Feed Milling Articles and Resources | FeedMachinery.com

Tips for appearance quality control of extruded feed

Sun, 26 Apr 2015 13:34:14 +0000

The preference of good-looking products on the fiercely competing market have had feed manufactures pay more attentions to the appearance quality of extruded feed pellets. Muyang therefore in here offers some operational tips to help eliminate appearance problems and add value to feed extrusion productions, with the support of our experienced service technicians. The most common problems on the appearance of extruded feed are size difference, irregular shape, and poor pellet surface smoothness. Size difference Size differences between feed pellets are inevitable in extrusion productions. An acceptable range therefore is defined to identify whether a pellet is qualified in size or not. Pellets that size in the range are “uniform” and qualified, while out of the range are nonconforming products and should not be delivered to customers. For example, feed pellets that extruded out from 3.0mm die openings if ranging from 4.2mm to 5.0mm are acceptable, while of 3.5mm or φ6.0mm diameter is unacceptable. Therefore, to control extrusion process and prevent nonuniform finished pellets from production is very important. There are four conditions, under any of which pellets of non-uniform sizes will be produced: 1) Feed mash and water added into the conditioner cannot be evenly mixed with each other because water added into the conditioner is not sufficiently atomized. In this case, the water atomizing nozzle should be checked and cleaned thoroughly to make it free of any blockage. 2) Die holes blocked by large ground particles or foreign matters (usually are accumulated residues), especially when extruding small pellets. Production problems in this case are easy to be identified. The finished pellets usually are uniform at the beginning of production, but this performance cannot sustain for a long time and pellets in large size and small size generated. In this case, it has to stop the extruder to clean the die holes. In order to avoid die hole blockage, the ground particle size of raw material should not exceed 1/3 of the die hole. 3) Screw is worn out and end of life. This situation can be identified through the clearance between chamber inner wall and screw flight profile. The normal clearance is 1.5mm-2.0mm. When it larger than 5mm, pellets in different sizes are produced. In this case, it is necessary to replace the worn screw with a new one. 4) Feed flow unevenly distributed to discharge at Venture tube because of severe wearing loss of the distributing cone. In this case, the distributing cone should be replaced with a new one. Quality problems related to pellet shape include unshaped pellets and pellets of irregular cutting ends. The reasons why such problems would rise are: Irregular shape 1) Improper number of blades on the cutting knife, and improper knife speed. As we all know, no matter what kinds of extruded feed to be produced, the knife speed should not larger than 1,000RPM. And the number of blades on knife can be varied to meet the needs of the specific sizing job, especially when producing products in large size, too many blades will result in extruded pellets of wedge-shape. 2) Incorrect installation of knife blades. This problem usually refers to knife blade that cannot be installed to touch the surface of die plate, and usually generate pellets with burrs or uneven cutting ends, especially when hard blades are used for cutting. In this case, readjust the installation of knife blades. And if soft blades are used, it is better to adjust the blades to touch the die plate with a tiny deformation. 3) Fiber residues adhering on knife blades. This is because the feed formula being treated is rich in fiber, which is not easily cut by knife blades, especially with soft ones. As the result, pellets of uneven cutting ends are produced. This problem could be improved if hard blades are applied, or to substitute other material that with lower fiber content for the fiber-rich material in feed formula, or to use a sieve with finer holes for grinding. 4) Knife blades are broken because of the presence of hard foreign matters. In this case, broken blades should be replaced with new ones. Poor pellet surface smoothness In order to bring down energy consumption, many feed mills adopt hammer mills with sieve apertures larger than 1.0mm for secondary grinding in extrusion production. The large ground particles reduce the surface smoothness of pellet products. Therefore, it is recommended to employ an ultra-fine pulverizer for the final grinding process, so as to ensure there are 85% ground particles passing through an 80 mesh screen. by Muyang

Energy efficiency improving & pellet uniformity control in the extrusion of aquafeed

