GB1141473A - Providing electrical signals able to be used for the discontinuous control of concentrations and/or signalling concentration deviations of mixtures and solutions - Google Patents

Abstract

1,141,473. Programmed control of chemical processes. CHEMIEFASERWERK "FRIEDRICH ENGELS", VEB. May 23, 1966, No. 22896/66. Heading G3N. [Also in Division G1l Electrical signals, indicative of whether a physical or physico chemical property of a material is above or below a limit value, are provided by on/ off evaluation of the property of a quantity of the material added to a chemical reagent in a mixing vessel, the result being stored as an on/ off signal and the mixing vessel emptied the operation being repeated periodically and the stored information retained until the completion of the next operation and is available for control or signalling of the concentration of a solution or mixture. As shown. Fig. 1, a titration apparatus comprises a proportioning container 2 for the material to be measured and a proportioning container 3 for the titration medium, containing a colour indicator, which are filled through magnetic valves 4, 5 and emptied through magnetic valves 6, 7, into a mixing chamber 1. The proportioning containers are provided with electrode pairs 10, 12; 14, 16 for determining the level to which they are filled. The electrode 16 is adjustable to set the desired limit value. The mixing chamber 1 is mounted below the proportioning chambers and contains a stirrer 20. A colour change occurring in the mixing chamber is determined with the aid of a photo-electric device 21 a colour filter 22 being situated in the light path. The mixing vessel has an outlet which is opened or closed by a magnetic valve 23. A programme controlled electric system, Fig. 2, for the titration apparatus is sequentially controlled by a programme transmitter 27 which controls level controls 25, 26 to fill containers 2, 3 through magnetic valves 4, 5, to levels determined by the electrodes 10-16. Subsequently the transmitter 27 controls the emptying of containers 2, 3 through valves 6, 7 into the mixing chamber 1 and, by a monitoring device 28, evaluates the attainment of a predetermined transmissivity to light, with the aid of the photo-electric device 21. Finally, the transmitter 27 controls the emptying of the mixing chamber 1 through the valve 23 and the transfer of the evaluation to a store 29 from which it is given up as an on/off signal. A number of examples are set out in the Specification relating to multi-component titration and the measurement of pH and electrical conductivity.