| 摘要 |
PURPOSE:To improve the control response by combining four pipes having a bore capable of specifying the rate of the chemical flowing into a chemicals injection pipeline, four pipelines having a bore capable of obtaining a flow rate 10 times that of the pipes, and four pipelines capable of obtaining a flow rate 100 times that of the pipes to control the amt. of the chemicals to be injected. CONSTITUTION:The flow rate ratios of injection pipelines 8 in a 1st group controlled to 1:2:4:8, and the bores of 2nd, 3rd groups are classified as to obtain 10, 100 times flow rate against the 1st group respectively. The pipelines 8 are connected to a chemical injection main pipe 6 through solenoid valves 7. The injection rates of 0.1-0.9l/h can be determined by opening SV11-SV14. The injection rates of 1-9l/h can be similarly determined by SV21-SV24, and the injection rates of 10-150l/h can be determined by SV31-SV34. Accordingly, the chemical injection amts. can be controlled to 166.5l/h in steps of 0.1l/h by the combination of the solenoid valves 7. The injection amt. is controlled in this way in the vicinity of the chemicals injection point, and the control response can be improved. |
