PROBLEM TO BE SOLVED: To provide a chemical spraying device which can stabilize a dilution concentration in the beginning of spraying and in repeating spraying and non-spraying.SOLUTION: A chemical spraying device includes a chemical tank 11 where a chemical is accumulated, a fresh water tank 2 where fresh water is accumulated, a spraying pump 3, and a spraying nozzle part 4. The chemical spraying device includes: a mixing part 12 which is provided on an upstream side of an inlet port of the spraying pump 3 for joining a flow passage F1 for making the fresh water from the fresh water tank 2 flow and a flow passage F2 for making the chemical from the chemical tank 11 flow a chemical pump 13 which is provided in the chemical flow passage F2 for pressure-feeding the chemical in the chemical tank 11 a three-way switching valve 14 for switching between feeding of the chemical pressure-fed by the chemical pump 13 to the mixing part 12 and returning of the chemical to the chemical tank 11 and a control part 5 for controlling the actuation of the chemical pump 13 and the switching of the three-way switching valve 14. The control part controls the chemical pump 13 at a fixed low pressure and switches the three-way switching valve 14 to the side for returning the chemical to the chemical tank 11 in halting the spraying, and switches the three-way switching valve 14 to the side for feeding the chemical to the mixing part 12 in spraying.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】散布開始の初期や散布・非散布の繰り返し時に希釈濃度を安定化させられる薬液散布装置を提供する。【解決手段】薬液が貯留される薬液タンク11と、清水が貯留される清水タンク2と、散布用ポンプ3と、散布用ノズル部4とを備え、散布用ポンプ3の入口上流側に設けられ、清水タンク2からの清水を流す流路F1と薬液タンク11からの薬液を流す流路F2とを合流させる混合部12と、薬液流路F2に設けられ、薬液タンク11内の薬液を圧送する薬液ポンプ13と、薬液ポンプ13によって圧送された薬液を混合部12に送るか薬液タンク11に戻すかを切り替える3方切り替え弁14と、薬液ポンプ13の作動と3方切り替え弁14の切り替えを制御する制御部5とを備え、散布停止時に薬液ポンプ13を一定の低圧に制御すると共に、3方切り替え弁14を薬液タンク11に戻す側に切り替え、散布時に3方切り替え弁14を混合部12に送る側に切り替える。【選択図】図1
