Containment annular space

The furnace and thermostatic mortar. For heating the tube packing, a small electric furnace N has been found to be more satisfactory than a row of gas burners. The type used consists of a silica tube (I s cm. in diameter and 25 cm. long) wound with nichrome wire and contained in an asbestos cylinder, the annular space being lagged the ends of the asbestos cylinder being closed by asbestos semi-circles built round the porcelain furnace tube. The furnace is controlled by a Simmerstat that has been calibrated at 680 against a bimetal pyrometer, and the furnace temperature is checked by this method from time to time. The furnace is equipped with a small steel bar attached to the asbestos and is thus mounted on an ordinary laboratory stand the Simmerstat may then be placed immediately underneath it on the baseplate of this stand, or alternatively the furnace may be built on to the top of the Simmerstat box. 

Apparatus 1-1 flask with a dropping funnel, a gas-tight mechanical stirrer and a very efficient reflux condenser the top of the condenser was connected with a trap. A tube containing anhydrous CaCl2 was placed between the trap and the water pump. The connection of the trap was made in such a way that the cumulene vapour could enter the large annular space (the long inner tube being connected to the water pump). 

Basically, tliere are two classes of anunonia converters, tubular and multiple bed. The tubular bed reactor is limited in capacity to a maximum of about 500 tons/day. In most reactor designs, the cold inlet synthesis gas flows tlirough an annular space between the converter shell and tlie catalyst cartridge. This maintains the shell at a low temperature, minimizing the possibility of hydrogen embrittlement, which can occur at normal synthesis pressures. The inlet gas is then preheated to syntliesis temperature by the exit gas in an internal heat e.xchaiiger, after which it enters tlie interior of the anunonia converter, which contains tlie promoted iron catalyst. 

Direct Indicating Viscometer. This is a rotational type instrument powered by an electric motor or by a hand crank. Mud is contained in the annular space between two cylinders. The outer cylinder or rotor sleeve is driven at a constant rotational velocity its rotation in the mud produces a torque on the inner cylinder or bob. A torsion spring restrains the movement. A dial attached to the bob indicates its displacement. Instrument constants have been so adjusted that plastic viscosity, apparent viscosity, and yield point are obtained by using readings from rotor sleeve speeds of 300 and 600 rpm. 

The cement slurry is pumped down the casing and up the annular space between the casing and the formation. The spacer and drilling fluid are thus displaced by the cement slurry. A compatible fluid (one that does not substantially alter the set time of the cement slurry) is pumped into the wellbore to displace nearly all the cement slurry into the annular space between the casing and the formation. The well is then shut in to allow the cement to set. This bonds the casing to the formation and isolates oil- and gas-bearing formations from aquifers and brine-containing formations. Fluid communication between formations can adversely affect production operations or lead to contamination of potable water aquifers. 

The adsorbent—a powder generally, but it could be a metal or oxide film— is placed in a glass tube (the adsorption cell C in Fig. 15) which is connected to the volumetric and vacuum lines. The bottom part of the tube, which contains the adsorbent and is located in the calorimeter cell, is made of thin-walled (0.2-0.3 mm) blown tubing (A in Fig. 18). In order to avoid the slow diffusion of gases through a thick layer of adsorbent (see Section VII.A), the sample is often placed in the annular space between the inner wall of the adsorption cell and the outer wall of a cylinder made of glass,... 

Bomb Igniter, AN-M9, shown in Fig 5-13, consists of two concentric steel tubes joined at both ends to form an annular space which is filled with 1.6-lb of WP for land bombing or Na for water bombing. Outside diam is 1.25-inches, inside diam 0.88-in and overall length 38.34-in. The inner tube, which is ca 1.25-in shorter than the outer tube, contains a small coil spring for snubbing inserted bomb burster Ml3 (Ref 51a, p5-21)... 

Finally, compression-extrusion testing involves an extrusion cell commonly used for weakly structured, homogeneous food products. This apparatus consists of a piston that is forced into a cylinder open at one end and containing the product (Figure H2.2.5). Beyond the point of rupture of the food, the compressed material is forced to flow back through the annular space between the piston and the cylinder (Bourne, 1976 Edwards, 1999). The gap between the piston and the cylinder is called the annulus (Bourne, 1982). Variation in the annulus width results in variation in the force required for extrusion (Bourne, 1982). 

Typical of this class of viscometer is the coaxial or Couette type of instrument described in Volume l, Section 3.7.4. The sample fluid is contained within the annular space between two coaxial cylinders, either of which may be rotated by a motor with the remaining cylinder suspended elastically in such a way that the torsional couple exerted on the latter can be measured. If the outer cylinder of radius r2 rotates with an angular velocity cou and the inner cylinder of radius r, is stationary, and the torque (or viscous drag) per unit length of cylinder exerted on the inner cylinder is T, then, for a Newtonian fluid(49) ... 

The design of double-walled tanks requires some special considerations. For instance, some large cryogenic ammonia tanks are enclosed in secondary containers with leak-detection devices placed in the annular space (CCPS, 1988a). The Chemical Industry Association (of the United Kingdom) recommends a variation in double-containment design where only refrigerated vapors are present in the annular space between the two walls (Chemical Industry Association, 1975). 

Figure 5.2 is an illustration of a vessel double-wall containment system. The annular space is kept at a higher pressure than the tank. Should a leak develop, the pressure in the annular space will fall because the flow capacity of the nitrogen pressure control system has been limited. A low pressure will occur, tripping a pressure alarm low (PAL), and alerting the operator to the leak. 

Double-wall tanks are known in various designs. In the simplest version an inner tank designed for storage temperature and pressure is surrounded by a second tank. The annular space between the two walls is filled with insulation material, for example, Perlite. The main purpose of the outer shell is to contain and hold the insulation. Today s usual practice is to design the outer shell to the same standard as the inner shell. This so-called double-integrity tank concept provides an additional safety measure as the outer tank can hold the full content if the inner shell fails. 

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