Grains, such as wheat, rice, barley, and many others, are harvested with a certain degree of moisture, which needs to be reduced to avoid the proliferation of microorganisms, mold growth, and product degradation during storage. We have seen in previous articles how forced-ventilation drying solutions are the most appropriate for drying grain quickly, efficiently, and cleanly.
But what is the exact temperature to best dry the grain? Is there one temperature that works for everyone?
As temperature for drying is a critical factor that affects the rate of moisture evaporation within the grain, it is important to find an optimal balance to ensure the highest quality of the dried product.
Therefore, in this article we will elaborate on the importance of temperature for drying grains and provide some guidelines for optimizing this key factor when drying. Follow along as you read!
Why should the temperature for drying be neither too low nor too high?
A low temperature tends to allow:
- Treat the product gently, not exposing the grains to high heat shock (typically a temperature of 40°C is used for rice).
- For some oilseeds, such as soybean or sunflower, it allows the oil in the seeds to be retained (so it is recommended not to exceed 55°C).
- Preserve the germinability of the grains for later processing (such as sowing or fermentation).
On the other hand, a low drying temperature lengthens the drying cycle of the grain, so productivity is reduced for the same machine.
Cereals that tolerate high drying temperatures (as high as 120°C for some corn varieties to get to remove 4% to 5% moisture per hour of drying) allow very fast drying, achieving high yields for the same dryer.
It should be remembered that the higher the drying temperature, the more important it is to follow and pay attention to the drying cycle so as to make sure that the flame combustion is well maintained and balanced so that the grain is continuously recirculated within the machine.
Ideal grain drying temperature: tips from Mecmar
Per un’essiccazione ottimale, al fine di non esporre il cereale a shock termici eccessivi, si consiglia di applicare un andamento della temperatura crescente nella fase iniziale di essiccazione e decrescente prima di iniziare il raffreddamento.
What factors should be considered to determine the combination that offers the best compromise between drying speed and production efficiency? To achieve the best results in grain drying, it is essential to pay attention to:
- The moisture level of the grain at the time of its harvest. Also, consider that some grains are more sensitive to mechanical and thermal effects. In fact, too high temperatures can cause it to crack or crack on the surface. This can make the grain more susceptible to contamination and spoilage, as well as reduce its commercial value.
- The final destination of the dried product (human food, animal feed, seeding or fermentation). The temperature used for drying must be adjusted to preserve the specific characteristics required for the end use of the grain-human and animal feed-while ensuring a high-quality product.
For optimal drying, in order not to expose the grain to excessive thermal shock, it is recommended that an increasing temperature trend be applied in the initial drying phase and a decreasing temperature trend be applied before cooling begins.
Before investing in the purchase of a dryer consider two aspects. On the one hand, the mechanical aspect of handling the grain to ensure homogeneous drying of the entire mass; on the other hand, it is essential that the dryer be equipped with a heat generation system that spreads the air evenly and controls the temperature precisely.
In this way we expose the grain to temperatures that are neither too high nor too low: only those that are optimal for the subsequent processing to be carried out.
Mecmar dryers guarantee variable grain drying temperatures depending on the moisture level and delicacy of the incoming grains, as well as the intended use and the conditions of the environment in which the dryer is working: the most informed choice you can make for your business.
At Mecmar we design and build mobile and tower dryers to help your business become more independent in processing and storing your crop, so that you can sell it only once you are happy with the price, without having to worry about its value diminishing over time. Contact us to learn more-our team is ready to answer all your questions.