Debris was being drawn into the cooling tower via the air intake fan and silencer duct. Unlike similar fans, the Elta unit had a mesh guard on the inlet with the motor cowl standing proud of the guard.
Manufacturing the cooling tower fan guard filter was not a problem, but what was the use of the tower in the tyre manufacturing system? Surely it should be all about heat, in order to allow the rubber compound to be mixed, spooled and otherwise prepared for vulcanization? In fact, up to four different compounds can be used to create the base, core, tread and wing of the tyre, plus additional extrusions for the sidewalls and inner liners.
It is a complex production system, with a dependence on accurate temperature control. But where does a cooling tower come into the operation?
Cooling is required for the removal of process heat from the rubber which is created during compound mixing, milling and extruding.
The energy for this cooling process represents almost two per cent of all electricity used within the rubber industry and is required to cool the chamber walls of the mixers and drums, plus the extrusion tool.
A recirculating water system takes the warm water to a wet cooling tower where it is then cooled by direct contact with the air. Using spray nozzles, the water is distributed over the pack and the evaporation of only three litres of water will reject 1kW of heat.
80 per cent of the cooling load is managed in this way, while the remaining 20 per cent is achieved from sensible heat transfer to the ambient air.
So why was a RABScreen filter required on the inlet?
To maintain optimum efficiency of the cooling pack, the inlet and fill must be kept free of debris. Until recently there was no option but to carry out frequent maintenance to ensure cleanliness – a time consuming and labour intensive task.
By reducing the debris, RABScreen has extended the time between cleans, as well as keeping the inlets cleaner and the water quality higher – saving time, saving energy, and saving money.
Visit the RABScreen website at www.rabscreen.com