Full-automatic cassava starch production line equipment
I. Production Process of Cassava Starch
Cassava selection, weighing and conveying, cleaning and conveying, cage cleaning, cleaning and conveying, coarse crushing, coarse crushing, pressure curved sieve, fine crushing, secondary to fifth curved sieve, desander, curved sieve and fine sieve, rotary filter, secondary disc separation, whitening, rotary filter, cyclone washing and refining, dehydration, airflow dryer and finished product packaging.
Second, the operation method (part of the process, operation introduction)
1. Selected raw materials:
The quality of starch is closely related to the selection and purchase of raw materials. Cassava flour output rate is low for less than 10 months, and the old cassava for more than 24 months has been degraded, causing greater difficulties in crushing and crushing, increasing the cost of rate reduction and affecting economic benefits. It is required that good raw materials must be put into storage in the first step.
2. Cleaning and transportation:
The purpose of cleaning is to remove sand, soil, peel and reduce starch ash, which is also convenient for the next process. Cleaning is carried out at the same time of conveying, so the feeding should be uniform, too many rotating cages have no gaps, cassava cannot roll, and the purpose of peeling and cleaning cannot be achieved. If there is too little, the production will not be reached. Operators should also pay attention to the pressure of water, the water pressure is too low to take away sediment, the general water pressure cannot be lower than 0.25Mpa, always pay attention to the operation of the rotating cage and conveyor, can't form a backlog of raw materials in the process. Machines are normally lubricated once every seven days.
Due to the long root of cassava, the part close to the main stem has been lignified, which cannot be pulverized without crushing. The first purpose of crushing is to ensure the normal operation of the crusher. Some factories do not have a crushing process to increase the crushing load and reduce the service life of the crusher. The second is to fully improve the yield and quality of starch and improve the yield of starch.
During operation, pay attention to the temperature of the motor and the sound of the machine. The sound suddenly decreases, indicating that there is too much material in the crusher. At this time, the feed rate should be reduced. The amount of return water should be added properly, so the crushed materials cannot be taken away without much water, thus causing waste. In addition, it is necessary to master the tightness of the triangular belt, which is too loose and reduces the efficiency of the crusher. Too tight will increase the motor load and damage the motor shaft, so the operators should concentrate, not leave the post and strictly follow the operation procedures. The quality of crushing directly affects the output of the class and the next process. The diameter of the crushed block is generally 1cm.
The crushed cassava (diameter about 1cm) pulp mixture enters a pulverizer for pulverization. The crushing process is divided into primary crushing and secondary crushing. Why should it be divided into two crushing? One is because cassava is too long and there are too many lignified substances. For example, once crushing, the yield of starch cannot meet the requirements. The other is that once crushing together destroys the starch quality of cassava, crushing large particles of cassava starch into small particles, which cannot fully free starch and increases the difficulty of filtering starch. So now we are divided into two crushing steps. The pulp residue after the first crushing step enters the first pressure curved screen to filter out the high-quality starch first. A certain amount of return water is added to the large residue under the first pressure curved screen to make it enter the second crushing step. The fine residue after the second crushing step enters the second pressure curved screen. This crushing process is the most advanced. It not only does not damage the quality of starch, but also adds return water during crushing to increase the starch yield by 3-5%.
Water consumption and starch yield are two important indicators in the economic accounting of starch factories. Therefore, in the process of using return water and adding clear water, a proper amount of return water must be mastered. The return water returned from the curved sieve must be in a certain amount and fully connected with the previous process. The amount of water used can take away the crushed materials without causing waste. After the pulverizer operates for one hour, contact the upper cover of the pulverizer bearing with the hand to see if the temperature rises, then observe if the motor temperature rises, and strictly control the feed rate. Because there are too many lignified materials, crushing is difficult. In case of abnormal operation of the machine, the machine should be shut down for cleaning. There is a square opening above the crusher. First, the upper part should be cleaned manually, then the bag should be connected to the opening, and the machine should be started to clean, thus the lignified crushed materials are completely discharged. When cleaning materials, special personnel shall be assigned to watch the start switch to prevent accidents.
At present, starch dehydration equipment can be divided into three categories: one is a three-legged feeding and discharging centrifuge, which has a high degree of labor. Second, the automatic scraper centrifuge, although operated automatically, consumes a large amount of electricity (30KW) and has expensive accessories (about 10,000 yuan per year). Thirdly, the vacuum rotary drum dehydrator equipped by our company at present consumes less power (8KW), is all stainless steel equipment, has low rotating speed (about 9-12 rpm), is not easy to damage, saves about 70% of energy saving effect compared with similar products, and is convenient to operate.
Before use, the vacuum rotary drum filter dehydrator rotates in the air and then puts in starch slurry. when the thickness of starch absorbed on the filter cloth surface of the machine is 5-6mm, adjust the scraper to scrape off starch. At the same time, keep starch with a thickness of 3-4mm on the filter cloth, adjust the pulp feeding speed and observe the dehydration effect. If the humidity of the material is too high to slow down the rotation speed of the machine, the dehydration effect will be better. Generally, the moisture content of dehydrated wet starch is better at about 39%, if the moisture content is high, the drying difficulty will increase.
It should be noted that the vacuum dehydration filter needs to be operated by professional personnel. Generally, it should not be disassembled randomly. When the equipment is running for a period of time, it should be cleaned in time to prevent acid substances from corroding the filter cloth. Dehydrated starch can be directly dried in a dryer.
The airflow collision dryer uses coal as fuel, and the hot airflow enters the heat exchanger, making the clean air entering the heat exchanger at the other end become dry hot air, which is sent to the drying tower to be mixed with wet starch with water content less than 40%, vaporizes the water in 2-3 seconds, and is discharged through the separator.
The drying tower adopts positive and negative pressure two-stage drying, wet air is discharged from the first stage, and air with higher temperature is discharged from the second stage, and enters the feed pipe for reuse. Compared with single-stage drying, energy can be saved by 20-40%.
The feeding conveyor adopts stepless speed change and can be adjusted arbitrarily according to different climates and materials.