Barrel jacket

Cooling water flow to the barrel jacket coolers for the secondary extruder removes the excess energy in the resin dissipated by the primary extruder and also the energy dissipated by the screw in the secondary machine. For a properly designed line, the performance of the secondary extruder determines the overall rate of the process. 

Depending on capital investment limitations, extruders may be heated by passing steam through the barrel jacket and/or by direct steam injection. Low-cost autogenous machines, which create heat by friction between the feed material and the surfaces of the barrel, screw and steam locks, and do not require steam-generating equipment, are also used (Wiejratne et al., 2004). This process is referred to as dry extrusion, and the extruder can be powered by a farm tractor and was originally developed to cook whole soybeans on-farm to prepare feeds. 

Immersion electrodes are the most common glass electrodes. These are roughly cylindrical and consist of a barrel or stem of inert glass that is sealed at the lower end to a tip, which is often hemispherical, of special pH-responsive glass. The tip is completely immersed in the solution during measurements. Miniature and microelectrodes are also used widely, particularly in physiological studies. Capillary electrodes permit the use of small samples and provide protection from exposure to air during the measurements, eg, for the determination of blood pH. This type of electrode may be provided with a water jacket for temperature control. 

Specimen Location Coolant piping connections in extrusion barrel cooling jacket... 

Figure 9.16 depicts the arrangement of connections in the extrusion barrel cooling jacket. Embrittlement and cracking of these stainless steel connections (Figs. 9.17 and 9.18) were occurring as frequently as every 4 to 6 weeks. 

Cylinder barrel, head, and air passages water-jacketed for cooling. 

In this MI instrument the plastic is contained in a barrel equipped with a thermometer and surrounded by an electrical heater and an insulating jacket. A weight drives a plunger that forces the melt through the die... 

OnSite Technology, L.L.C. (OnSite) has developed the portable indirect thermal desorption (ITD) system for the treatment of hazardous wastes. The ITD 6000 uses a rotating, heat-jacketed closed barrel to vaporize hydrocarbons from contaminated soils and drilling mud, allowing the hydrocarbons to be recovered while cleaning the contaminated sediment. The technology is commercially available. 

An extrusion is comprised of a basket (cylinder) to contain the mix and a hydraulically actuated piston to press the mass through multiple extrusion dies. The baskets are jacketed for temperature control and contain internal screens to retain large agglomerates. Since the casting powder strands are unperforated, the dies are simple cylindrical barrels with conical lead-in sections. Extrusion rates are normally controlled by orifices in the hydraulic supply line however, constant-rate positive displacement devices are also used. As they extrude, the strands are collected separately in suitable containers. 

The principal military use of brass was formerly for the manuf of cartridge cases (See Vol 2, pC78-R), but now other materials are used, such as steel, plastics and colloided smokeless proplnts. Another Cu alloy, bronze (Cu 90 Sn 10%) was formerly used for casting gun barrels (Ref 13, p 167), but now steel is used for that purpose. The so-called gilding metal (Cu 90 Zn 10%) has been used as a jacket for lead-alloy bullets (See Vol 2, p B327-R, under Bullets, Metal Jacketed)... 

A bullet jacket is normally harder than the bullet core material but soft enough to take up the rifling and not cause excessive wear to the barrel. Bullet jackets were for a long period made of cupronickel (80% copper, 20% nickel), gilding metal (90% to 95% copper, 10% to 5% zinc) or steel which was coated... 

There has been some innovative technology applied by some wineries to maintain the wines in a warm condition. Several wineries have been visited where small tanks, puncheons, or barrels were covered with electric blankets to maintain an adequate temperature for the malo-lactic fermentation. Larger wineries utilize an external heat source to warm the storage tanks in which the red wine is held. Where wineries are using ammonia refrigeration systems directly in the jacketed portion of the fermentors, these systems can be used as a heat pump. The hot ammonia gas from the compressors is desuperheated and the tank jacket used as a condenser to condense this gaseous ammonia. This has proven to be a very effective means of warming a tank. 

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