When fluid flow through a restriction, for example valve or orifice, pressure drop occurs adiabatically. If changes in kinetic or potential energy are negligible, which causes no change in enthalpy at the inlet and at the outlet, then we have ΔH = 0. Some properties of throttling process are expressed in figure below.
In previous post, I shared about how to size two-phase horizontal separator. In this pos, I want to share to you how to size two-phase vertical separator.
Schematic of Two-Phase Vertical Separator
Figure below is schematic drawing of two-phase vertical separator.
Separator is the initial processing vessel in any production facility. Therefore, it should be designed properly to prevent reduction of capacity of the entire facility.
Separators are classified into two-phase and three-phase separator. Two-phase separators are used to separate gas from the total liquid stream. Meanwhile, three-phase separators are used to separate gas from crude oil and water component.
Separators are designed in either horizontal, vertical, or spherical configuration. In this post, I want to share to you how to size two-phase horizontal separator.
Schematic of Two-Phase Horizontal Separator
Figure below is schematic drawing of two-phase horizontal separator.
Purging is an activity used to remove oxygen in piping or vessels to certain concentration, for example 2%-mole. It uses inert gas, usually nitrogen, to do that.
In this post, I want to share you how to calculate inert gas for purging activity. There are three different calculation methods used.
In dilution purging method, the inert gas simply flows through the vessel and reduces the concentration of unwanted component. It is used for tanks, reactors, and other vessels. Figure below is used to determine requirement of inert gas. Read More
I want to share you how to size or select minimum capacity of air compressor and instrument air dryer. Air compressor is usually used as feed air for:
- Instrument air (for instrumentation or feed air for nitrogen generator)
- Utility air (for utility station)
Instrument Air Requirement for Instrumentation
Instrument air is required in operation of control valve and shut down valve. The rules below is used to calculated instrument air requirement for instrumentation:
- Control valve (CV) – steady state condition: 1 scfm/valve
- Control valve (CV) – transient condition: 6.25 scfm/valve
- Shut down valve (SDV) – steady state condition: 0
- Shut down valve (SDV) – transient condition: 4.8 scfm/valve
I just read some pages on Handbook of Chemical Engineering Calculations 2nd edition, written by Nicholas P. Chopey and got interested in calculation of condensate load in order to determine the capacity of steam trap. I will take one example, where the steam indirectly heats a liquid through metallic surface, as in heat exchanger and kettles.
For example, we have 1892.5 L of water heated in 30 min from 22.2 to 100 oC with 50-psig (344.7-kPa) steam in the jacket of kettle. How much condensate formed?
For normal warm up load, the quantity of condensate can be calculated by the following equation: Read More