Method of filtering sewer scum and apparatus therefor

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It is an object of the present invention to provide an improved method for treating sewer scum which includes combustibles and debris and wherein the debris is filtered out from the scum for accumulating fluid combustibles.

It is another object to provide a method for the treating of sewer scum which includes the steps of collecting the scum from sewage and delivering the scum through a perforated filter drum while continuously rotating the drum upon a longitudinal axis inclined at an acute angle.

The method includes the step of applying heated air under pressure to the exterior wall of the drum along a line over its length and through the perforations therein during continuous rotation of the drum for successively lifting the debris from the perforations, heating and melting the combustibles and for advancing the accumulated debris along the length of the drum. Further steps including discharging the debris from the drum and the continuous collecting of filtered combustibles from the drum.

In the present method air is delivered to a pressure chamber enclosing the drum at approximately 1000 CFM, however, this can be varied between 500 and 1500 CFM. The air is delivered at a temperature in the range of 200 to 300 degrees F., approximately, preferably at 250 degrees.

While a preferred angle of inclination is 20° approximately, this angle can be varied as desired. The drum is rotated at a speed of between _l and 20 rpm. The collected scum is preheated before delivery to the filter drum. ' t

It is another object to provide apparatus for the filtering of sewer scum which contains combustibles and debris which includes an elongated cylindrical drum having a perforated portion throughout 360° and throughout a substantial portion‘ of its length and whose

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‘longitudinal axis is mounted and journaled upon a support and inclined at an acute angle to the horizontal. A rotative drive means is connected to the drum for continuously rotating the drum with the drum having an apertured upper end wall adapted to continuously receive preheated sewer scum and wherein the lower end wall of the drum is apertured for the axial discharge of collected debris. A cylindrical shell sealingly encloses the perforated portion of the drum and defines relative to the drum a pressure chamber thereabove and a filter scum collection chamber below the drum. An elongated air channel upon the interior of the shell along its length within the pressure chamber has a throated outlet extending along and spaced from the perforations of the drum for delivering high pressure heated air to exterior surface portions of the drum for direction thereinto. A plenum is mounted upon and connected to the shell intermediate its length and has an outlet which communicates with the channel. The plenum has an inlet which is connected through a suitable duct to the outlet of an air blower which has a heater for delivering heated air under pressure to said plenum. The shell has a valve outlet adjacent its lower end for delivery of scum from the collection chamber.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawings in which:

THE DRAWINGS

FIG. 1 is a fragmentary and schematic longitudinal section of illustrative filter apparatus for carrying out the present method.

FIG. 2 is a vertical section taken in the direction of arrows 2-2 of FIG’. 1.

FIG. 3 is a vertical section taken in the direction of arrows 3-3 of FIG. 1.

It will be understood that the above drawing illustrates merely a preferred embodiment of the apparatus for carrying out the present method and that other embodiments are contemplated within the scope of the claims hereafter set forth.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF TI-IE APPARATUS

Referring to the drawings the present reclamation 'apparatus for sewage scum is generally indicated at 11 and is adapted for the filtering of sewage scum which contains combustibles and debris. Upon a suitable support schematically shown in FIG. 1 at 13 is an upright base 15 mounting an adjustable screw 17 which extends through nut 19 on said base and adjustably supports block 21 which journals a pair of laterally spaced rollers 23.

An elongated cylindrical drum 25, in the illustrative embodiment 20 feet long and 2.5 feet in diameter, is cradled and supported and journaled at its upper end upon rollers 23 and has a centrally apertured upper inlet wall 27 and an annular seal 29 for snugly receiving a portion of the delivery tube or feed pipe 31, fragmentarily shown. Said pipe receives the outlet 33 from the scum storage hopper 35 which contains scum from municipal sewage, for example. ,

This scum is usually skimmed off the top of the municipal sewage and normally includes combustibles such as grease or the like mixed with small stones or rocks, sticks, cardboard, plastic items, sand, etc. The scum hopper 35 is suitably supported at 37 and includes an