Feed mill production; is hard to define as it is a combination of so many factors. Few Factors are as mentioned:
1.1.1) Feed Formulation & Raw material quality:
High fiber reduces the rate of production, as fiber is hard to compress into a pellet. But due to natural binders inherent to fiber, a good quality pellet is produced.
The fat content of ingredient or feed aids in increasing production rate but too much fat can affect pellet quality for eg. Too much fat affects pellet durability.
Starch with steam leads to Gelatinization. Gelatinization is defined as the irreversible destruction of the crystalline order in a starch granule so that the surface of every molecule is made accessible to solvents or reactants. Gelatinized material acts as a binder to produce the desired pellet quality. High starch material with good gelatinization enhances pellet quality.
Due to high moisture (more than 13 %) in raw material grains; it is difficult to maintain the balance of heat and moisture in the conditioning process. Too high moisture results in roll slippage and too low moisture results in die choking. At low and high moisture operator have to run the pellet mill @ 60 -70 % efficiency.
e. Protein & Density
Ingredients with high natural protein will plasticize under heat, which will cause good quality pellets. Ingredients or feeds with high density have high production rates. If an ingredient or feed is high in natural protein as well as density, the high production rates and good pellet quality can be expected.
At low oil & hard formulations project will give around 80 % of the stated production. 1.1.2) Particle size:
If there are bigger granules of maize or other grains the pellet will tend to break at that point after the pellet is formed, resulting in more fines. It is important to maintain uniformity of grinding.1.1.3) Pellet Durability:
Pellet quality is usually expressed as the pellet durability index(PDI) and measured by using a tumbling can device, in which the pellet sample to be tested is first sieved to remove fines, then tumbled in the tumbling can device for a defined period of time. Then after tumbling, we compare the fines produced during tumbling with actual weight.
PDI = weigh of the pellet after tumbling / weight of Pellet before tumbling x 100
At PDI lower than 88 pellet tends to break during crumbling; producing more fines which rresultin more recycling of feed and low final output. 1.1.4) Die configuration:
Selecting a die as per formulation is very important. As Broiler contain less fibers and more oil %age (soft formulation), which provides better pelleting properties, less frictional load on pellet die. Hence, we can use a compression ratio of 1:12, 1:13 & even more.
Using high compression ratio for layer feed may lead to poor die life, die chocking, non-uniform PDI, more power consumption in layer feed, low output, more wear & tear.
And using low compression dies in soft broiler formulation may lead to poor PDI (Pellet Durability Index – Pellet Strength). Considering all the above factors using a separate die for both layer & broiler feed is a better and cost-effective solution. Die selections govern approx. 10-15 % in pellet quality & output.
1.1.5) Operational Parameters:
a) Operators skill:
Operational parameters and skill, experience & knowledge of operator plays an important role in plant performance. The same die with similar technical specifications behaves differently in different pellet mills.
The operator should regularly check the:
1.1.5)1. State of wear on the deflectors and scrapers and also the roll adjustment: To avoid uneven wear on the die and consequently inefficient pelleting.1.1.5)2.
The state of wear of the conditioner paddles: To ensure efficient pre-conditioning.1.1.5)3.
Steam traps and filters: To ensure that no condensate is being passed into the conditioner.1.1.5)4.
Press Roll slippage due to increased moisture content, it leads to die roll over.1.1.5)5.
Observing wearing pattern of die; it is recommended to change the side of the die (front side – Back side) for more uniform wear.1.1.5)6.
Setting optimum parameters for different formulations and ingredient qualities.b) Using spare parts more than their optimum life.
Sometimes we use the consumable parts more than their standard life but loose much more in feed quality and life of other parts which directly are related to them. Like for an average die life cycle it is recommended to use 5 pieces (2.5 sets) of roll shells for a better die life and uniform PDI feed quality. Hence using the roll shells & beaters more than recommended life results in great losses in terms of grinding texture, conditioning & pelleting which directly affects pellet strength and PDI; and productivity and above all pellet quality.c)Steam quality and quantity:
Proper steam of good quality is required for better performance of machines and production of quality feed. Steam parameters required are:
d) Recipe Management:
- Dry Saturated Steam Minimum 9-10 kg/cm2 at the boiler.
- 2-2.5 Kg/Cm2 after PRV
- Good & reputed make boiler, Water softener.
- Proper Steam traps, insulation of steam line and supporting valves.
It will take around 30-40 minutes to change the recipe. It’s better if we run one recipe a shift as it saves lots of time. e) Manpower:
Good results certainly cannot be achieved without the adequate availability of qualified & skilled manpower. The timely response of labor & supervisors to automation controls, overfilling / under filling bins - alarms, etc. helps in smooth production.f) Power Failure/ Trips / jamming:
Machines require a starting time to achieve their full capacity load. One time power failure /jamming in pellet mill hamper the production by a minimum 20 minutes.
The above information is based on data collected from our existing customers & internet sources and is only for your reference. As expertise in feed mill engineering only, lark engineering will not be responsible for any type of loss occur due to above stated information.