Stubbing

Piebaked anodes aie produced by molding petroleum coke and coal tar pitch binder into blocks typically 70 cm x 125 cm x 50 cm, and baking to 1000—1200°C. Petroleum coke is used because of its low impurity (ash) content. The more noble impurities, such as iron and siUcon, deposit in the aluminum whereas less noble ones such as calcium and magnesium, accumulate as fluorides in the bath. Coal-based coke could be used, but extensive and expensive prepurification would be required. Steel stubs seated in the anode using cast iron support the anodes (via anode rods) in the electrolyte and conduct electric current into the anodes (Fig. 3). Electrical resistivity of prebaked anodes ranges from 5-6 Hm anode current density ranges from 0.65 to 1.3 A/crn. ... 

V-clamp joints (Fig. 10-140) are attached to the pipe by butt-weld or expanded joints. Theoretically, there is only one relative position of the parts in which the conical surfaces of the clamp are completely in contac t with the conical surfaces of the stub ends. In actual practice, there is considerable flexing of the stub ends and the clamp also complete contact is not required. This permits use of elastomeric gaskets... 

Lap-joint flange (with ANSI B16.9 lap-joint stub)... 

Older tank cars have a center sill or beam running the entire length of the car. Most modern cars have no continuous sill, only short stub sills at each end. Cars with full sills have tanks anchored longitudinally at the center of the sill. The anchor is designed to be weaker than either the tank shell or the doubler plate between anchor and shell. Cars with stub sills have similar safeguards. Anchors and other parts are designed to meet AAR requirements. 

Volume of vessel (free volume V) Shape of vessel (area and aspect ratio) Type of dust cloud distribution (ISO method/pneumatic-loading method) Dust explosihility characteristics Maximum explosion overpressure P ax Maximum explosion constant K ax Minimum ignition temperature MIT Type of explosion suppressant and its suppression efficiency Type of HRD suppressors number and free volume of HRD suppressors and the outlet diameter and valve opening time Suppressant charge and propelling agent pressure Fittings elbow and/or stub pipe and type of nozzle Type of explosion detector(s) dynamic or threshold pressure, UV or IR radiation, effective system activation overpressure Hardware deployment location of HRD suppressor(s) on vessel... 

The main part of the anode slurry, which can contain CaC03, depending on the hardness of the water, is chemically inert from the corrosion point of view, and settles to the bottom of the tank. The slurry must be removed once or twice a week through a stub with a stopcock this takes place in short bursts of opening and closing of the tap at full water pressure. The deslurrying outlet is at the end opposite to the water inlet in a horizontal tank. 

Most other rotor parts in gas turbines are individually forged. This includes compressor wheels, spacers, distance pieces, and stub shafts. All are made from quenched and tempered low-alloy steels (Cr-Mo-V or Ni-Cr-Mo-V) with the material and heat treatment optimized for the specific part. The intent is to achieve the best balance of strength, toughness with ductility, processing and nondestructive evaluation capability, particularly when it is recognized that some... 

The low speed gear shaft and the housing must be designed to permit installation of a stub shaft for a torsiograph unit if an operational problem occurs. API 613 gives the details of the shaft end requirements for attaching a torsiograph. This should be done on all synchronous motor compressors and on multiple driver or multiple compressor case trains. 

The interior of piping systems should be streamlined for easy drainage. Stubs and dead ends should be avoided, and pipelines should be sloped continuously downstream to their outlets. Elbows should be sloped for drainage purposes. 

Several 25 mm valved stubs should be provided at appropriate points in the header, to which temporary drain connections can be made from equipment where permanent connections would not be justified because of infrequent usage or small inventory. The stubs should be located at grade, within 30 m of such equipment. 

If primary control by the enclosure is under consideration, the extra wear and tear on electrode holding equipment by the escaping fume must be taken into account. This potential problem is particularly evident on ultra-high-power (UHP) furnaces where the holding equipment would be constantly exposed to high-temperature flame. As a possible solution, the furnace could be equipped with a roof-mounted water-coiled stub stack, which naturally draws fume from the furnace and into the enclosure. This approach would divert the fume and prevent damage to the electrode equipment. 

Gases are diseharged into the ambient atmosphere by means of staeks (referred to as chimneys by some in industry) of several t> pes. Stub or short stacks are usually fabrieated of steel and e.xtend a minimum distanee up from the diseharge of an indueed draft fan. These are eonstrueted of steel plate, either unlined or refraetory-lined, or entirely of refraetory and struetural briek. Tall... 

Stumpf, OT. stump stub ((jeom.) frustum, stum -eckig, a. blunt-comered. -kantig, a. 

Also known as redistribution baffles, these short stub baffles guide the liquid flow path to prevent excessive bypassing of the bubble cap field or active tray area. Unfortunately this action is overlooked by many designers with... 

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