Discussion on feed expansion process and equipment

With the development of China's feed industry, feed expansion technology has become more and more important for the feed industry. Using the puffing technology, it can not only pre-treat certain feed ingredients, but also achieve sterilization, disinfection, and elimination of anti-nutritional factors, improve feed efficiency, reduce feeding costs, and especially superior to aquaculture, poultry, young animals and pets. .

As far as the application of feed expansion technology in China is concerned, it is still only in its infancy. Most of the expansion process of feed force and mouth labor is limited to the configuration of a single set of extruders in the process, and there is still a lack of comprehensive understanding of the supporting processes and equipment after the feed is expanded. To this end, this paper combines the advanced experience of foreign feed expansion to discuss the feed expansion process and equipment.

1 Feed Puffing Brief

1.1 The basic principle of feed puffing Feed puffing is a process of pre-treatment, pulverization, etc., which is subjected to pressurization, heating, humidification and quenching, and mechanically extruding the die hole to cause sudden depressurization and volume expansion. A method of manual labor.

1.2 Classification of feed puffing According to the processing method, it can be divided into extrusion puffing and gas hot pressing puffing; it can be divided into wet and dry puffing according to whether steam and water are added. (The screw extrusion is described herein).

1.3 The scope of feed expansion The raw material is puffed and the product is puffed. The expansion of the raw material is to pretreat the raw materials to improve the quality and utilization rate. For example, corn, soybeans, feather meal, etc.; product puffing is mainly for the processing of puffed aquatic animals such as suckling pigs, fish and shrimp and pet food.

2 feed expansion process

The feed expansion process described herein is based on the powdery compound feed production process, taking into account the raw material expansion and product expansion. Figure 1 is a block diagram of the feed expansion process.

2.1 The raw material puffing material is cleaned and pulverized and then enters the puffing machine. After the puffing, the cutting machine needs to be cut by the cutting machine and then enters the dryer. It does not need to be cut directly into the dryer, and then after cooling, crushing and screening, it is metered and packaged. .

2.2 Puffing of the product After mixing the powdered product, it can directly enter the process of puffing, cutting, drying, etc., but the raw materials such as puffed fish and shrimp need to be pulverized and then puffed. If the material to be dried needs to be sprayed with liquid (referring to oil, water-soluble vitamins), it should be sprayed before liquid cooling, crushing, sieving and metering.

3 main equipment for feed expansion process

3.1 Puffing machine

The extruder is the key equipment for the production of feed expansion. At present, the most widely used in the feed industry is the single-screw extruder. The single-screw extruder is divided into two types: wet type and dry type. The dry type extruder is only used for dry steam heating pre-conditioning before the raw material enters the extruder. The extruder itself does not have steam and water. The pressure and temperature in the chamber should not be too high, and it is mostly used for the expansion of feed ingredients, such as the expansion of full-fat soybeans.

The difference between the wet puffing machine and the dry puffing machine is that it can add steam to the steam in the conditioner and the steam, add water and temper, and add steam to the steam adding holes in the various sections of the expansion chamber, and some in the puffing machine. There is also a water adding device at the material inlet, which can add a certain amount of water according to different puffing materials. At the same time, in order to control the temperature of each section of the puffing chamber, each pipe sleeve has a water-cooled jacket, and the material moisture after the puffing is compared. High, need to be dried before cooling. The wet puffing machine can also be used as a dry puffing machine, but the screw head needs to be replaced. Wet puffing machines are often used to produce full-price feed products, such as dairy feed, fish and shrimp, and other aquatic feeds. Basic structure of the extruder

3.2 dryer

Dryer horizontal dryer, coulter type drying and cooling machine, fluidized bed dryer, drum dryer, etc. are commonly used in feed mills. This article only briefly describes horizontal dryers and coulter dryers.

