Some Experiments on Temperature and Humidity in the Container : Methods for Protecting Sweat Damage

Abstract

Temperature and humidity of inside and outside of a model container (80×80×200cm in dimensions) are measured. Obtained results are as foollows: (1) Relative humidity in a closed dry container is controlled almost of the same values by evaporation or absorption of water vapor from the side board and the floor board. (2) It is possible to remove moisture from the air inside the container by means of ventilation. To increase the ventilating speed, it is necessary to improve the methods of stowage of cargo. (3) The moisture content in the container also considerably increases by the stevedore's long time work for loading. (4) Possibility of sweat damage increases by the evaporation of moisture from the carton wet by the rain. (5) Quantity of evaporated or absorpted water vapor from the side board and the floor board is estimated in both case of a closed container and mechanically ventilated one. (6) For protecting sweat damage in a dry container, the side board and the floor board must be dry as much as possible, and moistureless cargoes and packages are desierable. The vapor pressure in equilibrium moisture condition of cargo must be kept lower than that of the inside air of a container under the condition decided by the heat transmission in the wall of the container, the route of the ocean voyage, the season of the voyage and the sorts of the cargo.