1. Cleaning: Before cleaning, put the rapeseed into a bamboo basket, crush the mud (mud) with your feet, and then sieve. Remove ash impurities lighter than rapeseed with windmill. Then, impurities larger or smaller than rapeseed are removed by coarse screen and fine screen respectively.
2. Stir-fry seeds: use a sandwich pot (two pots can also be used together), and grass ash or fine sand can be placed in the interlayer. At the beginning of the speculation, the firepower can be slightly larger. After about 0.5 hours, the rape in the pot crackled, just to control the firepower. The fire should be suppressed 10 minutes before the rapeseed is taken out of the pot. When the temperature of rapeseed in the pot reaches 1 15 ~ 120℃ and the rapeseed shreds are golden yellow, the pot can be taken out. Always turn it over when frying.
3. Grinding: the grinding should be smooth, the height of the grinding center should be adjusted, the feed should be uniform, and the large and small seeds should be separated, so that the whole seed will not be produced during grinding. When grinding seeds, you should always turn over and sweep. When the first blank is about to be taken out of the tank, about 3% of coarse chaff or about 2% of 3 cm long straw core is added for mixing, and the extrusion thickness is less than 0.2 cm. After adding the specified coarse chaff or grass core, the blank can be steamed directly.
4. Steaming: steam the first blank for about 2 minutes, and steam the second blank for 25 minutes. When steaming, you should constantly add water to the pot to make up for the loss. The steam waist shall not leak, and the fire coal shall be added evenly. A layer of brown should be added to the bottom of the retort to protect the retort from sticking to the blank. At this time, the boiler water should be changed frequently.
5. Bread wrapping pressure: double lap for the first time, single lap for the second time, scattered wrapping, concentrated pressing, quick wrapping, and flat stepping. It's better to spread grass and make cakes.
6, squeezing: knocking, diligent. Quickly compact the cake, lightly press it after draining, and frequently press it. After 1 hour, most of the oil was extruded, and the pressure was increased by re-stirring and slow stirring. The bat should be even and straight, and the top and bottom tips should be even. The first pass took 3 hours, and the oil yield was 90%. The second pass took 4 hours, and it was squeezed out the next morning. To prevent the cold wind from blowing, cover the extrusion with insulation board or sack.