HETP Formula:
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Definition: The Height Equivalent to Theoretical Plate (HETP) is the height of packing required to achieve the same separation as one theoretical equilibrium stage.
Purpose: It helps chemical engineers design and evaluate the efficiency of packed columns used in distillation, absorption, and stripping operations.
The calculator uses the formula:
Where:
Explanation: The formula accounts for packing size (first term) and the relative flow rates of gas and liquid phases (second term).
Details: HETP values help determine the required height of packed columns for desired separation efficiency, impacting both design and operating costs.
Tips: Enter the diameter of Raschig rings (typically 0.025m for 25mm or 0.05m for 50mm rings), equilibrium slope, and gas/liquid flow rates. All values must be > 0.
Q1: What are typical HETP values for Raschig rings?
A: For 25mm rings: 0.3-0.6m, for 50mm rings: 0.5-1.0m, depending on system properties.
Q2: How does ring diameter affect HETP?
A: Smaller rings generally provide lower HETP (better efficiency) but increase pressure drop.
Q3: What factors influence the equilibrium slope?
A: It depends on the relative volatility of components in distillation or solubility in absorption systems.
Q4: When is this formula most accurate?
A: For random packings like Raschig rings at moderate flow rates (50-75% of flooding).
Q5: How do I convert between different packing sizes?
A: HETP is roughly proportional to packing diameter, but actual performance should be verified experimentally.