In the production of shrimp feed, it can be produced by two major methods, pelleting or extrusion, depending on the dietary of the shrimp species. For majority of the markets, pelleting solutions are still highly recommended. Below a pelleting process description will be proposed and for those who are interested in extrusion process can be found out more in fish feed production page.
Pelleting process description for aquatic feeds
Raw material intake system consisting of tip hopper, mechanical conveyors and elevators into storage bins. Raw material is sieved to remove any impurity and irons. Raw material, for example, for animal feeds are soy bean meal, corn meal or other grain sources. For aquatic feeds, material can be fish meal or flour.
Pre-grind systems is a size reduction process for raw materials that contains large particulates or grains by hammer mills. Pre-ground material is conveyed to storage bins.
Storage bins for raw materials
Formula batch dosing system Weighing hoppers to blend finished formulation blends of dry ingredients by batches.
First mixing system is followed for even material blend for balance forward process.
Pulverizer grinding is the second grinding process which prepare the formulation into finner powder with 80 mesh 95% pass.
Second mixing system Other sources like pre-mix, liquid, oil and fat are now added and mixed with raw material by batches. This is the step where the mixed recipe is ready.
Pelleting with Pre-conditioning The mixer feeds down through a feed hopper into the feed screws which meter the ingredients into differential diameter conditioner (DDC) and a double single-shaft conditioner are followed. Triple conditioning steps ensure longer retention time and high temperature cooking in gradual process. Direct and indirect steam are added in this step. Retention time can be controlled by frequency controller. Sizes of shrimp feeds are controlled by hole diameters of pellet dies and they can be 1.2, 1.4, 1.5, 1.6, 1.8, 2.0, 2.2, 2.3, and 2.5 mm. Compression ratio of the die is crucial to high quality of feeds and production throughput.
Post-conditioning and drying Additional water added in 2ndmixer plays big role in starch transformation. Pellets formed by pellet mill will be post-conditioning in this step for 25 to 30 minutes. A dryer is followed to evaporate the additional water added earlier. Shrimp feed will reach desired water stability and PDI in this process. IDAH is the first company proposed this post-conditioning concept to make shrimp feed in early 1980s.
Cooling: Cooler lowers the hot pellets temperature to + 2 °C of room temperature with 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 put pellets into bags with chosen quantity ex: 20 Kg. or 25 Kg. and seal the bags for storage. Finished products can also be loaded by trucks or in container bags.
Pellet crumbling system:Pellets conveyed into storage bins before either being packaged or being turned into crumble in the crumbling plant. Pellets can be processed by crumbler to produce smaller pellet as No.1, No.2, and No.3 products. (Sizes between 20 to 60 mesh) Fines will be recycled to pellet mill section for re-use and undesired bigger pellets that pass through the sieve will be re-crumbled again.
Features and Benefits of IDAH process design and equipment
IDAH firmly believe 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 process and equipment to maximize the success of our customers. The following describes some of the features and benefits resulting from this philosophy.
All our equipment is designed to be used in continuous operations, where it is expected that down time has to be minimized. It is our mission to see our equipment still working years after installation, with the only maintenance required being routine maintenance caused by normal fair wear and tear.
Formulation is important to two perspectives: culturing performances and efficiency of the machinery. For example, choose the right starch source (types of flour) is important. Inappropriate starch sources will prevent the level of steam to be added and causes jams at the pellet mills. Fat and moisture content play big roles in the hammer mill and pulverizer throughput. High fiber mixes will increase wear of all machineries in the process thus reducing the life cycle of the parts especially for the hammers, screens and dies. In addition, water stability relates to fiber content level.
We offer a range of mixers, depending on customer needs and preferences. Our mixers are all of 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 are firm believers in evenly reducing the particle size of the dry ingredients down to a very fine powder, our typical target being more than 95% passing through a 60 mesh screen. It is impossible to make products efficiently with good quality at or below 2mm in size without this fine grind, and even for larger products process efficiencies and product quality are improved when using finely ground material, not to mention that it is possible to use less expensive starch ingredients when the grind is fine. It is also extremely difficult to make small pellets from high fiber ingredient mixes unless the ingredients have been finely ground through a pulverizer. We do recognize the potential extra energy costs incurred when using a pulverizer, which is why we have created a revolutionary design that runs at much lower energy costs. The small extra energy requirement still used by the pulverizer is more than compensated for by the ability to use cheaper ingredients and downstream energy cost savings. Pellet surface will be smooth, shiny and attain good water stability when pulverized raw material is used.
We always recommend the use of pre-hydration in mixers designed to do this. The addition of even a small amount of water to dry ingredients at this early stage in the process dramatically improves throughput, energy costs and product quality. To ensure that the potentially more cohesive pre-hydrated mix can be evenly fed to the pellet mill we also supply our activated hopper system, with slowly rotating paddles in a semi-cylindrical hopper.
Our twin shaft pre-conditioners have an independent drive on each shaft, which improves power consumption and noise, and also allows the machine to be completely emptied by slowing and reversing the paddles. The addition of misting steam and water injectors further improves conditioner performance, followed by the use of steam jacketed mixer conveyors after the conditioner which creates an homogenous mix with little to no free water. Inappropriate pre-conditioning will cause cracks on pellet surface and creating more fines.
Pellet Milling Shrimp Feed
IDAH are in many regions the market leaders in this area. We pioneered the special design features that allowed us to be the first to make small water stable shrimp feed pellets. We have continued to improve design of our pellet mills with the recent launch of automation systems. IDAH makes its own dies and rollers for its pellet mills to ensure the most update arrangement of the compression ratio and holes patterns for change of formulation.
IDAH is the first company which proposes the post-conditioning solutions in producing shrimp feeds. Direct results are pellets are stronger bounded with fewer fines and higher water stability. Cost of formulation is saved because less binder needs to be added and this tremendously helps digest ability of shrimps.
We offer a range of dryers, both horizontal belt/conveyor dryers and vertical cross-counterflow designs. Wherever possible we prefer to offer the cross-counterflow model to save energy costs. IDAH VC2R dryer has an especially small footprint and height compared to typical vertical counterflow dryers and also uses a lot less electrical power than most other designs, cutting down on capital costs, energy costs, maintenance costs and noise. A round shaped VCR dryer generates a very homogeneous air flow stream inside the dryer which allows an extremely uniform treatment of the product. This process air flow leads simply to the fact that over drying of the product is not given. Constant tumbling (up to seven times) of the product to be dried leads to best results in uniform water evaporation.
Batch and semi batch counterflow cooling is the most efficient way to operate, so we offer this equipment whenever possible. Note that we like to stack dryers, coaters and coolers above one another whenever possible, allowing gravity to do the work, saving yet again on energy costs, capital costs and maintenance costs.
Dual stage crumbling enhances the size homogeneity of the crumbled feeds and dramatically reduces the fines to increase yield rate.
Models of Pellet mill for shrimp feed production
Capacity ( kg per hour)
※Above throughput are with regular white shrimp feed formulation with fat, oil using standard 1.8 mm pellet die.
Pellet sizes can be 1.2 1.4, 1.5, 1.6, 1.8, 2.0, 2.2, 2.3, 2.5 mm