Compressed air dryer

DETAILED DESCRIPTION I claim: 1.
Compressed air dryer comprising a base having an inlet communicated to a compressed air source, an outlet communicated to a storage reservoir, and exhaust, and valve means responsive to a control signal for opening and closing said exhaust; means for securing a desiccant canister to said base; said desiccant canister including circumferentially extending inner and outer walls defining an annular chamber therebetween; a desiccant in said annular chamber, a transversely extending end wall closing one end of annular chamber; means for securing the other end of said annular chamber to said base; said inner wall, said transversely extending wall, and said base defining a purge compartment within said desiccant canister for storing purge air for periodic backflowing through the desiccant for regeneration of the latter whereby said purge volume is defined within said desiccant canister; said base extending across the other end of said desiccant canister and purge compartment; and a flowpath defined by said base, said desiccant canister, and said purge compartment for communicating compressed air from said inlet to said outlet.
2.
Compressed air dryer as claimed in claim 1, wherein said securing means includes cooperating manually releasable means carried by said cannister and by said base to permit removal of the cannister from the base without disassembly of the base.
3.
Compressed air dryer as claimed in claim 2, wherein said releasable means includes a threaded connection permitting said canister to be removed from the base by rotating the cannister relative to the base.
4.
Compressed air dryer as claimed in claim 3, wherein said threaded connection includes threads carried on said inner wall and on said base.
5.
Compressed air dryer as claimed in claim 1, wherein said purge compartment is defined by wall means within the inner wall of the desiccant canister, said securing means includes cooperating manually releasable means carried by said cannister and by said base to permit removal of the cannister from the base without removal of the wall means defining the purge compartment