Peanut oil press
Peanut oil press
Production process of peanut oil pressing machine
1 Cleaning: the same equipment used for ordinary secondary oil
2 Classification: The immature grains, moldy grains, broken grains and other imperfect grains in peanuts are separated with a classification screen. This part can be used for the production of secondary oil and sold separately.
3 Drying/cooling: hot air dryer can be used for drying. After the peanuts are dried, the moisture content is controlled at 5%~6%. Then quickly use cold air to reduce the temperature of the oil particles to below 40℃.
4 Crushing/Peeling: The crusher can be used with tooth roller crusher, the purpose is to remove the infrared clothing. After crushing, the infrared clothing is sucked out with a wind separator or a suction flat screen. The separated peanut red skin can be used as medicine and chemical industry. raw material.
5 Hot air roasting: send 25%~30% of the peanuts to the coal-fired hot air roaster, where the oil is heated to 180℃~200℃. The temperature of roasting is the key factor for the aroma of peanut oil. The temperature is too low, the aroma is light; the temperature is too high, the oil is easy to lake.
6 Cooling and rolling grits: In order to prevent the oil from gelatinizing and spontaneous combustion, it should be quickly cooled and cooled after baking, and after cooling, it should be rolled into a granular shape with a tooth roller crusher.
7 Steaming: "The five-layer vertical steaming pan is used to steam and fry the green body. The 1st ~ 2nd layer of the filling should be full to play the role of steaming; the 3rd ~ 5th layer of the filling should be shallow to remove moisture The output temperature is 108℃～112℃, and the water content is 5%～7%. In order to ensure the rich aroma of peanut oil, the indirect steam pressure of the steaming boiler should not be less than 0.6mpa.
8 Oil extraction: This process uses a 200-type screw oil press. Taking into account the particularity of the production process of Luzhou-flavored peanut oil, the spindle speed of the oil press is appropriately adjusted. The spindle speed is increased from the original 8 rpm to 10 rpm, and is appropriate The thickness of the thick cake is generally controlled at about 10mm. The pressing temperature is 135℃, the pressing moisture is 1.5% to 2%, and the residual oil of the machine pressed cake is 9% to 10%.
The crude oil obtained is precipitated, filtered with a vertical blade filter and sent to the refining workshop
Peanut oil refining specific operation method
(1) Fast delivery of peanut oil Before the filter press crude oil is pumped into the refining tank, it is necessary to check whether the pipeline valves are normal. After the oil is delivered to each tank, the oil inlet valve should be closed immediately. The crude peanut oil to be refined into the oil tank must be cleaned of the oil surface foam to make the oil surface smooth, and allowed to stand for an appropriate time (not less than 15min) so that there is no foam in the oil. Adjust the crude oil temperature to 25-35℃.
(2) Preparation of alkaline solution Weigh out a specified amount of NaOH (purity must be identified first), mix with appropriate amount of water and stir, start the alkaline pump, and circulate the alkaline solution to completely dissolve the NaOH. Reduce the temperature of the lye to 25--30°C, let it stand for 20 minutes, measure the Baume degree of the lye with a Baume meter, and adjust to 10--12°Be.
(3) When the alkali mixing surface is smooth and the temperature is stable at 25-35℃, start the stirrer to start stirring. First, turn it slowly (20r/min) to stir for 1min, then change to fast turn (40r/min), and stir at the same time , Open the valve of the alkali tank and put the alkali solution. The time for adding lye is generally about 15 minutes. After the lye is placed, continue to rotate and stir until the oil and soap particles are clearly separated. The stirring time is about 3-3.5 hours. When the oil and soap feet are clearly separated, change to slow stirring, open the heating steam door (steam pressure 1.4kgf/C㎡), and increase the temperature of the oil to 60℃ (the oil temperature should be kept at 1℃/min, the highest The temperature must not exceed 65°C) Stop stirring immediately, close the steam valve and allow it to cool and settle on its own (precipitation time is about 8h). After checking that the pipeline of the delivery oil valve is normal, pump the oil into the water washing tank. When pumping to the interface between the oil and the soap foot, it must be highly careful not to pump the soap foot out, and at the same time, the oil must be pumped out.
