Gas temperature monitoring device

Abstract

A probe for measuring temperatures in a hot gaseous medium such as the gases inside the shaft of a blast furnace. A first tubular member extends from a base structure such as a blast furnace wall into the gaseous medium. Successively smaller, second and third tubular members are concentrically positioned inside this exterior tubular member. Preferably, an exterior protective member also surrounds the first tubular member. A refractory material is interposed between the exterior protective member and the first tubular member to minimize temperature fluctuations in the body of the probe itself. Thermocouple leads extend longitudinally in an air space between the second and third tubular members and then protrude to the exterior of the probe. A forward fluid coolant passageway is formed inside the third tubular member. This forward passageway connects at its terminal end with a radial fluid passageway which is formed between a radial flange on the fourth tubular member and a closure plate on the first tubular member. A rearward fluid coolant passageway is also formed between the first and second tubular members. Cooling efficiency is enhanced because the fluid coolant is maintained in the cooler center of the probe until it reaches the terminal end of the probe which is typically its hottest section.