EP3864055A1

EP3864055A1 - Method and device for the digestion of starch

Info

Publication number: EP3864055A1
Application number: EP19787171.8A
Authority: EP
Inventors: Christian Stirn; Roman Steindl; Klaus Bartelmuss
Original assignee: Pga Putz-Granitzer-Anlagenbau GmbH
Current assignee: Pga Putz-Granitzer-Anlagenbau GmbH
Priority date: 2018-10-08
Filing date: 2019-10-08
Publication date: 2021-08-18
Also published as: AT16656U2; CN112805304A; WO2020074471A1; CA3115723A1; BR112021006012A2; JP7457700B2; CA3115723C; JP2022504514A; AT16656U3; US20220010034A1; CN112805304B

Abstract

The invention relates to a method for the digestion of starch (native starch or processed starch, such as cationic starch), in which method an aqueous slurry of the starch is treated with steam in a cooking vessel (4) and is thereby subjected to shearing forces, wherein, by introducing steam, the slurry containing starch is heated in the cooking vessel (4) to a temperature between 85°C and 110°C, and the step of digestion is carried out until the desired degree of digestion has been reached. In the digestion of native starch, the digestion can be carried out with the addition of an enzyme, for example, an amylase. The invention further relates to a cooking vessel (4) which can be used when carrying out the method for the digestion of starch.

Description

METHOD AND DEVICE FOR DIGESTING STARCH

The invention relates to methods for digesting starch with the features of the introductory part of claim 1.

The invention also relates to a device which, when

Carrying out the method according to the invention can be used as a cooking container and which has the features of the introductory part of claim 19.

Methods for preparing starch by breaking down the starch are known. In a process for enzymatically breaking down starch, the native starch powder is made from storage bags

("BigBags") or fed from silos into a slurry station, in which the starch powder is introduced into water and a

Slurry (suspension) with up to 35% solids content is generated. The slurry of starch thus obtained is pumped from the slurry station into a cooking container, the enzyme causing the degradation (an amylase) in the

Slurry station or before or after the pump which

Promotes slurry from the slurry station to a cooking container, is metered. Usually, when entering the

Slurry into the cooking container by injection of steam, the slurry is heated to a temperature of 85 ° C to 95 ° C, whereby degradation (gelatinization) already occurs.

Static mixers or other internals can be provided in the inlet to the cooking container in order to prevent the slurry from shooting through and / or the inlet of the

To make the slurry more homogeneous.

In the cooking container in the known methods

Volume buffering, the dwell time for the desired degree of degradation is set. In various devices for carrying out the known process for enzymatically breaking down starch (native starch) are agitators and

if necessary, mixer disks are provided to accelerate the process.

The paste obtained by digesting the starch is drawn off from the cooking container using a pump and - if enzymes have been used - pumped through an inactivation section. The inactivation section is usually a tubular reactor in which the paste is heated to a temperature between 120 ° C. and 135 ° C. at the beginning by introducing steam. The

Inactivation time is determined by the pipe volume and / or the

Pump power controlled.

After the starch degradation is stopped by inactivating the enzyme, the paste is diluted and

then stored.

It is also known to use a cooking container instead

Labyrinth tube to be used after steam injection

is installed, whereby a dwell time can be achieved which is sufficient for the desired degree of degradation and additional shearing of the material in the suspension is achieved via shear edges.

The cooking container can - if it is big enough

is dimensioned - in the known method also in

Batch mode can be used.

A disadvantage of the known methods is that relatively large plants are required or only small throughputs can be obtained.

In a known process for the digestion of cationic starch, the cationic starch powder from storage bags (big bags) or silos is fed into a slurry station and the powder is introduced into water, a slurry (Suspension) with up to 15% solids content is generated. The starch slurry is pumped into a cooking tube.

In the known process for the digestion of cationic starch, the cooking tube is a tubular reactor in which the

Starch slurry is heated to 115 ° C to 135 ° C by introducing steam. The dwell time is controlled via the volume of the tubular reactor and / or the pump power. After the cooking process, it is usually diluted and the paste obtained is then stored.

Even with the digestion of cationic starch after the

Steam injection instead of the cooking tube a labyrinth tube

be used.

It is also known to replace the cooking tube with a cooking container which - if it is of sufficiently large size - can also be used in batch mode.

From US 3,371,018 A, WO 2018/011401 Al and CN 513 980 A, apparatus and methods for breaking down starch are known.

From US 3,371,018 A it is known to submerge starch using bacterial alpha amylase (amylase) in water

Convert heat (225-350 ° F) into a composition for the paper industry. A vertical is used

Reactor column in which a rotor with propeller surfaces rotates. Horizontal and vertical baffles are planned. A stirring effect with an upward flow is to be generated.

WO 2018/011401 Al describes an enzymatic hydrolysis of starch. The starch to be hydrolyzed, to which the enzyme is added, is to be subjected to shear forces during mixing. According to CH 513 980 A, starch milk is subjected to an enzymatic cleavage, the starch milk being gelatinized by heating to 140-150 ° C. The "paste" obtained is cooled and admixed with enzyme and broken down into maltose syrup. A reaction vessel in the form of a "high-speed mixer" with a rotor and with baffles is to be used.

