Application of Double Piping Theory to Parallel-Arrayed Low-Pressure Membrane Module Header Pipe and Experimental...

Area of Science:

• Fluid dynamics
• Chemical engineering
• Membrane technology

Background:

• Uneven flow distribution in parallel-arrayed membrane module header pipes leads to reduced efficiency.
• Existing header pipe structures exhibit significant flow rate variations between inlet and outlet branches.

Purpose of the Study:

• To quantitatively evaluate the improvement in flow distribution evenness by applying double piping theory to a membrane module header pipe.
• To assess the feasibility of using computational fluid dynamics (CFD) and orifice inner pipes for flow uniformity enhancement.

Main Methods:

• Designing orifice inner pipes using computational fluid dynamics (CFD).
• Implementing the double piping theory with inserted inner pipes (open and closed ends).
• Measuring real-time flow rates in 10 membrane modules using a portable ultrasonic flowmeter.

Main Results:

• CFD simulations and experiments revealed an uneven flow distribution, with the end branch flow rate being three times higher than the inlet branch.
• The application of double piping theory with orifice inner pipes improved flow distribution evenness.
• CFD simulations indicated over 70% improvement in flow uniformity, while experimental results showed over 50% improvement.

Conclusions:

• The double piping theory effectively enhances flow distribution evenness in parallel-arrayed low-pressure membrane module header pipes.
• CFD design and ultrasonic flowmeter measurements confirm the significant improvement in flow uniformity.
• This method presents a feasible approach to optimize membrane module performance and efficiency.