Sun, 26 Apr 2015 13:13:56 +0000

To substantially improve extruder performance in aquafeed production, in recent years Muyang Group made research efforts in five aspects and gained some achievements : to increase energy efficiency of extruder, to enhance pellet uniformity, to lengthen service life of wear parts, to increase production rate of sinking aquafeed as well as that of micro-aquafeed, among which, the energy efficiency improving technology and its application as well as the development on pellet uniformity control will be introduced in the present article. 1. How did Muyang increase energy efficiency of the extruder system With the development of extrusion technology, one of the development trends in aquafeed milling is that extruder is taking the place of pellet mill and becomes the most popular and most efficient milling machine because of its flexible production adaptability, high product quality and high sanitation assurance. However, the obstacle impeding extruder popularization is energy input, which must be decreased. As we all know, sufficient energy is required to put into the extrusion system to sustain the whole extrusion process, from material conditioning to kneading, shearing, cooking, extruding, forming and finally obtaining qualified aquafeed. Essentially, the input energy is normally defined into two forms: the specific mechanical energy (SME) and the specific thermal energy (STE). Analyzing from the energy inputs that required for cooking the raw recipe components, there are three possible ways to improve energy efficiency of an extrusion system, i.e. to increase production capacity while decrease the power consumption: (1) Improve the utilization efficiency of SME; (2) Improve the utilization efficiency of STE; (3) Try to input and utilize most STE from the relatively cheaper source -- steam to substitute some SME input. 1.1 Method to maximize SME utilization First of all, the approach was studied to match the SEM input with that required for material ripening. If lower than that required, the input SME could not ripen the material sufficiently even though it would result in higher production capacity, vice versa. Therefore, only proper SME input can guarantee high quality extruded aquafeed while maximizing production capacity. By quantifying the abilities of each screw segment (including conveying, shearing and mixing abilities) and testing the effects of different screw combinations, Muyang extruder research team found out the optimal screw configuration that can achieve proper SEM input for a given auquafeed production task. Based on above mentioned studies and a perceptual as well as rational knowledge of extrusion technology, Muyang extrusion team worked out a new concept — “stabilized shearing”. Usually, the whole extrusion process that material undergoes, from being fed into the extruding chamber up to being extruded out of the die plate, is a “hasty shearing” process accompanied by high pressure, high power consumption and high wearing of working parts, and also unconstant discharge of extrudates. The stabilized shearing technology brought by Muyang Group can largely stabilize the shearing efficiency in the whole extrusion process (see Fig.1). The optimal screw configuration can not only impart extrusion process proper SME inputs but also ensure the product gelatinization not less than that of the “hasty shearing technology”. It has been proven that, when producing aquafeed with the stabilized shearing technology, an extruder can increase the capacity by 15% with an energy savage of 12% per ton of feed. 1.2 Method to maximize STE utilization Aquafeed mash needs to be pre-cooked in the conditioner by hot steam before entering into the extruder chamber for extrusion. How to maximize the utilization of thermal energy from a given amount of steam to improve the gelatinization of aquafeed mash in the conditioner has been the focus of Muyang’s research efforts for years. The moisture and heat of steam is hard to penetrate into the core of feed mash particles and “cook” them just by the simple physical mixing function of a conventional conditioner, especially for the oil-rich aquafeed mash. That means more steam and longer conditioning time has to be given in order to achieve high mash gelatinization. Targeting the goal of improving steam utilization and enhancing feed gelatinization, Muyang has invented the “reinforced conditioning technology”, which can improve the mass and heat transfer efficiency and uniformity of steam effectively. In addition, Muyang has innovated the SPTZ series Complex Conditioner by combining the reinforced conditioning technology with a Muyang SCTZ DDC Conditioner, which achieves excellent conditioning performance. See Table 1 and Fig.2. Besides, the production capacity of an extrusion system equipped with a SPTZ Complex Conditioner is able to increase by 10-15% compared to that with a common DDC conditioner, because of the thorough pre-cooking function in the conditioning process. Furthermore, the enhanced pre-cooking could bring in more stable running of the machine and less wear of the working parts such as the segmented screws and extruding chamber liner, which alternatively is saving maintenance cost. 1.3 Substitute SME with steam thermal energy As we all know, the same energy in steam thermal form is far cheaper than that in electric power form. And the SME input to a running extruder always comes from electric power supply. What if some part of the required electric power is substituted with steam thermal energy, the production cost of aquafeed will be decreased significantly. During cooking, the amount of steam thermal energy utilized by feed mash is determined by conditioner pressure. For instance, conditioned by saturated steam, the highest conditioning temperature that feed mash can achieve is 100oC under 0.1MPa while can reach 164.19oC under 0.6MPa. Therefore, on one hand to make full use of steam thermal energy under ambient condition, on the other hand to optimize the conditioning pressure and maximize the steam energy utilization. The more the steam energy being utilized by feed mash, the less the SME required for extrusion. The “substituting SME with steam thermal energy” technology is widely used in the Muyang extruders and has been proven to be an effective and economic way. 2. How did Muyang control pellet uniformity in aquafeed extrusion Good pellet uniformity and pleasing appearance are the important and attractive characters for high quality aquafeed. However, the relationship between good pellet uniformity and high production capacity is hard to balance, just like you can’t have your cake and eat it too, especially for the single-screw extruder. As the production capacity increases, the pellet uniformity declines. Usually, good pellet uniformity can be gained when the extruder is running at 70~80% of its rated load. Essentially, the nonuniform extruded pellets are generated by materials lacking homogeneity in the whole feed milling process. From grinding to mixing, conditioning, extruding and forming, material’s lack of proper homogeneity in any of these processes will finally cause nonuniform extruded pellets. Fortunately, material homogeneity in the grinding, mixing and conditioning processes is easy to be controlled with available techniques. The most challenge is to control feed mash homogeneity during extruding. What are the causes of nonuniform feed mash during extruding? See Fig.3 (1) Nonuniform shearing force. The more difference of shearing force brought by extruding screw stressing on feed mash, the more nonuniform gelatinization and the more nonuniform pellet finally achieved. (2) Different flow rate. Flow rate of feed mash during extruding could be different in two zones: the screw zone and the non-screw zone (between the end of screw and the die plate). The different flow rate of feed mash in the extruder will cause different ripening time, and different gelatinization as well as different pellets quality accordingly. For a normal extruder, the difference of shearing force and that of flow rate are related to production capacity. The larger the actual capacity that is close to the rated value, the bigger the difference of shearing force and that of flow rate. In view of above impacting factors, Muyang has developed the so called “turbulent flow extruding technology” to control pellet uniformity in aquafeed extrusion (See Fig.4). It is applied to well distribute the shearing force in the screw zone and to unify the flow rate in both the screw zone and to unify the non-screw zone (between end of screw and die plate) in an extruder chamber. The turbulent flow extruding technology can help extruder (especially the single-screw extruder) perform outstandingly in aquafeed production. 3. Application of Muyang innovations By integrating the stabilized shearing technology and the reinforced conditioning technology as well as the turbulent flow extruding technology in one extruder, Muyang rolled out the MY120×2 I Twin-screw Extruder in Nov. 2009. With many sets’ reliably running in customers’ feed mills for more than one year, the MY120×2 I Twin-screw Extruder has been proven to perform well in energy efficiency improving and pellet uniformity control. by Ma Liang, Zhang Guiyang, Mi Changyu, Zhang Wenliang Muyang

