Accurate measurement to solve the selection problem in shrimp processing
challenge “The Siemens 600 Series offers an accurate feed control and provides us with a reliable solution to the difficult challenges,†says Paul Holmstock. It ensures that the shrimp is fed to the processing machine at the correct flow rate to protect product quality and system efficiency.
Located in Puurs near Antwerp, Belgium, ATKA SA is Europe's leading frozen fish and shell processor, with annual exports exceeding 10,000 tons. The shrimp processing plant had a major overhaul in 1997, including new scouring machines, food processors, freezers and food delivery equipment.
Food control is an important part of the processing process. If the supply rate is too high, the shrimp will become bad because it is not dry enough. If it is too low, the shrimp will burn out.
This food processing process is controlled by a weighing feeder system with a single strain gauge load cell that provides only 5% food flow accuracy.
Paul Holmstock, an operations engineer at the ATKA plant, realized that they needed a new feeder system with very high precision to ensure the most suitable feed flow.
In addition, ATKA needs equipment that can adapt to very humid environments and use high-pressure hoses for high-temperature CIP procedures. This system must be able to communicate with the plant's DCS system via the Profi bus-DP protocol.
solution
Holmstock found a very efficient solution, connected to a Siemens BW500 electronic calculator via the Siemens 600 SD series weighing feeder, with an optional SmartLinx® Profi bus-DP communication card.
He chose an Intralox belt that was driven by a gearbox and a tail pulley. This design offers additional advantages over conventional crown pulleys and plastic belts because it eliminates slippage of the belt and allows water to be removed during transport and before weighing. He chose a fully stainless steel feeder structure, including an IP68 sealed load cell and flush motor and gearbox.
The 600 series feeder is mounted at a 90o angle for the variable drive drive control vibratory feeder. The BW500 calculator uses another PID to control the output of the drive to change the vibration speed to ensure that the 600 Series does not clog. This double-ended feed control provides flow control that is tighter than a simple capacity metering system.
Advantage
The Siemens 600 series feed system is stable with an accuracy of 0.5%, which is five times higher than previous systems. High precision is a combination of a slide rail and a dual load cell, replacing the traditional system of mounting wheels and load cells. The weighing area is nearly twice as large as other systems can offer.
Stainless steel load bars prevent clogging of products and bacteria.
At the Belgium ATKA processing plant in Puurs, a Siemens hygienic weighing feeder feeds shrimp into a food processor. The Intralox belt allows the water to drain so that it weighs the weight of the product. This system offers a high degree of accuracy above ±0.5%.