Sintered metal tubes

The development of sintered metal tubes dates from the 1970s. A rough coating is applied to the exterior of the smooth new tubes. The hottest fluid is on the tube side. Boiling is intended to take place on the shell side or exterior of the tubes. This is only useful in flux-limited situations when boiling relatively pure components and when heat-transfer rates exceed 10,000 Btu/hr/fR In such circumstances, the sintered metal tubes act like boiling stones by the way in which they provide sites to initiate nucleate boiling and thereby 

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One way of maximising the area-to-volume ratio is to create a porous working electrode with a very large active surface. This can be achieved in various ways, e.g. use of stacks of metal gauze, sintered metal tubes, reticulated vitreous carbon or packed beds along the lines of HPLC columns composed of conducting material, such as carbon particles or silver granules. One method of construction is to fuse... 

Smooth high alloy tubes Low-finned tubes Sintered metal tubes Spiral heat exchanger Tube inserts Twisted tubes Helical tube support baffles... 

Inorganic membranes (29,36) are generaUy more stable than their polymeric counterparts. Mechanical property data have not been definitive for good comparisons. IndustriaUy, tube bundle and honeycomb constmctions predominate with surface areas 20 to 200 m. Cross-flow is generaUy the preferred mode of operation. Packing densities are greater than 1000 /m. Porous ceramics, sintered metal, and metal oxides on porous carbon support... 

Eitch indented into the tube. Tube 48 was a clean copper tube that ad 50 longitudinal flutes pressed into the wall (Gener Electric double-flute profile, Diedrich, U.S. Patent 3,244,601, Apr. 5, 1966). Tubes 47 and 39 had a specially patterned porous sintered-metal deposit on the boihng side to promote nucleate boiling (Minton, U.S. 

When the burner went out, the solenoid valve took a few see-onds to elose, and during this time some oil entered the furnaee. In addition, the line between the last valve and the furnaee may have drained into the furnaee. The flash point of the fuel oil was 65°C, too high for the oil to be deteeted by the eombustible gas deteetor. Even though the oil was vaporized by the hot furnaee, it would have eondensed in the sample tube of the gas deteetor or on the sintered metal that surrounds the deteetor head. 

Zirconia membranes on carbon supports were originally developed by Union Carbide. Ultrafiltration membranes are commercially available now under trade names like Ucarsep and Carbosep. Their outstanding quality is their high chemical resistance which allows steam sterilization and cleaning procedures in the pH range 0-14 at temperatures up to 80°C. These systems consist of a sintered carbon tube with an ultrafiltration layer of a metallic oxide, usually zirconia. Typical tube dimensions are 10 mm (outer diameter) with a wall thickness of 2 mm (Gerster and Veyre 1985). 

Modem bilayered catalysts have a mechanically strong and gas-permeable support. It may be a sheet of sintered metal powder or a tube made from a heat- and corrosion-... 

The sample tube in the original Roller analyzer was a U-tube attached at one end to the bottom of the elutriation chamber, and the catalyst was blown into the chamber by means of a high-velocity air jet (over 200 ft. per second). It was found that some attrition occurred during analysis, particularly with fresh ground catalyst. To avoid this difficulty, a modified sample tube was developed that consists of a straight cylinder fitted with a porous sintered metal disc at the bottom (206). The sample tube containing the weighed catalyst is attached to the bottom of the elutriation chamber, and air is introduced below the porous disc. 

The MF membranes are usually made from natural or synthetic polymers such as cellulose acetate (CA), polyvinylidene difiuoride, polyamides, polysulfone, polycarbonate, polypropylene, and polytetrafiuoroethylene (FIFE) (13). Some of the newer MF membranes are ceramic membranes based on alumina, membranes formed during the anodizing of aluminium, and carbon membrane. Glass is being used as a membrane material. Zirconium oxide can also be deposited onto a porous carbon tube. Sintered metal membranes are fabricated from stainless steel, silver, gold, platinum, and nickel, in disks and tubes. The properties of membrane materials are directly reflected in their end applications. Some criteria for their selection are mechanical strength, temperature resistance, chemical compatibility, hydrophobility, hydrophilicity, permeability, permselectivity and the cost of membrane material as well as manufacturing process. 

The candle filter element can be textile cloth over a supporting tube, sintered metal, ceramic or spaced rings. It can also be used for air or gas filtration. Metallic candles are particully suited for high temperature applications. 

The apparatus for the preparation of unstable metal hydrides such as FeTiH is shown in Figs. 1 and 2. It consists of a reactor and a pressure-vacuum manifold which is rated for pressures up to 68 atm and is constructed of stainless steel (300 series). The reactor is constructed of j" tubing welded to a metal plug which forms the bottom closure. The top of the tube is welded to a O-ring connector (VCO Type, Cajon Co. 32550, Old South Rd., Cleveland, OH) which in turn is socket-welded to a X tube reducer. A sintered metal disc ( 5 pm... 

The most common methods for manufacturing thin metal membranes include rolled foil, drawn tubes, and films deposited onto porous substrates (ceramic or sintered metal). Usually, electroless plating or electrolytic plating are the methods used to deposit the permselective metal onto the porous substrates although vapor deposition methods have been the subject of much research effort However, to date, vapor deposition methods have not proven to be a superior membrane fabrication method. There are pros and cons to each of these methods, but commercial membrane modules have only succeeded using rolled foil and drawn tubular membranes. 

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