Fish Feed Machine Knowleagde

Production process of aquatic extruded feed
Aquatic Feed Net News Aquatic feed can be roughly divided into four types in terms of its shape. The first type is powdered feed, which is a kind of powdered feed as its name suggests; the second type is soft pellets. Feed, the third type is hard pellet feed; the fourth type is extruded feed.

Extruded aquatic feed is a kind of high-quality environmentally friendly feed with low pollution, less waste, high efficiency and high conversion rate. Choosing kneaded and extruded feed is an important method for producing high-quality and safe animal products and ensuring human health, and it is also a trend for the feed industry in the future. It is the inevitable trend of the development of aquatic feed industry with the theme of green environmental protection at present and even in the future.

1, the principle of puffing processing skills
The extruded feed uses the extruder and shear effects of the screw and screw sleeve in the extruder to heat up and pressurize the material, and extrude the high temperature and high pressure material out of the die hole, so that the volume expansion is completed due to sudden pressure reduction. Great craftsmanship. Puffing can be divided into dry and wet processing methods. Dry puffing processing does not need to add water in the original guess. The material has not been quenched and tempered when it enters the puffing cavity. The heat generated during the puffing process is all caused by the material passing through the screw under the effect of mechanical energy. Shear plates and the inner wall of the expansion cavity occur. The structure of the wet extruder is more messy than that of the dry extruder. When the material enters the extruder cavity, it has been quenched and tempered to improve the degree of maturation. In order to strengthen the control of the maturation process, the extruder is also equipped with a device for introducing steam and adding water. Assist heating or cooling.

The typical puffing process is: the crushed and mixed materials are sent to the conditioner to give a certain amount of moisture and temperature. The quenched and tempered mixture is sent to the puffing bin, and the material passes through different areas under the advancement of the high-speed rotating screw. The temperature and pressure of the material are gradually increased due to friction, and the pressure control lock between the areas further adjusts the pressure. Expansion temperature and pressure reach the maximum at the cone-shaped spiral of the extruder head. The temperature of the material rises to 135～160℃, and the pressure is 15～40 atmospheres. At this time, although the water temperature is higher than 100℃, the pressure is far higher. At one atmosphere, the jubilation phenomenon is avoided. Finally, when the material enters the atmospheric pressure environment through the ring die hole, the pressure suddenly decreases, the steam escapes quickly, and then the material swells strongly.

Now the more advanced wet puffing is attributed to the high-humidity, short-time puffing process, which is considered to be particularly suitable for processing plant protein, starch, and grain products that are widely used in animal feeding. HTST puffing is superior to other processing technologies because it effectively damages the growth inhibitory factors and kills harmful microorganisms in the original plant, and the nutrient components of the original plant are damaged to the greatest extent.

2. Characteristics of extruded aquatic feed
a. Long feed storage period
Because of the drying process, the aquatic extruded feed has lower moisture content, harder particles, reduced particle powdering rate, and most of the microorganisms and fungi are killed during the extruded process, so its shelf life is longer, which is convenient for storage and transportation. .

b, avoid feed waste
Aquatic extruded feed is very stable in water, generally insoluble within 2 hours (some up to more than 10 hours), so it can prevent the nutrient components in the feed from dissolving and losing in the water and the feed sinking into the mud, and the residual bait is also Simply picking up and drying, can avoid the waste of feed to the greatest extent. According to experiments, it is shown that the general selection of aquatic extruded feed can save feed by about 10% compared with powdered or hard pellet feed.

c. Reduce water pollution
Aquatic extruded feed does not dissolve or sink in water, so it can avoid residual fermentation of feed in the water, reducing the oxygen consumption of organic matter in the water, and then effectively polluting the groundwater quality.

d. Improve feed energy
Hard pellet feed is difficult to increase the amount of fat, but extruded feed can increase the fat according to the nutrient requirements of aquatic animals, so that the fat can be evenly dispersed in the feed, and the energy level can be improved to fully satisfy the growth needs of aquatic animals.

e. Avoid the onset of disease
Feed is extruded and treated with instantaneous high temperature, which can effectively kill E. coli, Salmonella and other pathogens, and the extruded feed has strong water (oil) absorption, which is convenient for the increase of disease prevention drugs. Then it can avoid the unclean feed and cause various digestive tract diseases.

f, easy to handle breeding
Aquatic extruded feed can be suspended on the water surface for a longer period of time. There is no need to set up a special feeding table when feeding, only fixed-point feeding is enough. Fish need to be out of the water when eating, and can directly investigate the feeding status of the fish, adjust the feeding amount in time, and understand the growth and health status of the fish in time. Therefore, the selection of aquatic extruded feed is helpful for scientific breeding management. It not only saves a lot of time, but also improves labor productivity.