The horizontal dryer uses a steam coil to force the hot air, and the hot air is introduced into the drying box by the fan. The drying box is provided with a single-layer or double-layer crawler type bed, and the drying material is dried. The thickness of the layer is adjusted by the adjustment mechanism after the machine and the material is evenly distributed over the entire width of the bed. Hot air passes through the bed with perforations, drying and dewatering the material running on the bed, and the humid air is discharged from the machine by an induced draft fan. The running speed of the material bed is adjusted by the stepless speed regulating motor, the material moisture is high, the running speed is slowed down, and vice versa. This dryer is more suitable for producing expanded pellets.

The coulter type drying and cooling machine is a device that integrates material drying and cooling. The machine consists of two parts: a drying section and a cooling section. The material first enters the drying section, and the drying section is heated by the fan. Hot air is introduced, and the material is heated and dried by hot air in the agitation tumbling of the coulter and gradually fed into the cooling section. The cooling section is ventilated by the air inlet which is opened at the outlet end, and is sucked by the air intake port provided in the middle of the device to obtain heat by exchanging heat between the material and the cold air. The device is more suitable for drying and cooling after the puffing of the feed material, such as drying and cooling after the full-fat soybean powder is puffed.

3.3 cooler

The more common coolers in feed mills have horizontal coolers. Drum coolers, counterflow pendulum coolers, vertical coolers, etc. This article briefly describes the horizontal cooler.

The horizontal cooler has two types: single layer and double layer. The basic structure consists of a feed adjustment mechanism, a parallel movable bed, a box with air inlet and suction port, and a speed governing mechanism. The material to be cooled is uniformly distributed on the material bed under the adjustment of the feed adjustment mechanism, and the material bed is slowly moved to the other end under the chain drag. The cold air enters through the air inlet and vertically passes through the material layer on the bed under the action of the suction fan, so as to absorb the heat and moisture of the material, thereby cooling and drying the material. The running speed of the material bed is adjusted according to the temperature and moisture condition of the material. The material temperature is high and the water is high and can be adjusted slowly. Otherwise, it can be adjusted appropriately. Generally, the running speed of the material bed is between 0.15 and 1.5 m/min.

3.4 Drum type liquid spraying machine

In general, after high temperature and high pressure puffing, the vitamin loss is large. To compensate for the lack of vitamins in the feed, a liquid sprayer can be used to spray the liquid vitamin in the feed. In addition, for some feeds with high fat content, such as adding high fat before puffing, the puffing effect will be reduced. For this reason, after the puffing, the feed is subjected to grease spraying with a liquid spraying machine, which can ensure the puffing effect and improve the feed. The fat content.

The liquid spraying machine is mostly drum type, and its basic structure is composed of a feeding device, a drum with a spiral blade on the inner wall, a liquid spraying machine and a motor driving device. The drum can be adjusted by the adjusting mechanism so that the feeding end and the discharging end have a certain inclination angle in the horizontal direction to facilitate the flow of the material to the outlet end. The material to be sprayed by liquid is introduced into the rotating drum by the feeding device, and is driven to the discharge port by the spiral blade of the inner wall of the drum. Two sets of nozzles are arranged in the middle of the drum, and the liquid to be added is under the action of the pump. The tank is pumped out and sent to the nozzle through the pipeline to spray the material, so that the surface of the material is filled with liquid and partially sucked into the material, and finally discharged from the discharge port. Under normal circumstances, the material is directly into the liquid spraying machine after puffing and drying. The dry heat material is good for liquid absorption, but it is cooled after spraying.

70°C Masking Tapes

SUNPLUS MASKING TAPE Professional Automotive High Temperature Resistance. With a high temperature resistant masking tape coated with rubber based and has good stick firmness.

70°C Masking Tapes,Automotive Masking Tape,Auto Paint Masking Tapes,Rubber Based Masking Tape

GUANGZHOU SUNPLUS TECHNOLOGY CO.,LTD , https://www.sunplussandpaper.com