Aquafeed extrusion: production process explained

Sun, 26 Apr 2015 12:47:13 +0000

Driven by the increasing consumption of fish meat due to world population boom and the limitation of wild catch, volume growth rate of global aquaculture has been sustained at about 8% over the last 10 years, and must continuously undergo a tremendous development in order to fill the huge gap between supply and demand for the premier protein sources. This represents a divine opportunity and a promising future for the aquafeed industry. The unique physiology of aquatic animal is asking for special requirements in aquafeed manufacturing technology. This article will discuss the complete solution for aquafeed manufacturing based on Muyang’s years of experience as an aquafeed mill supplier and builder in such aquaculture regions as Asia, Latin America, etc. 1. Requirements of aquafeed 1) Grinding fineness: Proper particle size of ground materials can contribute to lower energy consumption of a feed mill, facilitate the subsequent conditioning process, increase the water stability of aquafeed pellets, and eventually obtain nutritional aquafeed that benefits the digestibility of aquatic animals. 2) Size of feed pellet: It is depending on the size of aquatic animal to be fed and its feeding habits. 3) Water stability: 45~90 min for shrimp feed and 5~30 min for common fish feed. 4) Floating / Sinking ability: Different aquatic animal species live in different depths of water (shallow water, middle water and deep water) and different habitats. Therefore, the feed for different aquatic animals should be sustainable in corresponding depths. 5) Palatability: Most of aquatic animals favor feed of special color, scent and flavor. 2. Aquafeed processing technology and equipment Both pelleting process and extrusion process are adaptable to aquafeed production. As the development of aquaculture, however feed extrusion technology is more and more popular in the aquafeed production because of its well- balanced nutrition, the excellent water stability, and most of all, the environment friendliness. Usually, the common (pre-grinding) aquafeed extrusion process flow is as Fig 1. 2.1 Raw material receiving and cleaning The designed capacity for raw material intake in an aquafeed mill shall be 2~3 times of its production capacity. For materials of different properties, special cleaning operation should be carried out where it is received. For instance, granular materials can be cleaned with a Muyang Drum Precleaner and the powdery materials with a Muyang Conical Precleaner, under the assistant of an aspiration system. 2.2 Primary grinding As the pretreatment of fine- grinding or ultra-fine grinding in aquafeed production, primary grinding (or coarse grinding) is designed to diminish the difference in and the variation of material particle size, to improve the working performance and working efficiency of the pulverizer thereof, and to ensure constant quality of finished products. 2.3 Primary proportioning and batch mixing In such processing section, the major ingredients, i.e. the ingredients of larger proportion in aquafeed formulation, are batched by an electronically controlled proportioning system, and then sent to the mixer for primary mixing. Primary proportioning and batch mixing are designed to limit the variation of material particle size before ultra-fine grinding, so as to further ensure constant quality of finished product. The proportioning bins in this process section should be designed to have a storage capacity to sustain the 4~6 hours’ uninterrupted production of subsequent process. 2.4 Secondary grinding Eating little, short digestive tract as well as bad digestibility of the aquatic animals require finely ground feed particles. See Table 1, Standard of grinding fineness for different aquafeed in China. Secondary grinding usually is executed by a specialised pulveriser (ultra-fine grinding) or a fine-grinding hammermill in Muyang solutions. 2.5 Secondary proportioning and batch mixing The finely ground ingredients are fed into the other mixer for secondary batch mixing after proportioning. Usually, a manual feeding inlet is provided for adding micro ingredients into the secondary mixing mixer. And also two liquid application devices are furnished for adding water and oil respectively. 2.6 Extrusion and drying 1) Conditioning Preconditioning is used to properly condition the material before the follow-up extruder cooking stage so as to supplies the extruder with a uniformly mixed and hydrated material by mechanical stirring and adding saturated steam. Under the turning and blending efforts of conditioner paddles, the moisture content of mash is uniform and the temperature is steady eventually. Conditioning brings such advantages for extrusion as follows (see Table 2). 2) Extrusion Extrusion process is mainly executed by an extruder that is basically composed of a stationary barrel housing in which such elements as segmented screws and shearlocks rotates, fulfilling extrusion operation together with a disc and knife assembly. There are two kinds of extruders that might be used in aquafeed production: the single-screw extruder and the twin- screw extruder. Single-screw extruder: As its name implies, a single-screw extruder has only one extruding screw and is of simple structure, so its price is relatively lower. Since it has been applied in aquafeed manufacturing for over 40 years, the single-screw extruding technology becomes mature, and the working performance is relative stable and reliable. Traditionally, single-screw extruders are widely used for producing the feeds for low protein adult fishes such as tilapia, catfish fish, grass carp, etc. Besides, for the cultivation of different fish species in lake, the grinding fineness of feed only requires that 95% of ground particles should pass through the screen of 30~50 mesh, which can be achieved by a common grinding process without ultra-fine grinding. In such case, the advantages of a single-screw extruder are obvious and superb, because of its low equipment cost and high production efficiency. Twin-screw extruder: The twin- screw extruder is characterised by its wide adaptability, sliding conveying in the barrel and self-cleaning function, etc. However, it is relatively expensive due to the high primary investment and operation and maintenance costs. Therefore, the twin-screw extruder is usually applied in the production of petfood and feed for high value-added aquatic animals such as eels, soft-shelled turtle and young fish. For other special aquafeed production like the production of micro aquafeed (pellet size: Φ0.8~1.5mm), oil-rich aquafeed and the aquafeeds with changeable formulas, the twin screw extruder is of genuine differentiation. Refer to Table 3 above for the differences between single-screw extruder and twin-screw extruder (co-rotation screws) with the same capacity. 3) Drying Once the product leaves the extrusion system, a drying step is required to remove the excess water and return the product back to a shelf-stable moisture condition. It is recommended to apply a crossflow dryer for drying wet extrudates, in which moisture and heat of product is exchanged with a perpendicular airflow. 2.7 Coating and cooling If necessary, liquid fats, flavours, and vitamins can be added externally to extruded feeds after drying. Post liquid application by coating will not only avoid the risk of damaging heat sensitive ingredients, but also improve the palatability and reduce powder generation of the finished product. After coating, extruded aquafeed is cooled as required. 2.8 Bagging When bagging aquafeed, the amount of air entrained in the bag or that penetrating into the bag should be controlled to a minimum, so as to prevent feed from oxidation and deterioration. Therefore, it is recommended to close the bag through sewing plus heat sealing (plastic film lining), which can prolong the shelf life of finished product by 50-100%. 3. Conclusion Aquafeed production solutions are different from case to case. They should be tailor-made on the basis of a good understanding of the customers’ needs, the local market’s requirements and the aquatic animals to be cultivated. The equipment and process applied for an aquafeed mill shall be optimised by considering the long-term sustainable profitability. Muyang extrusion aquafeed milling solution for CITICO Feed Following are the solution details of a classical floating fish feed production line that Muyang provided to CITICO Feed in Sichuan Province, China. As a full-line aquafeed mill, the plant also includes three pelleting lines (one preserved for further expansion). The feed mill is a turnkey project delivered by Muyang Group. Technical requirements of the extrusion line: 1. Floating fish feed, 4t/h 2. Proportioning accuracy: static 0.1%FS, dynamic 0.3% FS 3. Mixing homogeneity: CV≤7% 4. Dust concentration: ≤10 mg/m3 5. Noise level of central control room: ≤75dB(A) 6. Plant automation system: computer control system by Zheng Zhenhua Muyang

