(a) De Priester chart K-values for hydrocarbons, low temperature The UNIQUAC. For a single-component or azeotropic refrigerant, the operating pressure of the low side of a system can be found by cross referencing the desired coil temperature on the PT chart. If an experimental value of the latent heat at the boiling point is known. Note where the line crosses the methane axis. With the blend you read the saturated temperature next to the pressure in the liquid (bubble point) column of the chart.

Connect the points with a straight line.On the right-hand vertical axis, locate and mark the point containing the temperature 60вЏ.On the left-hand vertical axis, locate and mark the point containing the pressure 100 psia.Example ДЇor example, to find the K value of methane at 100 psia and 60В вЏ. Many DePriester charts have been printed for simple hydrocarbons. 'K' values, representing the tendency of a given chemical species to partition itself preferentially between liquid and vapor phases, are plotted in between. 50 ethanol 50 butanol) will boil at 91.3 вЊ. For example, an ethanol-butanol mixture that is 0.50 mole fraction in ethanol (i.e. The curve connecting the points can be used to determine the boiling point of any mixture of these two components. These nomograms have two vertical coordinates, one for pressure, and another for temperature. Notice that the boiling point for any mixture is between the boiling points of the pure components. A variety of alkanes with the generic formula C n H 2 n +2 are given in the table at the left with names, formulas, and physical properties.

DePriester in an article in Chemical Engineering Progress in 1953. the boiling point can be a rough measure of the amount of energy necessary to separate a liquid molecule from its nearest neighbors to form a gas molecule. DePriester Charts provide an efficient method to find the vapor-liquid equilibrium ratios for different substances at different conditions of pressure and temperature.

Depriester chart to read boiling point