Case Study

Accurate control with minimum energy usage for seed processing

Accurate control with minimum energy usage for seed processing

Problem

The process of drying and packing vegetable and flower seeds has to be undertaken in stringent environmental conditions, including moisture. The seeds must not be damaged in any way and specific criteria must be achieved for the condition of the seeds prior to packaging, to prevent bacteria growing inside the package.

Solution

The Optidrive E3 has been used as part of the seed drying and packaging process. This advanced process control is provided through a series of Optidrive E3s which are in turn controlled from a central PLC using Modbus. The system control has to be very accurate to ensure that the correct conditions are achieved to minimise the drying time whilst achieving the correct finished product quality.

BOUKENS ENKHUIZEN

Optidrive E3s are helping to set new performance and energy saving standards for specialist drying equipment used for vegetable and flower seeds throughout the world.

Boukens Enkhuizen, based in the Netherlands, have been designing and manufacturing specialist technical cooling and drying equipment for more than 16 years. Their latest innovation is used to carefully dry flower and vegetable seeds before packaging and is supplied to major seed producing companies all over the world.

This machine is required to process the seeds according to stringent standards. The seeds must not be damaged in any way and specific criteria must be achieved for the condition of the seeds prior to packaging, to prevent bacteria growing inside the package.

This advanced process control is provided through a series of Optidrive E3s which are in turn controlled from a central PLC using Modbus. The system control has to be very accurate to ensure that the correct conditions are achieved to minimise the drying time whilst achieving the correct finished product quality. The Optidrives were supplied by Hiflex Automatiseringstechniek B.V. Invertek Drives Sales Partner in the Netherlands.

Fast and Easy Commissioning

The key benefit to the machine builder in using Optidrives in this application is the very quick and simple installation and commissioning time. The drives are mounted in a common control panel, and linked together using RJ45 cables and splitters, allowing the Modbus network to be quickly connected together.

Each drive then requires only motor parameter data to be entered and control from Modbus to be selected, hence the commissioning time is very short.

Energy Efficient

The seed is loaded into rotating drums which are controlled by Optidrive E3 drives. The rotation of the drums allows the air to circulate around the seed, in a similar manner to a tumble dryer, to ensure that the seed is dried evenly. A series of Optidrives are used for highly energy efficient control of the fans which circulate warm air through the seed for the drying process. Finally, the machine has a built in condenser section, so that the moisture removed from the grain is condensed back into water and can be drained away safely.

Optidrives are used on all aspects of the process, controlling the ventilation speed, cooling compressor speed, condenser speed, and the speed of the rotation drums which contains the seeds to be dried. Monitoring signals from various sensors feed information, such as temperature and moisture content in the air, to the PLC. This enables the process to be controlled extremely accurately whilst ensuring that the minimum of energy is required, a dual benefit for the end user.

The drying process must be carefully monitored to ensure that strict global standards for seed drying are always adhered to. Using Optidrives controlled via Modbus allows these standards to be easily met by this equipment.