Producing small expanded pellets by single-screw aquafeed extruder

Sun, 26 Apr 2015 10:44:19 +0000

At present, aquafeed extruder has won some popularity in aquafeed industry. Expanded aquafeed, as a high- quality feed species featuring high feed intake, high conversion efficiency and environment-friendly advantage, has been more and more well recognized and accepted in market. With the enhancement of extrusion technology, more and more feed manufacturers would like to produce small pellet aquafeed through direct extrusion cooking instead of pelleting-crushing. The diameter of die hole for the extruder for aquafeed usually is 1.2 mm or 1.0 mm or 0.8 mm. Even a die with 0.6 mm die holes is required for producing expanded aquafeed in some feed mills. To produce small particle aquafeed by pelleting-crushing is more convenient and the cost is relatively lower. However, due to its high ingredients cost, high starch content, bad water stability and higher reworking rate, manufacturers would like to produce small pellet aquafeed by extruding directly, which has many advantages such as low ingredients cost, less fines generated, good water stability and pleasant appearance. However, producing small aquafeed pellets directly by extruding has a relatively high processing cost because of technological complexity, especially when extruding with a 0.6 mm- hole die. On the other hand, the productivity reduction makes strict limits to technological configuration, resulting in a high processing cost. Hereby, we’d like to discuss the requirements of technological configuration, technical parameters and relative attention points for the production of small pellet aquafeed, by ataking a 1.0 mm-die-hole single- screw extruder as an example. 1. Requirements for material fineness before extruding Producing small pellet aquafeed by extruder makes strict requirements on the grinding fineness of raw materials. Theoretically, if 100% of ground material can pass through a 60-mesh screen, the extruder with a die of 1.0 mm die holes will be able to work normally. However, production practices have proved that the material of such fineness will cause die holes blockage after the extruder has run for a period of time. In this case, the coefficient of expansion will be turned large, the length of the extrudates will become longer as well. When more and more holes are blocked, the length of the pellet will not be able to satisfy the requirement even if the cutter speed is adjusted to the upper limit. Finally, the machine has to be stopped for cleaning the die holes. To enable the extruder to run stably for a long time, it is suggested to have such a grinding fineness that 100% (at least 98%) ground material can pass through a 80-mesh screen, and also the diameter of the biggest overs should not exceed 0.3 mm. With such particle fineness, the extruder can operate stably for a long time, and since the ground material is finer, the expanded pellets can obtain a smooth and pleasant appearance. 2. Requirements for and control of the equipment before extrusion The processes prior to extrusion are grinding and sifting, so it is the grinder and the sifter that will guarantee the fineness of material to be extruded. 2.1 Requirements for and control of grinder The selection of grinder is the key of the whole process design. The grinding fineness is required to reach 80 meshes. Generally, a vertical pulverizer is adopted for grinding because the existing common hammer mill cannot meet the requirement. In addition, strict requirements are asked for the operating of ultra-fine pulverizer. Take the Muyang ultra-fine pulverizer as an example, the fineness of ground material is controlled by adjusting the rotating speed of the grading impeller on the pulverizer. In order to ensure the material fineness for common fish feed, the transducer of the grading impeller usually should be controlled to about 40HZ, and the door of fan should be adjusted to have an opening about 20%. After that, slowly increase the feeding rate till the load on main motor has been increased to over 90% of full load, and then let the pulverizer run stably. In this case, the fineness of product ground by the pulverizer is usually over 80 meshes. 2.2 Requirements for and control of sifter There will be a little of large particles mixed in the ground product after grinding. Meanwhile, there are also some latent impurities in the product during processing. Besides, some light fiber cannot be ground during grinding. If the mash mixed with big particles, impurities and fiber finally be sent to the extruder, part of them will possibly be “melted”, however, others will block the die holes when they just arrive there. Even if some fibers can pass through the die holes, part of them will adhere on the cutter when being cut, impacting the performance of cutter and the appearance of the extrudates. Therefore, sifters with good performance should be provided before extruding process. In this respect, it is better to install a plansifter after pulverizer and to install an ultra-fine grading sifter before extruder. The plansifter holes are usually of 40~60 meshes. As for the formula with little fat and good flowability, a sieve with 60 meshes holes is favorable; while for those formula of high-fat content and bad flowability, a 40-meshes sieve is proper. A plansifter is good enough to remove impurities out of the product except fibers. Furthermore, there is quite a long distance from the plansifter to the extruding bin, within which hand-adding is normally carried out, on such conditions, impurities will be probably brought into the product due to hand-adding or maintenance etc. Concerning about this, an ultra-fine grading sifter must be installed before the extruding bin. The sieve cover for ultra-fine grading sifter usually is of 60 meshes. 3. Requirements for formulation 3.1 Starch content requirement In order to find out the relationship among starch content in formula of common floating aquafeed and die hole diameter and floating ability, we carried out two sets of contrast tests, by which some data were got. In these tests, the starch ingredient used was wheat flour. The first set of tests was to produce floating aquafeed with the same technological parameters and the same formula with 16% starch content and 3% oil/fat content, but dies of different hole diameters. The objective of this set of tests was to find out the relationship between die hole diameter and floating ability of aquafeed. As for detail data, please refer to Table 2 below: The second set of tests was to produce floating aquafeed with the same technical parameters and the die plates of an equal small hole size, but with different formulas, aiming to find out the mini. starch content in a formula featuring 100% floating rate with the same die plate. See Table 3 below: From the above two sets of contrast tests the following conclusions can be drawn: 1 As for producing floating aquafeed with large die hole diameter and low-fat formula, the starch content should be <20%; 2 While with small die hole diameter, the starch content in formula should be≥20%. 3.2 Effects of wheat, corn and flour effect on extruding The wheat flour is recognized to be a relatively better starch ingredient. A test was once carried out on a same single- screw extruder with a same size die (1.0mm die hole), but three formulas with 26% corn, 26% wheat and 26% wheat flour respectively, other ingredients in the three formulas were the same. It was found out that with the same technical parameters, the floating rate of the formula with corn was lower than that with wheat, while that with wheat was lower than that with wheat flour. With wheat flour the floating rate was over 98% while that with corn was just about 80%. Furthermore, there were more fibers adhering on the cutter for corn, resulting in uneven kerfs and burrs on the surface of extrudates. 