Digester cover
AssigneeBlack & Veatch Holding Company, a Delaware Corporation
InventorsWilliam Wells, Mark Wilson
Life of this patent
Estimating the term…
Abstract
An anaerobic digester for use in wastewater treatment systems having a fixed cover including a central tower for controlling gas and foam. A constant operating level is maintained in the digester by utilization of an overflow weir located in the tower. The fixed cover having an under flat surface that is in direct contact with contents of the digester. The tower has a number of spray nozzles that operably direct movement of foam toward discharge locations.
Claims16
An anaerobic digester for use in treatment of sludge containing microorganisms;
- said digester comprising:
- a) a sludge receiving basin adapted to receive sludge therein;
- b) a cover positioned over said basin and having an under surface that is adapted to be in direct contact with respect to sludge contents within said digester;
- c) a tower mounted so as to extend above said cover and flow communicate with the contents in the digester;
- d) a weir positioned within the tower to provide sludge level control by allowing an overflow and discharge of sludge raising through said tower;
- and
- e) a gas dome located in said tower above said weir for collecting and discharging gas.
The digester according to claim 4 wherein:
- a) said under surface area is at least 10 times greater than said tower area.
A digester for biologically treating sludge comprising:
- a) a basin adapted to receive sludge;
- b) a cover secured to said basin and having an under surface that is adapted to contact said sludge during operation;
- and
- c) a level control weir located above said cover under surface and adapted to allow overflow of sludge from said basin so as to maintain sludge in continuous contact with said cover under surface during normal operation.
A method of biologically treating sludge in a digester while controlling sludge level and separating foam from gas produced in the digester comprising the steps of:
- a) providing an anaerobic digester having a cover and a tower extending above said cover and flow communicating with said digester;
- b) flowing sludge into said digester and filing said digester such that said sludge contacts an under surface of said cover and rises in said tower;
- c) providing a level control weir in said tower such that sludge and foam overflows said weir so as to maintain a generally constant height of sludge relative to said digester during normal operation;
- d) providing a gas collection dome in said tower spaced above said weir;
- and
- e) collecting gas in said dome and discharging collected gas from said tower.
In a concentrated sludge digester having a basin and a cover, the improvement comprising:
- a) placing an overflow for sludge in said digester above an under surface of said cover such that sludge continuously contacts said cover under surface during normal operation.
In a sludge digester, the improvement comprising:
- a) an overflow weir located at a desired sludge operating level so as to maintain a generally constant level of sludge in said digester.
In a sludge digester having an upper region wherein gas and foam collect, the improvement comprising:
- a) a fluid spray nozzle located in said region and being sized, shaped and positioned to operably spray fluid at foam in said tower so as to direct flow of foam within said region.
Dependencies are inferred from the claim text.