Condenser tubes

The purification train. The oxygen is led from the cylinder through Ordinary flexible rubber condenser tubing to the constant level device A (Fig. 85). This consists of two concentric tubes (approximately 2 cm. and 0-5 cm. respectively, in diameter the inner tube being narrowed and curved at the bottom as shown) immersed in 50% aqueous potassium hydroxide contained in the outer vessel (diameter 3-5 cm.). Then by adjusting the liquid level in A the pressure of oxygen may be kept constant, and at a maximum of about... 

The Mariotte bottle. l he perchlorate guard tube is attached by a length of ordinary rubber condenser tubing to the Mariotte bottle W. This is, in effect, a siphon bottle, and the lead-in tube X is a capillary provided with a tap T,. The bent capillaiy (drawn off slightly at the end) serves as exit tube it is fitted into W by a rubber bung and its level may be adjusted. 

A modified Hahn condenser, a form of partial condenser, is illustrated in Fig. VI, 12, 1 it is best constructed of Pyrex glass. The dimensions given are only approximate and may be varied slightly. The inside clearance should be approximately 0-3 cm. a water jacket should be fitted over the central portion of the side arm by moans of rubber stoppers. Alternatively, the side arm may have a length of about 10 cm. and a condenser fitted to this in the usual manner. An approximately 1 cm. layer of absolute alcohol is placed in the inner condensing tube and the top of the tube is connected to a reflux condenser. The outside of the condenser below the side arm should be insulated with asbestos cloth or paper. The refluxing mixture boils the ethyl alcohol in the inner tube, most of the isopropyl alcohol is returned to the flask and the acetone distils over. 

Before any remedial or preventive actions are implemented, an evaluation should be conducted as to appHcabiUty to the specific plant. The evaluation should continue while the actions are in progress. The main action should be to take measures to reduce the ingress of contaminants into the steam generator by using more rehable materials, such as in the condenser tubes, to reduce leakage. Contaminant control equipment, such as full-flow condensate deminerali2ers, should also be employed. 

J. M. O Coimor, T. C. Ginn, and G. V. Pase, The Evaluation and Description of a Power Plant Condenser Tube Simulator, Report No. 8-0248-956, New York University Medical Center, New York, 1977. 

The generated water vapor rises through a screen (demister) placed to remove entrained saline water droplets. Rising further, it then condenses on the condenser tube bank, and internal heat recovery is achieved by transferring its heat of condensation to the seawater feed that is thus being preheated. This internal heat recovery is another of the primary advantages of the MSF process. The energy performance of distillation plants is often evaluated by the performance ratio, PR, typically defined as... 

Phosphorized deoxidized arsenical copper (alloy 142 (23)) is used for heat exchangers and condenser tubes. Copper-arsenical leaded Muntz metal (alloy 366), Admiralty brass (alloy 443), naval brass (alloy 465), and aluminum brass (alloy 687), all find use in condensers, evaporators, ferrules, and heat exchanger and distillation tubes. The composition of these alloys is Hsted in Table 5. 

Admiralty Brass and Naval Brass are 30 and 40% zinc alloys, respectively, to which a 1% tin addition has been added. Resistance to dezincification of Cu—Zn alloys is increased by tin additions. Therefore, these alloys are important for thein corrosion resistance in condenser tube appHcations. In these, as weU as the other higher zinc compositions, it is common to use other alloying additives to enhance corrosion resistance. In particular, a small amount (0.02—0.10 wt %) of arsenic (C443), antimony (C444), or phosphoms (C445) is added to control dezincification. When any of these elements are used, the alloy is referred as being "inhibited." For good stress corrosion resistance, it is recommended that these alloys be used in the fiiUy annealed condition or in the cold worked plus stress reHef annealed condition. 

Iron is added in small (usually 0.5—1.0 wt %) amounts to increase strength. More importantly, iron additions also enhance corrosion resistance, especially when precautions are taken to retain the iron in solution. Precipitation of the iron—nickel-rich phase does not result in strengthening and can cause degradation of corrosion resistance (47). A small (up to 1.0 wt %) amount of manganese is usually added to both react with sulfur and deoxidi2e the melt. These copper alloys are most commonly applied where corrosion resistance is paramount, as in condenser tube or heat exchangers. 

Good Good 3S-62 9.3-S.5 Higli-iron types excellent for resisting higli-velocity effects in condenser tubes... 

Titanium Fresh and sea water condenser tubing, severe corrosion condition equipment... 

Figure 2.10 Wastage in a circumferential region where a 90 10 cupronickel main condenser tube passed through a baffle. In places, metal loss was greater than 25% of the nominal wall thickness.

Figure 4.5 Friable brown deposit patches on a brass condenser tube. The deposit contained more than 30% manganese.

Figure 4.6 A thin, glassy layer of predominantly manganese oxide on the internal surface of a brass condenser tube. The many white spots are pits at fractures in the manganese layer.

Figure 4.7 Small, manganese-rich nodules on a 90 10 cupronickel condenser tube. Note the small pits beneath each nodule. (Courtesy of National Association of Corrosion Engineers Andy Howell Public Service of Colorado. Corrosion 89 Paper No. 197 by H. M. Herro.)...

Figure 4.14 Silt layer on the internal surface of a 90 10 cupronickel condenser tube.

Figure 4.16 Thick calcium carbonate deposits on condenser tube and copper transfer pipe. Note the stratification.

Figure 4.24 Internal surface of condenser tube as shown in Fig. 4.23.

Specimen Location T wo sections of overhead condenser tubing... 

Two sections of steel condenser tubing experienced considerable metal loss from internal surfaces. An old section contained a perforation the newer section had not failed. A stratified oxide and deposit layer overlaid all internal surfaces (Fig. 5.14). Corrosion was severe along a longitudinal weld seam in the older section (Fig. 5.15). Differential oxygen concentration cells operated beneath the heavy accumulation of corrosion products and deposits. The older tube perforated along a weld seam. 

Finally, any living organism dies. Decomposition may generate ammonia at local concentrations high enough to produce stress-corrosion cracking of brass condenser tubes (Fig. 6.1). 

Figure 6.1 Stress-corrosion cracking of a brass condenser tube caused by ammonia from decomposing slime masses lodged on internal surfaces.

Figure 6.23/ A longitudinally split 304 stainless steel condenser tube covered with deposits.

Figure 7.1 Brass condenser tube inlet end severely corroded by an acid upset involving sulfuric acid.

Figure 7.8 Striations on the internal surface of admiralty brass condenser tube after acid cleaning. (Magnification 15x.)...

Figure 7.9 Network of shallow ditches caused by condensation of acidic fluids during acid cleaning of a copper condenser tube.

Figure 8.6 Severe grooving by ammonia-containing condensate on an admiralty brass condenser tube. Condensate flowed down the tube sheet and collected at the tube end, cutting an annular groove. Note the perforation just outside the tube roll.

Figure 8.9> A brass condenser tube severely wasted by condensing vapors containing ammonia.

Figure 9.3 Transverse stress-corrosion cracks in a condenser tube the presence of the cracks along just one side indicates that a bending moment provided the stress.

Specimen Location Orthodichlorobenzene (ODCB) column condenser tube... 

Specimen Location Surface condenser tube, iniet end... 

Specimen Location Condenser tube, top row immediately adjacent to steam inlet... 

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