Methods grain cleaning
One of the main grain quality criteria is the absence in it of impurities that may be dangerous to human health, as well as to influence the germination and the safety of the product. Since the harvested grain is always a part of various impurities, purification is an important step for its subsequent use in the food industry and agriculture.
Types of impurities
Harvest collected processor, called a heap. In addition to grain, it contains three kinds of impurities:
- Cereal. It is immature, damaged, sprouted grains and damaged by pests of the main culture. They are not harmful, but may affect the viability and shelf life of the product, as well as its nutritional value.
- Weed. They include stones, dust, sand, insect debris, chaff, straw, weeds and their seeds. They make up the lion's share in the purification of waste grain and bad for the quality of the crop.
- Harmful. In this category are hazardous to human health and animal and plant their seeds - the weeds, bitterling, cockle, ergot, etc.
Besides various impurities heap contains an excessive amount of moisture, which also must be disposed of. Standards of impurities and moisture government standards are set for each type of crops, depending on the nature of their use. For instance, for wheat trash content should be not more than 1%, and cereals - less than 3%.
How to clean the grain?
Initial purification is carried out more inside the combine, but this is insufficient. To permanently remove impurities pile must be processed in cleaning machines.
Cleaning takes place in three stages:
- Preliminary. This step is carried out no later than the day after the harvest. If the delay with the pre-treatment, the grain may increase humidity, and it began to sprout. In addition, the process of self-warming begins quickly, which seriously affects the quality of food. During the pre-treatment of the heap are removed the largest impurity.
- Primary. For its heap of humidity must be reduced to 18%. At this stage of the heap is removed most of the impurities of all sorts, whereupon their number should not exceed 3-4%.
- Secondary. This step is needed for the final separation of the impurities, and separation of the grain fractions on its value. Upon completion of this stage is divided into fodder grain and seed. Sometimes they perform more extensive separation, separating seed grain for seed and ware material.
The grain may also occur trudnootdelimye various impurities that are difficult to remove by conventional methods. For their screening need another cleaning step with the use of special equipment. For example, for removal of metal particles using magnetic grain separator.
Types of grain cleaners
Machines for cleaning grain separators are called - from the word separate, which means "to separate." Modern-cleaning machines can be divided into two types:
Simple shared heap into two fractions and often directed to the selection of any one type impurities. Complex may also be divided into several factions heap. In addition, these models can be a single machine, or the complex, where the grain passes from one another in a simple separator.
Classical separation often involves the use of sieve, air and indented grain cleaning machines:
- Sieve. These impurities are separated by means of various sieves. This allows you to work with different cultures and types of impurities.
- Air. Used to separate the light impurities. Most often, they constitute a vertical channel passing through which grain is blown by air. The air rises upward light impurities such as straw and husks, and leads them through the pipe.
- Indented. These machines are used to separate impurities puppeteer and wild oats. They are cylinders with cells which screened grain length.
These machines can be used individually, but most often are complex systems. Thus, most of the separators for primary air-cleaning sieve presented models. In addition to these classical purification grains can be used and other types of machines, e.g., magnetic, suction, etc. However, the classical methods of cleaning the grain heap always require the transmission of at least two-cleaning machines, as well as bear the loss of the product to 3-4%. An alternative to the classical methods of purification is to use aerodynamic separator.
What is an aerodynamic separator?
Such technology is relatively new, however, is already beginning to gradually replace classical methods of cleaning. The equipment is a large chamber having an impeller for circulating the air and sorting containers.
After falling asleep heap inside, he gets into a powerful stream of air. The air separates light impurities and will carry them to an opening in the end of the chamber. Heavy impurities are thus immediately fall vertically downwards into the container for the heavy waste. Qualitative grain continues its flight and separated into three fractions, and the residues purified from impurities.
Thus, one of our grain cleaning machine can perform a preliminary, primary, and secondary purification in just one pass. The use of these machines has a number of advantages:
- Saving. Besides the fact that the aerodynamic separator can replace several conventional, it consumes less electricity.
- Efficiency. After loading the waste into the aerodynamic separator of simple equipment, it is possible to obtain 30% of the grain quality. At the same time they are able to process up to 200 tons of harvest per hour.
- Versatility. In order to start working with other crops, only need to change the operating mode. Aerodynamic method allows you to clean all types of crops, as well as frozen berries and vegetable seeds.
- Reliability. The simple design, absence of complex parts and lubrication points makes the aerodynamic separators reliable and durable.