January 15, 2006

Paste Production Expertise

IN the highly-competitive food manufacturing industry, successful manufacture and handling of pastes offers a substantial commercial edge.  Flexibility and ease of operation are critical to the selection of machinery components, with one plant or process run frequently used by companies in the production a range of goods.

Paste is manufactured by the addition of three components - one powder and two fluids.  The flow-rate of the fluids is controlled in a specific ratio, with powder added in proportion to the combined fluid flow-rate.  A significant degree of precision is required, controlling the addition and mixing of all three components, in order that uniformity of product be achieved.

 

Caption: Paste flow schematic, showing use of Bürkert valves, instruments and networking systems.

The quantity of fluid A input to a mixing vat is detected by means of a flow-rate controlling instrument, and controlled continuously by a globe control valve.  The lower quantity fluid B is also measured and controlled by a separate globe control valve, in a given ratio with respect to the flow-rate of fluid A. 

Both fluids, and the proportionally added powder ingredient, are combined in the mixing vat in accordance with the programmed recipe formula.  The quantity of paste output from the mixing vat in this process is detected by means of a magnetic inductive flow meter, located at the vat outlet, and is controlled by a general-purpose controller with food-grade stainless steel diaphragm valve.

The set-point values of the closed-loop flow-rate control system for fluid A, the feed velocity of the powder, the speed of rotation of the agitator and the paste dose are output via an electric/pneumatic automation system. 

The set-point value of the closed loop flow-rate control system for fluid B is generated directly in the positioner of the control valve, as a function of the flow-rate of fluid A.  The flow-rate of fluid B is controlled in the required ratio via the process controller integrated in the positioner.  In addition, pneumatically operated on/off valves controlled directly by the automation system are fitted in all of the system's delivery lines.

With a global network spanning offices in 34 countries and operational outposts in an additional 80, Bürkert Fluid Control Systems is an established and mature global organisation celebrating its 60th Anniversary in 2006.  

Mr Chris Hoey, Managing Director of Bürkert Fluid Control Systems in Australia, has worked with fluid control for almost twenty years.