PROBLEM TO BE SOLVED: To provide a box ship capable of maintaining an acid treatment liquid at a desired pH value. Kind Code: A1 A box-shaped ship provided with an acid treatment tank for storing an acid treatment liquid, and a pair of winding rolls provided in the acid treatment tank for winding a laver net to which nori adheres. The pH sensor is provided in the tank to detect the pH of the acid treatment solution, and the stock solution discharge part that discharges the acid stock solution is provided at a position that does not interfere with the laver net wound on the take-up roll. And a stock solution supply device for automatically adjusting the supply amount of the acid stock solution to be supplied to the stock solution discharge section based on the stock solution discharge section. The stock solution discharge section is provided behind each take-up roll with respect to the intrusion direction of the nori net. [Selection diagram] Figure 1【課題】酸処理液を所望のｐＨ値に維持することが可能な箱型船を提供する。【解決手段】酸処理液を貯留する酸処理槽と、該酸処理槽内に設けられ、海苔が付着した海苔網を巻き取る一対の巻取ロールとを備える箱型船であって、酸処理槽に設けられ、酸処理液のｐＨを検出するｐＨセンサと、巻取ロールに巻き取られる海苔網と干渉しない位置に設けられ、酸原液を吐出する原液吐出部と、ｐＨセンサの検出値に基づいて原液吐出部に供給する酸原液の供給量を自動調節する原液供給装置とを備え、原液吐出部は海苔網の侵入方向に対して各々の巻取ロールの後方に設けられている。【選択図】図１
