The present invention relates to a cooling apparatus for circulating a cooled brine used for a freezing show case, a refrigerating show case, a freezer, a refrigerator and the like.
Conventionally, a freon refrigerant has been used as a refrigerant employed in a compression type refrigerating machine, however, by reconsidering an ozone layer breakage and an earth warming-up, it has been considered in a cooling apparatus to employ ammonia as a refrigerant. A flooded type cooling apparatus or a liquid circulating type cooling apparatus are described, for example, in Japanese Patent Unexamined Publication No. 10-170124 as a cooling apparatus employed in an ammonia freezer.
Further, in order to reduce an amount of the refrigerant sealed within a refrigerating cycle, it has been known to be proper to use a plate type heat exchanger represented by a herringbone plate, a corrugate plate and the like in an evaporator.
Since a large amount of refrigerant is required in the flooded type and liquid circulating type cooling apparatuses in accordance with the prior art, they do not address the problems of the ozone layer breakage and global warming, and it is necessary to sufficiently consider an efficiency, a risk and the like in the case of employing ammonia.
Further, in the case of using the plate type heat exchanger, it is necessary to consider a risk that an internal freezing is generated when a flow rate of the brine is reduced and a heat transmitting pipe forming the heat exchanger is clogged so as to be deformed or broken.