Cooling testing methods

A similar unit, modified in details such as location of condenser, use of an agitator and shape of the vessel, was used by Fisher and Whitney . Further substantial modifications to permit interface location of specimens, cooling of specimens and operation under applied pressure, have been described by Fisher . Earlier laboratory test methods tried by Fisher and Whitney included exposure of specimens heated by their own electrical resistance and of tubular specimens containing a pencil-type resistance-wire heater in a quartz tube. 

Since corrosion inhibitors are used in a wide range of applications, no universal test method exists. Recognised methods tend to relate to a product or process in which the inhibitor forms a part rather than to the inhibitor per se. Thus, tests exist for inhibited coolants, cooling waters, cutting oils, pickling liquids, etc. 

Upon cooling, molten and rubberlike polymers pass the glass transition and solidify as glassy materials. The temperature TB of the glass transition depends on the chemical nature of the polymer as well as on the number of crosslinks between the molecular chains. Two different test methods were used for the determination of the glass transition range ... 

Test method IP 309 is used to determine the low-temperature filterability of distillate fuels including those treated with a cold flow improver. The cold filter plugging point (CFPP) is defined as the highest temperature at which the fuel, when cooled under the prescribed conditions, will not flow through the filter or requires more than 60 seconds for 20 mL to pass through or fails to return completely to the test jar. This method is part of a series of standardized tests developed by the Institute of Petroleum. Test method IP 309 is summarized as follows ... 

Use Method 1001 of Federal Test Method Standard No 791, except that, due to the high viscosity of the material, cooling water at 40—45° shall be substituted for the ice-water in the condenser... 

Corrosion detection plays an important role in any corrosion control program. Most of the methods employ nondestructive test methods and include hydrogen evaluation, radiography, dynamic pressure, corrosion probes, strain gauges and eddy current measurements. Of these, the methods employed in cooling tower practice are hydrogen evaluation and corrosion probes. 

Unfortunately, there are no commonly accepted standard procedures for securing reliable corrosion data. Any data collected from any test methods will have value only if they can be interpreted properly. Many corrosion environments can vary widely from day to day and even from hour to hour. Even slight variations in operating procedures can drastically affect the corrosion characteristics of the cooling tower. Therefore, it is important to establish methods on how the corrosion data are to be accumulated, evaluated and put to use. 

Wind tunnel test methods were developed to determine wind induced stresses in cooling towers using aeroelastic models as part of a detailed model of a power station site. The turbulence and shear in the atmospheric wind are simulated. Tests on a model of Ferrybridge C Power Station show that resonant stresses are significant at the design wind speed. These increase as the fourth power of wind speed and can be greatly enhanced by turbulent wakes of upstream structures. 6 refs, cited. 

Copolymer test specimens were prepared by pressing slabs for 0.5-3 min at temperatures approximately 20°C above the copolymer melting point, followed by cooling under pressure to room temperature in 5-10 min. Test samples were conditioned at 24°C and 50% relative humidity for at least 48 hr before testing. Stress-strain and tear-strength measurements were made on 0.6 to 0.8-mm-thick specimens. Thicker specimens yield lower values for tensile strength and elongation at break. The test methods used were ... 

Primary Parameters. Table 1 lists these processes and associated wastes loadings. Separate subtotals are presented with and without salad dressing and mayonnaise, as these processes are often absent and portions of this article do not consider them. See (2) for clarification of terms and test methods. Table 1 excludes waste-water flows without organic contamination such as noncontact cooling tower blowdown and boiler blowdown. 

The objective of this test method is to measure the cohesive stress and the time to failure of a crystalline polymer craze layer under rapid, uniform extension. The method is an impact variant of the Full Notch Creep test used by Fleissner [12], Duan and Williams [13], Pandya and Williams [14] and others. The specimen (Fig. 2), a square-section tensile bar, is injection moulded. At the mid-plane of the gauge length a sharp, deep circumferential notch reduces the cross-section to about one fifth of its original area. This notch plane is formed by a moulded-in, hardened steel washer. Specimens were injection moulded at 210°C into a warm (100°C) mould and air cooled to 40 C using a hold pressure of 45-50 bar. 

A later test method (ASTM D-5853) covers two procedures for the determination of the pour point of crude oils down to -36°C. One method provides a measure of the maximum (upper) pour point temperature. The second method measures the minimum (lower) pour point temperature. In these methods, the test specimen is cooled (after preliminary heating) at a specifled rate and examined at intervals of 3°C (5.4°F) for flow character-... 

In the simple cloud point test method (ASTM D-2500), the sample is first heated to a temperature above the expected cloud point and then cooled at a specified rate and examined periodically. The temperature at which haziness is first observed at the bottom of the test jar is recorded as the cloud point. 

Alternatively, low-temperature flow test (ASTM D-4539) results are indicative of the low-temperature flow performance of fuel in some diesel vehicles. This test method is especially useful for the evaluation of fuels containing flow improver additives. In this test method, the temperature of a series of test specimens of fuel is lowered at a prescribed cooling rate. At the commencing temperature and at each 1°C interval thereafter, a separate specimen from the series is Altered through a 17-mm screen until a minimum low-temperature flow test pass temperature is obtained. The minimum low-temperature flow test pass temperature is the lowest temperature, expressed as a multiple of 1°C, at which a test specimen can be Altered in 60 s or less. 

In the original (and stUl widely used) test for pour point (ASTM D-97, IP 15), a sample is cooled at a specified rate and examined at intervals of 3°C (5.4°F) for flow characteristics. The lowest temperature at which the movement of the oil is observed is recorded as the pour point. A later test method (ASTM D-5853) covers two procedures for the determination of the pour point of petroleum and petroleum products down to -36°C (-33°F). One method provides a measure of the maximum (upper) pour point temperature. The second method measures the minimum (lower) pour point temperature. In these methods, the test specimen is cooled (after preliminary heating) at a specified rate and examined at intervals of 3°C (5.4°F) for flow characteristics. Again, the lowest temperature at which movement of the test specimen is observed is recorded as the pour point. 

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