Method and apparatus for withdrawing effluent from a solids-contacting vessel
AssigneeChicago Bridge & Iron Company
InventorsJohn J. Fassbender, Donald N. Ruehrwein, Daniel H. Phillips
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Abstract
A method and apparatus are disclosed which provide enhanced solids-contacting vessel performance in which untreated liquid is injected into a lower portion of the vessel so as to flow in substantially helical and upward directions, solids separating from the untreated liquid into a suspended and rotating sludge blanket. The apparatus includes devices for withdrawing effluent from the vessel from a variety of locations depending upon the flow characteristics of the liquid in the vessel. The apparatus may include a radial weir trough that can be moved vertically within the vessel.
Claims16
A method for withdrawing effluent from a solids-contacting vessel in which untreated liquid is injected into a lower portion of the vessel and flows in a substantially helical and upward direction, separating the solids from the liquid in a suspended and rotating sludge blanket below the surface of the liquid in the vessel, the method comprising the steps of:
- monitoring the velocity of the liquid above the rotating sludge blanket to identify areas of relatively low velocity and to identify areas of relatively high velocity across the surface of the liquid;
- identifying areas of optimum liquid velocity;
- and
- adjusting the withdrawal of effluent from the identified areas of optimum liquid velocity by adjusting the height of effluent withdrawal devices positioned at different radial distances from the center of the vessel across the rotating surface of the liquid.
A method for withdrawing effluent from a solids-contacting vessel in which untreated liquid is injected into a lower portion of the vessel and flows in substantially helical and upward directions, separating the solids from the liquid in a suspended and rotating sludge blanket below the surface of the liquid in the vessel, the method comprising the steps of:
- monitoring the velocity of the liquid above the sludge blanket to identify areas of relatively low rotational velocity and areas of relatively high velocity across the surface of the liquid;
- selectively raising a portion of a radial weir trough at one radial distance from the center of the vessel near an area of relatively undesireable velocity;
- and
- withdrawing liquid from the vessel through a portion of the radial weir trough another radial distance near an area of desired liquid velocity on the rotating surface of the liquid.
Apparatus comprising:
- a solids-contacting vessel in which untreated liquid is injected into a lower portion of the vessel and flows in substantially helical and upward directions, separating the solids from the liquid in a suspended and rotating sludge blanket below the rotating surface of the liquid in the vessel;
- first and second weir trough portions on one or more troughs, each portion comprising means for withdrawing effluent from the rotating surface of liquid in the solids-contacting vessel, one of the portions being disposed radially between the other portion and the center of the vessel;
- means for selectively raising or lowering each of the weir trough portions to control the amount of liquid that flows into that portion;
- and
- means for removing liquid from the troughs.
Dependencies are inferred from the claim text.