Development of a pelleting plant for dry chicken manure
Why this project was necessary
For a long time, there was no marketable pelleting system in the 500 to 750 kg/h capacity class for processing dry chicken manure. The material properties posed considerable challenges for previous machines: high variability in moisture and structure, high dust content, uneven particle sizes and a pronounced risk of jamming and bridging.
Several trials by other manufacturers had previously failed to produce a stable, functioning solution. The industry therefore needed a system that was specially adapted to this particular class of raw materials and that would reliably map the process chain from the intake to the finished pellet.
This is exactly where this development project began.
Objective of the development
The project had a clearly defined task:
To develop a complete pelleting plant for dry chicken manure that
- enables a stable throughput of between 500 and 750 kg/h
- can deal with strongly fluctuating material properties
- works continuously, safely and with little disruption
- is designed to be easy to maintain
- can be integrated into existing farm structures
In addition, the system should be designed in such a way that later variants or performance expansions remain possible.
Analysis of the challenges of the raw material
Dry chicken manure has a number of special properties that strongly influence process engineering.
The development had to solve the following problems in particular:
- inhomogeneous particle sizes, partly fibrous components
- Fluctuating residual moisture and uneven drying
- Tendency to form bridges in containers
- Dust formation and local incrustations
- Strongly fluctuating pressing behavior in the pellet press
A standard pelleting line was not suitable for these tasks.
An independent technical concept had to be developed.
Engineering the entire process chain
The system was developed as a continuous process line consisting of coordinated process steps:
Material acceptance and dosing
A specially designed feed hopper with defined geometries prevents bridging and ensures an even feed. A dosing screw feeds the material to the next process stage in a controlled manner.
Pre-processing and homogenization
A uniform structure is essential for this material. The process chain supports mechanical homogenization to reduce pressing fluctuations and stabilize pellet quality.
Conditioning and humidity adjustment
As dry chicken manure has highly fluctuating moisture levels, an adjustable conditioning system was integrated. Stable process moisture is crucial for the abrasion resistance and shape of the pellets.
Integrated hygienization as a unique process module
A crucial part of this development was the design of a separate, compact hygienization unit, which was fully integrated into the system and its container architecture. Defined thermal sanitization is absolutely essential for the processing of animal residues, but until now there was no system available on the market for this performance class that could be implemented in a mobile or compact system.
The objectives of hygienization were
- Reliable germ reduction
- Defined thermal dwell time
- Automated temperature control
- Short start-up times
- Compact, service-friendly design
- Complete integration into the process control system
The unit works with controlled material movement and homogeneous heat transfer so that the entire product volume is safely and evenly sanitized. Documented monitoring of temperature and dwell time is carried out automatically via the control system.
This module is a unique technical feature of the system. A comparable solution was not previously available on the market and has significantly upgraded the entire process line both technically and in terms of regulation.
Pelletizing
The pellet press was designed to work stably despite fluctuating material consistency and high dust content. The die, roller dimensions and press channel parameters have been specially adapted to the characteristics of the material in order to achieve the necessary compaction and pellet strength.
Cooling and product stabilization
After pressing, the pellets must be degassed and cooled to achieve their strength. The counterflow cooler was designed according to the performance class and the thermal properties of the pellets.
Screening and recirculation
Fines and oversize particles are separated by a separate sieving stage and automatically returned to the process. This keeps the line output constant and the product quality reproducible.
Project responsibility and development process
Throughout the entire project, design, engineering and coordination were in one hand.
This included:
- Analysis of the initial technical situation
- Development of all relevant machine assemblies
- Complete 3D design of the process line
- Construction and support of two prototypes
- Management of internal project participants
- Optimization rounds based on real test results
Thanks to the close integration of design and test support, technical weaknesses were quickly identified and rectified.
Result
The development led to a functional, stable pelleting plant for dry chicken manure in the desired performance class. It is capable of reliably processing the difficult material, achieving reproducible pellet quality and enabling economical plant operation.
The prototypes formed the basis for later expansion stages and variants suitable for series production.
Conclusion
This project shows how challenging and at the same time solvable the pelleting of difficult residues can be when analysis, design and practical implementation are carried out from a single source.
The integrated hygienization, the specially coordinated process chain and the consistent technical development have resulted in a system that closes a gap in the market and sets technical standards in this material class.
