DE102008000945A1 - Process for the production of pressed products from fibrous raw materials - Google Patents

Abstract

The invention relates to a process for the production of pressed products from fibrous raw materials such as wood, straw, peat or the like, which are also referred to as renewable raw materials. In order to produce well-pressed products, fiber-containing raw materials are mixed with water, steam and possibly other additives while heating the raw materials and additives, wherein the mixture is kept for a long time at high temperature in an intermediate container (4) before being pressed.

Description

The The invention relates to a process for the production of pressed Products from fibrous raw materials such as wood, straw, peat, compound feed or the like, also referred to as renewable resources become.

The The invention further relates to a device for execution of such a procedure.

Pellet mills or Feed Cube Presses or Pellet Presses have been around for many years Years in practical use in the feed and food industry or in the non-food area. Grainy, are squeezed powdery and / or pasty materials with different moisture contents and compositions.

They have molds and scrapers to produce cubes or pellets in the desired size. Such a cube press is z. B. in the EP-A-371519 disclosed. The material to be pressed passes from a hopper into a conveyor and dosing and from there into a mixer. Both apparatuses are arranged at the top of the housing of the actual press, wherein the output of the mixer promotes into a kinked filling box (and into a mold lid) arranged underneath but not rigidly connected to the mixer. From the mold lid, the material enters the mold.

A Press mold is firmly connected to a rotating mold holder. Fixed is also a roller carrier with a attached roller bar. Two rollers are by means of a piston-cylinder unit arranged adjustable so that different column and pressing pressures are adjustable on the form of die.

Another pelleting press shows the EP-B-489046 , in which the mold and at least one press roller with variable speed and depending on the gap height can be driven.

Various solutions are known to attach the forms in a cube press. The aforementioned fixed arrangement, which includes a simple screwing the mold, although cost-effective but a time-consuming change of shape. But are also known solutions for a quick change z. B. after US Pat. No. 4,997,887 in which z. B. the individual clamping segments are actuated by short-stroke hydraulic cylinder on the circumference of a Schleissringes. To change the shape, the hydraulic cylinders are connected to an external hydraulic pump.

After DE-OS 2108326 It is also known, for better mounting to hold the clamping segments by means of spring elements in the die clamping position, wherein adjusting means are provided to release the clamping segments against the spring action. By overcoming the spring tension forces, the matrix should simply be released from the column or re-attached. As adjusting means hydraulic winches are used. A similar solution shows the DE-OS 2756647 in which a conical ring is used to attach the matrix.

Mixing units are for example from the EP-B-231 764 and EP-B-610789 known. Such a mixer is preceded by a metering device and in turn a mold or an expander is fed from the mixer. The mixing unit is provided with a heating jacket and contains a rotating shaft, which is equipped with mixing and conveying elements.

such Aggregates are either for use in press or expander systems tailored or solitary usable, since the adjustment effort is high.

Pressing or Expanderanlagen are primarily used for the production of food or feed, but also known is the production of pellets of wood or waste from the grain milling, for example, from wheat bran. In the DE-A-10205105 discloses a process for the production of pellets made of wood, in which wood material is pressed with a preset moisture in a pelleting press, wherein the material is pre-pelletized with higher humidity with evolution of heat and then moisture is removed. From the DE-A-10010414 It is known to mix wood fibers o. The like. With up to 50 wt .-% of a thermosetting resin and to extrude the mixture.

Of the Invention is based on the object, a process for the preparation to develop from pressed products from fibrous raw materials, which for example, the production of pellets of wood, straw, peat or Paper, plastic mixtures, or any kind of renewable Raw materials that can be pelleted for energy production). The method should also for the production of compound feed u. a. Suitable feed. This task is with the features of claim 1.

The process is characterized by a longer residence time (long-term conditioning) at high temperature after the mixing in of water, steam and optionally further additives (for example fat or lignin). Lingering is preceded by pressing. The conditioning temperature is up to 200 ° C and the conditioning can be unpressurized or be carried out under pressure.

Under Long term conditioning is considered to be one above the normal mixing time of about 15-20 seconds (each mixer, if necessary, two consecutive switched mixer) lying process, or residence time to understand. There is also an additional dwell time in a buffer depot. The total residence time is preferably greater than one minute.

preferred Embodiments of the method are in the subclaims disclosed. These concern defined temperature and / or humidity ranges as well as a defined product transfer from Verweiler // Zwischenbehälter in a press. The latter allows a uniformity of product flow and performance increases of about 30-40%.

Of the Invention is another object of the creation of a device to carry out a method according to the claims 1 to. This object is achieved with the features of claim 7 solved.

The Device has a, a mixer downstream sub-tank on, in which the mixed intermediate for a long time at high Temperature lingers, so that admixed additives in sufficient Way into the raw material can penetrate to a good crimping to ensure.

moreover can through the intermediate container and a metering device a pulsating product entry into a press or an expander be avoided.

The Invention will be hereinafter in an embodiment described in detail with reference to a drawing. The drawing shows a pelletizing plant in a schematic representation.

A press line includes a mixer 2 and a dweller 3 (Long-term conditioner), which are arranged one above the other. The mixer 2 and the detainees 3 each have similar face plates.

