Abstract: A method of drying material uses two different temperature zones within a single chamber. The material enters the first temperature zone where it is indirectly heated by structures heated to a first temperature. The material then moves to the second temperature zone where it is indirectly heated by structures heated to a second temperature different from the first temperature. The second temperature may be greater than or less than the first temperature. The method is particularly useful for drying materials that have a tendency to foul the heated structures of a dryer, such as wastewater treatment sludges.

Abstract: Apparatus for enhancing dewatering of sludge on a filter belt by the use of conical plows that elevate and mix the sludge. The angles of the plows with the horizontal may be progressively increased, and thereby increase elevation and mixing of the sludge as it moves downstream on the belt toward discharge position.

Abstract: A hopper assembly for uniform distribution of sludge, in which distribution elements on the bottom of the hopper are rotatable about vertical axes to enhance uniformity of distribution of the sludge issuing from the hopper.

Abstract: A side seal assembly adapted for use in a belt-type filtering device. The assembly comprises a hollow elongated holder having at least one open end and a longitudinal slot extending the length thereof. The assembly further includes a rod received within the holder, the rod being of a length approximately equal to the length of the holder and of cross-sectional dimensions greater than the slot of the holder, and a flexible curtain secured to the rod along its length and extending outwardly through the slot in the holder.

Abstract: A hopper for retaining a suspension is disclosed, in which the hopper is in the form of a shallow pan that is adjustable in front-to-back and side-to-side relationship so that the retention time of the suspension may be varied and an even flow from the hopper attained.

Abstract: Disclosed is a plow assembly adapted for use with an endless conveyor type filtering device. The assembly comprises an elongated support member and at least one plow depending therefrom. The plow comprises a shaft affixed to the support member, a plow body having a central bore through which the shaft partially extends, the body being capable of rotary movement on the shaft, and a stop retaining the plow body on the shaft.

Abstract: Disclosed is a filtering device comprising an endless perforate conveyor belt adapted to carry a liquid-containing material and extract liquid from the material through the belt, and a plow assembly for disrupting the material carried by the belt. The plow assembly comprises a generally horizontally positioned cross-member extending across the width of the belt, the cross-member supporting at least one plow such that the plow is capable of contacting the material carried by the belt, the cross-member is mounted adjacent its ends on slide means that enable the cross-member to be raised and lowered with respect to the perforate belt. The device further includes selectively actuatable member for raising and lowering the cross-member with respect to the belt to thereby move the plows into and out of material contacting position.

Abstract: The apparatus extracts samples of a fluid stream containing colloidal suspended solids at a detection station wherein the electrophoretic mobility (EM) of the colloidal suspended solids is determined. The detection station automatically measures the EM and provides such data to a computer, which computes the Zeta Potential. The computer also receives other information relating to the characteristics of the colloidal suspended solids, such as temperature, the percent of solids, and the flow rate of the fluid system. The computer is programmed to interpret the input data and to provide corrective signals to processing apparatus which automatically adjust and control the additives fed into the fluid stream to achieve automatic flocculation correction so that the agglomeration of the colloidal suspended solids in the fluid stream is optimized.