The case
The customer, a company in Russia, asks to be able to use a machine capable of drying about 200 tons of corn and 120 tons of soy in one day. This production need is combined with the necessity to dry and clean as quickly as possible for logistical and market reasons.
Based on the experience related to dryers installed in grain management and handling systems, therefore, Mecmar assisted the customer on the design and definition of the plant layout, consisting of:
- loading pit
- elevator for the wet product
- pre-cleaner
- loading hopper
- elevator for clean corn
- two silos for the wet and clean product
- Mecmar dryer
- elevator for the dry product
- two storage silos for the dried product
- conveyor belt
- unloading elevator
The loading area (1) is suitable for vehicles and allows for the accumulation of up to 200 tons of freshly threshed corn. To prevent the accumulation of organic product from rotting, thus ruining the fresh product, the tank is cleaned regularly (at least once a week).
Usually, dryers are equipped with integrated cleaning systems (gravity cleaner and extractor hood). However, the installation of a pre-cleaner (3) can be convenient, especially in medium-high production plants. Although it represents a fixed cost, the pre-cleaner is a benefit to any drying plant. In this way, the dust that covers the cereals is removed before ending up in the dryer, avoiding wasting energy to dry powder and focusing the drying energy to treat only the cereals.
The dust separated from the cleaner is accumulated in a special room; however, it is an organic product, reusable for bedding or feed.
If the pre-cleaner is able to process 20 tons of cereal in an hour, the silos for the wet and clean product (6) are filled in about four hours. Inside the plant there are also two silos for the storage (9) of the already dried product. While these are being filled, the dryer continues to operate. The Mecmar dryer (7) unloads the grain to an elevator (8) which has the function of filling one of the two silos intended to contain the dry product. From here, the cereal can be unloaded outside thanks to a special unloading elevator (11).
The presence of sensors allows the correct operation of the system to be monitored at all times, in particular with regard to augers and elevators and to follow the treatment and handling.
Drying of corn and soybeans
In order to be properly stored, corn should be dried when the moisture level of the grain is above 13%. To ensure optimal product storage, it is advisable to dry the cereal as soon as possible after harvesting. In this way, it is avoided that the grains are subjected to degenerative processes that could affect their quality.
Corn is a type of cereal that is rather robust to the drying process: in fact, it can be treated with air at high temperatures, even up to 120 °C, without compromising the strength of the grains. In this way, 5% moisture can be removed from the grain in just one hour.
It should be keep in mind that, by treating the corn with air at these temperatures, the grains are degerminated; therefore, if corn is to be dried by sowing, it is essential to reduce the drying temperature to below 60 °C.
Soybeans, on the other hand, are mainly used for animal feed, thanks to the vegetable fats and the high protein content it has, which help livestock to grow healthy and strong. Delicate and rich in proteins, soybeans need to be dried through a process that takes into account their fragility. Freshly harvested soybeans have a moisture content of 18-25%. To ensure that the cereal does not deteriorate, this level is lowered below 13%.
Advantages of the adopted solution
The system chosen to best meet customer needs is the MECMAR S 40/310 T2 mobile grain dryer. Belonging to the S series, this grain dryer is ideal for processing medium-large quantities of cereal. Unlike other Mecmar mobile grain dryers, its strong point is not its portability, but its larger dimensions, which allow high volumes of product to be dried in a shorter time.
The fact that the machine is telescopic allows for easier maintenance of some points, thanks to the possibility of lowering the extension tube (for example, to inspect tubes and augers).
The system developed together with the customer is extremely automated, in fact, from the entire line it is possible to manage the daily production and monitor the operation of the various parts of the system. The silos containing the wet or dry product allow to manage the single batches in a totally independent way, making the cleaning and drying process easier and more comfortable.
Thanks to the structure of the plant, it is very easy, as well as quick, to change the product, whether it is corn, soy or another cereal chosen by the customer. The shed that covers the plant allows you to always keep all the equipment repaired and in excellent condition, even when the weather conditions are adverse. In addition to this, the high height of the shed makes the plant scalable, so it can contain silos and dryers of increasingly important dimensions.
Published data refer to corn and are calculated with mathematical models that use clean and ripe products and in normal operating conditions with 120°C drying air temperature and one hour cool-down time. Please do not hesitate to contact the nearest Mecmar dealer for more information.
Under our policy of continuous improvement, we reserve the right to change specifications provided without prior notice.
