Thermocouples protection

Chemically Functional. Refractory coatings are used for corrosion-resistant high temperature service in gas turbine and diesel engines, components such as cmcibles, thermocouple protection tubing, valve parts, etc. 

In addition to aerospace uses, sihca fibers can be twisted into sewing threads and yams for weaving into fabrics. These fabrics are used extensively for heat-resistant clothing, flame curtains for furnace openings, thermocouple protection, and electrical insulation. The cloth can also be used to encapsulate other fibers to produce flexible sheets. 

High Temperature. The low coefficient of thermal expansion and high thermal conductivity of sihcon carbide bestow it with excellent thermal shock resistance. Combined with its outstanding corrosion resistance, it is used in heat-transfer components such as recuperator tubes, and furnace components such as thermocouple protection tubes, cmcibles, and burner components. Sihcon carbide is being used for prototype automotive gas turbine engine components such as transition ducts, combustor baffles, and pilot combustor support (145). It is also being used in the fabrication of rotors, vanes, vortex, and combustor. 

Table 7.29 Service experience with thermocouple protection tubes in reducing gases and other...

As in other types of corrosion, attack by molten metals depends to a great extent on the detailed conditions of corrosion. Thus satisfactory service life has been reported for Inconel (Ni-16Cr-7Fe) thermocouple protection tubes... 

Special products include transparent vitreosil springs, which are ideal for continuous measurement in corrosive atmospheres, and quick-immersion thermocouple protection sheaths for rapid temperature measurement. 

Use Refractory for aircraft and rocket applications, thermocouple protection tubes, high temperature electrical conductor, cutting tool component, coating tantalum, cathode in high-temperature electrochemical systems. 

EINECS 234-963-5 Zirconium boride Zirconium boride (ZrB2) Zirconium diboride Zirconium diboride (ZrB2). Refractory for aircraft and rocket applications, thermocouple protection tubes, high-temp, electrical conductor, cutting-tool component, coating tantalum, cathode in high-temp, electrochemical systems oxidation-resistant composites. Atomergic Chemetals Cerac Noah Cham. 

After reaction vessel a has been opened, the filled crucible is placed in it and the vessel sealed directly above the side tube (dotted line in figure), leaving as little dead space as possible. The reaction vessel is placed inside the heater o and its top is wrapped as well as possible in asbestos wool, to prevent cold spots where later on the alkali metal vapor could condense. Heating under high vacuum is then started. The temperature is checked with a thermocouple, protected by a thin ceramic sheath and inserted between the vessel wall and the heater. The thermocouple sheath must not touch the vessel wall and is prevented from adhering to the latter by a few tufts of asbestos. 

Silicon carbide fibers wifh diameters between 100 and 500 pm and alumina hollow fibers with a wall thickness of 30 pm were successfully produced for microtool applications like heat exchanger tubes, refractory tools, thermocouple protection tubes and electric heating elements. Examples of these two fibers are shown in Fig. 5. The strength of the SiC fibers was shown to be as high as for SiC bulk material 800 MPa (tensile test with a free clamping length of 50 mm), which is sufficient for microtool applications. 

Ceramics differ from some other materials (viz. metals, plastics, wood products, textiles) in a number of individual properties, but perhaps the most distinctive difference to a designer or potential user of eeramic ware is the particularity of the individual ceramic piece. Actually ceramics are not readily shaped or worked after firing, except for some simple shapes of limited sizes. Many ceramies are manufactured as standard items refractoiy bricks and shapes, crucibles, furnace tubes, insulators, thermocouple protection tube, fibre tubes etc. 

Any thermocouple protecting wells inside the converter must be located in their proper places while the catalyst is being installed. They should be located exactly at the dividing line between the catalyst and the quartz pebbles in each instance as shown on the drawings. A handful of quartz may be placed under the end of the thermocouple well to prevent the tip of the thermocouple from being buried in the catalyst. 

One possibility of maintaining the reactor temperature is by adjusting the coolant flow through the jacket. In this case the measuring device could be a thermocouple, protected by a thermowell. As ejq)lained in chapter 12, there are three possible operating points of which oidy two are stable. Operating point P2 is an unstable operating point, the reactor can only be kept in this point by a temperature controller. 

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