US 6,412,716 B1 · Method and apparatus for processing municipal sludge waste

Abstract

A process for the comminution and dehydration of municipal sludge waste by feeding the municipal sludge waste into a cyclonic, dehydrating comminuter facilitates the further processing of the comminuted and dehydrated sludge material discharged from the comminuter. Both the comminuted and dehydrated sludge material and the air flow discharged from the cyclonic comminuter are sterilized to remove pathogens therefrom. The rate at which the municipal sludge material is fed into the cyclonic comminuter is directly related to the moisture content of the comminuted and dehydrated material discharged from the material discharge opening of the comminuter. Preferably, the moisture content of the discharged material is in the range of 25% to 35% to facilitate the sterilization of the discharged material. An alternative process can be used, however, to dry the discharged comminuted and dehydrated municipal sludge waste material to about 10%, such as by passing the material discharged from the first cyclonic dehydrating comminuter into a second cyclonic dehydrating comminuter until the finally discharged material has a powdery consistency.

Claims18

Dependent claims

A method of processing sewage sludge, comprising the steps of:

feeding said sewage sludge into an air flow of a cyclonic dehumidifying comminuter to comminute said sewage sludge and to effect dehydration thereof, the comminuted and dehydrated sewage sludge being discharged through a material discharge opening at a bottom portion of said cyclonic comminuter while moisture laden air flow is discharged through an air discharge opening;
metering the flow of said sewage sludge into said cyclonic comminuter as a function of the moisture level of said sewage sludge;
sterilizing said discharged air flow after being exhausted from said comminuter to remove pathogens therefrom before being released to the atmosphere;
passing said comminuted and dehydrated sewage sludge through a sterilization apparatus after being discharged from said cyclonic comminuter to destroy pathogens therein;
and
further processing said sterilized sewage sludge for shipment to a remote location.

3 more elements

A method of processing municipal sludge, comprising the steps of:

feeding said municipal sludge into an air flow of a first cyclonic dehumidifying comminuter to comminute said municipal sludge and to effect dehydration thereof, the comminuted and dehydrated municipal sludge being discharged at a first moisture content through a material discharge opening at a bottom portion of said cyclonic comminuter while moisture laden air flow is discharged through an air discharge opening, the rate at which said municipal sludge is fed into said cyclonic comminuter being a function of the actual moisture content of said comminuted and dehydrated municipal sludge discharged through said material discharge opening compared to a desired moisture content;
monitoring the actual moisture content of said comminuted and dehydrated municipal sludge discharged through said material discharge opening;
sterilizing said discharged air flow after being exhausted from said comminuter to remove pathogens therefrom before being released to the atmosphere;
passing said comminuted and dehydrated municipal sludge through a sterilization device after being discharged from said cyclonic comminuter to destroy pathogens therein;
and
further processing said sterilized municipal sludge for shipment to a remote location.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for processing municipal sludge waste

Life of this patent

Method and apparatus for processing municipal sludge waste

Life of this patent

Abstract

Claims18