According to DE 10 2007 011 409 A1, starch paste is to be fed to a reaction vessel in which a turbulent flow is generated when producing enzymatically degraded starch paste. The starch paste is produced in a venturi tube-type gelatinization module by the action of enzyme and heating with steam.

The invention has for its object to provide an improved and more economical to operate method for the digestion of starch and a cooking container that can be used when carrying out the method.

This object is achieved according to the invention with a method which has the features of claim 1 and with a

Device having the features of claim 19.

It is advantageous in the method according to the invention that the heating of the slurry (suspension) of starch is carried out directly in a cooking container by introducing steam into the

The cooking container takes place and shear forces act on the slurry, so that a more economical procedure is possible.

In particular, it is preferred that the slurry in the cooking container is heated to a gelatinization temperature which is between 85 ° C and 135 ° C.

If native starch is broken down enzymatically by an amylase, an inactivation section is provided after the cooking container, which can be designed as a tubular reactor in which the paste obtained by decomposing native starch is heated to a temperature between 120 ° C. and 135 ° C. at the beginning by introducing water vapor.

The inactivation time can be regulated via the pipe volume and / or the pump quantity and / or output.

Preferred and advantageous embodiments of the

The procedure according to the invention and the device according to the invention are the subject of the dependent claims.

The known digestion methods, namely enzymatic starch degradation, oxidative starch degradation and

Starch degradation through a thermo / mechanical degradation process, improved.

An advantage of the thermo / mechanical according to the invention

Starch digestion is that, in contrast to oxidative and enzymatic processes for the digestion of starch into paste, no chemical additives are required, so that there is only a slight change in molar mass. This in turn has the advantage that the thermally / mechanically treated native starch has a higher binding force, so that higher

Paper strengths can be achieved. Furthermore, a higher starch yield is achieved through a small change in molar mass.

Another advantage of the invention is that no deactivation is required in the thermo / mechanical starch digestion according to the invention. With the term

"Thermo / mechanical starch digestion" is understood to mean the treatment of starch by the application of heat and by applying shear forces in order to obtain paste. Advantages of the invention for performing the

Device proposed by the method according to the invention are that they have a compact design, so that they are small

Circulation volumes and short dwell times can be achieved. Another advantage is that the process parameters

Speed, temperature, stator / rotor design a good one

Controllability result.

Finally, starch slurries with a high concentration can be processed in the device according to the invention. Another advantage of the device according to the invention is that a direct steam metering is provided in the device, whereby the enzyme - if used - can be metered in before, in or after the device (cooker). With the device according to the invention, the following results

conventional starch cookers (tube cookers, converters etc.) due to the additional mechanical energy introduced

(Shear forces) considerable advantages.

Because a rotor is used in combination with a stator in the device according to the invention and steam is introduced at the same time, the starch slurry acting on the starch slurry results in a quick and easily adjustable gelatinization of the starch. This in turn means that the process time can be shortened. Another advantage is that many types of starch (e.g. corn, wheat, potatoes) can be processed.

If an increased in the device according to the invention

Reaction temperature (cooking temperature) is applied, there is a decrease in the viscosity of the starch paste obtained and a more stable operation.

The mechanical shear insertion reduces the size of large colloidal starch particles, what a Reducing the viscosity of the starch paste obtained is responsible.

If in the device according to the invention and the

the specific enzyme use according to the invention is increased, lower viscosities are achieved. Even at a cooking temperature of 115 ° C. The viscosity of the starch paste obtained can be adjusted by choosing the shape of the rotor of the device according to the invention (height and diameter of the rotor and its speed).

An advantage of the method for the digestion of starch is that at least one enzyme can be added to the paste obtained by the digestion in order to

enzymatic degradation and the resulting adjustment of the desired small viscosity of the paste e.g. to achieve a usable product in the paper industry.

If an enzyme is used in the process according to the invention, this is either in the process or at the end of the

Process made ineffective by inactivation.

In one possible embodiment, this can be

characterized in that water vapor from a hollow displacement body, which is arranged in the cooking container, through at least one outlet opening for

Water vapor escapes in the area of the rotor.

In one possible embodiment, this can be

The method according to the invention is characterized in that the slurry containing starch is heated to a temperature between 85 ° C. and 135 ° C. in step c) by introducing steam.

In one possible embodiment, this can be Characterized method according to the invention in that step c) is carried out for a period of 1 to 5 hours.

In one possible embodiment, this can be

Characterized method according to the invention in that in step a) a slurry with at most 35-45% starch powder is produced as a solid.

In one possible embodiment, this can be

characterized by the fact that the

Slurry is heated to a temperature between 85 ° C and 95 ° C before step b).

In one possible embodiment, this can be

The method according to the invention is characterized in that the starch is broken down with the addition of at least one enzyme.

