Although the steel plate warehouse has thin wall, easy to form temperature difference inside and outside, large external influence (sunlight and other climatic factors), condensation phenomenon, uneven temperature distribution of grain pile and other factors, which bring some difficulties to safe grain storage, if we can take relatively perfect supporting measures for grain storage, especially carry out closed thermal insulation treatment for steel plate warehouse, master the law of steel plate stored grain, and make good use of the situation, we can also achieve safe grain storage. Generally speaking, the thermal insulation measures of steel plate warehouse include the following:
1. Spray thermal insulation coating. There are many kinds of thermal insulation coatings, among which the imported high-efficiency hollow ceramsite thermal insulation coating has a better effect. For example, the American shield coating was originally used on the outer wall of the space shuttle, which has a good effect of heat preservation, heat insulation and abrasion resistance. Before using the thermal insulation coating, the air tightness of the warehouse wall, top and other gaps still needs to be filled and blocked with polyurethane foaming material or resin glue. The thermal insulation effect of some thermal insulation coatings is equivalent to 150 ~ 200tran thick thermal insulation cotton, which can reduce the temperature in the warehouse by half, but the adhesion, aging performance and cost of thermal insulation coatings need to be further improved or reduced.
2. Japanese experts believe that the thermal insulation of steel silo is poor, and it is easy to cause grain dewing and mildew in high temperature season. The double wall steel plate warehouse is equipped with heat insulation layer and filled with heat insulation materials, which can achieve good sealing and heat insulation effect.
3. The outer wall of the steel silo is coated with reflective materials to minimize the heat absorption of the steel silo, so as to reduce the temperature change range of the grain storage temperature change area and avoid moisture transfer and mildew caused by moisture and heat exchange.
4. The United States once reported that when using the steel silo, as long as there is 10cm thick grain as the thermal insulation layer, the grain in the silo will not cause fever and mildew. Spraying a kind of chemical flame retardant and fireproof cellulose on the inner wall of the steel silo can play a good role in thermal insulation.
5. Studies in China and the United States believe that when using steel plate silos to store grain, for those with good heat resistance, such as wheat, the grain layer within 18cm from the cylinder wall is greatly affected by the external climate change, but the grain is a poor conductor of heat. This layer of grain can be regarded as a thermal insulation layer, which is beneficial to grain storage. In addition, the reasonable design of grain storage process ensures the safety of grain stored in steel plate silos. For grains with poor heat resistance, such as rice and barley, steel silo can be used for storage only when the grain storage process design is reasonable and the grain storage facilities are fully equipped, but it is not suitable for long-term storage. The steel plate warehouse built by Hengxin company for storing barley adopts polyurethane foam or rock wool board as the thermal insulation layer for the warehouse wall and top, and is surrounded by ultra-thin iron sheet. The barley storage effect is good. Due to the complete grain storage facilities, there is no problem in storage for one year.
6. Canada uses a laminated steel warehouse to enhance thermal insulation; The United Kingdom proposed the measure of painting the outer wall of steel plate warehouse white.
7. At present, polyurethane foam is generally used as the thermal insulation layer for the warehouse top; The silo body adopts 50 mm thick self extinguishing PE insulation board or rock wool board for thermal insulation treatment, and the joints of the insulation board are sealed with joint agent, which can enhance the thermal insulation performance of the steel silo.
In short, heat preservation, heat insulation and sealing are very important for the safe storage of grain in steel warehouse. It can reduce the contact between grain and external air, avoid the influence of external temperature and humidity, the infection of insects and the harm of rats and birds, and keep the grain temperature and moisture in the warehouse relatively stable; It can ensure the air tightness of the steel warehouse, maintain the effective concentration and ratio of fumigation gas in the warehouse, and enhance the ventilation, fumigation and insecticidal effect, so as to ensure the safe grain storage effect of the steel warehouse.