The product guide from the mixer 2 in the Verweiler 3 via the corresponding product feed opening 7 , About the product discharge opening 8th of the dweller 3 the transfer of the product takes place in the intermediate container 4 and from this via a twin screw 9 and a downstream metering device 5 in a cube press 1 ,

From the intermediate container 4 is done by means of the twin screw 9 whose worm gears are coupled mechanically offset by 180 ° to each other, the press pulsationsminimiert fed with the product to be pressed.

The further equalization of the product flow is served by the metering device 5 in a canal 6 is arranged. The metering device 5 assigns you to a depository 51 swiveling dosing slide 52 and a roll-shaped bent walerboard 53 on. The walerboard 53 is rotatable by means of a frequency-controlled drive. While with the metering slide 52 a rough dosage of the product takes place, serves the walmblech 53 also the fine dosage. The metering slide 52 is by means of a lifting cylinder 54 (eg electrically or pneumatically actuated). The channel 6 is designed so that it completely through the metering slide 52 and the walerboard 53 is lockable.

Consequently the product is always moved during feeding and it takes place at the same time a fine dosage.

The mixer 2 has a high-speed rotor for intensive product mixing with steam, gases and / or liquids. The Verweiler 3 is, however, provided with a slow-running rotor. In the verweiler 3 The heated, mixed product is already held for a predetermined time at a defined temperature.

In the mixer ( 2 ) is the mixture by steam or other energy sources up to max. Heated to 100 ° C. Further, in the mixer 2 Water to achieve the optimum Pelletierwassergehaltes and added other additives for Pelletierprozessoptimierung.

The Verweiler 3 is an intermediate container 4 (Buffer depot) downstream.

After the product in the mixer 2 was brought to temperature and the optimum water content, the product lingers over a defined residence time in Verweiler 3 wherein the conditioning temperature is maintained over the previously defined dwell time. This is done via insulation or external heating mats at Verweiler 3 achieved. First In-First Out applies.

The intermediate container 4 prolongs the residence time and counteracts or compensates for a pulsating food of the press.

The walls of the intermediate container 4 are insulated or equipped with external heating mats.

mixer 3 and Verweiler 4 have tightly closable openings in the respective jacket. Coats and transfer openings as well as the face plates 5 . 6 If required, they can be completely covered with heating mats and insulating materials. Preferably, the inner surfaces of the sheaths, including the product transfer openings ( 7 and 8th ) completely smooth.

mixer 2 and Verweiler 3 contain rotors with working elements. These are in the verweiler 3 snail-shaped (full screw) and in the mixer 2 paddle-shaped.

All Components are preferably compatible and combinable.

The Verweiler 3 points towards the mixer 2 Lower speeds of the rotor, so that the capacity of the individual units is tuned for continuous operation.

The pellets are left after the dice press 1 cooled in a cooler and then supplied in a conventional manner to other stations.

• – ruhiger, optimierter Pelletierprozess
• – höherer Durchsatz
• – weniger Energieaufwand pro Tonne Pellets
• – höhere Standzeiten der Maschinen-, und Schleissteile
• – bessere Pelletierbarkeit, von schlecht pelletierbarem Produkten

Advantages of such long-term conditioning are:

• - quiet, optimized pelleting process
• - higher throughput
• - Less energy required per tonne of pellets
• - longer service life of machine parts and parts
• - better pelletability, from poorly pelletized products

1

pellet mill

2

mixer

3

Dweller

4

intermediate container

5

metering

6

channel

7

product supply

8th

Produktabführöffnung

9

twin screw

51

depository

52

metering

53

Walmblech

54

lifting cylinder

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 371519 A [0004]
• EP 489046 B [0006]
• US 4979887 P [0007]
• - DE 2108326 [0008]
• - DE 2756647 A [0008]
• - EP 231764 B [0009]
• - EP 610789 B [0009]
• - DE 10205105 A [0011]
• DE 10010414 A [0011]

Claims (11)

Process for the production of pressed products from fibrous raw materials such as compound feed, wood, straw, peat or the like in a press or expander plant by mixing fiber-containing raw materials with water, steam and optionally further additives while heating the raw materials and additives, characterized in that the mixture is kept for a long time at high temperature and defined humidity before pressing. A method according to claim 1, characterized in that the mixture in an intermediate container ( 4 held) and evenly dosed out of this in a press o. The like. Is discharged. Method according to claim 1 or 2, characterized that the mixture is preferably at a temperature of up to 200 ° C. is held. Method according to claim 3, characterized that the mixture is preferably at a temperature of up to 150 ° C. is held. Method according to one of claims 1 to 3, characterized in that the raw materials in addition Fat and / or lignin are added. Method according to one of claims 1 to 5, characterized in that the conditioning pressure or at overpressure occurs. Device for producing pressed products from fibrous raw materials such as wood, straw, peat or the like in a pressing or expander plant, carrying out a method according to at least one of claims 1 to 4, characterized in that a mixer ( 2 ) following Verweiler ( 2 ) an intermediate container ( 4 ) is subordinate. Device according to claim 7, characterized in that the intermediate container ( 4 ) a metering device ( 5 ) is subordinate. Device according to claim 7, characterized in that the intermediate container ( 4 ) of a cube press ( 1 ) or an expander is upstream. Device according to one of claims 7 to 9, characterized in that the intermediate container ( 4 ) a twin screw ( 9 ), whose worm gears are coupled mechanically offset by 180 ° to each other. Device according to one of claims 7 to 9, characterized in that at least the intermediate container ( 4 ) is thermally isolated.