4. Attention points prior to extruding step The twin-screw extruder has more advantages for producing extruded small aquafeed pellets. Its adjusting range is wider than the single-screw extruder, and also has better material adaptability. However, the single-screw extruder can also produce good quality small pellets if under good control. 4.1 Selection and installation of the cutter Whether the selection as well as installation of the extruder cutter are reasonable or not is decisive to the appearance of the extrudates. It is recommended to adopt 0.3 mm thick soft knives with good elasticity for cutting small pellets. When installing the knives, each of them should be tightly against the die plate and a little bit curved. It is suggested to adopt a cutting device which the clearance between the cutting blade and die plate is adjustable during production operation. Since the blade will be worn after being used for a period of time, which will leave a small prick on the pellet edge, influencing the trimness as well as the appearance of the pellet. With an adjustable cutting device, the clearance can be adjusted during operation without stopping, ensuring the extruder to work stably for a long time. Take the single-screw extruder (power of main motor: 160KW, screw diameter: 165mm) as an example, when producing small pellets with a Ø1.0 mm-hole die plate, a cutting device with ten or twelve knives is usually used, and its rotating speed is about 1200~1400 rpm. If there are impurities blocking the die holes, the rotating speed of the cutter must exceed 1500 rpm so as to ensure the uniformity of pellets. So, as for a Grade 4 motor, the upper limit of frequency of an inverter must be over 50HZ. 4.2 Flow path cleaning Most feed mills produce not only small expanded pellets but also large expanded pellets. As we all known, the requirement for grinding fineness of large extruded pellets is different with that for small extruded pellets. So the operator should pay attention to the following points when producing small pellets after the production of large pellets. There will be some large impurities and fibers left in the flow path after the production of large extruded pellets. Prior to producing small extruded pellets, grind at least 10 tons of raw materials based on the requirement for producing small extruded pellets, and then sift them by a plansifter for small pellet extrusion (It is possible not to use an ultra- fine screen). In this way, large impurities and fibers will be cleared out of the flow path together with the finely ground materials. 4.3 Extrusion system cleaning If the extruder has been made a halt for more than 8 hours, it is necessary to clean the whole extrusion system thoroughly, including the anti-bridging feeding bin, the feeding auger, the conditioner and the principle machine of extruder. When cleaning the anti-bridging feeding bin and the feeding auger, it is necessary to empty the material in them, after that, blow compressed air into them for completely cleaning. Do not use tools like besom or brush for cleaning, because the fibrous components of such tools are possible to fall down and bring in more impurities. When cleaning the conditioner, if the residues on the inner wall of the barrel and on the paddles are dry, use a scraper to remove them, and then flush them with compressed air for complete cleaning. If the residues are relatively wet, only the dry residue on the surface of cylinder’s inner wall needs to be scraped and removed out of the conditioner. Since the single-screw extruder does not have the self-cleaning function like the twin-screw extruder, residues are inevitable after each machine stopping. After a period of time, the residues will be dewatered and become try and hard, which will block the die holes, even if there is a little, when starting a new production. When cleaning the principal machine, inject steam into the extruding chamber for cleaning while keeping the screw static for 20~30 min, so as to soften the residues in the chamber. After that, start the motor and give the chamber a good flushing with sufficient water till clean water flows out. 5. Production process of small extruded pellets and troubleshooting 5.1 Startup of the extruder It is able to startup the extruder for production after all is well prepared. At the beginning of a production, the feeding rate usually is 2/3 of that for normal production. Once mash flows out of the by-pass, first add steam into the extruding chamber, and when all condensate has been drained off at estimate, add water into the extruding chamber so as to prevent material in the chamber from aggregation because of too much moisture. In the production of floating aquafeed, the moisture content in the product after conditioning is about 26~28% (that of sinking feed is about 30~33%) and the temperature is about 90~95°C (that of sinking aquafeed is about 80~90°C ). Do not start the motors for principal machine and cutting device until the material being conditioned as desired and the conditioner is running stably. The initial rotating speed of the cutting device is about 1200 rpm. After the start- up of main motor is completed, close the bypass to let the mash get into the extruding chamber for processing, then add some water and about 1~3% steam in the extruding chamber so as to get pleasant appearance of the extrudates (Steam is unnecessary for sinking aquafeed, but about 3% water is good for it). Adjust the rotating speed of the cutting device according to the required pellet length after product is discharged out of the extruder. After that, check the shape as well as the main technical parameters of the extruder regularly. 5.2 Die blockage Die bockage is the common trouble when producing small extruded feed pellets, which possibly is caused by incorrect operating as mentioned above. When blocking, the length of pellets are uniform as desired at the beginning, but several minutes later, the length become longer, at this time it is necessary to increase the cutting speed to keep the length. If the situation still gets worse after accelerating the cutting speed for three times, it means there are foreign matters blocking the die holes. If further blockage occurs, moisture will be very low because of flash evaporation, resulting in increased motor current. In this case, adding more water won’t do any good. It is necessary to stop the extruder to clean the blockage when the cutter rotating speed exceeds 80% of its full speed, or when the pellet is of ugly appearance. Prepare at least two die plates for producing small extruded pellet feed so as to ensure its steady production. Since cleaning time is long (2~3 hours), only one die plate prepared for production will influence the normal production. Clean the die holes by using a small drill bit less than 1.0 mm in diameter or a steel wire, or by immersing the die plate in hot water, and then blow it with compressed water. 6. Control of dryer Since the product produced is of small size, it is necessary to have the opening of circulating fan of the dryer in a good control. Or else, the product will be blown into the middle of the dryer if the opening is too large, resulting in a non- uniform moisture content. Attentions must be paid to the distribution conditions of the product on the conveying belt, so as to adjust the opening of the circulating fan properly so that the extruded pellets are distributed uniformly on the belt. Meanwhile, the temperature for drying small pellets is lower than that for drying big pellets due to its small output and easy operation. High-temperature quick drying is suitable for floating feed and the drying time should be controlled at about 20~30 min, while low-temperature slow drying is suitable for sinking feed, the drying time is about 40~60 min. by Lan Wenqin & Ma Liang Muyang

