For the purpose of increasing in the terms of safe storage of rice grain with optimum technological humidity and the excluding of losses the installation or processing of rice wet grain by organic preservative before laying on storage was developed. The installation belongs to the equipment for preservation of wet grain with use of phase transition of pre-servative and is intended for rice-grain processing by pre- servative in the stream. It contains a horizontal screw con-veyor with two steam chambers, one of which covers its cas-ing, and the second is located in the body of the screw, the means of loading and unloading grain, a container with propi-onic acid and a boiler, adjacent to steam chambers connected in turn through the nozzle openings with the cavity of convey-or housing. The use of installation allows to increase the uni-formity of distribution of the preservative in canned grain mass, the reliability of sterilization of grain by increasing the probability of destruction acid resistant forms of microflora and significantly reduce the consumption of propionic acid by increasing the uniformity of its distribution on the surface of the grains and minimize the thickness formed on the surface of the film of propionic acid, as well as to improve the food safety of the rice grain. The grain of optimum technological humidity processed on the offered installation grain of rice can be stored up to 6 months, and then recycled in wet condition, while increasing the total yield of cereals and, in particular, the whole kernel by reducing the cracking of endosperm grains when peeling and grinding and by eliminating the dry-ing process of rice-grain. Technical result of using offered installation is uniformity of distribution of preservative in pre-served grain weight, full suppression of development of all forms of microflora on processed grain. The design of installa-tion allows increasing the probability of destruction not only vegetative, but also sporous forms of the microorganisms occupying grain weight at generation in the stream of propion-ic acid of ultrasonic fluctuations.