ZINC PROCESSING

To melt and pour this alloy at between 430-520oC, a rule-of-thumb heating value of between 1.1-1.4 MJ/kg (500-600 BTU/lb) can be applied. Most processes use the pressure die casting method and as the temperatures are lower, torch burners or the compact package type burners with accurate temperature control can be the most suitable. Package burners incorporate the fan and safety system in a neat unit.

If there are multiple furnaces to heat it is usually more economical to use a single fan and premix type burners.

Galvanizing baths require careful heating to minimise hot spots
and reduce losses. High velocity or flat flame burners are more commonly employed. We can advise on this process.

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LEAD/SOLDER ALLOYS

This metal has a working temperature of around 330-380oC and as the rule-of-thumb factor is quite low at approx. .16 -.35 MJ/kg (70-150 BTU/lb) an economical, atmospheric burner would be suitable for most smaller furnaces. These are usually arranged to directly heat the base and sides from underneath with thermoelectric flame safety and a pilot burner fitted. It is important to include temperature control to ensure the process does not overheat. Larger capacity furnaces would utilise the nozzle mixing or premixing burners with automatic controls. Please ask for the relevant data.

TRANSFER TUBE HEATING

Frequently during the heating process it is necessary to transfer the alloy from the melting area to the processing zone. Transfer tubes or launders need to be heated to ensure the metal does not solidify.

sbheat.jpg (9187 bytes) Our range of stainless steel tube burners or pipe line burners are the most suitable for this stage.

These line burners are also utilised to heat tanks and solder baths that require a temperature range of approx. 210-260oC.

GOLD AND SILVER

With small quantities of gold to melt a simple air/gas premix torch burner can be used utilising a compressed air supply or air from a small blower. Gold has melting and pouring temperatures of approx. 1070oC and 1180oC. Silver is worked at lower temperatures, approx. 960oC to melt and 1060oC to pour. Premix or nozzle mix burners are used for larger quantities and industrial applications.

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