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MOISTURE CONTROL
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Best practice for controlling in-silo moisture levels by Bentall Rowlands
ith the capabilities to design, manufacture, supply, and install storage systems from an extensive range of products, Bentall Rowlands Storage Systems Limited is a leading UK manufacturer in complete storage and processing equipment solutions for the agricultural and industrial markets. They offer a wide range of galvanized steel silos and hoppers, water tanks, catwalks and platforms, material handling equipment, cleaning and grading and weighing and drying systems that are assembled worldwide. Providing a comprehensive end to end solution which can be designed to any specific clients’ requirements, Bentall Rowlands have designed and installed silos worldwide in countries that include the UK, Kenya, Thailand, Holland, France, Germany, Ukraine, Malawi, New Zealand and many more. Technical Director, Kevin Groom says, “Our storage systems are individually designed for all clients. Each project has a bespoke design that is sure to match, if not exceed clients’ expectations. We are extremely proud of the projects that we have undertaken in these geographically challenged areas, proving
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that whatever the specification, we are sure to provide the most suitable design necessary.”
Moisture levels and unwanted consequences
Getting the moisture levels right in a silo can be challenging but it is essential that the target level be reached within the shortest possible time. If this does not occur, the results would be the formation of mycotoxin and quality degradation. The main causes of spoilage in stored grain are fungi, insects and mites. Fungi are one of the main consequences of a variety of different moisture contents and temperatures stored in grain. In order to control this, a principal method known as drying and cooling needs to be put in place. No storage fungi will grow below a moisture content of 14.5 percent but they do continue to grow slowly at near 0°C. This means that cooling alone is not sufficient but the lower the temperature, the slower the rate of growth. Another nuisance are storage mites, which breed rapidly under favourable conditions and will cause direct damage to the grain by hollowing out oilseeds or eating the germ. Physical control methods are used for mites. If the grain is dried to 14.5 percent moisture content then the mites are unable to breed. If you cool the grain to 5°C, this can also help to prevent the build up of them. However, if you are storing oilseed rape, this is less susceptible to insect attack than cereals. This will protect the grain bulk, but during winter, the moisture