Ozone has sterilization, disinfection, and deodorization effects due to its high oxidation power, and also has the property of decomposing into oxygen to become harmless as time passes. Accordingly, ozone is effective for preservation of perishable foods, purification of water, etc. However, since ozone easily decomposes into oxygen, ozone has a drawback that it cannot be stored for a long period of time. Thus, ice containing ozone has been produced by cooling down and freezing ozonated water in which ozone is dissolved in a high concentration.
For example, Publication of Examined Japanese Patent Application No. 08-27111 discloses a method for producing ice containing ozone, wherein ozonated water is sealed in a bag made of synthetic resin unreactive to ozone, and the bag containing the ozonated water is quick-frozen to produce ice containing ozone.
Furthermore, Japanese Laid-Open Patent Publication No. 2000-39239 discloses an apparatus for producing ice containing ozone. The apparatus includes an ozonated water manufacturing device for producing water containing ozone; an ozonated water packing device for filling vessels made of a resin with the ozonated water produced by the ozonated water manufacturing device through a water filling pipe, and for sealing water supply ports disposed at the vessels; and an ice making device for immersing packages in which the ozonated water is housed and sealed by the ozonated water packing device in liquid refrigerant, and for successively conveying the packages to make ice from the ozonated water in the resin vessels.
Still furthermore, Japanese Laid-Open Patent Publication No. 09-105570 discloses an apparatus for manufacturing ice containing ozone, wherein ozonated water is injected into a freezing cylinder provided with an auger so as to freeze the ozonated water, and ice containing ozone produced on an inner wall of the freezing cylinder is shaved using the auger.
Yet furthermore, Japanese Laid-Open Patent Publication No. 10-267476 discloses a method for manufacturing ice containing ozone. In the method, ozonated water is brought into contact with a member having a smooth surface cooled to 0° C. or less to generate ice containing ozone, the ice containing ozone is forcibly scraped off to manufacture cracked or foil-shaped ice, and a mixture of the ice pieces and water or the ice pieces and the ozonated water is cooled down to obtain block-shaped ice containing ozone.
However, the conventional methods for producing ice containing ozone have problems to be solved as follows.
In the arts disclosed in Publication of Examined Japanese Patent Application No. 08-27111 and Japanese Laid-Open Patent Publication No. 2000-39239, the ozonated water is fed into the container, and the container is cooled down in the coolant to form ice containing ozone. This brings about problems that the apparatus is complicated in structure and increased in size, and that production of the ice containing ozone requires a great deal of time and work.
In the arts disclosed in Japanese Laid-Open Patent Publication Nos. 09-105570, 10-267476, the ozonated water is cooled down to produce the ice containing ozone, the ice is scraped off into the ice pieces, and furthermore, the ice pieces are formed into the block-shaped ice containing ozone. This causes a problem that it takes time and labor to manufacture the ice containing ozone. Another problem is that ozone bubbles generated in the cooling step are emitted from the ozonated water into the air, and thereby less ozone is enclosed in the ice containing ozone.