to be available for a campaign; rather, production takes place continuously. This is essentially achieved by the pulp mashing station, to which the continuously washed sugar beet pulp is fed, so that an essentially constant filling level of sugar beet pulp is achieved in the pulp mashing station. In the pulp mashing station, the sugar beet pulp is prepared so that it is pumpable at the exit of the pulp mashing station and can be pumped into at least one downstream cooking container. Accordingly, the schnitzel mashing station is provided in order to turn the non-pumpable mixture of sugar beet chips and water into a pumpable mass, which is then further thermally treated in the further stations, namely the at least one subsequent cooking container, until the pressing and thickening can take place. It goes without saying that the pumpable mash can also continuously pass through the at least one downstream cooking container.

In contrast to the prior art, the sugar beet pulp is moved within the pulp mashing station and the at least one downstream cooking container, they each pass through these containers from an inlet to an outlet. The conveyance can take place either by a special drive, for example by paddle wheels, by pump pressure or the like, or else by gravitation. The time period within which the sugar beet pulp remains in the pulp mashing station and the at least one downstream cooking container is determined by the throughput time that the sugar beet pulp needs for the passage through the pulp mashing station or the cooking container. The total time essentially corresponds to the time which is also known for the batch processes. The total throughput time is typically around twelve hours.

Predefined temperatures must be maintained in the pulp mashing station and in the at least one downstream cooking container. The temperatures in the schnitzel mashing station are lower than in the cooking container. The temperature in the schnitzel mashing station is below 100 ° C. Accordingly, the schnitzel mashing station does not have to be pressure-proof. However, temperatures of more than 100 ° C are reached in the cooking container, so these containers are designed as pressure vessels.

The sugar beet pulp should be heated up in the pulp mashing station and remain until the cell structures of the sugar beet pulp have essentially broken open. The residence time within the schnitzel mashing station is typically around 3 1/2 hours.

A level sensor is preferably provided in the pulp mashing station. The supply of fresh, cleaned sugar beet pulp is adjusted so that there is a uniform filling level in the pulp mashing station, which is monitored by the level sensor.

In a preferred embodiment, a heat exchanger is arranged between the schnitzel mashing station and the subsequent cooking container. It heats the pumpable sugar beet mash from the temperature prevailing in the pulp mashing station to the temperature of the subsequent cooking container. This saves a direct supply of heat to the subsequent cooking container. Therefore, no or only as much heat needs to be added to it as is necessary to maintain the temperature.

However, this solution does not exclude that the cooking container downstream of the schnitzel mashing station is equipped with devices for supplying heat which are sufficient without raising the pumpable mash to the temperature in the cooking container without intermediate heat exchangers. Heat can be supplied via superheated steam or via heating coils. When supplying superheated steam, it must be taken into account that water, namely condensed water, is also always introduced. There is no additional water input in the case of heat loops in the tank or in the intermediate heat exchanger discussed above.

How many cooking containers are connected to the schnitzel mashing station is up to you. The only important thing is that the cooking containers are designed so that the entire length of stay is reached. With a total residence time of about twelve hours, the at least one cooking container typically takes 8 1/2 hours. If it is large enough, it can take over the function alone. But it is also possible to connect two or more cooking containers in series. The last cooking container essentially has the function of a ripening container, in which the mash matures. It does not have its own heat supply.

A method is particularly preferred in which water is fed to the pulp mashing station in a controlled manner and is kept in circulation in particular. In particular, it is advantageous for water to be supplied with up to 10% by volume of water based on the volume of the sugar beet pulp. For continuous operation, it is advantageous to remove an aqueous circulation juice from the pulp mashing station and to feed it back to the pulp mashing station in counterflow to the beet pulp. In this way, additional heat can be supplied to the schnitzel mashing station by first increasing the temperature of the circulating juice after it has been removed, for example increasing it by about 20 ° C. before it is fed back to the schnitzel mashing station. In this way too, the introduction of liquid can be carried out in a targeted manner and there is no disadvantage of steam plants which always introduce water.

With the two alternatives for the formation of the pulp mashing station, the continuous mode of operation according to the invention is achieved. In the case of the essentially vertically arranged container, the chips are introduced at the top, and a continuous filling level is maintained. The chips pass through the container from top to bottom and are drawn off at the bottom, for example by means of a pump.

The use of a countercurrent mash was particularly preferred. Here a device is used, as it is known in a similar form, but with a somewhat different training from the sugar industry. The countercurrent pulp mash has a drum that is essentially one horizontal axis is arranged. The sugar beet chips are gradually transported from one end region of the drum to the other end region by guide vanes arranged in it. The guide vanes are usually rotated, but the drum can also be rotated. Water is added as described above, so that an extractable mixture is present at the outlet, where the pumpable mash is removed. A strainer is provided near the inlet through which circulation juice can be removed from the drum. It is preferably rotation-proof and is constantly cleaned by wipers that rotate with or vice versa, the sieve rotates with the drum and stationary wipers are provided. A circulation juice is removed through the sieve and, after heating in a heat exchanger, is fed back to the pulp mashing station in countercurrent to the sugar beet pulp.

