Liquid temperature

Triple point Heat of Heat of Liquid liquid Temperature Temperature... 

Liquid temperatures in the tubes of an LT evaporator are far from uniform and are difficult to predict. At the lower end, the hquid is usually not boihng, and the hquor picks up heat as sensible heat. Since entering hquid velocities are usually veiy low, true heat-transfer coef-... 

ASTM [vacuum, often 10 torr (1.3 kPa)] ASTM D 1160 Heavy petroleum fractions or products that tend to decompose in the ASTM D 86 test but can be partially or completely vaporized at a maximiim liquid temperature of 750°F (400°C) at pressures down to 1 torr (0.13 kPa)... 

For prehminary screening and easibility studies or for rough cost estimates, one may wish to employ a version of the isothermal method which assumes that the liquid temperatures in the tower are everywhere equal to the inlet-liquid temperature. In their analysis of packed-tower designs, von Stockar and Wilke [Ind. Eng. Chem. Fun-dam. 16, 89 (1977)] showed that the isothermal method tended to underestimate the reqmred depth of packing by a factor of as much as 1.5 to 2. Thus, for rough estimates one may wish to employ the assumption that the temperature is equal to the inlet-liquid temperature and then apply a design fac tor to the result. 

The shiny should always be defined as completely as possible by noting suspended solids concentration, particle size distribution, viscosity, density of solids and liquid, temperature, chemical composition, and so on. 

In view of the above adverse effects a safety factor should be applied where flammability is assessed using flash point. For pure liquids in containers the vapor should be considered potentially flammable if the liquid temperature is upward of at least 5°C below the reported flash point. For mixtures whose composition is less certain, such as petroleum mixtures, the safety factor should be about 15°C relative to the flash point [55]. Where combinations of adverse effects are identified the safety factors should be increased accordingly. A simple but very conservative approach is to assume that all liquids having a flash point <141°F may produce a flammable atmosphere under some ambient conditions, even where no mist or froth production is involved. A more practical approach is to assume that liquids handled in air at least 5-15°C below their closed cup flash points will not present ignition risks unless... 

Loading hot liquids temperature checks, line heating and insulation. 

The following example helps to illustrate the use of the equations presented up to this point. An aqueous slurry was filtered in a small laboratory filter press with a pressure drop of 0.5 atm and at a temperature of 20 C. After 10 minutes, 4.7 liters of filtrate were obtained after 20 minutes, 7.0 liters were collected. From experiments at other pressures, it was determined that the cake compression coefficient was s = 0.4. We wish to determine the volume of filtrate expected after 30 minutes from a filter press having a filtering area 10 times greater than the laboratory press if the filtration is to be performed at 1.5 atm pressure. The liquid temperature will be 55 °C. We also wish to determine the rate of filtration at the end of the process. 

Determine the maximum diameter of spherical chalk particles entrained by an upward-moving water stream with a velocity of 0.5 m/sec. The liquid temperature is t = 10° C, and the specific weight of the chalk is 2,710 kg/10° C. 

From a hydrate melting standpoint it is possible in the winter time to have too cold a liquid temperature and thus plug the liquid outlet of the low temperature separator. It is easier for field personnel to understand and operate a line heater for hydrate control and a multistage flash or condensate stabilizer system to maximize liquids recovery. 

The use of Figure 9.2 requires that liquid propane s temperature relative to its boiling point and superheat-limit temperature be known. Table 6.1 gives these temperatures T, = 231 K, and T j = 326 K. It is obvious that the liquid temperature can easily rise above the superheat-limit temperature when the vessel is exposed to a fire. Therefore, the explosively flashing-liquid method must be selected. The... 

The calculation method can be selected by application of the decision tree in Figure 9.2. The liquid temperature is believed to be about 339 K, which is the temperature equivalent to the relief valve set pressure. The superheat limit temperatures of propane and butane, the constituents of LPG, can be found in Table 6.1. For propane, T, = 326 K, and for butane, T i = 377 K. The figure specifies that, if the liquid is above its critical superheat limit temperature, the explosively flashing liquid method must be chosen. However, because the temperature of the LPG is below the superheat limit temperature (T i) for butane and above it for propane, it is uncertain whether the liquid will flash. Therefore, the calculation will first be performed with the inclusion of vapor energy only, then with the combined energy of vapor and liquid. 

In the first case, internal temperature rises slowly, so the liquid propane is also heated. At failure, the liquid temperature will be above superheat limit temperature, and it will flash on release. 

To calculate the equilibrium curve taking the heat of solution into accoimt, i.e., operate adiabatically with liquid temperature variable, follow the steps ... 

Fixed 10-lC Both tubesheets Condensers liquid-liquid Temperature difference at 1.0... 

ATl = actual liquid temperature rise ATLniax = maximum possible liquid temperature rise (to vapor inlet temperature.)... 

Both the refillable and non-refillable cylinders must, of course, be designed for the internal pressure conditions likely to be experienced during their lifetime. Welded steel cylinders are designed based upon a maximum liquid temperature of 55°C and the associated vapor pressure... 

The safety relief valve will protect the liquid-wetted areas of the storage vessel. The metal temperature will not significantly exceed the liquid temperature, which will be absorbing the latent heat of vaporization. However, above the liquid line no such cooling will take place. The metal temperature at the top of the vessel could therefore exceed safe limits. 

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