DE1933393C3 - Method and apparatus for the continuous production of expanded food - Google Patents

Description

40

The invention relates to a method and an apparatus for the continuous production of expanded food. In particular, the invention is concerned with a continuous, uniform Expansion of such commodities (e.g. polished rice, sticky rice, etc.) caused by heat easily gelled and therefore tends to adhere to the wall of a heater in which it is heated and to harden or to form agglomerates by sticking together with other particles, of heat-sensitive goods (e.g. vegetables, fruits, fish and crustaceans) as well as goods with uneven cooking Grain size (wide grain size range) and of course from the usual granular foods.

It is the object of the invention to continuously provide food of the type mentioned to be able to heat evenly and expand effectively in a short time.

As a discontinuous process for producing expanded food, the so-called indirect Heating method known in which the material to be expanded is heated in that it is in a closed cylindrical pressure vessel or a so-called "puff drum" is filled, the heated from the outside with the help of a gas burner or the like and rotated at the same time. With this Method, however, it is impossible to heat all the particles of the material to be expanded evenly, and If the heating is too strong or too weak, the yield of the product is considerably reduced. Since that Good to be expanded adhere to the wall and the particles are also in contact with one another In addition, the particles on the wall of the container or on each other and harden in this state, if the property has a particularly large proportion of water or moisture in general Surface has; the surface thickness of the goods may also immediately gelatinize, so that the quality of the expanded food thus produced is unsatisfactory.

In another known discontinuous process with direct heating of the to be expanded Good this is filled in one of the above-mentioned or such a container, in the means are arranged for mechanical stirring or transporting the material, and the material is in the Container by a blown heating means, e.g. B. a heating gas under pressure heated. This method is the first method in terms of heat transfer efficiency and Considering heat utilization, but still brings with it the already mentioned difficulty that the particles are in intimate contact with one another.

The so-called fluidized bed heating process is known as a process for the continuous production of expanded foodstuffs (e.g. DL-PS 59 235 or GB-PS 8 27 652). In this case, the material is continuously fed into a superheated hot gas stream which, if necessary, is blown in an upward direction through a plate of a pressure line provided with openings (DL-PS 59 235). In the upward heating gas flow, a fluidized bed is formed, from which the particles of the goods after dehydration and the associated weight loss automatically through the hot gas flow to a separation point in a relaxation zone, e.g. B. a cyclone (DL-PS 59 235), are discharged. In terms of efficiency, heat utilization and heat transfer, this continuous process is far superior to the two aforementioned discontinuous processes, and also in that the material is heated in a dispersed state, so that the risk of agglomeration of the particles is substantially reduced. However, it is not suitable for expanding a product that contains a relatively large proportion of water, which easily gelatinizes the starch of the product, or a product that is heat-sensitive or consists of particles of uneven size, i.e. the length of time the product remains in the The fluidized bed is typically one minute or more and the particles are selected based on their aerodynamic properties, in particular their weight loss due to dehydration.

Based on this known fluidized bed heating process is according to the invention at a Method in which the goods to be expanded ar an input point from a pressurized one Hot gas flow entrained, swirled in this and from this after heating to a separator separation point in a relaxation zone

3 4

is solved the underlying task. Pipeline provided with a hot gas supply

that the material is from the hot gas flow in the direction of and opens into a separation chamber, which with

the input point for Abschr.destcüc entrained a hot gas outlet and a Gutsauslaß in one

and the heating duration is provided by the choice of the length expansion chamber, and provides that

the conveyor line and / or the speed of the 5 the pipeline is surrounded by a heating jacket,

Hot gas flow is set. wherein the flow channel formed thereby with

The invention takes advantage of the fact that the heat an exhaust gas outlet of a heating device for the

transfer coefficient is related between the hot gas to be heated. Through the heat supply

Good and the hot gas flow is extraordinarily large, while the goods remain in the device

or, in other words, the heat transfer io tion will affect the quality of the product under

speed is very high, so that the shortening of the running time can be improved with simple means.

Duration in the hot gas flow depends on the running time and is very sert. Since the device is also not a moving part

can be set briefly. The heating time or the time required to transport the goods during the heating

The length of time the goods remain in the heating gas flow is free of charge and includes operation, maintenance and control.

changeable by changing the flow rate of the device easily.

The hot gas flow is set or loaded accordingly

may be changed. Realize at constant speed.