In one possible embodiment, this can be

characterized by the fact that the enzyme is added when performing step a).

In one possible embodiment, this can be

characterized by the fact that the enzyme is added when performing step b).

In one possible embodiment, this can be

characterized by the fact that the enzyme is added when performing step c).

In one possible embodiment, this can be

characterized by the fact that the

Performing step c) the degree of digestion of the starch is set by selecting the speed at which the slurry is stirred in the cooking container. In one possible embodiment, this can be

characterized by the fact that the

Carrying out step c) the degree of digestion of the starch is set by choosing the throughput of the slurry.

In one possible embodiment, this can be

characterized by the fact that the

Performing step c) the degree of disintegration of the starch is adjusted by choosing the temperature of the slurry.

In one possible embodiment, this can be

characterized by the fact that after step d) the enzyme is inactivated.

In one possible embodiment, this can be

characterized by the fact that the

Inactivating the enzyme is carried out by heating the paste to a temperature between 120 ° C and 135 ° C.

In one possible embodiment, this can be

characterized by the fact that the

Temperature is increased by introducing water vapor.

In one possible embodiment, this can be

characterized by the fact that the

Throughput of slurry through the cooking tank in step c) by impeding the flow of the slurry through the

Cooking vessel and / or by static mixing of the slurry in or after the cooking vessel is regulated.

In one possible embodiment, this can be

characterized by the fact that in step a) cationic starch powder is used to the

To produce slurry. In one possible embodiment, this can be

Characterized method according to the invention in that in step a) native starch powder is used to produce the slurry.

In one possible embodiment, the

Characterized device according to the invention in that the line for supplying water vapor opens into the hollow displacement body and that the displacement body on its side opposite the mouth of the line and adjacent to the rotor at least one outlet opening for

Has water vapor.

In one possible embodiment, the

Characterized device according to the invention in that the outlet openings are provided distributed over the annular end face of the displacement body facing the rotor.

In one possible embodiment, the

Characterized device according to the invention in that the line for supplying water vapor opens into a hollow ring with at least one outlet opening for water vapor.

In one possible embodiment, the

Characterized device according to the invention in that the ring is arranged on the side of the rotor facing away from the displacement body.

In one possible embodiment, the

Characterized device according to the invention in that the outlet opening is provided in the wall of the ring facing the rotor.

In one possible embodiment, the Characterized device according to the invention in that the ring arranged several distributed over its extent

Has outlet openings.

In one possible embodiment, the

Characterized device according to the invention in that the

Stator plates protrude from the displacement body and up to

The inner surface of the container protrudes.

In one possible embodiment, the

Characterized device according to the invention in that the rotor carries ribs at least on one of its sides.

In one possible embodiment, the

Characterized device according to the invention in that the opening of the displacement body which is coaxial with the axis of the rotor is funnel-shaped, the enlarged area of the opening pointing towards the cover of the container.

In one possible embodiment, the

Characterized device according to the invention in that the axis of the line is aligned coaxially to the annular displacement body and to the rotor.

In one possible embodiment, the

Characterized device according to the invention in that the

Increase the ribs on the dispersing disc from the inside out.

In one possible embodiment, the

Characterized device according to the invention in that the

Ribs are inclined to radial planes that go through the axis of the rotor.

In one possible embodiment, the Characterized device according to the invention in that the rotor protrudes through the bottom of the container into the interior of the container.

In one possible embodiment, the

Characterized device according to the invention in that

Area of the mouth of the line acting as a diffuser

Narrowing is provided.

In one possible embodiment, the

Characterized device according to the invention in that the

Constriction is formed by an annular rib, in particular an annular rib with a triangular cross section.

Further details and features of the invention will become apparent from the following description with reference to the

Drawings in which known systems and procedures, procedures according to the invention and systems according to the invention and a cooking container usable according to the invention are exemplified. It shows:

Fig. 1 shows schematically a (known) plant for enzymatic

Mining native strength,

Fig. 2 schematically shows a (known) plant for mining

cationic strength,

Fig. 3 a system for carrying out the invention

(Continuous) process for enzymatic

Mining native strength,

Fig. 4 shows a system for executing the invention

Cationic starch degradation process,

Fig. 5 shows in a block diagram a known method for the enzymatic degradation of starch,

Fig. 6 shows in a block diagram the method according to the invention for the enzymatic degradation of starch,

Fig. 7 in a block diagram a known method for

Digestion of cationic starch, 8 is a block diagram of a method according to the invention for the digestion of cationic starch,

Fig. 9 partially and in section two embodiments of a

Cooking container that when running the

the inventive method can be used and

Fig. 10 is a system for executing the invention

Procedure.

The known method for starch to be broken down enzymatically, which can be carried out continuously in a plant according to FIG. 1 and according to the block diagram of FIG. 5, can be described as follows:

The following are used as raw components:

Native starch powder,

Water,

Steam and

Enzyme (amylase).

