Dried green peas.
In the production of dried green peas, round-seeded and marrowfat breeds are used. Treatment of these breeds allows to save green color and saleable condition when drying. Peas breed can be determined by their density. The raw material for dried green peas production is collected at the technical ripeness stage. At this stage, peas have not yet reached their ripeness, having indicative green color without any white spew. The immature peas contain the highest percentage of sugar and have high consumer value.
Raw materials collected in the field (pods separated from or with haulm) enter the plant in bags of 18 kg. Peas in grain can be in boxes of no more than 20 kg. Green peas should be transported in cold water (temperature of 5°C) in thermally insulated road-tankers. Grain storage duration is not more than 4 hours and for pods- not more than 10 hours.
The process of preparing peas for drying includes the following operations:
– peas pods thrashing,
– removal of extraneous impurities-heavy (rocks, mud) and lightweight (shells, leaves, peavine fragments, crushed pods);
Thrashing of peas pods. At this stage, peas are separated from shells of pods. Technological operations are performed on threshing or peeling machines.
Threshing equipment processes raw materials ready for threshing. The main working part of such equipment is a drum screen. The drum is located in cover and is slowly rotating around its axis. Inside the larger drum there is a small inner drum. The small drum is fitted with blades and rotates at a higher speed tcomparing with the large one. Cleaned peas pass through the grid surface and then transporter directs them to the next technological operation. When the process is finished, wastes are removed from the machine. Such wastes are rich in carbohydrates, nitrogenous agents and minerals; they are used as fodder for livestock or being buried into soil as fertilizer.
Viming equipment is designed to release seeds from pods. These machines have a rotating shaft with blades smashing the pods. The raw material is loaded into the reception bunker by elevator. From bunker, the raw material goes to the screw feeder, which moves it into the outer drum, covered with metal grid. The dimensions of holes in the grid are gradually increasing from the point of entry to the point of output. The inner drum consists of several sections with different hole sizes.
The inner surface of the outside drum is fortified with lags that raise the pods up and move them along the drum. Climbing up, the pods under gravity fall and put under the impact of inner drum.
Under the influence the pods are obstructed and the peas through the openings in the outer drum grid are placed on inclined conveyor designed to separate peas from the small particles of the pods passing through the holes in the outer drum grid. Peas having spherical shape, slide on inclined conveyor to collecting tank while flat pieces of pods are removed upwards by inclined conveyor where they are removed by scraping conveyor, moving perpenidiculary to the movement of inclined conveyor. At the end of the inner drum on its inner surface, the screw coils are mounted to bring the pods out of the machine.
Extraneous impurities removal. A special separator is used to remove extraneous impurities. It operates on the principle of shaker screen, and the process of sorting takes place due to in and out movements and the system of sieves. In general, three sieves with different holes are enough for this process.
-the first level with the largest openings skips peas and catches main wastes and impurities;
-the second level holds and separates medium-size impurities;
-the third level with openings holds the peas directly, outletting impurities.
In addition, if there is an aspirator built in the equipment so with the help of air flow generated by such aspirator light impurities come off, improving performance figures.
Washing. Recently threshed and peeled green peas are sent to the flotation washing machine. In such washing mashine the peas are rinseded under a shower and inspected on a conveyor belt.
While inspection residual extraneous impurities, shell fragments and damaged grains are removed.
Calibration. In general green peas are calibrated into two fractions: small and large. Processes following after calibration are performed separately for each fraction.
Inspection. A subsequent process of inspection of already calibrated green peas makes it possible to detect tramped foreign matters in total mass of raw materials. Each additional inspection improves the quality of finished product.
Blanching. To blanch green peas, water blanching machines are used. In this type of equipment an appropriate temperature mode of water is created where the product goes through heat-processing. During this process, peas should change their color from light green to dark green. Blanching process makes the product softer than raw materials, permitting to spend less resources on drying.
Drying. Having passed all the preparatory procedures green peas undergo drying in belt dryers. The end humidity should not exceed 14%. Dried peas are also inspected to remove from the total mass undried, burned, spoiled and defective peas. At the end of the process, finished product passes through metal catchers and are placed in appropriate packaging.