A continuous sterilizing apparatus in which a hot water storage vessel is mounted within a pressure tank held at a high pressure and an article to be sterilized is moved through the hot water in the hot water storage vessel by a conveyor means such as chain or the like and is thereby sterilized continuously, is already known.
In such conventional continuous sterilizing apparatus, the hot water storage vessel is formed of a thin plate material into a box-like shape and this box-like vessel is directly mounted within the tank. And in the case of mounting a cooling water storage vessel together with the hot water storage vessel, both are mounted in contact with each other within the tank. In a certain conventional construction, moreover, a cooling water is charged directly into the tank and the hot water storage tank is mounted within the tank while being surrounded with the cooling water. Consequently, the hot water in the hot water storage vessel is always in a state of heat dissipation and also in a state of being cooled by the cooling water. In any case, a very large heat loss has heretofore been unavoidable.
Further, according to the foregoing conventional continuous sterilizing apparatus, the article to be sterilized passes through both hot water and cooling water as mentioned above, and this movement of the article under sterilization is performed by means of chain, and since bearings are mounted directly in the hot water storage vessel, sprockets which guide the movement of the chain undergo a direct influence of heat. Besides, the chain has heretofore been driven by a single, rotatably mounted, driving sprocket. When the chain, which is fairly long, is driven by a single driving sprocket, a large force is exerted thereon, so it is necessary to use a strong and thick chain. But since the chain passes through both cooling water and hot water together with the article to be sterilized, the use of a thick chain, namely, the use of a chain having a large heat capacity, leads to a larger heat loss in the hot water and cooling water storage vessels.
Thus, the conventional continuous sterilizing apparatus inevitably undergoes a large heat loss which is attributable to the structure of the hot water storage vessel and also to the size of the chain. And in order to compensate for such heat loss, there has heretofore been consumed heat energy in an amount larger than necessary.
In an effort to remedy such drawback, the present inventor has previously proposed an invention (see Japanese Patent Laid Open Publication No. 129677/1982) in which a cooling water storage vessel and a hot water storage vessel are mounted separately from each other. the former having a double structure with a heat insulating material being packed therebetween to diminish heat loss, and plural sprockets are let serve as driving sprockets thereby permitting the use of a thinner chain to diminish heat loss induced by the chain. However, reduction in size and weight of chain and sprockets results in the chain and sprockets being easily affected by heat, so that there arises another problem such as elongation of the chain and distortion of the sprockets. This phenomenon tends to be conspicuous particularly in hot water sterilization under pressure, that is, when the chain and sprockets are driven in hot water at 100.degree. C. or higher. In view of such an inconvenience, the present invention further improves the above invention to minimize the influence of heat upon sprockets and chain in hot water at 100.degree. C. or higher.