FIG. 1:

eine schematische Darstellung der wesentlichen Verfahrensschritte einer Vorrichtung zur Herstellung von Rübenkraut,

FIG. 2:

eine Darstellung in anderer Form eines Teilstückes aus Figur 1, nämlich eine Schnitzelmaischestation und eine nachfolgende Kochstation und

FIG. 3:

eine schematische Darstellung einer Gegenstromschnitzelmaische, wie sie schon als Schnitzelmaischestation in Figur 1 angedeutet ist.

Further advantages and features of the invention result from the remaining claims and the following description of exemplary embodiments, which are explained in more detail with reference to the drawing. In this show:

FIG. 1:

1 shows a schematic representation of the essential process steps of a device for producing beet herb,

FIG. 2:

a representation in another form of a section of Figure 1, namely a schnitzel mashing station and a subsequent cooking station and

FIG. 3:

is a schematic representation of a countercurrent pulp mash, as already indicated as a pulp mashing station in Figure 1.

Washed beets are filled into beet bunkers 20 and fall from there to cutting machines 22, where they are cut into pieces about the size of a finger. They are recorded on a conveyor belt and, at the same time, also weighed. They are continuously fed into a pulp mashing station 24, hereinafter only called pulp mash. By means of a mash pump 26, they are fed to a cooking system 28, which here consists of three individual cooking containers. The pumpable pulp mash is introduced into the first cooking container 30 and passes through the cooking container and is drawn off below by means of a pump 32. It is then pressed into the second cooking container at the bottom and conveyed upwards against gravity, and it reaches the third cooking container via an overflow 34. There, the mash is removed at the bottom by a pump 36 and fed to a pre-filter 38. From there, the chips reach again with the interposition of a pump, to presses 40, four individual presses are shown. At the exit of the presses, 42 raw juice is present in the container. It is then cleaned and is then in the container 44 as clear juice. From there it is fed to other systems for thickening, for example an evaporation system, via a pump shown. From this the beet herb, which now has a pH of about 4.6 to 4.7 and a solids content of about 78 Brix, is fed into storage tanks and then bottled.

FIG. 2 shows a possible embodiment for the schnitzel mash 24 and the downstream cooking system 28. Thereafter, a substantially vertically arranged cylindrical container is used as the pulp mash 24, as it could also be used as a cooking container. The sugar beet pulp is introduced into the top of it at an inlet 46, they fill it up to about 80%, as indicated. By means of a sensor 48 for level detection, which is designed, for example, as a float or as an ultrasound device, the filling level in the pulp mash 24 designed as a container is always checked and kept at the specified level. Thus, only so much shredded sugar beet is fed in via the conveyor belt that the filling height remains essentially constant.

In the embodiment shown, steam 50 is introduced into the vertical container at two different heights, each through several steam lances distributed over the circumference. As a result, the sugar beet chips are heated to a temperature of, for example, 95 ° C. At the same time, however, water is also introduced. The steam condenses, the condensed water remains. The aim is to introduce up to 10% by volume of water.

The beet pulp passes through the container of the pulp mash 24 from top to bottom, an outlet 52 is provided below, and the mash pump 26 is also connected there. It promotes the now pumpable mixture from beet pulp and liquid via a line 54 below into the first cooking container 30 of the cooking system 28. Steam is also injected into this container via steam lances, again two lances are shown, which are arranged at different heights. Here, too, they each represent several lances distributed around the circumference at the same height. So water is re-introduced here, namely condensed water. Furthermore, stirring devices 56 are provided in the first cooking container 30, which are intended to bring about better radial mixing. In this way, deposits on the walls of the container 30 are avoided.

The pressure of the mash pump 26 pushes the beet pulp upwards in the cooking container 30, they finally reach the overflow 34 and from there into the second container of the cooking system 28, which is operated as a ripening container. This means that it does not have its own heat supply. The chips move slowly downwards in this container and are finally fed to the pre-filter 38 (not shown in FIG. 2) via the pump 36.

In the device according to FIG. 2, some water can always be added at the same time as the shredded beets at the inlet 46. The steam lances for introducing steam 50 are arranged in the container of the pulp mash 24 in the lower third. They protrude into the mash. The residence time in the container of the schnitzel mash 24 is about four hours. During this time, the beet pulp is cooked through, then they are pumpable. The discharge of the mash can be further improved by the fact that extraction screws 58 are provided in the immediate vicinity of the outlet 52; in the embodiment shown, three such extraction screws 58 are provided.

The two containers of the cooking system 28 are designed as pressure vessels, and temperatures in them exceed 100 degrees. The residence time in the two containers of the cooking system 28 is about eight hours. An additional pressure setting by means of a control valve 60 which is arranged in a line which connects the upper region of the container of the pulp mash 24 to the upper region of the second cooking container of the cooking system 28 causes a constant temperature.

