Cooling temperatures

Evaporation Retardants. Small molecule solvents that make up the most effective paint removers also have high vapor pressure and evaporate easily, sometimes before the remover has time to penetrate the finish. Low vapor pressure cosolvents are added to help reduce evaporation. The best approach has been to add a low melting point paraffin wax (mp = 46-57° C) to the paint remover formulation. When evaporation occurs the solvent is chilled and the wax is shocked-out forming a film on the surface of the remover that acts as a barrier to evaporation (5,6). The addition of certain esters enhances the effectiveness of the wax film. It is important not to break the wax film with excessive bmshing or scraping until the remover has penetrated and lifted the finish from the substrate. Likewise, it is important that the remover be used at warm temperatures, since at cool temperatures the wax film may not form, or if it does it will be brittle and fracture. Rapid evaporation occurs when the wax film is absent or broken. 

Bromothiophenes, if not stored and treated correcdy, may decompose, Hberate HBr gas, and lead to pressurizing of containers. Prior treatment with alkah, avoiding metal contaminants, and keeping a cool temperature can avert any problems. Acylthiophenes are transported under U.N. No. 2810, Toxic Hquids, organic, N.O.S., Class 6.1, Packaging Group 111. 

Loss of effective cooling. Temperature excursion outside the safe operating envelop. 

Heat build-up Monitor and alarm temperature due to loss of, coolant flow/temperature sensors or product cooling. temperature sensors. CCPS G-12 CCPS G-23 CCPS G-29... 

The most common light hydrocarbon refrigerant cooling temperature ranges are ... 

BATCH REACTOR HEATING AND COOLING TEMPERATURE PREDICTION... 

Hence the nylon bush would need to be cooled by 143°C to achieve the necessary contraction to have easy assembly. This suggests a cooled temperature of -123°C. 

Commonly used hydrocarbon refrigerants and their cooling temperatures are/ ... 

Arctic Drilling. Corrosion problems encountered in arctic area drilling are no different from problems faced in other areas of the world. It is a general misconception that during arctic drilling corrosion-related problems are either not very severe or totally absent due to low temperatures. Cool temperatures may slow down the corrosion process. However, they also increase the solubility of oxygen, carbon dioxide and hydrogen sulfide. Therefore, the net result can be an increase in the rate of corrosion. While cold temperatures may cause problems, the temperature fluctuation common in arctic environments can be a more severe source of corrosion-related problems [215]. 

Direct expansion cooling Temperature difference Air changes (room volumes) per hour Air-handling unit Static water gauge... 

The use of dry coolers cannot take advantage of the lower cooling temperatures available by the evaporation of the cooling water, and is limited by the ambient dry bulb temperature, rather than the wet bulb Higher power is therefore required, and a given size compressor will perform less cooling duty. 

A better cooling efficiency of the compound can be achieved by a lower cooling temperature of the mixing chamber and rotors. Tests were done in order to measure the effect of a decreasing cooling temperature on the silanization efficiency. Figure 29.14 shows the effect of this measure in a... 

FIGURE 29.14 Influence of cooling temperature on silanization efficiency in a tangential mixer (mixer volume 3.6 L, open mixer, fill factor 0.6, silanization temperature 145°C, time 150 s). 

In simple cases the Jacket or cooling temperature, Tj, may be assumed to be constant. In more complex dynamic problems, however, it may be necessary to allow for the dynamics of the cooling jacket, in which case Tj becomes a system variable. The model representation of this is shown in Fig. 3.3. 

Dry-ice has been used on occasion in attempts to freeze the urine as the sample is collected. About 1 kg of dry-ice is needed in each cooler to make sure the dry-ice does not sublime and disappear during the collection process. When using dry-ice, a combination of blue ice and dry-ice will ensure that the samples remain at least at cool temperatures throughout the 24-h sampling period if the dry-ice disappears. 

Figure 264. Air Dehumidification and energy storage capacity in an ideal absorption process as a function of the air to solution mass ratio (cooling temperature 24°C, inlet humidity ratio 14.5 g/kg, LICL-H20 solution)...

Grows in cool temperatures with high humidity. Leaves of the rice must remain wet for 8-24 h for infection to occur. It overwinters on crop debris. 

Many people love cool autumn mornings, with the scent of the cool air and a rich dew underfoot on the grass and paths. The dew forms when molecules of water from the air coalesce, because of the cool temperature, to form minute aggregates that subsequently nucleate to form visible drops of water. These water drops form a stable colloid (see Chapter 10). 

The energy is transferred to the glass inner surface of the condenser. We maintain a cool temperature inside the condenser by running a constant flow of water through the condenser s jacketed sleeve. The solvent releases a large amount of heat energy as it converts back to liquid, which passes to the water circulating within the jacket, and is then swept away. 

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