Depending on genetically modified food sources can be divided into plant genetically modified food, genetically modified yeast vaccines, antibiotics, genetically engineered bacteria, animal and microbial genetically modified food genetically modified foods.
Species of edible vegetable oil
Currently there are families of edible vegetable oil, peanut oil, rapeseed oil, soybean oil, cottonseed oil, sesame oil, sunflower oil, a lot of species. To identify the various oils, it is necessary to understand the characteristics of various types of oil.
Peanut oil: oil color yello
w, fine smell peanut flavor, oil foam micro white.
Rapeseed oil: greenish, fragrant taste in the mouth a little spicy, oil foam yellow.
Soybean Oil: Oil deep yellow color, beany large mouth taste astringency, oil foam white.
Cottonseed oil: Oil yellowish color, no taste tasting, oil foam yellow.
Sesame oil: reddish brown, smell, taste has a deep flavor.
Sunflower oil: color, clear and transparent, aromatic and delicious.
oil processing in operation, the preform processed into the hopper, oil from the hopper into the press bore. Screw a screw to in advance by pressing, the preform is in running condition in the press the squeezing chamber, in the squeezing chamber under conditions of high pressure, friction force between the blank and many of the screw, the press bore. The main is to make the friction material blank and blank, resulting in relative motion. On the other hand, root diameter screw is gradually enlarged, when the screw motion, thread the preform can move forward and can be turned outwards, material layer and near the screw thread surface with the pressing shaft to rotate, so that the oil plant chamber in each blank particles are not equal with Fang Xiangyun. The particles also exist between the relative motion. There is friction heat and meet a heat required for oil of process operation, help to promote the protein thermal denaturation of billet, destruction of the colloid, increased the plastic, but also reduce the oil viscosity, easy to press out the oil, thus improving the oil press oil rate.
The hydraulic press is the oil pressure, oil press the oil pressure in static state.According to the power source pump has two types of manual and electric; byapplying pressure to the blank form can be divided into vertical and horizontal.Vertical hydraulic oil press (Figure 1) has 1 cylinder is fixed on the base, the cylinderwith cylindrical piston, piston upper part and pie plate are connected into a whole.Blank after pre pressed into a round cake, cake circle coat, with 20 ~ 40 round cakestacked between the pie plate and roof, bread and cake between separated by thinplate with holes, driving the piston top, pressure, oil press cake. Pumps stoppedpressing, pressing after the whereabouts of the piston, the cake unloading, reinstalled on the cake, so repeated intermittent oil, each pressing one of about 2 ~ 5 hours.
The electric pump can form a circulation oil system, control of several hydraulic press operations at the same time. Horizontal hydraulic press. The structure and workingprinciple and vertical is basically the same, the installation is convenient, the oil flow is smooth, cake circle does not accumulate oil; but covers an area of large, need a backpressing with the hammer, a pulley or a screw mechanism. Hydraulic press pressure,a high rate of oil, a few moving parts, convenient repair and maintenance; the labor intensity is big cake handling.
Oil production efficiency and capacity of technical and economic indexes of machineoil, is the preferred conditions on product evaluation of user. Only meet the pressprocess conditions, and continuous press 24 hours (at least one shift), in order to achieve good economic benefit. Determine the oil efficiency and production capacity,technical and economic indicators, is the mean value refers to the continuous work.So, when pressed to stop or only crush tens of kilograms, hundreds of kilograms ofoil, not to have the good economic benefits, but also not as evaluation of evidence.
It should be pointed out, some users use the "oil rate" (that is, per 100 kg of oil can besqueezed out of several kilograms of fat) concept, this is not scientific argument. How much oil, process, and raw material oil and the rate is related to the mode ofoperation. As a stereotypical screw press, mainly to ensure the oil extraction efficiencyand residual oil rate.
1. the operator
The main reasons are the unskilled, operation skills are not high, don't abide by the rules; be negligent, poor quality consciousness operation; personnel does not close;the effective use of the low rate of equipment.
The new machine while the quality inspection of the factory, but after the storage,handling, transportation, may cause damage. Especially the installation of improper adjustment, assembly quality is poor, not in the correct use and maintenance of safety operation procedures, will enable the machine can not function. Man-made repaircomplex troubleshooting, accident, directly affect the product quality and production capacity. The opening of the new machine, derusting, must be carried out on the press bore running, try pressing, try to raise the pressing chamber temperature in formal pressing, keeping the feed - the cake.
