Vane Mist Eliminator RFQs: What Data Determine the Quoted Vane Geometry?
A vane mist eliminator cannot be quoted reliably from vessel diameter and material alone.
The internal blade geometry is closely connected to:
gas velocity, liquid characteristics, flow direction, and allowable pressure drop.
Therefore, a serious RFQ should distinguish between a budgetary module price and a technically selected vane system.
Gas Flow Direction
The first requirement is whether gas flows:
vertically, horizontally, or in another project-specific direction.
This affects both vane orientation and liquid drainage.
Gas Rate
The supplier should know the operating gas rate.
Where several conditions exist, provide:
normal and maximum operating cases.
This allows the proposed vane geometry to be reviewed against the actual velocity range.
Gas Properties
Pressure and temperature are relevant because they influence gas density.
For more detailed design, composition and density may also be useful.
Liquid Phase
The supplier should understand what droplets are being removed.
Useful information may include:
liquid composition, density, viscosity, and expected liquid loading.
The more demanding the application, the more valuable this data becomes.
Allowable Pressure Drop
Vane spacing and profile cannot be optimized without considering hydraulic resistance.
If the project has a maximum allowable pressure drop, state it in the RFQ.
Required Droplet Removal
If the process design requires a particular minimum droplet size or separation target, that requirement should be stated.
The buyer should distinguish between:
a general demisting duty and a guaranteed separation duty.
Material
Material selection should reflect both:
gas and collected liquid.
The RFQ should define whether blade, frame, fasteners, and support all require the same material.
Module Size and Access
The supplier requires:
duct or vessel dimensions, manway size, and any maximum module dimensions.
The system may need to be supplied in multiple modules.
Drainage
The technical offer should identify how collected liquid drains from the vane system.
This becomes especially important for horizontal-flow separators.
Engineering Takeaway
The vane profile itself should be the result of a defined operating basis.
Procurement should therefore provide sufficient gas, liquid, pressure-drop, orientation, material, and installation information to justify the geometry being quoted.