Screws and dies to improve extrusion productivity

Sat, 25 Apr 2015 21:54:09 +0000

Screws and dies are critical parts of the extruder. The wear of screws and dies can significantly effects throughput and quality of extrusion products. For feed and food extrusion, the wear of metal parts may also put the products under the risk of metal pollution and cause food safety issue. Suppliers should take the responsibility and positive role in reducing the wear of metal parts in production and in improving feed-to-food safety. FAMSUN provides spare parts solutions that can not only maintain production lines at optimal levels, but also upgrade replacement parts to minimized wear and prolong service life, ensuring optimum efficiency and productivity for customers manufacturing facilities. This article will introduce the new FAMSUN screws and dies that developed to increase lifecycle and enhance the productivity of raw material extrusion and aquafeed production. Ways access to improvement Extrusion process helps to improve the bioavailability of raw material, which means the high temperature, short time process including gelatinization of starch components, denaturation of protein, stretching or restructuring of tactile components, and exothermic expansion of the extrudate can maximizes the benefits of heating feed ingredients (improved digestibility, inactivation of anti-nutritional factors, and pasteurization), while minimizing nutrient degradation. Feed conversation rates of extruded rations are usually better, because the cooking process increases the digestibility of raw materials, particularly the starch fraction. Extrusion adds value to low-cost raw materials and promotes the utilization of alternative ingredients, allowing for more flexible feed formulas design and production. It also offers additional advantages such as product of better flavor, more environment-friendly and reduced waste of valuable ingredients. With its distinguished performance, the technology is more and more used in large-scale commercial feed production. Wear of working parts can occur through both abrasion and/or corrosion during production. In FAMSUN's attempt to minimize wear from both of these resources, developing new materials for spare part construction and improving metal heat treatments are referred. The new screws and dies FAMSUN developed to improve extrusion performance are made of new materials and processed by improved heat treatment solutions. New single screw for raw material extrusion Screws as the most important working parts, its wearing resistance performance is directly related to the operation performance and production capacity of the raw material extruder, as well as the operation cost and maintenance cost of feed mills. In continues extrusion production, raw material moving forward along the flow channel of the extruder screw, and friction between material flow and screws is increased as compression of incoming material in the chamber increase, wearing of screws then occur. Wearing will increase the gap between screw profile and inner wall of barrel, and leakage flow is liable to release from the feeding inlet, which dramatically reducing the energy efficiency and throughput of extrusion production. On the other hand, frequently downtimes due to worn screws replacement will further decrease the production efficiency of the whole system. Therefore, upgrading the wear-resistance of extruder screw is very important to the stable and reliable of the extrusion production. FAMSUN used to produce single-screw for raw material extrusion with 38CrMoAl nitrided steel, which is of improved hardness and wear resistance protection on the surface and excellent strength and toughness in the center. In order to make continuous improvement, the new single-screw was developed by using special steel and alloys based on the previous edition. The heat treating solutions used to improve its properties are also specially designed. Tests and actual application in productions prove that the new parts can produce more feed at its best performance. Its lifecycle for raw material extrusion is increased by 2-2.5 times. Taking the application on a FAMSUN PHY260 Raw Material Extruder for example, the regular single-screw made of 38CrMoAl nitrided steel can process corn for 2,000 tons in its lifecycle, while the new single-screw can extrude 6,000 tons corn at its best performance. The replacement frequency of a screw can be prolonged to three months from previous one month, which is also a maintenance and cost saver. New twin-screw for aquafeed extrusion FAMSUN had developed two regular twin-screw products for aquafeed production: MY 105 and MY1045, both are characterized by high wear-resistance and hardness on the surface. However, the former is not common used because it is more brittle and will crack if heavily impacted by feed mash during extrusion. The later makes an improvement on surface resistance. Its surface hardness is increased to 60-65HRC, but still has bad roughness and liable to crack if impacted by hard particles during production. MY105 twin-screw is able to process 10,000-15,000 tons of aquafeed in its lifecycle, while the production capacity of MY1045 twin-screw is 25,000-35,000 tons. To make constantly improvement, the research of new twin-screw mainly focuses on improving its surface performance. After studying the characteristics of common feed and food formulas, analyzing the properties of possible base steels, using new hardening technologies and developing new methods to strengthen the combination of surface protection material and base material, FAMSUN new twin-screw was successfully rolled out. The new twin screws are made of alloy-structural steel as base, which provides better toughness and prevent screws from cracking during extrusion. Special alloy is combined on the flight of screw to improve wear resistance and prolong service life. The surface hardness of new screws is up to 1500HV and can process 60,000-80,000 tons of feed at high performance constantly. New extrusion dies Extruder dies are liable to crack under the stress of feed mash to be extruded out of die holes. FAMSUN new dies use special steel and alloy in material construction, and makes improvement during the processes of forging, pre- and post- heat treatments. Different from the regular dies that made of Cr12 steel, the combination efforts of special alloy and vacuum heat treatment in the new die improve the toughness of dies with small openings, minimize the deformation of die holes and ensure them of better streamlines, which facilitates discharge and produces more uniform feed pellets. Most of all, the surface hardness of new dies is improved to 58-63HRC from 50-55HRC of the regular ones, which further prolongs the lifecycle and maintain the efficient production of the extrusion system. And with vacuum heat treatments, the new dies are free of pollutants such as sodium nitrite and potassium dichromate that generated during traditional blackening and salt bath processes. It is safer for feed and food production.