It is also possible to move the goods over a large amount of volatility of the goods from their physical distance while they are being heated.
Properties, for example the particle size, the renewed heating and guidance of the hot gas stream, water content and the shape, are determined. If one is floating around are also possible.
Preferably the device according to the invention, the particles, which have a relatively manure characterized by a mixer with a small diameter and are rapidly heated, are perforated inner cylinders which heat the input device at a relatively high speed device connects to the pipeline and is entrained by a gas stream and heated in a shorter time, the outer cylinder is surrounded, which has a hot gas inlet while the has a relatively large through-hole.

Knife-having particles, which are relatively

take a long time to be heated, introduce it slowly into the hot gas flow,

nism moderately low speed in the hot gas stream 30 The invention is described below with reference to

taken along and over a longer period of time. Drawings of a preferred embodiment

get heated. Consequently, all particles are explained in more detail in the same way. It shows

moderately heated, and a uniformly ex- F i g is obtained. 1 shows a schematic overall arrangement of a

panded food. Embodiment of a device according to the

In practice this means that conventional 35 invention and expanded

Grain continuously within 10 seconds each. Fig. 2 shows another embodiment of a

which can be produced if the material is mixed with a mixer for use in a device

a hot gas is heated, which under a measure of the invention.

Overpressure of 5 to 15 kg / cm ² and a temperature of 200 to 250 ° C which is subjected to a pretreatment has to be pufperatur. In general, the ₄₀ fende material is continuously filled into a hopper 1. The method according to the invention is expediently filled with a hot gas, e.g. B. exceeded device 2 at predetermined time intervals superheated steam with a pressure of 3 to continuously through a chute 3 to Ge 15 below kg / cm ² and a temperature of 100 to 300 ⁰ C and enters a promotes Feststoffördereinrichdurchgeführt, wherein the running time 10 seconds and 45 device 5, which an inevitable dispenser 4 can be less. and between closed, under-According to the invention, the material is arranged with constant pressure containers in the direction of flow whirling in the hot gas flow, is intense. In this case, the conveying device S and are agitated and dispersed without the particles, like the rotary feed device 2, being operationally coordinated via a single chain in a fluidized bed with oppositely directed 50 such that movement can collide. The good can fall out of the rotary feeder, even in a horizontally directed hot gas if an inlet opening 6 of the conveyor is entered stream and only comes relatively exactly at the top of the conveyor is located with the device wall or with each other in ordet. The device described forms a contact. Therefore, even a good can be an input device for the good to be buffered.
If the process has hardened the use of superheated surface water or moisture or if steam is provided as hot gas, the surface thickness of the boiler 7, whose surface thickness is immediately gelatinized by heat, is regenerated in a superheater 8, or even a proportionate one heats, and the resulting, the superheater 8 has large surface moisture (e.g. polished 60 send superheated steam is poured into a mixer 9 rice, vegetables, fruits, etc.), easily handled and flows from there through a heated pipe delt . line 10.

Powdery goods can also be treated. On the other hand, this is done by the displacement equipment. device 5 under seal displaced good against A device for carrying out the invention 65 the high pressure of the superheated steam in the According to the method, in turn, goes from the well-known mixer 9 and then from the through the tubes Fluidized bed heating consisting of a line 10 flowing steam in a dispersed feed device for the good to be puffed a »\ one stood taken along and in the pipeline

moved on a conveyor line, wherein it is subjected to a heat treatment. Im described here In the case, the heating time or the dwell time of the goods can optionally be changed by changing the length of the pipeline 10 and thus the conveying path and / or the speed of the flowing in the pipeline Steam is changed. The good that is entrained while in the steam stream, a predetermined Is heated for a long time in the pipeline, flows into a serving as a separation chamber Cyclone 11, in which it is separated from steam and then with the help of another conveyor 12 of same design as the above-mentioned conveyor 5 through a Gutsauslaß abruptly into a relaxation zone in the form of an expansion chamber 13 formed by a vessel with atmospheric Pressure is released, whereby the good is expanded with relaxation. The cyclone 11 on the superheated steam leaving its top is passed through a pressure regulating valve serving as a hot gas outlet 14 fed to another insert part where it is used as a heating source, e.g. B. to Drying the expanded product or, if necessary, for preheating the product. on the other hand the superheated steam that has already been used can also be used with the aid of a compressor, not shown here be circulated for reuse. The time it takes to heat the goods to a temperature at which it takes on the amount of heat necessary for expansion is required, and on the speed at which the goods, together with the superheated steam, move through the pipeline moved, the length of the pipeline 10 can be determined.

The mixer 9, the pipeline 10 and the cyclone 11 are heated by the exhaust gases from the superheater 8, which circulate through a heating jacket 15 and through an exhaust gas opening 16 under suction be given to him.

