PROBLEM TO BE SOLVED: To provide a chemical liquid-mixing and spraying apparatus that prevents reversed flow of a spray solution mixed with a chemical liquid to a first tank.SOLUTION: A chemical liquid-mixing and spraying apparatus includes a suction channel 10 for connecting a first tank 2 to the suction side of a first pump 5, a force feed channel 11 for connecting the force feed side of the first pump 5 to a spray nozzle part 4, a chemical liquid supply route 20 that is connected to the joining part 17 of the suction channel 10 and supplies a chemical liquid in a second tank 3 to the suction channel 10, a second pump 6 for sending the chemical liquid in the second tank 3 to the joining part 17, a circulating flow route 13 for circulating the flow of the force feed channel 11 to the downstream side of the joining part 17 in the suction channel 10, a change valve 12 for changing a flow toward the spray nozzle part 4 to a flow toward the circulating flow route 13, a force feed condition detection means 16 for detecting the force feed condition of the force feed channel 11 at the downstream side of the change valve 12 and a control part 7 for controlling the drive of the second pump 6 on the basis of detection by the force feed condition detection means 16. The control part 7 reversely drives the second pump 6 only in a short period on the basis of a drop in flow rate detected by the force feed condition detection means 16.COPYRIGHT: (C)2014,JPO&INPIT【課題】第1タンク内に薬液の混合した散布液が逆流するのを防止する薬液混合散布装置の提供。【解決手段】第1タンク2と第1ポンプ5の吸引側を接続する吸引流路10と、第1ポンプ5の圧送側と散布ノズル部4を接続する圧送流路11と、吸引流路10の合流部17に接続されて第2タンク3の薬液を吸引流路10に供給する薬液供給路20と、第2タンク3の薬液を合流部17に送る第2ポンプ6と、圧送流路11の流れを吸引流路10における合流部17の下流側に環流する環流路13と、散布ノズル部4に向かう流れを環流路13への流れに切り替える切り替え弁12と、切り替え弁12の下流側で圧送流路11の圧送状態を検知する圧送状態検知手段16と、圧送状態検知手段16による検知に基づいて第2ポンプ6の駆動を制御する制御部7とを備え、制御部7は、圧送状態検知16が検知した流量低下に基づいて、第2ポンプ6を短期間だけ逆転駆動する。【選択図】図1
