The tea seed oil production line is a production equipment configuration from raw materials to finished tea seed oil. The process requires cleaning, peeling, crushing, steaming, pressing, refining and other processing steps to obtain healthy and high-quality tea seed oil. The main processes used in industrial production of tea seed oil include pressing and extraction. Pressing is a physical extraction process that does not add any additives during production, preserving the original flavor and nutrition of tea seed oil, which is in line with consumers’ green and healthy concepts. However, the oil yield is low, making it suitable for small capacity oil mills; The leaching process can fully extract residual oil from tea seed oil, further improve oil yield, reduce production costs, and improve the quality of tea seed meal, making it suitable for high-capacity oil factories.
The raw material for the production of rapeseed oil is generally rapeseed, with an oil content of 30%-48%. There are two main ways to prepare rapeseed oil, one is the pre-extraction method, and the other is the pressing method. From the perspective of return on investment, production projects with an output of more than 30 tons/day are suitable for the pre-expression leaching method. If the output is 1-10 tons/day, the cost of oil production by the pretreatment pressing method will be lower. The equipment used in the two production methods is also different.
Tea Seed Oil Production Line Introduction
Tea seed oil production line adopts low-temperature screw pressing technology to extract oil from raw tea seeds. The oil extraction production line is compact in design, has a small footprint, and it is easy to operate and easy to maintain. It is widely used in small and medium oil production plants.
Production process description of tea seed oil press line
Squeezing process: Rapeseed-cleaning-softening-piercing embryo-steaming and frying-pressing-crude oil
Extraction process: rapeseed-cleaning-softening-rolling-steaming-pre-pressing-leaching-one steaming-two steaming-steam stripping-crude oil
Raw material cleaning equipment
This part of the equipment is designed to remove impurities such as sediment, stones, branches, and leaves from tea seeds, avoiding their impact on oil yield, reducing oil quality, and accelerating equipment wear during production. If it is a manufacturer that directly purchases oil tea fruits, it is necessary to add equipment such as fruit peelers and dryers to remove the fruit shells and dry the tea seeds to ensure their dryness and avoid affecting subsequent processing. The commonly used raw material cleaning equipment in tea seed production lines include specific gravity stone removal machines, vibrating cleaning screens, dust collectors, etc.
Raw material pretreatment equipment
After drying, the tea seeds undergo a series of pretreatment processes such as shelling, crushing, steaming, and frying. The pretreatment process can adjust the structure and properties of the oil, improve the oil yield and quality of the oil, and is an important preparation work before oil pressing. Common tea seed pretreatment equipment includes hullers, crushers, steaming and frying pans, etc
Shelling and Separation
The impact mill is used to break the seed husk, and the husk is thin, and after drying, it contains few moistures and is easily broken. The requirements of shelling and kernel shell separation are: high shell breaking rate, no seed leakage, small powder degree; and there are two main indicators for the separation of kernel shells, that is, shell percentage in kernel and kernel percentage in the shell. Obviously, the lower the kernel percentage in the shell, the better the oil output rate, which is beneficial to the full utilization of raw materials and the increase of oil yield and cake yield.
The kernel percentage in the shell can be set to 0.3%. The shell percentage in the kernel is hoped to be as low as possible, but there are two points to consider: one is that, with a low shell content, the squeezing chamber of the oil press is easily locked by the pressed material, causing slippery buckling. The squeezing is difficult to carry out. The second is to consider the solvent leaching of the cake. When the cake contains fewer shells, there is no skeleton, the material layer is easily compacted, and the solvent penetrates difficultly, resulting in high residual oil in the oil cake, affecting leaching efficiency and solvent consumption. Based on the above two points, after repeated testing, we found that the best value for shelling is to separate about 75% of the tea seed shell content.
Crushing
A toothed roll crusher is used to crush the kernels containing a certain amount of shells. The purpose is to granulate and homogenize the seeds of different sizes so that they have the largest surface area and are conducive to the water conditioning. However, the degree of powder cannot be too large, so the spacing between the two-toothed rollers should be strictly controlled.
Tea seed oil extraction equipment
There are currently two commonly used processes for extracting tea seed oil in the industry: pressing and leaching. The equipment used includes spiral oil presses, hydraulic oil presses, and leaching equipment. Tea seed oil extraction is commonly used for extracting residual oil from tea seed cakes. The extraction process can fully extract the oil and fat in the tea seed cake, and the residual oil in the cake after extraction is controlled within 1%, reducing production costs and improving oil yield. However, there may be solvent residues in the extracted tea seed oil. Although they will be removed through processes or controlled within the national standard range, for consumers, the physical pressing of tea seed oil is more in line with their preferences. Therefore, most tea seed oil processing plants choose the pressing process to produce tea seed oil.
