Device of preliminary condensation DPC

Fig. 14.1 Element of the technological scheme device of preliminary condensation (DPC) - inlet pipeline - separator 1, 3 inlet pipeline 2 DPC 4 - separator G gas L liquid.

In the scheme of low-temperature separation, a device of preliminary condensation (DPC) is placed before the separator. This may be a throttle, a heat-exchanger, or a turbo-expander, which serves to decrease the temperature of the mixture. Upon passage of a gas-condensate mixture through these devices, the phase balance established by the flow of the mixture in the pipeline is disrupted. As a result, there will be probable formation of a liquid phase due to the process of nucleation, and transition of components from one phase to another owing to the processes of mass-exchange, evaporation, and condensation. Violation of the... 

The quality of separation of gas-liquid mixture in separators depends on the velocity (flow rate) of gas, thermobaric conditions, physical and chemical properties of the phases, geometrical parameters and, most importantly, dispersiveness of the liquid phase (distribution of drops over sizes and the parameters of this distribution) that goes into the separator together with the gas flow from the delivery pipeline. The key parameter of this distribution is the average size of drops that are formed in the gas flow in the delivery pipeline. Therefore, it depends on the parameters of the pipeline and also on the parameters of the device of preliminary condensation (DPC), which, as a rule, is placed at some distance from the separator (see technological schemes in Chapter 1). Therefore, the efficiency of gas-liquid mixture separation is influenced not only by the parameters of the separator, but also by the particular details of the technological circuit before the separator. 

In the previous paragraphs, we considered the processes occurring in a device of preliminary condensation (DPC), in a supply pipeline, and in a separator. It was shown that separation efficiency essentially depends on the behavior of the gas-liquid mixture in all three elements of the technological scheme. We are now interested in the question about the influence of relative positioning of these elements. In particular, one important parameter is the distance between the DPC and the separator, that is, the length of the connecting pipeline. 

Mole fraction of liquid phase Work of friction forces Work done on a unit mass of gas Distance between device of preliminary condensation (DPC) and separator... 

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