The grid screen is the simplest cleaning equipment. The main function is to prevent large impurities such as mud, stones and ropes from entering the material discharge hole, preventing blockage of the discharge hole and the later conveying and other processing equipment; it also prevents the feeding personnel from falling into the material feeding inlet to protect personnel safety. The grid screen is the first cleaning equipment, and almost every feeding inlet should be set up, such as in the main and auxiliary material feeding inlet of the main workshop, and the manual adding inlet of the additive next to the batching scale, etc. The gap of the grid screen should be determined according to different discharge ports and different materials. For example, the gap between the grids in the feed main workshop for corn and powdery auxiliary materials is about 30 mm. In the corn feed port in front of the vertical storage silo, because of the large output required, the gap between the grids can be larger. For the cake materials, due to its poor scattering, the gap between the grids should be about 40 mm. The grid screen should be fixed at the feeding port and ensure an inclination angle of 8 to 10 degrees, so as to pour out the material in the bag and reduce the labor intensity of the feeding. The cleaner is the main equipment for the cleaning of impurities of the feed mill. Commonly used are the drum cleaner, powder cleaner and vibrating cleaner. Drum cleaner is mainly used to clean granular raw materials, such as corn cob, hemp rope, cloth, stone, clods, straw and so on. Drum cleaner is not suitable for the powder, mainly because the powder is less scattered than the particles, and it is easy to accumulate and block on the chute of the feeding, so that the production cannot be smoothly carried out. The drum cleaner has the characteristics of simple structure, small volume, large output, low power, convenient installation and maintenance, etc. According to the nature of the material, the sieve cylinder with suitable sieve hole can be selected. Vibrating cleaner can be used for the cleaning of granular materials and for the cleaning of powdered materials. As a cleaning screen, it can effectively remove large impurities in the raw material. The device changes the screen surface from above, which saves the space occupied by the screen change, and the screen surface is fixed by the buckle, so the screen change operation is very convenient. As a cleaning sieve, vibrating cleaner has strong adaptability to materials and high impurity removal efficiency, but the discharge port is small and sometimes has poor discharging of impurities; For the same amount of processing, its power consumption and larger floor space cover, the price is higher and it is easy to produce noise and vibration. Magnetic separation equipment can be divided into electromagnetic equipment and permanent magnet equipment according to the type of magnet. When power off, the iron miscellaneous in the electromagnetic equipment will fall into the material and it is inconvenient to use. Therefore, the feed mill now uses permanent magnet equipment.
Operation cautions for Pellet mill
Pellet mill is the key equipment for feed production enterprises, the running condition of the pellet mill will be related with the enterprises' economic benefit. So it will be very important to operate the pellet mill right.
First of all, the operator should be careful and responsible, he should strictly follow the pellet mill operating procedures, the start and stop should base on the manual.
1.Keep the steam dry, 0.3-0.4kg pressure into the conditioner
2.Adjust the distance between mould and roller, usually it is 0.2mm-0.5mm, the ring die can slightly drive the roller rotate, so make it not too tight or loose, too tight will reduce the work life of ring die, too loose will make the roller slip.
3.The moisture of raw material required to be 12%-15%, after conditioning it will be 14%-14.5%, the feed must be evenly.
4.The currency should be controlled based on the regulated load, over-load production long time is not allowed, it will be the main reason to damage the machine
5.Watch the Current fluctuations of pellet mill during production, stop and check in time when find something unusual
6.The driven box need to change the oil after working 500hours when the new machine put into production, after that change the oil every 3-6month according to the production. Use 68#machine oil or100#-120# industrial gear oil
7.If there is block in pellet mill, adjust the roller loose, do not start again until the inside of the ring die is cleaned. Any force start when the machine is blocked is forbidden, do not use the pipe wrench to pull the gear shaft. Added the lubrication oil to roller every 2hours when the pellet mill in normal running.
8.Check the wear parts condition of pellet mill often to avoid the breakdown of machine and the crack of ring die.
1. coefficient of fullness
No matter the type of mixer is, the suitable loading condition is the precondition for the mixer to work normally and get the expected mixing effect.
In batch type mixer, the appropriate filling coefficient of horizontal ribbon mixer is 0.6 ~ 0.8, and the highest material level should not exceed the top of rotor. The filling coefficient of batch type vertical mixer is generally controlled at 0.8 ~ 0.85.The filling coefficient of single-shaft or double-shaft mixer is 0.8 ~ 1.When the bulk density of the material is > 0.6, it shall be calculated according to the mixing amount of each batch. When the bulk density of the material is ≤0.6, the range of bulk density can be considered. 2.Operation sequence
There are a little of various vitamins, medicament and other additives or concentrates in the feed need to be diluted with the carrier to be premix , and then entering the mixer with other materials.
In the feeding sequence, generally the large proportion of the components will be added first or most of this part will be added, then small proportion or trace components placed on the material. In all kinds of materials, the large particle size is generally added to the mixer first, and the small particle size is added later. The density of the material will also have differences, when there is a big difference, generally add the material with small density first, after adding the large one.
This problem does not exist for continuous mixer, but for batch mixer, it is very important to determine the mixing time for the quality of mixed materials:
(1) mixing time is too short, the material which is not fully mixed in the mixer will be discharged, product mixing quality will be affected;
(2) too long mixing time, the material is mixed in the mixer for a long time, which not only causes the increase of energy consumption and the decline of output, but also causes the separation and accumulation of components due to excessive mixing, which reduces the mixing uniformity.