Starch powder is stored in BigBags 1 or Silos 2. The starch powder is transferred from this supply to the slurry station 1

fed. In this station 3, the starch powder is introduced into water and a slurry (suspension) with a solids content of up to 35% is produced. From there the slurry

(Starch suspension) pumped into a cooking container 4 using a pump 5. The enzymes can be added in the slurry station 3, before or after the pump 5 from a storage container 6. In most plants, the slurry is brought to the gelatinization temperature (85 ° C. to 95 ° C.) before entering the cooking vessel 4 by means of steam injection 9.

In addition, 4 static in the inlet of the cooking container

Mixers or other internals can be installed to a

Shoot through slurry and prevent the inlet to make it more homogeneous. The necessary dwell time (8 to 20

Minutes) for the desired degree of degradation. in the

Cooking vessels 4 have agitators and / or mixer disks installed to accelerate the degradation process by introducing shear forces into the slurry in the cooking vessel 4.

Using a pump 7, paste is continuously withdrawn from the cooking container 4 and pumped through an inactivation section 8. The inactivation section 8 is a tubular reactor in which the paste is heated to 120 ° C. to 135 ° C. at the beginning by means of steam injection 9, the inactivation time being able to be controlled via the pipe volume and / or the pump power.

After the mining process is stopped, the obtained one

If necessary, paste is diluted with water from a line 15 and then stored.

It is known to use steam injection instead of

Cooking vessel 4 to provide a labyrinth tube in which, firstly, the required dwell time can be achieved and secondly, additional shearing of the slurry is effected via shear edges.

The cooking container can - if it is designed appropriately large - also be used in batch mode. Then everyone

Process steps from the preparation of the suspension in the cooking container 4. The disadvantage is that relatively large plants

are necessary, or correspondingly small throughputs can be driven.

In the known methods of a cooking process for cationic starch, which are carried out in a system according to FIG. 2 and which can proceed according to the block diagram of FIG. 7, the procedure can be as follows: The following are used as raw components:

Cationic starch powder,

water and

Steam.

Starch powder is stored in BigBags 1 or Silos 2. The slurry station 3 is fed from this supply. In this station 3, the powder is introduced into water and a slurry (suspension) with a solids content of up to 15% is produced. From there, the starch suspension is pumped into the cooking tube 10.

The cooking tube 10 is a tube reactor in which the starch suspension is heated to 115 ° C. to 135 ° C. at the beginning by means of steam injection 9, the residence time being via the tube volume

and / or the pump power can be controlled. After this

Cooking process, the paste obtained (digested starch) is optionally further diluted (water from line 15) and

then stored.

It is known to provide a labyrinth tube instead of the cooking tube 10 after the steam injection 9, in which firstly the

required residence time can be achieved and secondly an additional shear of the slurry is effected via shear edges.

The cooking tube can be replaced by a cooking container 10. If it is designed to be large enough, the cooking container 10 can also be used in batch mode. Then everyone

Process steps driven from the preparation of the suspension in the cooking container 10. The disadvantage is that relatively large plants are necessary, or correspondingly small throughputs can be run.

In one embodiment of a method according to the invention for the enzymatic degradation of native starch in a plant 3 with a cooking container according to FIG. 9 and can run according to the block diagram shown in FIG. 6, the procedure can be as follows:

The following are used as raw components:

Native starch powder,

Water,

Steam and

Enzyme (amylase).

Starch powder is stored in BigBags 1 or Silos 2. The slurry station 3 is fed from this supply. In this station 3, the powder is introduced into water supplied via a line 11 and a slurry (suspension) with a solids content of up to 35% is produced. From there the slurry

(Starch suspension) pumped into the cooker 4 with a pump 5. Enzymes can be stored in a reservoir 12 in the

Slurry station 3, before and / or after the pump 5 or directly into the cooker 4. The steam injection 9 takes place directly in the cooker 4, where the slurry is on

Gelatinization temperature (85 ° C to 110 ° C) is brought.

In addition, static mixers or other internals can be installed in the wake in order to shoot through the

To prevent slurry from the cooker 4 and / or to make the cooking process more homogeneous. In the cooker 4, the desired degree of degradation can be set by changing the speed, changing the throughput and / or the cooking temperature.

In the downstream inactivation section 8 is a

Pipe reactor installed in which at the beginning by means of steam injection 9 the paste obtained by breaking down the starch is heated to 120 ° C to 135 ° C. About the pipe volume and / or the

Pumping power, the inactivation time can be controlled.

After the degradation process has been stopped, the paste is optionally diluted with water from a line 15 and then stored.

By selecting the enzyme (one of the amylases) and the temperature, the inactivation can be dispensed with at best.

A process for the digestion of cationic starch according to the invention can be carried out in a plant which is shown in FIG.

4 is shown and uses a cooking container according to FIG. 9, wherein the method can run according to the block diagram according to FIG. 8. The individual procedure can be as follows:

The following are used as raw components:

Cationic starch powder,

water and

Steam.