Infographic: Overview of global feed production in 2013

Mon, 03 Feb 2014 23:39:00 +0000

In 2013 the global feed indsutry comprised of 28,200 feed mills, according to the latest data published by ALLTECH as part of their annual feed survey. The world's total feed production was estimated at 963 million tonnes, up 1% on the previous year. The estimate of the total value of the feed industry was revised to around USD$500 billion, much higher than the USD$350 billion estimation of last year To help visualize the data, and provide an overview of global feed production in 2013, we have created the following infograhic. Feel free to use this infographic on your site, please follow the instructions below and provide a link back. Use This Graphic for FREE on Your Site! You may use the infographic above on your website, however, the license we grant to you requires that you properly and correctly attribute the work to us with a link back to our website by using the following embed code. Embed Code

Infographic authored by FeedMachinery.com. To view the original post, see the original Feed industry 2013 infographic.

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Infographic: A look at the global feed production 2012

Sun, 28 Apr 2013 02:06:54 +0000

In 2012 the global feed indsutry comprised of 26,240 feed mills, according to the latest data published by ALLTECH as part of their annual feed survey. The world's total feed production was estimated at 954.4 million tonnes. To help visualize the data, and provide an overview of global feed production, we have created the following infogrpahic. You can use this infographic on your site if you follow the instructions below. Use This Graphic for FREE on Your Site! You may use the infographic above on your website, however, the license we grant to you requires that you properly and correctly attribute the work to us with a link back to our website by using the following embed code. Embed Code

Infographic authored by FeedMachinery.com. To view the original post, see the original Feed industry infographic.

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2012 Summary of the global feed processing industry