High quality raw materials containing impurities, lower level, will directly affect the oilproduction efficiency and capacity. For the harvest, exposure, transportation and storage process, the impurity band into organic impurities (such as plant stems and leaves, husks, grass, hemp rope,
A piece of cloth, paper and all kinds of grain, inorganic impurities such as dust, dirt,gravel, tile, etc.) and oily impurity (pest grain, grain and oilseed not dissimilar metal impurities (such), nails, screws, etc.) shall be cleaned, screening the use of machinery and equipment, and according to the practical application of pretreatment processprocess.
Processing environment, should meet the requirements of oil producing process.Prepare production tools and process the necessary (such as pre processing andreprocessing) equipment, to improve production efficiency, reduce the invalid labor,ensure the machining process
1 pressing water and pressing temperature
Countless facts have proved, although the machine behavior control is good, but because of pressing water and pressing temperature control is not good or unstable,equally difficult to produce normal effect. Pressing water and temperature affected thestock of physical properties and chemical process.
The results of the theoretical research shows: blank should have the appropriate moisture and temperature, namely blank fluidity, oil viscosity and surface tension tominimize, ensure material embryo plastic and elastic appropriate, to keep pressing chamber pressure is normal. The actual test also indicated that: blank pressing water content can not be less than the limit of the suitable range into cakes, while pressingtemperature 110 ～ 130 ℃.
If the water is too high, will make the material embryo produces clumps of oil andwater; too low, material were pressed into powder, easy to coke instead of blockingbore. Similarly, if the temperature is too high, the material in the embryo carbohydratecoking, protein and other ingredients are destroyed, color darker, affect the oil quality;on the contrary, when the temperature is too low, the physical changes of normal andbiochemical condition cannot form.
Pressing water and temperature, usually by the pretreatment process to achieve.
Practice has proved that, in general, the "hot press method" in the oil extraction efficiency and economic benefit are significantly better than that of cold pressing. The"cold pressing method", will cause the pressing times increasing, daily processing capacity of greatly reduced, residual oil rate increased, consumption increased power,economic decline. It should be pointed out that, by using the cold pressing, because the oil with high moisture content, press the cake is not easy to be broken; secondpress, easily overhead in the hopper, effects of feeding and often stirring,troublesome operation, poor efficiency. Therefore, where possible, should try to use"hot press method".
2, the press bore pressure
The essence of pressing oil, is putting pressure on the stock removal of grease. Main reasons affecting the pressing chamber pressure is the cake thickness, feed quantity and quality of pretreatment (pressing the moisture and temperature etc.). The cakethickness and the oil efficiency relationship. The cake is thicker, the press borepressure is small, load is small, low oil yield; on the contrary, the cake is thin, high oil yield efficiency. But the thin, it will increase the machine load, causing the accident.The feed quantity should be controlled in a moderate flow, in order to avoid the "bypass' 'phenomenon, pressing chamber pressure to maintain the normal stable.
3, the time of pressing
Press time and the efficiency of oil has certain correlation. Generally, press time, oil flows out of a man, but the press time not too long, otherwise more heat loss, but the impact of the oil production efficiency and capacity. Therefore, in the premise ofefficiency of oil, as far as possible to shorten the time of pressing. The residence time of material embryo in the press bore, mainly depend on the screw shaft speed,followed by screw pressing ring recency and cake thickness. For some high oil content oilseed, can prolong the time of pressing, should choose the appropriatespeed.
SYL series spiral oil press belonging to the "high speed Griddle Cake", the so-called"high speed", refers to the spindle speed, feed the embryo in the press bore short residence time (generally only tens of seconds); the so-called "Griddle Cake" is that the cake thickness 1.5 ~ 3 mm, therefore, screw and the pressing ring wear phasequickly when. According to experience, usually 40 ~ 50 tons of rapeseed processingneed to check, partial replacement of wearing parts (especially the 3 - 4 screw and the adjustable cake). Since the 6YL series spiral oil press press time is short, for some oil (such as soybean protein and cold pressing, etc.) is good, but other oilfurther reduce residual oil rate is subject to certain restrictions, for different fuel, there should be a corresponding spindle speed.
4, pressing chamber temperature
The process of squeezing, squeezing chamber temperature directly affects theefficiency of oil, oil quality. The squeezing chamber temperature internal frictioncaused by external Fu heating mature embryo and pressing ring and the screw shaftsurface friction heat, stock turnover and heat generation, compensation metal bodyheat loss, to maintain the proper temperature required by the press. Howeverpressing chamber temperature is too high, will lead to oil and cake color even coke,total oils loss increased. Therefore, must establish the press bore heat balance between normal.