PROBLEM TO BE SOLVED: To provide a nourishing solution circulating sterilization apparatus 2 which supplies carbon dioxide necessary for indoor culture to suppress a reduction thereof, reduces the necessity of purchasing and supplying the carbon dioxide separately, prolongs a burning time of a gas heater 42 to stably supply carbon dioxide by passing through a constant temperature tank 43, while achieving the reduction of running cost, and can secure the circulating sterilization of a nourishing solution, furthermore, can miniaturize entire apparatus, and can be manufactured inexpensively.SOLUTION: A heat sterilization apparatus 4 is composed of a body tank 41 which comprises a heat sterilization apparatus 4 interior of which a spiral-tubes body 411 for coil type heat exchange and a constant temperature tank 43 for controlling the constant temperature by the accumulation flow of a nourishing solution in sterilization are provided and a gas heater 42 which heats water for water-bath in the tank. An unsterilized used nourishing solution sent from the cultivation bed 11 and a sterilized nourishing solution subjected to heat sterilization in the heat sterilization apparatus 4 are sent out to the cultivation bed 11 through a heat exchanger 3 for performing heat exchange.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】 室内栽培に必要な二酸化炭素を供給してその減少を抑制し、別途二酸化炭素を購入供給する必要性を少なくし、ランニングコストの低減化を図ると共に、定温化タンク43を経由することで、ガス加熱器42による燃焼時間を長くして二酸化炭素を安定供給し、かつ養液の確実な循環殺菌が行え、しかも、装置全体が小型化され安価に製作できる養液循環殺菌装置2を提供する。【解決手段】 加熱殺菌装置4を、その内部にコイル式熱交換用の螺旋管体411と殺菌中養液を蓄積流動して定温化する定温化タンク43とが設けられた加熱殺菌装置4を備える本体タンク41と、該タンク内湯煎水を加熱するガス加熱器42とで構成し、栽培ベッド11から送られる使用済み未殺菌養液と、加熱殺菌装置4で加熱殺菌された殺菌済み養液とを、熱交換器3を介して熱交換を行なって栽培ベッド11へ送出する。【選択図】 図1
