The present invention relates to a compostor for processing organic waste, comprising a compostor container, a supply conveyor for conveying the waste to the compostor container, an exit conveyor for removing the processed waste from the compostor, and transport members for transporting the mass removed from the compostor container further, for instance to a heap.

Composting means mouldering, that is, slow combusting, in which process the micro-organisms convert organic waste products such as agricultural waste, fur animal farm waste, household waste, precipitation waste, and sewage treatment plant waste into compost soil. Mechanical composting is known of prior art, in which endeavours have been made to create optimal circumstances for the micro-organisms to decompose different kind of waste. It is known that the characteristic features of waste products may be observed in the compostors, and a rapid and efficient decomposition may be obtained.

Various mechanical compostors are known in the art, one such compostor being disclosed in the FI patent publication No.77 836, in which an apparatus of drum compostor type for composting organic waste is described.

The waste product to be fed to a compostor generally contains e.g. manure and some litter material such as chapped straw. Prior to moving to the compostor, the litter manure mixture has usually been gathered into heaps in which liquid substances like urea are separated into a well, or the liquids are bound in the used litter material. Half of the litter manure generally contains manure and the other half is litter. Before being taken into the compostor, about two parts of other Utter material such as peat is added to the Utter manure mixture. There¬ fore, a lot of peat has to be used in the compostor designs, said peat being a Umited natural- resource in quantity and, moreover, difficult to get in many

places. Also chapped straw or equivalent Utter material may be used instead of peat. The Utter material intensifies combustion while acting within the manure as air introducer, thus adding the Ughtness of the manure. Peat is extremely useful for litter because it has a high absorption capacity, whereby the manure material may be very dry and Ught. Manure and peat are mixed e.g. by means of screws in the compostor.

Plant-originated, organic materials present in the waste products decompose during the combustion process. For instance, manure contains protein and such plant-originated waste which as a result of combustion turns into CO and H _p O. Peat contains Ugnosulphonates and ceUulose which are very slowly decomposing components, whereby the body of the matter taken out of the compostor is composed of the support structure of the peat, πiicro ceUs, and the waste such as manure has almost completely burned off.

An object of the invention is to provide a compostor design that, when used, does not require litter material, such as peat, to be mixed with the waste.

The processing of the moist waste material causes problems because of the liquid gathering on the bottom of the compostor, which may result in that anaerobic conditions will be generated in the compostor. An object of the invention is also to solve the problems associated with what to do with moist waste ingredients.

The object of the invention is specifically to provide a design in which no anaerobic circumstances will be generated within the compostor and in which no organic Utter material need be added into the waste ingredients.

The preceding aims and those to be described below are obtained with the compostor of the invention which is mainly characterized in that balls or equival¬ ent bodies have been placed in the compostor for introducing air into the waste to be processed, for drying and mixing the waste, and that the compostor is

provided with a member in the outlet end of the compostor container for separating the balls or equivalent members from the mass, and with a transport means or transport means for returning said balls or equivalent to the supply end of the compostor container.

In the compostor of the invention peat or other equivalent litter material is replaced partly or completely with balls or equivalent bodies which have been so mixed into the waste material that no anaerobic circumstances will be created.

In addition, the balls or equivalent bodies of the invention, being mixed in the waste, are returned in the form of continuous circulation to the first end of the compostor, whereby no new material has to be added in the process, and a con¬ tinuous-action composting process is produced.

While using balls or equivalent bodies 11 of the invention, the organic material burns very efficiently. Besides, savings are produced in the use of Utter, and a mixture of moister waste ingredients than before can be processed in the com¬ postor container. Furthermore, more heat is generated than in any designs of prior art.

The invention is described below more in detail referring to a preferable embodiment of the invention illustrated by the accompanying drawings, whereto the invention is not, however, exclusively confined.

Figure 1 presents the compostor system of the invention schematically in elevational view, and

Figure 2 presents schematically the container of the compostor of the invention in schematical cross-section.