The determination of mixing time depends on the mixing speed of mixer, which is mainly determined by the type of mixer. For example, horizontal ribbon mixer, its mixing mainly by convection, usually 2 ~ 5min each batch, the time depends on the nature of raw materials, such as moisture content, particle size, fat content, etc..For the double shaft high-efficiency mixer mainly use shear and convective mixing, it can generally meet the requirement of mixing uniformity with a shorter mixing period of 40 ~ 60s.
4. Try to avoid separation
In order to avoid separation, the following four methods are adopted:
①Try to make the mixture of the various components of the same particle size, liquid can be also added to avoid separation.
② control the mixing time, do not over-mix, it is generally considered that the material should be discharged before approaching the mixing uniformity, complete the mixing during transportation or transit process
③ Try to decrease the unloading work after mixing, the falling, rolling ,sliding of material should be as little as possible.
④ The mixture should be granulated immediately after mixing
After mixing machine is used for a long time, the sealing of door will appear the problem of aging and wear. The operator should check the mixing machine door part regularly for leakage. Repair and replace the spare part in time if there is leakage.
The accessories of any equipment have a life, the normal operation of equipment can bring us benefits, so we need daily maintenance. So how long is the service life of the ring dies of feed pellet machine and biomass pellet machine? How to maintain?
Quality is also divided into good and general of the ring die of feed pellet machine and biomass pellet machine. The service life of the feed pellet machine is usually calculated by the weight of the processed material, of general quality is around 3000 tons, that means that the ring die of general quality will be useless basically after pellet machine producing 3000 tons of pellets; of best quality is around 7000 tons. As to biomass pellet machine, the service life of general quality is around 1000 tons, of good quality is about 3000 tons.
So the price will be always adequate to the quality, the price of equipment is high for a certain reason. Secondly, the service life depends on the degree of use and maintenance. Usually pay attention to the maintenance of pellet machine ring die can extend the life:
1.Find a manufacturer with professional production technology, design and customize different ring dies according to different raw materials and practical application, in order to make full use of the ring dies.
2.The space between the roller and ring die must be controlled between 0.1 ~ 0.3mm (the space between the biomass pellet machine roller and ring die must be controlled between 1~3mm), do not let the eccentric roller contact the surface of the ring die or the space of one side too large, avoid cause abrasion of ring die and roller.
3.When the pellet machine starts, feeding must be from low speed to high speed, do not run at high speed at first, cause damage to the ring die and pellet machine due to sudden overload or ring die plugging.
Maintenance for pellet machine ring die：
1.When the ring die is not used, extrude the residual raw materials, in case the ring die heat make the residual in the die hole to be dried and hard, resulting in no material or ring die cracking.
2.Check the inner surface of the ring die for local protrusions after a period of use. If so, wear off the convex part, to ensure ring die the capacity and the service life of the ring die and roller.
3.When loading and unloading ring die, don’t use hammer and other hard tools to hammer the ring die surface.
4. The ring die must be kept in a dry and clean place. If it is kept in a damp place, it will corrode the hole and reduce the service life of the ring die.
The above is our company's experience of maintenance for ring die based on many years production and use, hope it will be helpful for customers. If you have any further questions, please feel free to contact us.
Clogging is one of the common faults in the use of the hammer mill. In many cases, when we use the hammer mill, there will be clogging of the powder materials. The reason for this kind of fault is mainly due to improper operation. If your material often blocking from the beginning, and with a period of time using, it is not blocked. It may be the new equipment is not smooth enough in the running-in period, after a period of time it becomes smooth and not blockage and the material is also smoothly to come out. There were so many times, improper operation can also cause this failure, we will give you an analysis of the general reasons and solutions in the following
First, check whether the feeding speed is too fast. If too fast,it will make the hammer mill fan plug; Improper matching with conveying equipment will cause the outlet pipe to be blocked after wind weakens or there is no wind. At this time, we should adjust the amount of feed to make the equipment run normally. Otherwise, the increase of equipment load will cause blockage. In our feeding process of hammer mill, we should always pay attention to the ammeter pointer deflection Angle. if more than the rated current, it indicates that the motor overload. If overload for a long time, it will burn our hammer mill motor. In this case,we should immediately reduce or close the material door, and we can also change the way of feeding, by increasing the screw feeder of bucket elevator to control the amount of feed.The user shall select the appropriate screw feeder of bucket elevator according to the actual situation. Because the rotation speed of the hammer mill is high, the load is large, and the load fluctuation is strong, when the hammer mill works, the current is generally controlled at about 85% of the rated current and try not to overload of our motors.
Second, the discharging pipe is not smooth or blocked. Most often we shut down hammer mill once we can not hear the sound of corn grinding, this is wrong. You should let the crusher idle for a few minutes, waiting all the materials in the material pipeline enter the mixing tank and then turn off the crusher. Otherwise, the residual materials will sometimes get wet and agglomerate after a few days, it will causes blocking of hammer mill.
Third, the hammer slice is broken, and the wear is severe, the hammer screen hole is closed to block and the broken, the water content of the crushed material is too high, which will block the hammer mill. The broken and severely aged hammer slices should be regularly replace to keep the hammer mill in good working condition, and the hammer screen should be inspected regularly. The moisture content of the material for grinding should be lower than 14%, which can not only improve the production efficiency, but also prevent the hammer mill from being blocked to enhance the reliability of the work of the hammer mill. At the peak of production, please reduce the feeding speed to ensure that the motor does not burn and the equipment does not block the material.