Abstract A high speed bowl centrifuge of the type having a rotatably mounted bowl and an independently, rotatably mounted central support member which is enclosed thereby upon which a plurality of disks are coaxially mounted for rotation therewith. The periphery of the disks and the inner surface of the bowl define therebetween a substantially annular space, into which, in the preferred embodiment, at least one pitched extension protrudes from at least one disk. Under normal centrifuging operations, the central support member and bowl are rotated in a common direction at a common rotational speed and thus sludge builds up at the inner surface of said bowl. During the cleaning operation the central support member is rotated in such a direction as to urge sludge towards said sludge outlet due to the pitch of said extension. The bowl may also be rotated in the opposite direction as to apply a stripping force to the sludge. Furthermore, both of the above-mentioned rotations are at a substantially lower rotational speed than the centrifuging speed so that the extension encounters less compacted sludge.
In a high speed bowl centrifuge including a bowl having a central longitudinal axis, a first support means for rotatably mounting said bowl, a first power means for rotating said bowl about its longitudinal axis, a central support member coaxially disposed within and completely enclosed by said bowl, a second support means for rotatably mounting said central support member independent from said bowl, a second power means for rotating said central support member, and a set of disks, rigidly and coaxially mounted upon said central supporting member so as to define an annular space between the periphery of said disks and the inner surface of said bowl, and a sludge outlet from said bowl, the improvement comprising that at least one of said disks includes at least one radial extension which extends into said annular space and is pitched to urge sludge therein toward said outlet on relative rotation between said bowl and said one disk, that at least one of said first and second power means is capable of various speeds of rotation, and including means for changing the mode of operation of said one power means so that, in the centrifuging mode, said bowl and said central support member may be rotated at a common rotational speed but, in the cleaning mode, said bowl and said central support member may be operated at different rotational speeds so that said extension urges sludge towards said sludge outlet, said changing means comprising a sludge sensor for measuring sludge buildup on the inner surface of said bowl and a control circuit connected to said sensor for controlling the operation of said one power means.
Claim 2
Dependent Claim
273 words
In a high speed bowl centrifuge including a bowl having a central longitudinal axis, a first support means for rotatably mounting said bowl, a first power means for rotating said bowl about its longitudinal axis, a central support member coaxially disposed within and completely enclosed by said bowl, a second support means for rotatably mounting said central support member independent from said bowl, a second power means for rotating said central support member, and a set of disks, rigidly and coaxially mounted upon said central supporting member so as to define an annular space between the periphery of said disks and the inner surface of said bowl, and a sludge outlet from said bowl, the improvement comprising that at least one of said disks includes at least one radial extension which extends into said annular space and is pitched to urge sludge therein toward said outlet on relative rotation between said bowl and said one disk, that at least one of said first and second power means is capable of various speeds of rotation, and including means for changing the mode of operation of said one power means so that, in the centrifuging mode, said bowl and said central support member may be rotated at a common rotational speed but, in the cleaning mode, said bowl and said central support member may be operated at different rotational speeds so that said extension urges sludge towards said sludge outlet, said changing means comprising a sludge sensor for measuring sludge buildup on the inner surface of said bowl and a control circuit connected to said sensor for controlling the operation of said one power means.