Clearer dosing

The customer, a leading supplier of daily contact lenses to the global market, needed to significantly increase their productivity whilst simultaneously tightening process parameters and increasing quality.

A partnership between the engineering teams developed a tween-solution dosing system that ensures both complete mixing and a highly accurate and repeatable dosing rate even with a variable main water flow.

This ensures that a uniform and strictly controlled concentration of the cleaning agent is applied to the process machinery after each production run.

This in turn ensures the integrity of every production run, surpassing each quality inspection and, most importantly, fulfilling the demanding needs of the consumer.

Having identified various options, the team determined that the best solution for global implementation was the design of a compact system ideally configured to simply retro-fit onto the existing production machine.

Dimensions needed to be exact, all wetted parts needed to be 316 stainless steel and the liquid process connections needed to be Tri-Clamp.

Further discussions culminated in the decision to utilise Coriolis Technology further enhanced by Master/Slave ratio control.

The main, variable, water flow is measured by the Master Coriolis Meter and an output signal sent to the Slave. The slave consists of a Coriolis Flow Controller with the control device being a close-coupled pump.

Using the in-built PID function of the instruments and the Bronkhorst

FLOWBUS communications protocol resulted in a small network within which the instruments worked in unison. A single dosage rate command meant that the operator could very simply, and in real-time, adjust the dosing ratio as set by the process requirements for that day or even for that “run”.

With a flow rate of 1000 kilograms/hour for the main water feed and 1 kilogram/hour for the concentrated cleaning agent the flow-rates proved to be ideal for the low flow experience and expertise of Bronkhorst.

All the necessary parts were supplied and fitted, including valves, filters, connectors, a static mixer and the stainless steel housing. In doing so the cabinet was virtually “plug and play” thereby minimising time and cost for installation.

Bronkhorst has developed the technology and know-how to be able to offer chemical dosing systems with its Coriolis Flowmeter range using its CORIFILL firmware.

This is further extended by utilising Master/Slave Dosing and mixing. Bronkhorst is able to offer accuracy of +/-0.2% reading with the instruments being certified to ATEX Zones one and two.

On-board PID control is standard as is over-run protection and a self-learning function. The turn-down ratio is 2000:1, with flow rates down to 0.1 grams and lower depending on application.

The physical size has proven to be perfect for multiple injection points within a confined space. The Coriolis system can be integrated with virtually any pump technology, control valves or indeed shut-off valves should the application demand it.

For more information, please contact: sales@bronkhorst.co.uk