Starch powder is stored in BigBags 1 or Silos 2. The slurry station 3 is fed from this supply. In this station 3, the powder is introduced into water from line 11 and a slurry (suspension) with a solids content of up to 35% is produced. From there, the starch suspension is pumped into the cooker 4 using the pump 5.

The steam injection takes place via a line 13 directly into the cooker 4, where the slurry is brought to a gelatinization temperature (85 ° C. to 135 ° C.).

To prevent slurry from the cooker 4 and / or to make the cooking process more homogeneous. In the cooker 4, the desired starch properties can be set by changing the speed, changing the throughput and / or cooking temperature.

The paste obtained is optionally made with water from the Line 15 diluted and then stored.

A device (cooker 4) that when executing the

The method according to the invention can be used both for the enzymatic degradation of native starch and for the digestion of cationic starch can have the structure shown in FIG. 9.

A device according to the invention, which serves as a cooking container 4, comprises a container 40 which is closed on its upper side by a lid 41. A rotor 42 projects into the container 40 from below and is mounted in a bearing body (not shown) arranged below the container 40.

The passage of the rotor 42 into the container 40 is sealed by mechanical seals 43.

The rotor 42 is supported in the bearing body by roller bearings (not shown).

The rotor 42 carries in its part arranged in the lower region of the container 40 a dispersing disc 44, which on its

Top has ribs 45 which are inclined with respect to the radial direction. The orientation of the ribs 45 is based on the direction of rotation of the rotor 42 in one

Embodiment selected so that the radially inner ends of the ribs 45 are further forward in relation to the direction of rotation than the radially outer ends of the ribs.

In a modified embodiment, the ribs 45 are oriented in such a way that their radially outer ends are further back in relation to the direction of rotation than their radially inner ends.

In addition, the ribs 45 can increase in height from the inside out. The ribs 45 on the top of the dispersion disk 44 are curved, for example. Curved ribs 45 are either aligned so that the convex side of the ribs 45 faces forward with respect to the direction of rotation of the dispersing disk 44 or aligned so that the convex side relative to the

Direction of rotation of the dispersing disk 44 points to the rear.

The ribs 45 on the upper side of the dispersing disk 44 can therefore also be curved such that the concave side of the ribs 45 points forwards or backwards in relation to the direction of rotation of the dispersing disk 44.

The ribs 45 on the upper side of the dispersing disk 44 can also be straight ribs.

The rotating rotor 42 with the dispersion disk 44 provided in the cooking container 40 (cooker) shear forces into the slurry of starch introduced into the container 40

entered, which is beneficial in unlocking the strength

supported.

The rotor 42 has, for example, a diameter of 100 to 150 mm, preferably 130 mm, and, including the ribs 45 on the dispersion disk 44, a height of, for example, 3 to 10 mm, in particular 5 to 7 mm. The rotor 42 is set in rotation, for example, at a speed between 3000 and 5000 rpm. The speed of the rotor 42 is chosen depending on its diameter to the required

To achieve peripheral speed.

Provided on the rotor 42 above the dispersing disk 44 is a propeller 46 with blades 47, which in the one to be processed

Suspension down towards the dispersing disk 44 directional flow generated. The propeller 46 is not mandatory.

A line 50, through which the suspension flows into the container 40, opens into the cover 41 coaxially with the rotor 42.

On the inside of the cover 41, a conical projection 51 is provided pointing inwards, in the middle of which the

Line 50 for feeding the suspension opens.

This arrangement of the line 50 results in an optimal mixing of the suspension, which is in the circuit 40 in the circuit, with the new suspension fed into the container 40.

The fact that at the end of the line 50 (opening into the container 40) there is a constriction 52 acting as a diffuser (formed by an annular rib with a triangular cross section), the aforementioned mixing of supplied suspension with suspension, which is already in the container 40 and processed, advantageously supported.

Leakage lines (or

at least one) for the removal of prepared suspension

(open-minded strength).

The lid 41 is screwed to the container 40.

In the interior of the container 40 is an annular one

Displacement body 60 is provided, the inner opening of which may be approximately funnel-shaped. Between the outer surface of the displacer 60 and the inside of the wall of the

Container 40 is an annular channel in which

Suspension flows upward after leaving the dispersing disk 44. Suspension flows through the inner opening of the displacement body 60, optionally supported by the Propeller 45 on the rotor 42, down towards the

Dispersing disc 44.

In the exemplary embodiment shown, the upper end of the rotor 42 is covered by a flow-shaped cover which is fixed in the rotor 42 with the aid of an Allen screw.

On the outside of the displacement body 60, stator sheets 61 are provided as baffles, which cover the annular channel (gap) between the outside of the displacement body 60 and the

Bridge the inside of the wall of the container 40 (in particular in its lower part), that is to say rest with its free edges against the inside of the wall of the container 40.

Around the displacer 60 inside the container

holding screws can be provided.