Fig. 2 shows a mixer 9 in which sticky substances, such as polished rice, in the superheated steam stream and which is used in place of the mixer 9 shown in FIG. This mixer has a good inlet port 31 and a hot gas inlet 33 for superheated steam. Another hot gas inlet 32 is on the pipeline 10 upstream of the connection of the mixer 9 is provided. Inside the material inlet opening 31 is a perforated inner cylinder 35 with a large number before. Openings 34 distributed over its entire surface are arranged. the Superheated steam entering the mixer through hot gas inlet 33 fills an annular one Space between the inner wall of the material inlet opening 31 and the outer wall of the perforated inner cylinder 35 and is sucked through the openings 34 into the interior of the perforated inner cylinder. Therefore, the material located inside the perforated inner cylinder 35 is separated from the material through the openings 34 jet inwardly flowing steam is blown radially inward in each cylinder and thus prevented from adhering to the inner surface of the inner cylinder 35. In certain circumstances all the required superheated steam can be passed through the inlet opening 33 into the mixer so that the hot gas inlet 32 can be omitted.

With a device according to the invention, for example, the following methods for producing expanded Exported food.

B e i s ρ i e 1 1

Good: polished rice
(with or without bran)

Hot gas:
superheated steam

Good handling capacity:

(on continuous
Base)

Treatment time
(Dwell time):

properties
of the product:

Bulk weight - 1000kg / m ^{: i}

Water content - 14.5 to 15%

Pressure - 6 kg / cm ² positive pressure

Temperature - 250 ° C (at the hot gas supply

Temperature - 200 ° C (at the hot gas outlet)

Steam speed - 25 m / sec.

100 kg / hour 6 sec.

Water content - 8 ° / o

Bulk weight - 100kg / na>

Conversion to α-starch

98 ° / o

Example 2

Good: wheat

Hot gas:
superheated steam

Good handling capacity

Treatment time
(Dwell time):

properties
of the product:

Bulk weight - 780 kg / na *

Water content - 13.5 to 14.5 <> / o

Pressure - 7 kg / cm ² positive pressure

Temperature - 280 ° C (at the hot gas supply

Temperature - 220 ° C (at the hot gas outlet)

Steam speed - 20 m / sec.

1000 kg / hour

8 sec.

Water content - 10 per cent

Bulk weight - 150 kg / m3

(Expansion ratio - about 1: 5)

Conversion to α-starch

99 "»

19th 7th Be Bulk weight - 33 393 I _n 8th 450 kg / m3 Water content - ispi el 3 Good: 9.5 to 10.5% Hot gas: Pressure - 5 kg / cm ² defatted soybeans Grain size range 5 superheated steam Overpressure Screen size 4 (Tyler Standard) Temperature -250 ⁰ C. (Mesh size approx
4.7 mm) and above - (at the hot gas supply 68.5 ° / o Temperature - 220 ° C Screen size 4 to 8
(Tyler Standard)
(Mesh size approx 10 (at the hot gas outlet) 4.7 to 2.4 mm) - Steam speed -
lSm / sec. 18.9% Screen size 8 to 32 15th Good treatment 500 kg / hour (Tyler Standard) capacity:
(on continuous
Base) (Mesh size approx Treatment time 5 sec. 2.4 to 0.48 mm) - 20th (Dwell time): 12.6% properties Water content - 4 ° / o of the product: can be completely denaturia (Note: the egg white will.)

For this purpose 2 sheets of drawings

Claims (3)

Patent Claims: 1. Process for the continuous production of expanded food in which the Goods to be expanded taken from a pressurized hot gas stream at an input point, swirled in this and nus this after heating at a separation point in a relaxation zone is deposited, d a characterized in that the material of is entrained by the hot gas flow in the direction from the input point to the separating element and the heating time by choosing the length of the conveyor line and / or the speed the hot gas flow is set. 2. Apparatus for performing the method according to claim 1, consisting of an input device for the material to be puffed on a pipeline with a hot gas supply is and opens into a separation chamber with a hot gas outlet and a Gutsauslaß is provided in an expansion chamber, characterized in that the pipe (10) is surrounded by a heating jacket (15), the flow channel formed thereby with a Exhaust outlet of a heating device (8) for the hot gas is in communication. 3. Apparatus according to claim 2, characterized by a mixer (9) with a perforating th inner cylinder (34, 35) which connects the input device (1 to 5) with the pipeline (10) and is surrounded by an outer cylinder having a hot gas inlet (33). 35