Cold temperature problems

Problem A knockback condenser mounted on a C3 splitter reflux drum exhibited liquid carryover (as evidenced by the vent line icing-up). This indicated product loss from liquid caixying over rather than dripping back into the reflux drum. Also the vent line metallurgy would not withstand the cold temperatures produced. 

Bigger is not better when it comes to heating and cooling equipment. Oversized equipment is not only more expensive to purchase but it also can reduce comfort. The most prevalent examples are the rapid temperature fluctuations and humidity control problems caused by frequent on/oft cycling of oversized equipment. Poor dehumidification occurs because the cooling coils do not sustain cold temperatures long enough to effectively condense moisture out of the air. 

For winter operation, it is important to consider the effect of cold temperatures on process fluid (gelling, freezing, etc.), and this may dictate the controls. In addition, tarpaulins or other moveable barriers may be added to reduce air intake or discharge. This can be a serious control problem. 

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]. 

For the mixture described in the previous problem, calculate the adiabatic (deflagration) temperature when the initial cold temperature is 298 K and the pressure is the same as that calculated for the C-J point. 

Elements of the environment continually impact fuel performance. The effect of water, cold temperatures, heat, air, light, and external contamination can initiate a variety of problems. The first place to begin looking for the cause of a fuel handling or performance problem would be these environmental sources. 

In cold-temperature environments and during winter months, fuel refiners and marketers will often blend kerosene or 1 diesel fuel into 2 diesel fuel to help combat the problems associated with paraffin wax in fuel. This technique is effective to a limited extent due to the reduction in fuel BTU and specific-gravity values by these lighter fuels. 

The cloud point test is one of the most commonly used methods to evaluate the low-temperature characteristics of distillate fuel. The cloud point temperature identifies the point when wax begins to form into crystals large enough to become visible in the fuel. At this temperature, wax can settle from fuel, deposit onto fuel filters, and interfere with the flow of fuel through small tubes and pipes. During cold weather months, distillate fuels with lower cloud point values are refined and blended to minimize the low-temperature problems associated with wax. 

An additional problem may arise in the lacking cold temperature change stability of the formulated oils, i.e., the cold filter plugging point value of the oils attained rises gradually when the oil is stored for a prolonged period at changing temperatures in the region of the cloud-point or below. 

For cold-temperature service, moisture ingress is a problem that musl be designed against and the material selected for its resistance to moisture and potential freezing... 

A major winter storm can be lethal. Winter storms bring ice, snow, cold temperatures, and often dangerous driving conditions. Even small amounts of snow and ice can cause severe problems for southern states where storms are infrequent (see Figure 17.5). 

A problem of this type that has been subjected to careful analysis beginning with the early work of Marble and Adamson [62] is illustrated schematically in Figure 12.4. At the point x = 0, a stream of cold (temperature Tj) combustible gas traveling at the velocity Uj comes into contact with a stream of hot (temperature T2) inert gas traveling at the velocity U2. As... 

You may also want to till or cultivate the soil in garden beds that are cleared out in the faU to help reduce pest problems. Tilling exposes soil pests to the surface, where they may be killed by cold temperatures or spotted and eaten by predators. 

The most important application of gum arable in winemaking is in preventing the precipitation of phenols and coloring matter in red wines. It is well known that the coloring matter in red wines is partially colloidal and thus liable to precipitate at cold temperature. These problems... 

Cold temperatures are not effective for treating microbial problems. The development of microorganisms slows down at low temperatures, but they become fully active again when the temperature rises. 

In many parts of the country construction workers who brave outdoor conditions face the hazard of exposure to cold temperatures. Prolonged exposure to cold temperatures can result in health problems like trench foot, frostbite, and h5 othermia. Employers need to be especially mindful of the weather, its effects on workers, and techniques to prevent injuries. 

Testability This is perhaps the most serious problem with devices in the die form. It is difficult to perform functional testing at high speeds and at temperature extremes as a result of the difficulties in probing. Testing at cold temperatures is virtually prohibitive as a result of moisture condensation. The net result when several devices must be utilized in a single hybrid is lower yields at first... 

The exterior surfaces of airplanes are always exposed to the elements, and are, hence, affected by world and local climatic conditions, e.g., rain, humidity, airborne industrial pollutants, hot and/or cold temperatures, dust, runway dirt, and spray from the oceans and seas. Corrosive contaminants trapped in exterior cavities and cove areas, e.g., wheel wells, wing front and rear spar cove areas, and fairing areas, are not washed off by rain in contrast to aerodynamic surfaces, thereby compounding potential corrosion problems. 

This problem results in a condition called anemia in which a person feels tired, listless, and susceptible to cold temperatures. Meat, fish, poultry, clams, legumes, and green leafy vegetables are all foods that are rich in iron. 

Proper ventilation of these as well as other vented batteries, although not as much a problem here as with other battery systems, is required to avoid the accumulation of hazardous hydrogen, especially during charge. For larger installations, forced air or fans may also be required to prevent undesirable temperature buildups. When close voltage regulation is required at cold temperatures, thermostatically controlled heaters are often used with the batteries. 

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