Process for sludge thickening
AssigneeHitachi, Ltd.
InventorsKenji Baba, Shoji Watanabe, Hayao Yahagi, Hitoshi Ogasawara
Life of this patent
Estimating the term…
Abstract
An apparatus for sludge thickening including a sludge thickener allowing suspended solids of sludge supplied thereto to settle by their own weight while being thickened. The sludge supplied to the sludge thickener is subjected to aeration for a predetermined period of time in a sludge aerator. Aeration of the sludge strips the anaerobic gas, which is attached to the suspended solids in the form of bubbles or dissolved in the sludge, to atmosphere. By aeration of the sludge before being fed to the sludge thickener, floating of the thickened sludge in the thickener can be avoided.
Claims9
A process for sludge thickening, the processing comprising:
- allowing suspended solids of a sludge supplied to a gravity settling type sludge thickener to settle by their own weight while being thickened;
- subjecting the sludge to be supplied to the sludge thickener to aeration in a sludge aerator means;
- retaining the sludge in the sludge aerator means for less than one hour for stripping gas bubbles on surfaces around and interiorly of the sludge particles and dissolved gas in a mixed liquour containing sludge particles to the atmosphere without biological decomposition of organic materials contained in the sludge.
A process of sludge thickening, the process comprising the steps of:
- allowing suspended solids of sludge supplied to a gravity settling type sludge thickener to settle by their own weight while being thickened;
- subjecting the sludge to be supplied to the sludge thickener to aeration in a sludge aerator means;
- retaining the sludge in the sludge aerator means for less than one hour for stripping gas bubbles on surfaces around the interiorly of the sludge particles and dissolved gas in a mixed liquour containing sludge particles to the atmosphere without biological decomposition of organic materials contained in the sludge;
- sensing anaerobic conditions of the sludge admitted to the sludge aerator means by an anaerobic condition sensing means;
- and controlling the aeration gas flow rate in accordance with the anaerobic conditions sensed by the anaerobic condition sensing means.
A process for sludge thickening, the process comprising the steps of:
- allowing suspended solids of sludge supplied to a gravity settling type sludge thickener to settle by their own weight while being thickened;
- subjecting the sludge to be supplied to the sludge thickener to aeration in a sludge aerator means;
- retaining the sludge in the sludge aerator means for less than one hour for stripping gas bubbles on surfaces around and interiorly of the sludge particles and dissolved gas in a mixed liquour containing sludge particles to the atmosphere without biologically decomposition of organic materials contained in the sludge;
- sensing a flow rate of the sludge flowing into the sludge aerator means by a flow rate sensing means;
- and controlling an aeration gas flow rate supplied to the sludge aerator means in accordance with the sludge flow rate sensed by the flow rate sensing means.
Dependencies are inferred from the claim text.