PROCESS AND APPARATUS FOR THE SUPPLY OF ORYGEN IN REGULATED QUANTITY INTO THE ACTIVE SLUDGE REACTOR OF BIOLOGICAL SEWAGE PURIFYING EQUIPMENT, AS WELL AS AUXILIARY REACTOR FOR THE DETERMINATION OF THE VARIATION OF THE RELATIVE OXYGEN CONCENTRATION OF SEWAGE SAMPLE CONTAINING ACTIVE SLUDGE, PARTICULARLY FOR THE EXECUTION OF THE PROCESS

摘要

The supply of oxygen to the live mud reactors of biological waste water treatment plants is controlled by determining the rate of oxygen consumption on a sample of the reactor contents and governing the oxygen feed accordingly. The sample is aerated to bring its oxygen content to a predetermined upper level, the time is then measured in which the oxygen content of the stirred sample reaches a set lower level. The oxygen need of the reactor contents is calculated from the elapsed time and the two oxygen levels. The measurements are performed in a measuring reactor contg. in its vessel an oxygen measuring cell, a stirrer and airlift and a sampling pipe. The equipment comprises also a time measuring device, a signal transformer, a recorder, a limit switch and a revolution controller for the oxygen pump.