Solutions of Abnormal Pelletizing
Now more and more people are using the feed pellet machine to make feed pellets. During the processing, we may meet different problems with abnormal pelletizing. What causes them and how to solve them? We might not know. The following are the common problems, causes, and solutions. Shall we study together?

Wood-Pellets-Waste-and-Recycling

PROBLEM:
The surface of the feed pellet is light, but its inside is dry and hard.
CAUSE:
The moisture of feed after conditioning through the feed pellet mill is too low.
SOLUTION:
◆Increase the steam volume;
◆Decrease the steam pressure;
◆If the feed has a low ability of humidity absorption, increase the steam pressure;
◆Spray water at the conditioner;
◆Decrease die thickness.
PROBLEM:
Low stability of pellet.
CAUSE:
Raw material contains high-fat content.
SOLUTION:
◆Spraying fat on the die face instead of adding in the mixer;
◆Control feed’s moisture content between 16%—17% after conditioning;
◆Increase the temperature up to 85 °C;
◆Increase the steam pressure;
◆Increase the die’s thickness.
PROBLEM:
The shape of the pellet is like a pine tree.
CAUSE:
●Feed contains high-fiber raw material;
●Feed density is low and contains much content of carbamide;
●Length of ingredient fiber is longer than pellet diameter;
●Feed contains high fat.
SOLUTION:
◆Increase the die’s thickness;
◆Grind the material finer;
◆Reduce the steam volume, increase the steam pressure;
◆Add fat at die instead of adding in the mixer;
◆Reduce the speed of the feeder.
PROBLEM:
Pellet cracks on one side.
CAUSE:
The density of pellets is low. Shearing of the pellet occurred much more than cutting.
SOLUTION:
◆Reduce the distance between the die and the cutter;
◆Grind the material finer;
◆Increase the die’s thickness;
◆Increase the gelatinization of feed in the conditioner.
PROBLEM:
The shape of the pellet is like a block.
CAUSE:
●Pellet surface is mostly rough. Too much dust returned from the grading sieve;
●Die is too thin;
●There is water in the steam that suddenly evaporates after coming out from the die.
SOLUTION:
◆Particle size of raw material should be suitable;
◆Use the thicker die;
◆Inspect the water trap and steam system to reduce the steam pressure;
◆Decrease the steam volume.
PROBLEM:
Pellet cracks lengthwise after cooling.
CAUSE:
The raw material is of low density and high fiber.
SOLUTION:
◆Grind the raw material finer;
◆Increase the die’s thickness;
◆Increase the steam pressure.
PROBLEM:
Because of the low moisture absorption ability of rough raw material, pellet cracks.
CAUSE:
●Mixture contains both rough and fine material;
●Coarse raw material absorbs lower moisture, so the combined ability of mash decreases and causes pellet split;
●More returned dust from the grading sieve.
SOLUTION:
◆Grind the material finer;
◆Adjust the steam pressure which will make the mash glutinous;
◆Check the leak of the grading sieve.
PROBLEM:
Pellet is frilled.
CAUSE:
Mash contains high fiber that well absorbs moisture, when coming out of die the pressure changes rapidly. The fiber in the pellet will suddenly expand.
SOLUTION:
◆Reduce the steam volume;
◆Make the steam pressure as required. If steam pressure is low, there will be water in the steam, so the moisture of the mash will increase; if steam pressure is high, there will be water in the pellet after dies and suddenly evaporate, so the fiber will expand;
◆Increase the die’s thickness.

Related product: Complete Animal Feed Pellet Plant

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