(WO9712031-A1)      A composter has a frame rotatably mounting an airtight housing (320) with two air headers, each connected to the housing via a number of air manifolds (354,356). Air can be directed into the housing through one header and its manifolds, and out via the second manifolds and header, the manifolds included in the two sets pref. depending on the rotational position of the housing. The housing pref. has a material inlet and outlet at opposite ends, and the headers are formed by a partitioned (440) tube (410) extending axially from the housing end, the manifolds extending radially from the tube and formed of PVC or chlorinated PVC. There are pref. screens to pass air into the housing while preventing material entering the manifolds.    USE -   The appts. is used for composting all types of material.    ADVANTAGE -   The appts. permits controlled air circulation without requiring internal air tubes. The manifolds can be made of inexpensive materials and be easily repaired.    (EP862613-A1)      A composter has a frame rotatably mounting an airtight housing (320) with two air headers, each connected to the housing via a number of air manifolds (354,356). Air can be directed into the housing through one header and its manifolds, and out via the second manifolds and header, the manifolds included in the two sets pref. depending on the rotational position of the housing. The housing pref. has a material inlet and outlet at opposite ends, and the headers are formed by a partitioned (440) tube (410) extending axially from the housing end, the manifolds extending radially from the tube and formed of PVC or chlorinated PVC. There are pref. screens to pass air into the housing while preventing material entering the manifolds.    USE -   The appts. is used for composting all types of material.    ADVANTAGE -   The appts. permits controlled air circulation without requiring internal air tubes. The manifolds can be made of inexpensive materials and be easily repaired.