Optional step for coarse material.
Pre-grinding will lower the
energy needed for ultra-fine grinding.
In general, the production line will utilize 12 raw material bins.
Every bin will be filled with around 5-6 batches of material.
The material will be dosed based on the formula.
In the pet
food line, usually, the material will be processed by batch.
Post-grinding is the final size reduction in the system.
It is common to use a pulverizer for producing ultra-fine powder.
In this step, trace ingredients such as vitamins and minerals will
be added and mixed.
Extrusion starts with pre-conditioning and hydrating by adding steam
and water or other liquid.
The material will undergo high pressure, high temperature, and
shearing in the barrel, and then be formed by mold at the outlet.
Drying in extrusion is a must, wet pellets will enter the dryer and
come out as dry pellets.
No matter horizontal or vertical dryer, good moisture control
is the most important feature that a dryer needs.
It is common to coat the pellets with oil or enzymes to increase the
nutrient value of the pellets.
Depending on the liquid coating level, drum coater or vacuum
coater can be used.
Cooling utilizes ambient air to cool down the hot pellet from the
dryer.
Thorough cooling is needed to prevent condensation inside the
packaging.
Packing gives protection to the pellets and also give easiness to
handle and transport to customer's hand
Extrusion process description for pet food
Raw material intake system consisting of tip hopper, mechanical conveyors, and elevators into
storage bins. Raw material such as soybean meal, corn, fish meal, and
other grain or powder is sieved to remove any impurity and metals.
Pre-grind systems are a size
reduction process for raw materials that contain large particulates or
grains by hammer mills. Pre-ground material is conveyed to storage bins.
Storage bins are used for
the temporary storage of raw materials.
Formula batch dosing system weighing hoppers to proportionally weigh dry ingredients by batches
based on every formulation.
The first mixing system is used for dry material mixing to stabilize the following process.
Pulverizer grinding is the
second grinding process that grinds the formulation into finer powder
with fineness up to 80 mesh 95% pass. This step becomes optional when
making big extrudates with sizes of 2.5 mm and up.
Second mixing system
Other sources like pre-mix, liquid, oil, and fat are now added and mixed
with raw material. Too much fat added here will affect the floatability,
so a post-extrusion oil coater will be used to account for the total fat
content required.
Extrusion cooking with pre-conditioning
The mixer feeds down through a feed hopper into the feed screws which
continuously feed the ingredients into a differential diameter
conditioner (DDC). Water, steam, and/or oil are added in DDC, the
retention time inside DDC is controlled by shaft speed. Two types of
extrusion technology can be chosen: single screw extruder or ContraTwin
screw extruder.
Drying The dryer will lower
the moisture content of the extrudate from 20% to 28% in the dryer inlet
down to 10-12%. This drying is needed to lower the water activity and
achieve shelf-stable moisture for the products.
Coating
Oil coating is needed to increase the nutritional value and palatability
of the feed. Depend on the fat content that needs to be added, a drum
coater or A vacuum coater can be chosen.
Cooling
Cooler lowers the temperature of the hot pellets to +3°C of room
temperature by utilizing ambient air.
Impurity and dust sieve
All pellets will go through a vibration sieve to remove any irregular
pellets or impurity before bagging.
Bagging and sealing system
Weighing cell and bagging machines bag pellets with chosen quantity ex:
20 Kg. or 25 Kg. per bag and seal the bags for storage. Finished
products can also be loaded by trucks or in container bags.
Features and Benefits of IDAH Process Design and Equipment
IDAH firmly believes in a strategy of design fit for purpose. We
recognize the constraints our customers face with rising ingredient
costs, energy costs, and overheads costs, yet in the face of these
challenges, it is still expected that high-quality products be
supplied into a very competitive market. Our design philosophy is to
work continuously to refine and improve processes and equipment to
maximize the success of our customers. The following describes some of
the features and benefits resulting from this philosophy.
Rugged 24/7 Design
We design our equipment for continuous operations and fulfill the
expectation for minimal downtime. Our mission is to see our equipment
still working years after installation, with only maintenance required
being routine maintenance caused by normal fair wear and tear.
