Abstract
A national project entitled “SEA WATER DESALTING AND BY-PRODUCT RECOVERY” started in 1969, and a test plant of multi-stage flash evaporators having a capacity of 3,000m3/D was constructed in 1970 and was operated from 1971 to 1973. This paper concerns the data acquisition system which was designed and equipped with a view to operating the test plant for the purpose of obtaining information rather than producing desalted water.
The system was composed of the computer with 8 kilo-word memory, a couple of magnetic tape recorders, an I/O controller and digital measurement instruments.
The system was able to deal with about 200 signals from the plant such as temperature (147 points), pressure (2 points), concentration (9 points), flow rate (16 points), level (16 points) and pH (5 points). The signals were led to the AD converter via the amplifier in accordance with the programmed code for scanning. When the scanning was completed, all the data were tagged and transmitted to the magnetic tape, and some of them were computed and printed out.
For the measurement of temperature, the accuracy at the order of 0.05°C was attained by improving the bridge balancer.
The system was improved to attain the function of running without employing an operator by surmounting the noise and irregular signals, and recorded enormous data in magnetic tapes during the 3 years' operation. The data printed out gave such a sufficient amount of information about the test plant operation that another analysis was scarcely needed to be conducted.