FIG. 3 shows a pulp mash 24 as it is particularly preferred becomes. It is also indicated in Figure 1. It is a horizontally arranged cylinder or drum closed on both sides. It has an axis 62. A worm 64, which is indicated by dotted lines in FIG. 3, can be rotated about the axis 62 therein. For example, there are 1.5 revolutions per minute.

Sugar beet pulp and water are introduced through inlet 46. Again, a sensor 48 is provided for the fill level within the container of the pulp mash 24. The sugar beet chips are slowly fed to the outlet 52 by the rotated screw 64. There the mash pump 26 is connected, which is realized here by two pumps connected in parallel. The pumpable mash is now fed to a first heat exchanger 66, in which it is heated by approximately 20 ° C. While the temperature in the container of the pulp mash 24 is approximately 80 to 85 ° C., it is above 100 ° C. at the outlet 68 of the heat exchanger 66. From the outlet 68 of the heat exchanger, the mash is then fed to a cooking system. In this case, for example, the cooking installation 28 from FIG. 2 can be used, but now the lances for the introduction of steam are no longer necessary, since the heat has already been supplied through the heat exchanger 66 without water being introduced.

A fine-pored screen 70 is provided on the end face of the drum adjacent to the inlet 46. It is designed in such a way that essentially only water can pass through; solid should not pass through this sieve if possible. On the sieve side, the screw 64 is provided with wipers which ensure that the sieve is kept clean. Circulation juice passes through the sieve, which accumulates to the left of the sieve and is fed to a second heat exchanger 74 by means of pumps 72. There the juice, which has an inlet temperature of around 70 ° C, is warmed up to around 95 ° C. As with the first heat exchanger 66, steam is used as the heating medium, but other media can also be used, for example oil or the like. For steam operation, as shown, a control valve is provided, which is located in the supply path, a condensate collection and a pump are provided in the discharge line. The first heat exchanger 66 is also heated.

Due to the heat input by means of a heat exchanger, there is no dilution of the product by condensate as in the device according to FIG. 2 more instead. The aforementioned separate addition of water can now be used to react optimally to changed conditions, for example the dry content of the sugar beet, etc. It can be seen that heat can only be supplied via heat exchangers, so that steam can generally not be introduced.

Claims (9)

1. Method for manufacturing sugar beet syrup consisting in substantially continuously filling washed sugar beet slices into a slice crystalliser station (24) in which a first temperature is maintained, said sugar beet slices passing through this slice crystalliser station (24) and gathering as a pumpable mass at the outlet of the slice crystalliser station (24), in subsequently giving this pumpable beet pulp into a boiling vessel (30) in which a second temperature, higher than the first temperature prevailing in the slice crystalliser station (24) is maintained, and finally in pressing said beet pulp and in thickening the thus extracted raw juice to preferably 78 Brix degrees.
2. Method according to claim 1, characterized in that the first temperature amounts to 75 to 95°C, preferably to 80 to 90°C and, more particularly, to approximately 85° and that the second temperature ranges from 95 to 115°C, preferably from 100 to 110°C and more particularly amounts to approximately 105 to 106°C.
3. Method according to claim 1, characterized in that the slice crystalliser station (24) has a level sensor (48) and that the supply of sugar beet slices is adjusted in such a manner that a constant filling level prevails in the slice crystalliser station (24).
4. Method according to claim 1, characterized in that a first heat exchanger (66) is arranged between the slice crystalliser station (24) and the boiling vessel (30), the beet pulp being heated in said heat exchanger from the temperature of the slice crystalliser station (24) to the temperature of the boiling vessel (30).
5. Method according to claim 1, characterized in that at least one further boiling vessel is arranged behind the boiling vessel (30).
6. Method according to claim 1, characterized in that the overall passage time of the sugar beet slices from their entrance (46) into the slice crystalliser station (24) to their discharge from the last boiling vessel ranges between 10 and 14 hours and particularly amounts to 12 hours.
7. Method according to claim 1, characterized in that the slice crystalliser station (24) is fed with water in a controlled way and particularly that water is supplied in a quantity of 10 percent by volume relative to the volume of the sugar beet slices.
8. Method according to claim 1, characterized in that an aqueous circulation juice is drawn out of the slice crystalliser station (24) and is returned to the slice crystalliser station in reverse direction to the flow of the sugar beet slices, and that the circulation juice is fed back to the slice crystalliser station (24) after having been heated up in particular.
9. Device to carry out the method according to one of the claims 1 through 8, characterized in that the slice crystalliser station (24) is a counter current slice crystalliser that is provided with a cylinder arranged about an essentially horizontal axis (62) and having rotatable blades around this axis (62), and that the cylinder is provided in the vicinity of a first end area with an entrance (46) for sugar beet slices, in the vicinity of the other end area with an outlet (52) for the pumpable beet pulp and in the vicinity of the first end area with a sieve (70) through which the circulation juice may be drawn from the cylinder.