Formulation
Two perspectives are influencing the formulation: culturing performances
and efficiency of the machinery. For example, choose the right starch
source (types of flour) is essential. Inappropriate starch sources will
lower the steam incorporation level and causes jams at the pellet mills.
Fat and moisture content play inseparable roles in the hammer mill and
pulverizer throughput. Formulation with high fiber content not only
increases the risk of broken pellets, lowering the water stability of
the pellets. High fiber content also increases the wear of all machinery
in the process. Reducing the use-life of the parts such as the hammers,
screens, and dies.
Mixing
We offer a range of mixers, depending on customer needs and preferences.
Our mixers are all of the very rugged design and we continue to develop
new features, such as geared shaft drives on our twin shaft mixers,
which reduce noise, energy costs, and maintenance costs.
Two-Stage Grinding and Pulverizing
We firmly believe in the benefit of even particle reduction to
ultra-fine powder. The typical target is to reach more than 95% passing
through a 60 mesh screen. It is impossible to efficiently produce
small-size products with size 2.0 mm and below without this ultra-fine
grind process. Ultra-fine grinding will increase production efficiency
and end product quality during the production of larger-size products.
It will also open the possibility to utilize less expensive starchy
ingredients.
IDAH understands that many production practitioners
might worry about the extra energy cost of utilizing a pulverizer, which
is why we designed a revolutionary pulverizer that runs at much lower
energy costs. The ability to substitute with cheaper ingredients cost
will compensate for the small extra energy requirement of the
pulverizer. The ultra-fine raw material will produce a smooth, shiny,
and water-stable product.
Pre-conditioning
The independent drive on each shaft of the IDAH twin shaft lowers power
consumption and noise. The paddles' reverse rotation allows completely
emptying the chamber. The misting steam and water injectors further
improve conditioner performance. The following conditioner system used
steam jacketed (or heat jacketed) to create a homogenous mix with little
to no free water. Insufficient pre-conditioning will cause cracks on the
pellet surface and creating dust fines.
ContraTwin screw extrusion with pre-conditioning
The ContraTwin screw extruder is a guaranteed solution to increase
product quality standards, with lower energy costs and wear costs. This
extruder is suitable for processing high fiber formulations. Our
machines typically make high-quality pet food and aqua feeds with specific mechanical
energies of 25kWh/tonne or lower. The very positive conveying action
inside these machines allows us to run high fiber and small diameter
products at rates others find difficult to believe.
Drying
IDAH offers the carousel dryer T-series and the horizontal dryer
CDX-series for your drying solution.
When choosing the correct dryer for your application, moisture control
should be one of the most critical selection criteria. Moisture has a
direct impact on your product quality, production cost, and profits in
your business. One aspect of moisture control is uniformity, together
with drying result consistency–in-time will determine the target average
moisture content. The closer the average moisture to the maximum
moisture levels, then the less raw material is lost through over-drying,
generating more profit for your company.
Cooling
The counterflow cooler is used for cooling pellet and extrudate. Warm
(hot) pellets get into the cooling chamber, the suction fan will
transport out the air inside the chamber, and fresh ambient air will
enter the chamber from the bottom, promoting pellet cooling action. When
pellets are accumulated and touch the high-level limit sensor, a
pneumatic discharge swivel valve will operate immediately to discharge
the products. Counterflow air heat exchange ensures to achieve high
cooling efficiency.
Coating
In food and feed production, many kinds of ingredients with different
properties are used. IDAH provides a high-efficiency mixer for mixing
powder and liquid material depending on the formulation requirement. In
many foods and feed production, additional liquid may be applied for
improving the quality nutritional value, and palatability. IDAH mixing
and coating ensured precise mixing for producing a high-quality product.
Specification of ContraTwin screw extruders (for Pet food)
Model |
EP-76D |
EP-156D |
EP-156DL |
EP-190D |
Main Motor (HP) |
150 |
250 |
350 |
450 |
Capacity1 (t/h) |
1.0-2.0 |
5.0-7.0 |
5.0-8.0 |
8.0-12.0 |
Note:
2) pet food, plate die hole size Ø 4.0 -
10.0 mm