I was working with a customer recently who had a fairly interesting application that I’d like to share with you. The customer operates a steel furnace and they have an automatic, liquid steel temperature probe that does not have sufficient time to cool down before they take another temperature measurement which should be a minimum of 5 minutes.
The probe consists of a 6 foot long, ¾” pipe, attached to the end of a 12 foot long beam. The beam lowers the pipe with the probe attached into the steel bath to take the temperature (see sketch below). The pipe is covered with a consumable, cardboard type of tube (pictured above) which is the thermocouple. A contact block with wiring inside the pipe connects to the thermocouple. This contact block becomes heat damaged because the pipe does not have enough time to cool between temperature measurements.
The customer was originally thinking about using a Super Air Knife to cool the probe and pipe between temperature measurements. After discussing options, the customer took our advice and went with (2) of our 2” Stainless Steel Adjustable Air Amplifiers (model 6042) instead. The Air Amplifiers are able to be mounted at the “parked” position of the pipe / probe and actuated to blow down the pipe and thermocouple length-wise during this time.
The high velocity airflow was able to carry enough heat out of the assembly between temperature measurements that the contact block was no longer becoming overheated and damaged as it was before. We decided to suggest this option to the customer because the air usage for this option was less than that of a 60” long Air Knife and the Stainless Adjustable Air Amplifier has temperature rating of 400°F which was easily able to withstand the heat in the application.
Neal Raker, Application Engineer
nealraker@exair.com