摘要:
A thermowell for a fixed-bed reactor which has a vertical spine portion, and multiple spider portions spaced along the spine portion. At least one thermocouple and preferable a plurality of thermocouples are located in each arm of the spider portions with thermocouple leads extending upwardly through the spine portion to a monitor outside of the reactor. The thermowell is constructed in the reactor while loading the catalyst by first positioning the spine portion in the reactor, and then fabricating a spider portion at the lowermost level of the spine portion with at least one thermocouple in each arm of the spider portion and thermocouple leads extending through the arms and upwardly through the spine portion. Catalyst is then added to the reactor to cover the spider portion at the lowermost level. At each successive level, repeating the steps of fabricating another spider portion, and of adding catalyst to cover the spider portion.
摘要:
A thermocouple element (10) for use in high-pressure, high temperature fluid applications having a cylindrical body portion (12) formed from a first metal and a cap (14) formed from a dissimilar metal. The cap is fused to the body such that the junction (18) forms an axial thermocouple junction. A plurality of grooves (13, 20) is formed in the cap and body to reduce the mass of material adjacent the junction for rapid conduction heat transfer from the fluid being monitored.
摘要:
The invention is an improved theroelement which comprises a graphite/boron carbide thermocouple, the arms of which are constructed as a tube and a rod, arranged concentrically inside the tube, which are electrically connected at one end. One of the arms of the thermocouple consists essentially of boron carbide formed from self bonding boron carbide by pressureless sintering. Prefabricated sleeves of high-purity, boron-oxide-free hexagonal boron nitride are used between the arms of the thermocouple as spacers. Only the end of the arm of the thermocouple constructed as a rod is secured in an electrically conductive connecting piece and the arm is freely mobile in the direction towards the cold junction. As the material for the arm of the thermocouple constructed as a rod, there can be used, for example, boron carbide having a coarse-grained structure and a density of from 60 to 80% TD, which has been manufactured from boron carbide powder having bimodal particle size distribution by means of extrusion, followed by pressureless sintering at from 2000.degree. to 2250.degree. C.The thermoelement can also be manufactured in one operation by means of pressureless sintering of the boron carbide powder in situ. Such a thermoelement comprises, for example, a flexible graphite cord for the arm of the thermocouple constructed as a rod, a boron-nitride envelope and a boron-carbide casing, the envelope and casing having been formed from powders sintered in situ without pressure.
摘要:
The materials forming the inner and outer conductors of the tip of a safety thermoelement are assembled in disk form, stacked above each other, preferably bonded together, for example by soldering, brazing, welding or the like. The disks are then extruded through an extrusion die which shapes the assembly of the disks into a pin or rodlike inner conductor, surrounded by a closed sleeve or cap formed of the outer conductor material. Preferably, the die additionally is shaped to provide an end terminal portion to the inner conductor, offset by a shoulder to permit assembly of the entire unit into a structural holder.
摘要:
A thermocouple assembly in which the inner end of the tip is provided with a straight knurl which is forced into the bore of the base fitting so that the teeth of the knurl become embedded in the wall of the base fitting, the end of the tip having a beveled surface clamping a flared end of the conductor tubing against a similarly beveled surface of the fitting within the bore so that the tip, fitting and tubing are mechanically and electrically connected.
摘要:
A thermocouple having a cut Taylor which constitutes one leg of the thermocouple. The Taylor wire is coaxially sealed in a glass capillary tube. A metal tube at least partly coaxially encloses the glass capillary tube and constitutes the lead of the other thermoelectric leg. The metal core of the Taylor wire is made of one thermocouple material which is connected with the metal tube by an at least barely electrically conducting layer of the other thermoelectric material, thus constituting the thermoelectrically active measurement junction at the point of contact between the metal core and the layer. In practice, the glass capillary tube with the Taylor wire coaxially sealed in it may be bent by 90* in the region outside the metal tube. The above-described thermocouple is made as follows. After the Taylor wire has been sealed in the glass capillary tube, it is bent together with the latter and cut off only afterwards, thus exposing the metal core. The glass capillary tube is sealed in the metal tube. Subsequently, both the thermoelectric measurement junction proper and, at the same time, the connecting lead with the metal tube is made between the metal tube and the front faces of the metal core, by precipitating a thin metal layer of the proper material.