What is hold-up time in vessel?
Liquid retention time is combined from holdup and surge time. Holdup, considered for smooth and safe operation of downstream facilities, is defined as the time it takes to reduce the liquid level from normal to low liquid level by closing inlet flow while maintaining a normal outlet flow.
What is hold-up time separator?
According to Svrcek and Monnery (1993), separator holdup is defined as the time it takes to reduce the liquid level from normal (NLL) to empty (LLL) with a constant outlet drain rate and a closed inlet. Holdup is the capacity to keep a constant outlet flow rate without interrupting the inlet flow rate.
What is a hold-up volume?
The system hold-up volume is defined as the volume of mobile phase contained within the chromatographic system between the injector and the detector [690]. It can be determined by the elution volume of an unretained and unexcluded solute.
How do you calculate liquid holding up?
The nondimensional area of the liquid film, the ratio of the area of the liquid film to the cross-sectional area of the pipe, was 0.29. Since, the liquid holdup is defined as the area of liquid divided by the area of the pipe, the nondimensional area is equal to the liquid holdup of the liquid film before the slug.
How do you calculate vessel size?
In order to calculate the expansion vessel size, you need to know the following values:
- V – water volume of the entire heating system (boiler, piping, heating radiators, other devices) [l]
- Tmax – max.
- ph,dov – max.
- H – elevation of the heating system’s highest point above the expansion vessel [m].
- ph,min – min.
What is liquid holdup in multiphase flow?
With reference to multiphase flow in pipes, the fraction of a particular fluid present in an interval of a pipe. In multiphase flow, each fluid moves at a different speed due to different gravitational forces and other factors, with the heavier phase moving slower, or being more held up, than the lighter phase.
How do you size a separator?
- Calculate vessel diameter and length with Eq.
- Calculate Leff and Lss = Leff + d/12 for different values of d.
- Calculate the vessel diameter and length for liquid retention time with Eq.
- Calculate Leff and Lss = Leff + d/12 for different values of d.
- Select vessel that satisfies both gas and liquid capacity.
How does a gas liquid separator work?
Gas liquid separation is often based on the principle of gravity settling, when liquid droplets suspended in rising gas vapors settle down at the bottom of the separation vessel and are eventually taken out through the bottom. Gas stream separated from liquid is taken out from the top of the separation vessel.
What is hold up volume filter?
During filtration, all systems retain some liquid that cannot be recovered. This is called “hold-up” volume. The larger the hold-up volume, the greater the loss of media and reagents.
What is liquid holdup in distillation column?
The liquid holdup is another critical parameter for the reactive distillation because it determines the residence time. In this work, the liquid holdup was defined as the total volume of the liquid at the pack surfaces as well as that in the pack pores, the holdup regions and the column bottom.
What does liquid hold up mean?
[′lik·wəd ′hōl‚dəp] (fluid mechanics) A condition in two-phase flow through a vertical pipe; when gas flows at a greater linear velocity than the liquid, slippage takes place and liquid holdup occurs.
Why liquid holdup is important?
The pressure gradient prediction for multiphase flow Among them, the liquid holdup is essential to the design of multiphase flow pipe, due to its close correlation with the pressure gradient of the pipe, which is an important theoretical foundation for the design and analysis of oil and gas wells [1- 2] .