As shown in Fig. 1, the compostor 10 comprises a compostor container 14 with

waste material 15 such as manure. Waste material is fed in the direction of arrow F by means of e.g. a screw-driven conveyor 16 into the compostor con¬ tainer 14. The outlet end of the compostor container is provided with an exit conveyor 17, operating e.g. by screws, which drops the mass into a funnel 18 provided with a vibrator 19. The mass faUs through the vibrator onto a conveyor 20 or something Uke that which transports the mass to a piston-cyUnder system 21, or equivalent transport means which pushes the mass, as shown e.g. by arrow S, to a heap 25.

The compostor container 14 revolves slowly in the direction shown by arrow R. The revolution may be periodical e.g. in the manner that the compostor con¬ tainer 14 revolves for 15 seconds and remains stationary for 60 seconds.

In Fig. 1 is marked with arrow G the gas discharging from the compostor container 14, said gas containing carbon dioxide, water and air.

As taught by the invention, baUs or equivalent bodies 11 have been placed among the manure 15 in the compostor container 14. The balls or equivalent bodies 11 are removed from the outlet end 17 of the compostor container 14 with e.g. an exit conveyor 17 which drops the baUs 11 through the funnel 18 onto the vibrator 19. From the vibrator 19 the balls are guided into a return tube 23 containing e.g. a conveyor 24 for moving the baUs back to the supply end 16 of the compostor container 14, where the baUs are returned to the container 14, as shown by arrow B.

As shown in Fig. 2, the balls or equivalent bodies 11 rotate when the compostor container 14 revolves in the direction of arrow R, whereby the balls 11 dry, while rotating, the Uquid 13 from the bottom of the container 14. During said rotation also the waste material 15 rises upwards.

The baUs 11 increase the drying surface area in the container 14, whereby the drying will be intensified.

The density of the waste material is below 1,000 kg per cubic meter and the density of the baUs 11 is below, equal to or over 1,000 kg per cubic meter. Balls of different densities and sizes may be used together or in separation, dependent on the material to be composted.

The material of the baUs or equivalent bodies 11 may be selected from a number of different materials. The material of the baUs 11 is preferably e.g. ceramic or titanium oxide mixed in polyethylene, whereby the specific weight of the balls 11 can be altered using titanium oxide. The density of pure polyethylene is approxi- mately 900 kg/m , whereby the weight of the balls 11 has to be increased, in order to obtain their weight to be equal to or over 1,000 kg/m . The balls 11 may also be made lighter by foaming the polyethylene material before making balls out of it. Pure polyethylene is a very hard material, that is why it will not wear off when in use. It is also possible to add e.g. starch in polyethylene.

The material to be used for manufacturing balls or equivalent bodies 11 is characterized in that a hard and porous surface is obtained; e.g. ceramic ma¬ terials are well appropriate for use as a material for balls 11. Suitable ball materials are also various pure plastics, composite plastics and ceramics.

The porosity of the balls or equivalent bodies 11 causes that water is absorbed into the balls at the first end of the compostor container where the temperature is about 10 to 20°C, and the microorganisms remain on the surface of the balls 11 and oxidize the waste material. As a result of the combustion, the tempera- ture in the compostor container 14 rises even as high as to 60 to 70 C. At the rear end of the compostor container 1, where the temperature is optimally 65°C, the baUs or equivalent bodies 11 become warmer, whereby the water is removed from the pores of the balls or equivalent bodies 11. The temperature of the air coming out of the compostor container 14 is about 40°C and the temperature of the mass to be removed is about 60°C.

The diameter of the balls or equivalent bodies 11 is for example 10 to 100 mm.

The size of the balls, the mass and the number of the baUs are chosen according to the waste to be composted.

The balls or equivalent bodies 11 keep the bottom of the compostor container 14 dry and clean. In addition, the balls or equivalent bodies 11 transport to the first end of the compostor container 14 in conjunction with the returning in their pores pure mass such as soil and microorganisms, these being used as acceler¬ ators in the initial reaction.

The invention is described in the foregoing, reference being made only to one of its advantageous embodiment examples. This will not, however, restrict the invention to concern only the present example; instead, a pluraUty of variations and modifications are feasible within the scope of the inventive idea determined by the claims below.