In the embodiment shown in Fig. 9 left

Cooking vessel 4, the displacement body 60 is hollow and is steamed via a line 62, which is passed through the cover 41 of the housing 40 of the cooking vessel 4

loaded. The line 62 opens into the upper end face of the hollow displacement body 60. The displacement body 60 has on its underside - distributed around the inner opening of the displacement body 60 - a plurality of outlet openings 63, so that via the line 62 into the interior of the

Displacement body 60 introduced steam can escape into the interior of the container 40 in the region of the rotor 42, in particular in the region of its dispersing disk 44.

In the embodiment shown on the right in FIG. 9, a hollow ring 70 (diffuser ring) is provided, in which openings are provided for the escape of water vapor. As shown on the right in Fig. 9, the ring 70 is on that of the displacer 60 facing away from the dispersing disc 44 of the rotor 40, wherein the outlet openings in the ring 70 are directed upward, ie in the direction of the displacement body 40. For the sake of clarity, the line via which steam (steam) is fed to the ring 70 is not shown in FIG. 9.

For certain applications, it can be advantageous if the supply of steam into the interior of the container 40

Cooking container 4 both over the hollow

Displacement body 60 as well as via the ring 70.

In the starch processing plant shown in FIG. 10

(Digestion of starch) Starch with or without enzyme addition is gelatinized in the starch dispersion cooker (e.g. cooking container 4). After the gelatinization, the paste after the exit of the

Starch cooker enzyme is metered in and homogeneously incorporated using a static mixer. After a variable dwell time using the appropriate pipe construction, the enzyme is inactivated by increasing the temperature. The advantage here is that a) the starch with almost no molecular weight reduction in

Starch dispersion cooker (e.g. cooking container 4), and

b) with the subsequent enzyme treatment

Starch properties, such as viscosity and degree of digestion, can be individually adjusted to customer needs.

In addition, the shear energy input in the

Starch dispersion cookers (e.g. cooking container 4) can also be influenced on further use. Fig. 10 shows a system in which the previously described

Embodiment of the method according to the invention can be carried out.

The system shown in Fig. 10 comprises a cooking container 4 ("starch dispersion cooker"), which can be designed like the cooking container 4 shown in Fig. 9. A line 20 opens into the cooking container 4, through which enzyme 21 is released by means of a pump a reservoir 21 for enzyme is supplied.

Via a further line 23, starch is conveyed into the cooking container 4 by means of a pump 24.

(Water) steam is introduced into the cooking vessel 4 through a line 25.

Starch broken down into paste and, for example, at least partially degraded, is withdrawn from the cooking container 4 via a line 26. In front of a static mixer 27, enzyme is removed from a storage container 28 (using a pump 29)

added.

In the lower area of the cooking container 4 can

Line 30 supported by a pump 31 water as

Barrier water for the mechanical seal 43 are supplied.

Examples of the process according to the invention are given below:

Example 1 :

Wheat starch (Collamyl 7411) with 13% moisture is mixed with water to form a slurry with 30% by weight

To achieve wheat starch. The slurry thus obtained was at a throughput of 750 1 / h at a cooking temperature of 115 ° C gelatinized in a device according to FIG. 9.

Immediately after the device according to FIG. 9, the enzyme V Warozym A152 was metered in before the static mixer in a constant amount of 4.28 l / h. The in the device according to FIG.

9 rotor 42 used had a height of 7 mm.

At a rotor speed of 4,200 rpm with a rotor 42, the diameter of which was 130 mm, with a current consumption of the motor driving the rotor 42 at 35 amperes, a paste with a viscosity of 12,500 mPas was achieved.

Example 2:

The procedure was as in Example 1, the rotor speed being increased to 4,400 rpm and the current consumption of the motor being 41 amperes. A paste with a viscosity of 9,700 mPas was achieved.

Example 3:

The procedure was as in Example 1, the rotor speed being increased to 4,400 rpm and the enzyme being added at a rate of 2.14 l / h. A paste with a viscosity of 9,500 mPas was achieved.

Example 4:

The procedure was as in Example 3, the

Enzyme addition was increased to 4.28 1 / h. A paste with a viscosity of 7,800 mPas was achieved.

Example 5:

The procedure was as in Example 3, the

Enzyme addition was increased to 8.56 1 / h. It became a paste achieved a viscosity of 7,400 mPas.

Example 6:

The procedure was as given in Example 1, with a rotor speed of 4,400 rpm and a rotor 42 with a

Diameter of 130 mm was worked. The reaction temperature was set to 100 ° C, the current consumption of the motor driving the rotor 42 was 38 amps. The paste obtained had a viscosity of 13,950 mPas.

Example 7:

The procedure was as in Example 6, with a reaction temperature of 115 ° C. The

Current consumption of the motor was 35 amps. The paste had a viscosity of 9,700 mPas.

Example 8:

The procedure was as in Example 1, the

Reaction temperature was 115 ° C and the rotor 42 was operating at a speed of 4,400 rpm. The rotor 42 had a diameter of 130 mm and a height of 5 mm. The current consumption of the motor was 37 amperes. A viscosity of the paste of 10,700 mPas was reached.

