Method for protecting a bioreactor pressurized head tank against extreme surges of influent waste water

• US 4,272,379 A
• Filed: 06/13/1980
• Issued: 06/09/1981
• Est. Priority Date: 10/26/1979
• Status: Expired due to Term

• Current Assignee: Zeneca Incorporated (Astrazeneca PLC)
• Original Assignee: CIL Inc. (Nouryon BV)
• Inventors: Pollock, David C. I.
• Primary Examiner(s): Therkorn, Ernest G.
• Application Number:
  US06/159,349
• Time in Patent Office: 361 Days
• Field of Search: 210/608, 210/621, 210/622, 210/623, 210/626, 210/627, 210/629, 210/741, 210/744, 210/97, 210/104, 210/109, 210/123, 210/128, 210/129, 210/130, 210/132, 210/195.1 , 210/195.3, 210/220, 210/221.2, 210/744, 137/571, 137/593
• US Class Current: 210/621
• CPC Class Codes: C02F 1/006 Water distributors either inside a treatment tank or directing the water to several treatment tanks; Water treatment plants incorporating these distributors, with or without chemical or biological tanks for settling tanks B01D21/24
• CPC Class Codes: C02F 2209/03 Pressure
• CPC Class Codes: C02F 2209/40 Liquid flow rate
• CPC Class Codes: C02F 2209/42 Liquid level
• CPC Class Codes: C02F 3/006 Regulation methods for biological treatment
• CPC Class Codes: C02F 3/226 "Deep shaft" processes
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage
• CPC Class Codes: Y10T 137/86187 Plural tanks or compartments connected for serial flow

Abstract

A method and apparatus is provided whereby a pressurized long vertical shaft bioreactor is protected against extreme surges of influent waste liquid. The method provides for the transfer of excess waste from the top of the bioreactor head tank to an adjacent collection vessel where, in response to the pressure created in the bioreactor, the collected waste is caused to overflow and is returned to the influent waste stream. The method permits the return of waste from the reactor to the influent stream while bypassing the normal circulation route through the reactor. Simplification of control is provided and float or level control valves may be eliminated thereby reducing construction, operating and maintenance costs.

Claims

1. An improved long vertical shaft bioreactor apparatus comprising an enclosed head tank, a downcomer chamber and a riser chamber operatively communicating with each other at their upper and lower extremities, communication at the upper extremities being through the said head tank, means for directing influent waste to said riser, means for removing treated effluent from said riser, means for injecting oxygen-containing gas into the waste within said riser and downcomer, the improvement comprising gas conduit means in the said head tank for venting gas therethrough into an adjacent collection vessel, the end of said gas-venting conduit in said collection vessel being immersed in a predetermined depth of waste liquid in the said collection vessel, liquid conduit means in said head tank for venting liquid therethrough into the said adjacent collection vessel, the end of said liquid venting conduit being immersed in the said collection vessel liquid at a lower level than the end of said gas-venting conduit, the said collection vessel having overflow conduit means for transferring waste liquid therefrom to the bioreactor influent steam, said overflow conduit means being positioned so as to control the level of liquid in the said collection vesel thereby controlling the pressure exerted by the said liquid upon the gas vented from the said head tank.

2. An apparatus as claimed in claim 1 wherein the inlet of the said liquid venting conduit in said head tank is positioned substantially at the normal operating level of liquid in the said head tank.

3. An apparatus as claimed in claim 1 wherein the said gas venting conduit and the said liquid venting conduit comprise inverted J-shaped ducts extending from said head tank to said collection tank.

4. A method of protecting a long vertical shaft pressurized bioreactor against the effect of surges of influent waste liquid comprising the steps of transferring excess liquid waste from the said pressurized bioreactor to an adjacent collection vessel, the rate of flow of said excess waste from the said bioreactor to the said collection vessel being proportional to the pressure within the said bioreactor and collection vessel and returning the said excess waste from the said collection vessel to the bioreactor waste influent stream.