(4) Water washing Heat up the oil pumped into the washing tank, and at the same time start the stirrer to add 75-80 ℃ hot water to keep the oil temperature at 80-85 ℃ (temperature must not exceed 85 ℃). When the water is added (the amount of water added is 15%-20% of the amount of oil, the time of water addition is 38-40 minutes), stop heating and continue stirring for 15min, that is, stirring is stopped, precipitation 2h (first time), the bottom of the tank is washed with water The drain valve is opened, and about 3/4 of the washing water is discharged (before removing the washing water, first put the oil remaining in the pipeline into the oil-water separation tank to recover). Then close the drain valve, open the valve to the oil-water separation tank, and slowly put the remaining oil-water mixture into it. During the first water wash, all the viscous material in the oil-water intermediate layer must be placed in the separation tank until the oil is seen, and then the valve should be closed.
Separation of oil and water must be controlled by a special person. When separating in the separation tank, the heating coil in the tank must be opened to increase the temperature (not more than 80 ℃). After the separation, the water is released and the residual oil is recovered.
Follow the above method to continue washing the oil machine until the washing water is completely clear, and the precipitation time of the second water washing is 1.5h.
(5) Before the dehydration transportation, check whether the related pipeline valves are normal, and then pump the water-washed oil into the vacuum dehydration tank, at the same time open the steam valve, start the vacuum pump and agitator, adjust the cooling water of the condenser, and start the circulating oil pump to accelerate The circulation of oil in the vacuum dehydration tank. The vacuum degree of the vacuum dehydration tank is kept above 0.0867MPa. The dehydration time is about 3h. After the oil is transported from the dehydration tank, the dehydrated oil should be sampled and inspected by the quality inspector. When dehydration is found to be insufficient, dehydration must be continued. The dehydration temperature is maintained at about 70°C.
After dehydration is complete, stop the vacuum pump, open the air valve, and slowly add air. Check whether the pipeline valve is normal, and then transfer the oil to 25--30°C through the cooling pipe and flow into the sedimentation tank to prepare for pressure filtration.
(6) Filter press Check whether the valve of the filter press is normal. Check the oil temperature must be below 30 ℃. After the oil is filtered, stop the oil filter pump and close the valve, gently open the filter plate to let the internal oil flow into the oil pan, and then remove the filter residue on the filter cloth. Check the usage of the filter cloth and prepare for replacement or washing. The residual oil of the filter cloth should be separated and recovered by centrifuge.
(7) Residual oil recovery Use the oil-water separation tank to separate the recovered oil and refining it. The filter cloth with residual oil is folded neatly and evenly, put into the centrifuge, after separation, the residual oil is recovered and refined. When the centrifuge is in operation, the speed of the centrifuge must be strictly controlled, and it will gradually increase from slow to fast when starting. If you need to stop in the middle of the rotation, you should stop the motor, but when the centrifuge is not completely still, it is absolutely not allowed to continue to open.
The amount of caustic soda added and the concentration of lye depend on the acid value and the content of impurities in the pressure-filtered crude peanut oil. If the acid value is high, the amount of alkali required to neutralize free fatty acids is higher, the concentration is higher, the acid value is lower, the alkali content is less, and the concentrated bottom is lower. When there are many impurities, the amount of super-alkali is more. According to the impurity content of peanut oil, the super-alkali amount is generally 0.1%-0.2%. However, the components collected in the crude oil are complex. For example, the acid value and impurities alone determine the amount of alkali and the concentration of the lye, and sometimes they may not be able to obtain good results. Therefore, it is best to do a small cup test before refining. The alkali addition temperature must not be too high. After neutralization with alkali, the oil temperature is increased to destroy its emulsified state, so that the soap particles and oil are completely separated. The stirring speed when adding alkali to neutralize should be fast, the purpose is to make the lye fully contact with the oil, so that the free fatty acids in the oil can be quickly neutralized. After the free fatty acids are completely neutralized, the stirring should be slow during the heating period to prevent the formation The soap granules are broken into small granules and difficult to sink. Then wash with water to remove traces of soap particles and free alkali dissolved in the oil. After being washed with water, peanut oil has a high water content (0.3%), and it is easy to change the quality during storage, so it must be dehydrated. The final process of refining is cold and pressure filtration to remove waxy substances contained in the oil.