Example 9:

The procedure was as given in Example 8, using a rotor 42 with a height of 7 mm and the current consumption of the motor being 41 amperes. As a result, a paste with a viscosity of 9,700 mPas was achieved.

Example 10: Potato starch (Collamyl 9100) with 13% moisture was added to water to obtain a slurry with 20% by weight potato starch. The slurry thus obtained was processed at a throughput of 750 l / h at 115 ° C. in a device according to FIG.

9 gelatinized. The enzyme from Example 1 was after the

However, the device according to FIG. 9 was added before the static mixer.

The slurry emerging from the device according to FIG. 9 was passed through a tubular reactor with a reaction length of 7,500 mm. As a result, a paste with a

Viscosity of 1,660 mPas reached and the achieved

Starch paste was clear and optimally resolved.

Example 11:

The procedure was as in Example 10, with the proviso that the reaction length of the tubular reactor was 10,000 mm. The

The viscosity of the starch paste obtained was 1,540 mPas. The starch paste was clear and the starch was optimally solved.

Example 12:

The procedure was as in Example 10, using a slurry of 25% by weight of potato starch. The starch paste achieved was clear and the starch was optimally resolved.

Example 13:

Wheat starch with a moisture content of 13% was mixed with water to a 30% slurry and cooked at 98 ° C in a device according to FIG. 9. The height of the rotor in the device according to FIG. 9 was 7 mm. The enzyme (Warozym A152) was added directly after the device according to FIG. 9 and after the slurry emerged from the device of FIG. 9, a temperature of 95 ° C was maintained. Subsequent dilution was then carried out with water at 60 ° C. and a throughput of 240 l / h. At a constant

Rotor speed of 4,200 rpm and an enzyme addition of 1,400 ml / h a viscosity of the paste of 440 mPas could be achieved.

Example 14:

The procedure was as in Example 13, using an enzyme addition in the amount of 1,800 ml / h. The viscosity of the starch paste obtained was 240 mPas.

Example 15:

The procedure was as in Example 13, the enzyme addition being increased to 2,200 ml / h. The viscosity of the obtained

Starch paste was 140 mPas.

Example 16:

The procedure was as in Example 13, using a rotor speed of 3800 rpm and a rotor with a diameter of 130 mm. A viscosity of the paste of 580 mPas was achieved.

Example 17:

The procedure was as in Example 17, using a rotor speed of 4,200 rpm. It became a

Starch paste with a viscosity of 270 mPas.

Example 18: The procedure was as in Example 16, the rotor speed being increased to 4,800 rpm. The viscosity of the

Starch paste of 250 mPas achieved.

Example 19:

The procedure was as in Example 16, using a rotor speed of 5,000 rpm. The scored

Starch paste had a viscosity of 180 mPas.

Example 20:

Cationized potato starch (Cationamyl 9853K) was also used

Water to a slurry with 7.5% potato starch

mixed. The slurry thus obtained was used in a

Throughput of 500 l / h in a device according to FIG. 9 boiled at 98 ° C. and then subsequently diluted to a 4% content. In this example, better digestion was achieved due to the internal friction with higher consistency. This could be verified visually by a check using a microscope.

Example 21:

A slurry with 15% potato starch content was processed as in Example 20, cooking in the device according to FIG. 9 at 110 ° C. The starch paste showed lower porosity at higher strengths of paper, which was proven by means of a laboratory sheet.

In summary, an embodiment of the invention can be described as follows:

In a process for the digestion of starch (native starch or processed starch, such as cationic starch), an aqueous slurry of the starch is used in a cooking container 4 Water vapor treated and exposed to shear forces, the starch-containing slurry in the cooking vessel 4 is heated to a temperature between 85 ° C and 110 ° C by introducing water vapor and the digestion step is carried out until the desired degree of digestion has been reached. When digesting native starch, the digest can be carried out with the addition of an enzyme, for example an amylase.

Claims

Expectations :

1. Process for the digestion of starch, characterized by the following process steps: a) production of an aqueous slurry of powdered starch,

b) introducing the slurry into a cooking container (4), c) treating the slurry in the cooking container (4) with steam, the slurry being subjected to mechanical action by shear forces generated by a rotor

Dispersion disk with ribs are exposed, and wherein water vapor is supplied to a from a hollow, arranged below the rotor ring (70), in which openings towards the rotor (42) are provided for the escape of water vapor

carry out thermomechanical digestion,

d) stripping the at least partially in paste

converted starch from the cooking container (4) and

e) optionally diluting the paste.

2. The method according to claim 1, characterized in that water vapor emerges from a hollow displacement body (60), which is arranged in the cooking container (4), through at least one outlet opening (63) for water vapor in the region of the rotor (42).

3. The method according to claim 1 or 2, characterized in that the starch-containing slurry in the cooking container (4) in step c) is heated to a temperature between 85 ° C and 135 ° C by introducing steam.