There are two types of tea seed oil presses: hydraulic oil press and spiral oil press. The oil extracted by hydraulic oil press is clear and of high quality; Spiral oil press has a high degree of automation and efficiency, but the quality of oil is not as good as hydraulic oil press. The specific equipment to be selected depends on the needs of the oil factory,
Crude oil refining of Tea seed oil production line
Crude oil-degumming-deacidification-decolorization-vacuum deodorization-edible oil
The pressed crude oil and the leached tea seed oil must be physically and chemically refined to become edible camellia oil. Because the content of gum in tea seed oil is not high, no special degumming process is required. Due to the consumption of tea seed oil has high requirements for acid value, color, and other impurities, deacidification, decolorization, and deodorization are essential procedures in the refining process.
Alkali refining
According to the properties and uses of tea seed oil, we adopt low-temperature alkali refining method. The initial temperature of crude oil is controlled at 25℃, and the added amount of alkali is based on the actual acid value of tea seed oil: (the amount of alkali= 7.1310-4oil weight*acid value), the concentration of alkali liquor is adjusted at 12.66%~14.35%, and the alkali liquor is required to be added in oil within 10 minutes.
In the beginning, the stirring speed is around 70r/min. After the alkali liquor is added, stirring should be continued and samples should be observed. When the soap particles are condensed and separated from the oil, the stirring speed is slowed down to 30r/min. At the same time, steam heating begins. The heating rate is controlled at about 1.5℃/min. Samples are observed again: When the soap particles are large and strong and are quickly separated from the oil, the steam heating should be stopped. Meanwhile, the salt water is added, then stirring is stopped, and keep the oil stand for precipitation. The general precipitation time requires more than 10 hours.
Washing
After alkali refining, the upper oil is sucked into a water washing pot, the oil is stirred and heated to about 80℃, then the oil is washed for 3 times with hot water at 85℃. The water content is about 10% of the oil weight, and the stirring speed should be slow during the washing process. The washing quality is tested by using pre-configured titration solution, and the qualifying standard is that the oil solution shows no obvious alkalinity.
Decoloring
The oil is inhaled into the decolorizing tank by vacuum pressure and heated up to 95℃. Then the oil is dehydrated for 20~30 minutes, and the moisture content is reduced to less than 0.1%. When the temperature drops to about 90℃, the oil is pumped into the vacuum dryer for drying. After drying, 97% of the oil is pumped into the decolorizing tower and 3% of the oil goes into the pulping tank and the clay is added into the decolorizing tower for decolorization, which requires a disposable inhalation. The decolorization time is controlled in 20 minutes, the vacuum degree is 97~99 KPa, finally, the oil is cooled to below 80℃ for filtration.
Deodorizing
The decolorized oil is sucked into the specially designed deodorization pot, and the temperature is first raised to 110℃ by indirect steam. Secondly, when the oil is heated up to 150℃ by heat-conductive oil, the direct steam is inputted into the pot.
While the temperature continues to increase to 240℃, at this time the sample is taken from the separator for observation, and the sample is retained for two hours and then compared with the new sample. If the sample color is faded and the consistency is reduced, switch off the direct steam valve. After another two hours, turn off the heating system and the direct steam, and then cool down the oil. When the oil temperature drops to 70℃, shut down the steam-jet pump to let the oil continue to cool until the oil temperature is around 25℃.
Nitrogen filling and packaging
The tea seed oil after deodorization is inhaled into the nitrogen filling tank, then the valve of the nitrogen tank is switched on, the nitrogen gas is filled into the oil, and the packing is carried out according to the required amount of nitrogen pressure. Generally, the oil is packaged in barrels in dark, dry place.
Both untreated oils produced by pressing and extraction processes are called crude oils. Crude oil does not meet the standards for edible oil, therefore it cannot be sold as a commodity. After being pressed by an oil press, the tea seed oil is subjected to simple filtration and then sent to a refining equipment to remove impurities, pigments, and harmful substances from the oil. After refining and removing impurities, tea seed oil that meets the standards for edible oil is obtained. The main refining processes include degumming, deacidification, decolorization, deodorization, and dewaxing. The tea seed oil refined through these processes can meet the standards of first-class tea seed oil.