Sat, 27 Apr 2013 03:53:25 +0000

2013 ALLTECH Global Feed Summary : Global feed production statistics have traditionally been difficult to quantify because many countries lack national feed associations. For this reason, Alltech began in late 2011 to leverage its global presence to obtain a more accurate estimate of the world's feed tonnage. The results of the annual year-end assessment were announced in January as an industry outlook resource for the new calendar year. For its second report, Alltech assessed the compound feed production of 134 countries in December 2012. Where possible, information was obtained in partnership with local feed associations and, when not possible, it was done utilizing information gathered by the more than 500 members of Alltech’s global salesforce, who visit more than 26,000 feed mills on an annual basis. When reviewing the data, there are two considerations to bear in mind. First, numbers for less developed countries may be less accurate, but given their size, this will have little numerical influence on the overall dataset. Second, the definition of feed, feed mill and species varies from country to country. Overall, the new results affirm a growing feed industry with a global feed tonnage of 954.4 million, a 9 percent increase over the late 2011 estimates of 873 million. The actual underlying growth is likely to be about 4 to 5 percent since the latest results include new sources of information not available in 2011 and identify more accurately the statistics for individual species. China, Brazil, India and Russia (BRIC) represented 33 million tons of the increase. No. Country Total Tonnage (million) 2012 1 China 198.340 2 USA 168.460 3 Brazil 66.285 4 Mexico 28.536 5 Spain 28.231 6 India 26.837 7 Japan 25.220 8 Russia 23.350 9 Germany 22.252 10 France 21.613 11 Canada 19.642 12 Thailand 15.750 13 Netherlands 14.762 14 Italy 14.633 15 Indonesia 13.801 16 UK 13.551 17 Korea 13.515 18 Turkey 12.995 19 Iran 12.000 20 Vietnam 12.000 21 Phillipines 11.917 22 South Africa 11.027 23 Argentina 10.115 24 Poland 8.255 25 Taiwan 7.893 26 Australia 7.548 27 Pakistan 7.410 28 Ireland 6.728 29 Belgium 6.281 30 Colombia 5.500 31 Egypt 5.400 32 Venezula 5.315 33 Ukraine 5.160 34 Saudi Arabia 4.530 35 Chile 4.523 36 Malaysia 4.400 37 Denmark 4.200 38 Algeria 4.000 39 Belarus 4.000 40 Hungary 3.832 41 Israel 3.500 42 Peru 3.391 43 Serbia 3.391 44 Greece and Cyprus 3.221 45 Portugal 3.085 46 Morocco 2.995 47 Norway 2.940 48 Bangladesh 2.730 49 Romania 2.295 50 Ecuador 2.245 51 Czech Republic 1.986 52 Bosnia 1.962 53 Sweden 1.925 54 Nigeria 1.900 55 Uruguay 1.419 56 Finland 1.395 57 Paraguay 1.345 58 Bolivia 1.313 59 Kazakhstan 1.280 60 Switzerland 1.265 61 Dominican Republic 1.162 62 Guatemala 1.137 63 Jordan 1.100 64 Libya 1.060 65 Albania 1.000 66 Tunisia 1.000 67 Austria 0.965 68 Kenya 0.955 69 New Zealand 0.899 70 Bulgaria 0.887 71 Dubai 0.850 72 Costa Rica 0.821 73 UAE 0.767 74 Croatia 0.750 75 Cuba 0.750 76 El Salvador 0.744 77 Nepal 0.739 78 Honduras 0.703 79 Iraq 0.700 80 Sri Lanka 0.615 81 Myanmar 0.600 82 Slovakia 0.600 83 Panama 0.568 84 Lebanon 0.500 85 Macedonia 0.500 86 Moldova 0.500 87 Uzbekistan 0.500 88 Armenia 0.500 89 Estonia 0.480 90 Uganda 0.467 91 Oman 0.464 92 Lithuania 0.462 93 Slovenia 0.450 94 Jamaica 0.320 95 Azerbaijan 0.320 96 Nicaragua 0.318 97 Puerto Rico 0.276 98 Tanzania 0.258 99 Zambia 0.240 100 Latvia 0.234 101 Reunion 0.230 102 Kuwait 0.230 103 Georgia 0.200 104 Kyrgyzstan 0.200 105 Turkish Cyprus 0.200 106 Cote D'ivoire 0.160 107 Bahrain 0.150 108 Caribbean 0.146 109 Senegal 0.125 110 Turkmenistan 0.101 111 Ghana 0.100 112 Kosovo 0.100 113 Sudan 0.100 114 Trinidad & Tobago 0.094 115 Iceland 0.090 116 Mauritius 0.090 117 Haiti 0.090 118 Luxembourg 0.090 119 Malta 0.080 120 Botswana 0.057 121 Namibia 0.052 122 Zimbabwe 0.040 123 Barbados 0.039 124 Mozambique 0.030 125 Guyana 0.022 126 Seychelles 0.015 127 Suriname 0.012 128 Bahamas 0.008 129 Cameroon 0.000 130 Lesotho 0.000 131 Mongolia 0.000 132 Montenegro 0.000 133 San Marino 0.000 134 Singapore 0.000 Among the 134 countries reviewed, China was once again the leading producer of feed with 198.3 million tons manufactured in the official estimate of more than 10,000 feed mills. Consistent with late 2011 assessments, the United States and Brazil followed in second and third places, with 168.5 million tons from 5,251 feed mills and 66 million tons from 1,237 feed mills respectively. No. Country Number of Feed Mills Total Tonnage 1 China 10.000 198.34 2 USA 5.251 168.46 3 Brazil 1.237 66.285 4 Mexico 430 28.536 5 Spain 700 28.231 6 India 862 26.837 7 Japan 156 25.22 8 Russia 500 23.35 9 Germany 340 22.252 10 France 294 21.613 11 Canada 72 19.642 12 Thailand 30 15.75 13 Netherlands 50 14.762 14 Italy 340 14.633 15 Indonesia 70 13.801 16 UK 340 13.551 17 Korea 41 13.515 18 Turkey 350 12.995 19 Iran 240 12 20 Vietnam 230 12 Asia continues to be the world’s leading feed producing region at 356 million tons. One region, however, exceeded Asia in percent growth over 2011 results. Africa was found to be the fastest growing area in terms of tons of feed manufactured, increasing its tonnage 19 percent from 47 million in 2011 to 56 million in 2012. The Middle East was estimated to have the largest feed mills, with an average of more than 63,000 tons produced per mill. Continent/Region Total Tonnage Asia 356 Million Europe 207 Million North America 188 Million Latin America 137 Million Middle East/Africa 56 Million Other 10 Million Total 954 Million Region Total Number of Feed Mills Total Tonnage Average Tonnage per region Africa 794 30305000 38168 Asia 12149 356542000 29347 Europe 4449 208400000 46842 Latin America 2975 137048000 46067 Middle East 385 25411000 66003 North America 5323 188102000 35338 Other 165 8593000 52079 Total 26240 954401000 36372 Number of Feed Mills (Estimate): 26,240 Total Tonnage (million) 2012: 954.4 When analyzed by species, poultry continues to dominate with a 44 percent share of the feed market at 417.8 million tons, likely due to religious and taste preferences as well as cost. It grew by approximately 10 percent over 2011 estimates. Sixty percent of all poultry tonnage is dedicated to broilers, with the rest fed to egg layers, turkeys, duck and other fowl. Total Tonnage per million Pig Ruminant Poultry Aqua Other Dairy Beef Calf Other Ruminants Layers Broilers Turkeys Other Poultry Pets Horse 130.7 97.9 1.4 22.5 141.1 246.1 13.2 17.2 218.1 252.6 417.8 34.4 20.4 10.8 Species Total Tonnage Poultry 418 Million Ruminant 253 Million Pig 218 Million Aqua 34 Million Pet 20 Million Equine 11 Million Total 954 Million The pig feed sector matched poultry’s 8 percent growth, moving to 218 million tons globally. The ruminant feed market, comprising dairy, beef and small ruminants, grew more than 13 percent between late 2011 and December 2012, and now requires 254 million tons. Equine feed tonnage increased almost 17 percent to 10.8 million tons. Aquaculture grew nearly 16 percent since 2011. Pet food represents 20.5 million tons, 40 percent of which are produced in the United States, but Brazil continues to make considerable advances in this sector. Top 20 detailed results: Country No. of Feed Mills Total Tonnes (million) 2012 Pig Ruminant Poultry Aqua Other Dairy Beef Calf Other Layers Broilers Turkeys Other Pets Horse China 10,000 198.34 58.14 35.5 30 0 29.4 20 0 11 13.3 1 0 USA 5,251 168.46 23.59 19.51 23.41 0.1 0 23.09 57.22 6.54 0 1 8 6 Brazil 1,237 66.28 15.4 5.1 2.9 0 5.1 33.2 0.84 0 0.63 2.5 0.61 Mexico 430 28.54 4.21 4.61 3.027 0.45 4.56 10.34 0 0 0.21 0.71 0.42 Spain 700 28.23 13.24 2.9 4 2.34 1.6 3 0.45 0 0.10 0.37 0.23 India 862 26.84 0 5.85 0 0.01 7.01 10.46 0 0.001 3.5 0.002 0.002 Japan 156 25.22 6.11 3.3 4.598 0.05 6.39 3.95 0 0.05 0.43 0.31 0.02 Russia 500 23.35 6.2 2 1.75 0 3.8 9.4 0.2 0 0 0 0 Germany 340 22.25 9.2 0 0 0.15 6.4 2.1 3.3 0 0 0 0.7 0.4 France 294 21.61 5.7 3.12 1.55 0.36 0.6 2.3 3.5 1.44 1.67 0.12 1 0.25 Canada 72 19.64 4 10 0.78 0.18 0.8 0.96 0.18 0.18 0.76 1.22 0.58 Thailand 30 15.75 6 0.6 0.2 0 0.7 6 0 0.3 1.6 0.25 0.1 Holland 50 14.76 5.5 0 0 0.65 2.8 2.8 2.5 0 0 0 0.31 0.2 Italy 340 14.63 3.5 2.02 1.755 0.15 0.23 3.5 2.75 0 0 0.10 0.57 0.05 Indonesia 70 13.80 0.5 0.6 0 0.05 5.06 6.19 0 0.1 1.3 0 0 UK 340 13.55 1.51 2.73 0.98 0.001 0.9 1.79 3.29 0.52 0.81 0.14 0.7 0.18 Korea 41 13.51 4.61 1.11 4.224 0 1.68 1.78 0 0 0.12 0 0 Turkey 350 12.99 0 5.5 1.7 0 1.5 4 0 0 0.25 0.045 0 Iran 240 12 0 3 0.9 0 4 4 0 0 0.1 0 0 Vietnam 230 12 6.5 0.12 0 0 0.85 1.2 0 0.36 2.92 0 0 The 2012 assessment identified a total of 26,240 feed mills globally, with Asia and North America being home to more than half of them. Sixty percent of the feed produced is pelleted, and this is even more prevalent in Europe.