4. The method according to any one of claims 1 to 3, characterized

characterized in that step c) is carried out for a period of 1 to 5 hours.

5. The method according to any one of claims 1 to 4, characterized

characterized in that a slurry with a maximum of 35-45% starch powder as a solid is produced in step a).

6. The method according to any one of claims 1 to 5, characterized

characterized in that the slurry is heated to a temperature between 85 ° C and 95 ° C before step b).

7. The method according to claim 1 brs 6, characterized

characterized in that the degradation of the starch is carried out with the addition of at least one enzyme.

8. The method according to claim 7, characterized in that the enzyme is added when performing step a).

9. The method according to claim 7, characterized in that the enzyme is added when performing step b).

10. The method according to claim 7, characterized in that the enzyme is added when performing step c).

11. The method according to any one of claims 1 to 10, characterized

characterized in that when step c) is carried out, the degree of digestion of the starch is set by selecting the speed at which the slurry is stirred in the cooking container.

12. The method according to any one of claims 1 to 11, characterized

characterized in that when step c) is carried out, the degree of disintegration of the starch is set by selecting the throughput of the slurry.

13. The method according to any one of claims 1 to 12, characterized

characterized in that when performing step c) the Degree of disintegration of the starch is set by choosing the temperature of the slurry.

14. The method according to any one of claims 7 to 13, characterized

characterized in that after step d) the enzyme

is deactivated.

15. The method according to claim 14, characterized in that the inactivation of the enzyme is carried out by heating the paste to a temperature between 120 ° C and 135 ° C.

16. The method according to claim 15, characterized in that the temperature is increased by introducing water vapor.

17. The method according to any one of claims 1 to 16, characterized

characterized in that the throughput of slurry through the cooking container (4) in step c) is controlled by obstructing the flow of the slurry through the cooking container (4) and / or by statically mixing the slurry in or after the cooking container (4).

18. The method according to any one of claims 1 to 17, characterized

characterized in that in step a) cationic

Starch powder is used to produce the slurry.

19. The method according to any one of claims 1 to 17, characterized

characterized in that in step a) native starch powder is used to produce the slurry.

20. Device in the form of a cooking container (4) for performing step c) of the method according to claim 1, with a container (40), a lid (41), a conduit (50) opening into the lid for the slurry, one in the lid (41) provided line for the discharge of at least partially converted starch (paste), provided in the interior of the container (40), designed as baffles

Stator plates (61), a rotor (42) and an annular displacement body (60), the outer surface of which

Has an inner surface of the container (40) and the inner opening of which is arranged coaxially with the rotor (42), characterized by a line (62) for supplying water vapor which opens into the interior of the container (40).

21. The apparatus according to claim 20, characterized in that the line (62) for supplying water vapor opens into the hollow displacement body (60) and that the displacement body (60) at its opposite the mouth of the line (62) and the rotor (42 ) adjacent side has at least one outlet opening (63) for water vapor.

22. The apparatus according to claim 21, characterized in that the outlet openings (63) are provided distributed over the annular end face of the displacement body (60) facing the rotor (42).

23. The device according to claim 20, characterized in that the line (62) for supplying water vapor opens into a hollow ring (70) with at least one outlet opening for water vapor.

24. The device according to claim 23, characterized in that the ring (70) on the displacement body (60)

opposite side of the rotor (42) is arranged.

25. The device according to claim 23 or 24, characterized

characterized in that the outlet opening is provided in the wall of the ring (70) facing the rotor (42).

26. Device according to one of claims 23 to 25, characterized in that the ring (70) has a plurality of outlet openings arranged distributed over its extension

having .

27. The device according to one of claims 20 to 26, characterized

characterized in that the stator plates (61) from

Stand out displacement body (60) and protrude to the inner surface of the container (40).

28. Device according to one of claims 20 to 27, characterized

characterized in that the rotor (42) carries ribs (45) on at least one of its sides.

29. Device according to one of claims 20 to 28, characterized

characterized in that the opening of the displacement body (60) coaxial to the axis of the rotor (42) is funnel-shaped, the enlarged area of the opening pointing towards the cover (41) of the container (40).

30. Device according to one of claims 20 to 29, characterized

characterized in that the axis of the line (50) is aligned coaxially to the annular displacement body (60) and to the rotor (42).

31. The device according to any one of claims 20 to 30, characterized

characterized in that the ribs (45) on the

Dispersing disc (44) from the inside to the outside in height

increase.

32. Device according to one of claims 20 to 31, characterized

characterized in that the ribs (45) are inclined to radial planes which pass through the axis of the rotor (42).

33. Device according to one of claims 20 to 32, characterized in that the rotor (42) projects through the bottom of the container into the interior of the container (40).

34. Device according to one of claims 20 to 33, characterized in that a narrowing (52) acting as a diffuser is provided in the region of the mouth of the line (50).

35. Device according to one of claims 20 to 34, characterized in that the constriction (52) by a

Ring rib, in particular a ring rib with a triangular cross section, is formed.