DE916998C - Plant for drying vegetable matter, preferably forage plants u. like - Google Patents

Description

. Plant for drying vegetable matter, preferably forage plants and the like. B. forage plants and the like., Is drying is made more difficult by the fact that the fabrics come from drying are generally considered to be very inhomogeneous to address, as they are partly made up of relatively easily drying leaves and more delicate plant parts, partly off Coarser plant parts that are difficult to dry out, such as coarse stems, root crop parts and the like. As a result, great care eats when carrying out drying necessary if you can design it economically and at the same time pay attention to it wants no nutrients and vitamins from green plants due to partial overheating of the dry material or due to loss of dust. This is especially true in to a high degree for so-called rapid drying with a relatively high drying gas temperature.

The drying process can be made much easier if the dry goods could be converted into a very homogeneous form. One has this through a far Driven fine comminution of the dry material in the drying system or the Reach larger plants before placing them in the drying facility tries. However, this requires a large amount of power and expensive equipment, in addition are the dry matter losses through dust formation 'both Significant drying because especially the leaf can easily be completely shredded is pulverized. The coarser parts of the plant, which are generally due to their larger cellulose content have a much greater strength than that Leaf, on the other hand, are not pulverized by the fine shredding, but kept also afterwards a certain size, which excludes the formation of dust.

Accordingly, it is desirable to use the more delicate and easily drying Components of the goods to be dried, e.g. B. the green plants, already at the beginning before drying or separating them from the coarser and more difficult-to-dry parts, so that this is then a suitable fine crushing unit before drying can be subjected. Such a division of the dry material as long as this is still moist, however, is made more difficult by the fact that at this stage the various Components have the same specific weight and also have a tendency to stick to one another.

The present invention now relates to a method for a effective separation of the easily drying from the hard drying components to carry out the dry goods in the very first stage of the drying process, which essentially happens that the light dry goods through an upward directed and appropriately sized gas flow of high temperature falls. It will In addition to an inlet opening for the material to be dried into the gas stream, an appropriately arranged one: Outlet opening for those heavier components of the dry material that are deposited are provided.

In the method of the invention, the dry material is preferred by continuous feeding, in one first essentially horizontal and then drying gas flow of high temperature directed essentially vertically upwards, preferably 600 to 100 ° C, at a height of at least z. B. about: 2 m and introduced at most about 10 m above the deflection point of the gas flow. The speed of the current is chosen in the upward part so that the easily drying Components of the goods are taken up to the drying point while the heavier components that are difficult to dry fall down against the gas flow, to be eliminated at the diversion point and then completely or partially again, : if necessary after suitable treatment, into the gas stream above the deflection point to be introduced for final drying or recirculation.

Due to the high gas temperature, the easily drying components give the main part of the water content of the goods already at the first contact with the gases while the hard-drying components at the same time only reduce their surface moisture lose and maintain a relatively high level of moisture inside. This creates very quickly a difference between the specific gravity of the easily drying ones and that of the difficult-to-dry components, which leads to rapid separation of these various constituents occurs under the action of the gas flow. The lighter components are prevented from falling against the gas flow and carried by it upwards, while the heavier components downwards and Fall out of the gas stream at the deflection point and in a suitable manner Way to be collected. Due to the quick removal of surface moisture the various components of the dry goods also show their tendency to stick to one another, eliminated, causing accumulations or lump formation of the material under the action of the Gas flow are quickly dissolved and distributed over its cross section.

The height of the inlet opening for the material above the gas flow deflection point is for the fall time or the fall path of the heavy components. through the gas flow decisive. The time should be long enough for the components to dry easily to stop in their case and to dissolve any accumulations or clumps of material; on the other hand .may not be so long that .the heavier particles deposited before they reach the deflection point: of the gas flow, are so overheated that a Quality deterioration occurs. The fall distance is at least about: 2 m and at most about io m, where a. some relationship between the cross-section of the gas flow and the fall path is in the direction that a smaller cross-section shorter fall distance heard.

To have a better effect in separating the various components To achieve, it is useful that the cross section of the gas flow from the deflection point decreases towards the top.

For the purpose of better distribution of the dry material in the gas flow, its Cross-section oval or rectangular with the largest dimension perpendicular to that through the vertical plane laid in both main channel directions, and the dry material should be be introduced from the side of the gas flow which is opposite its horizontal part. For the same reason, it is advisable to control the gas flow at the inlet opening for the Bringing dry material into turbulent motion.

It has proven to be advantageous, the drying gas flow after Deflection point from the horizontal flow direction via a below the Inlet opening for the line lying to be dried first has a slope of up to 30 ° against the vertical, expediently by about 15 °, and then vertically afterwards to lead past the inlet opening.

In general, it is necessary for the movement of the drying gas flow, to maintain a certain negative pressure in the apparatus. As a result is it is desirable to prevent false air from eating at the inlet and outlet openings for the dry material penetrates into the gas flow, which is achieved by -suitable inward and outward transfer of the dry material is reached.

The heavier dry material that is separated in the dry gas flow and from it on: the outlet opening eliminated in its lower part generally consist of coarser stem parts, flowers, root crop parts and the like. They are conveniently comminuted after excretion and in this way converted into a more easily drying form before being put back into the gas stream reach. There are sometimes heavy foreign bodies in the dry material, such as stones, pieces of iron and the like, which fall out of the gas flow due to their weight, it is advisable to remove these foreign bodies from the dry material before the shredding process to be eliminated.

