Manufacturing & Supply Chain

GEA Nu-Con’s recently announced Generation 3 Rotor Detection System (RDS) for rotary valves will help protect food processors from the crippling costs of contamination during production and also provide a range of unique technical innovations to improve reliability and diagnose faults.

As recent high-profile cases have shown, the slightest doubt about the integrity of food products often results in the recall of the product and severe damage to previously trusted brands. In developing Generation 3, GEA Nu-Con set out to not only design a system that would detect contamination taking place during production but also monitor the condition of the critical components within the rotary valve and warn operators when their replacement becomes necessary.

Contamination Alarm

Contamination is usually caused either by the rotor making contact with the body of the valve resulting in metal entering the product, or by an increase in substances such as moisture or fats. By measuring the electrical resistance in the valve against a known value, the system is able to detect changes that would indicate a fault. For example, a valve with nothing passing through it would give a resistance of 100 Ohms. If contact was made between the rotor and the body resulting in a short circuit that would drop to zero and a contact alarm would be triggered. Any contaminants would reduce the resistance to a level below 100 Ohms and trigger a contamination warning.

Seal Controller

The system is also able to continually monitor the condition of the valve’s seals using flow metering. As the seals wear the flow increases, so by analysing the data the degree of wear can be ascertained without the need of a physical inspection allowing engineers to strategically plan maintenance and minimise downtime. Gareth Kretzer, Product Development Manager for GEA Nu-Con said that this was an important feature for many users. “The condition of seals is very important for many of our customers,” he explained. “By removing the need for physical inspections our customers can be confident that seals are performing correctly, without interrupting production, and can plan downtime more effectively.” Pressure on the seals is also monitored to make sure the correct pressure is maintained. If a reduction in pressure is detected a controller automatically adjusts the pressure to maximise efficiency and prolong the life of the seals.

Maintenance Warnings

Again with the aim of simplifying maintenance, Generation 3 RDS incorporates a number of systems to log the running time of the valve and give advance warning of when critical components, such as bearings and drive chains, need to be checked or replaced. In applications using valves with ATEX certification, tip clearance is alerted as a maintenance warning to ensure the correct tolerances are maintained and that the valve will protect the rest of the plant in the event of an explosion. Gareth Kretzer feels that this is a critical feature of the new design. “As soon as an ATEX certified valve becomes worn beyond what it was certified to it’s no longer doing the job properly. The Gen 3 RDS takes away that uncertainty.”

Data Logging

Data showing the running resistance, speed, operating pressure and any contact or circuit faults in the rotary valve, is continually logged by the system. In the event of an anomaly, the data can be remotely accessed by GEA Nu-Con to assist engineers in diagnosing the problem.

Gareth Kretzer said that he believed that many of the features of the Generation 3 RDS were unique. “We believe that this system is the most advanced of its kind in the market today,” he said. “Not only have we produced a rotary valve that is highly efficient, its self-diagnostic features can have a dramatic effect on plant productivity and reliability.”