As a result, the difficult-to-dry parts of the material to be dried through the gas flow through and out of it, to again at a point that higher than the outlet opening, both in recirculation and after suitable Crushing to be introduced into it was able to improve the quality the efficiency of the drying system increased by up to about 2o% and at the same time the heat consumption by 5 to 100 / o and the power required to drive the system, be.-reduced to the dried amount by io to i5o / o.

To carry out the method according to the invention, a dry gas generator, a fireplace or the like a horizontally running gas duct can be connected, which is at a suitable distance from the dry gas generator up to essentially perpendicular is bent and communicates with a pneumatic dryer. In the upstairs directed part of the gas duct, expediently on its side, the horizontally extending Channel part is opposite, are one or more inlet openings for the material to be dried provided, and at the bend point of the channel is an outlet opening for the Heavier dry goods falling downwards. Also are devices for feeding the dry material into the gas stream through the inlet opening and for re-feeding all or part of the heavier excreted through the outlet opening Components of the dry material present.

The gas duct is preferably oval or rectangular in cross section with the greatest extent perpendicular to the vertical plane through its horizontal and vertical part executed. The area of the channel cross-section should depend on the To remove the bending point upwards and above the inlet opening for the dry material from rectangular to circular for the purpose of connecting the one leading to the dryer Go over the riser pipe.

An edge, a shoulder ad, extending from the channel wall into the gas flow, is advantageously under the inlet opening for the dry material. Like. Arranged, which brings the gas flow in a turbulent motion.

Finally, the gas duct is expediently immediately after the Bend from the horizontal direction first an incline against the vertical of at most 30 °, preferably 15 °, and then leads it from a point below .the inlet opening for the material to be dried from essentially vertically upwards. Through this one achieves, among other things, that the channel of the free fall movement of the side imported dry material connects better and that also the accumulation the falling heavier components at the duct outlet opening more easily leaves without the risk that these components in the horizontal channel part fall.

In order to prevent in the event that there is negative pressure in the gas duct, that false air penetrates into the inlet and outlet openings for the material to be dried suitable locks at these openings, e.g. B in the form of in caps or housings mounted rotating cellular wheels, which the dry material passes through.

The desired crushing of the hard-drying, from the rest Well-separated coarser constituents can either be obtained in that one; sends them through the cutting machine again, in which all of the dry goods before drying is divided into chopped or 'schnitzel, or by the fact that a special shredding apparatus, defibrator or the like. Provides the separated components on their return to the inlet opening in the gas channel .thin happen. At the same time, a separator for heavy foreign bodies is expedient, such as stones, iron parts and the like., Arranged.

A system according to the invention is shown schematically in the drawing in an exemplary embodiment.

The combustion gases, which have a temperature of about 100 degrees, are emitted from the fireplace i passed through the horizontal gas channel a, which at 3 at an angle of about 15 ° upwards against the vertical. At q. the canal goes in essentially perpendicular direction. At 5 a paragraph or an edge is arranged, the or which sets the gas flow in a turbulent motion, and at 6 it closes the riser pipe for the pneumatic dryer, in which the treatment is carried out, is attached to the gas duct of the dry material is continued. The cutting machine 7 shreds the dry material in chaff or schnitzel; the crushed material falls into the funnel 8 and is from it with the help of the elevator 9 .the lock io supplied from which it is in the upward gas flow falls. This is where the easily drying ingredients give of the goods very quickly and lose most of their water content at the same time significantly in weight in relation to the difficult-to-dry components. the The speed of the drying gas flow is like this. chosen that the easily drying and therefore specifically lighter components after contact with the dry material of the items to be dried are carried upwards, while the heavy ones that are difficult to dry Components fall down in the gas flow and finally fall out of it at i i, from where it enters the suction line by means of the sluice wheel 12 and the worm 13 14 arrive. From the suction line 1q., In which the separator 15 for foreign bodies, Like stones or the like. Is provided, they come into the defibrator 16 in which they in brought a more easily drying form and from which it is again the elevator 9 are fed.

Claims (3)

PATENT CLAIMS: i. Plant for drying vegetable matter, preferably Forage plants or the like, in a gas stream of high temperature, preferably 600 to i 100 ° C, at which the duct for the dry gas flow consists of an essentially horizontal, backwards with a dry gas generator, a fireplace or the like. In connection standing and an upward part, characterized in that, that the upwardly directed channel part (4) behind the deflection point (3) first an inclination of up to 30 ° to the vertical, expediently of about 15 °, and then vertically upwards at one or more, at most about 10 m above the duct diversion point (3), expediently on the channel side that corresponds to the essentially horizontal channel part (2) opposite j, arranged inlet openings (io) for .the dry material, whose easily drying components are taken up by the gas stream, over runs and at the channel deflection point (3) with one or more outlet openings (ii) for the difficult-to-dry material components falling down against the gas flow is provided, which are fed in again after intermediate shredding. 2. Plant according to claim i, characterized in that the cross section of the channel for the drying gas flow is oval or rectangular, with the greatest extent perpendicular to a vertical plane laid through the two channel parts (2, q.). 3. Appendix after Claim i or 2, characterized by one of .der channel wall in the gas flow edge reaching into it, a shoulder or the like to generate a turbulent movement of the gas flow.