Design of Column Internals

Roben, Mfg., Inc. specializes in the custom engineering and fabrication of design of internals: trays, supports and other for chemical, fine chemical, petrochemical, pharmaceutical, food and beverage, defense, and power-generation industries. Every project is designed to ASME Section VIII Division 1 (with optional Division 2), is National Board registered, complies with the European Pressure Equipment Directive (PED 2014/68/EU) for CE marking, and is registered under the Canadian Registration Number (CRN) system for all Canadian provinces.

What Design of Internals: Trays, Supports and Other Are

Column internals include all the components inside a distillation, absorption, or stripping column that drive vapor-liquid mass transfer: trays (sieve, valve, bubble cap), packing supports, distributors, downcomers, support rings, demisters/mist eliminators, and feed inlets. The performance of a column depends as much on its internals as on its shell.

Why Design of Internals: Trays, Supports and Other Matter

Process performance — separation efficiency, pressure drop, turndown, and capacity — is determined by internals geometry. Roben's engineers design and fabricate internals as part of the column package, ensuring tight tolerance fit-up, correct hydraulic performance, and reliable long-term operation.

Design of Internals: Trays, Supports and Other — Specifications and Capabilities

Trays: Sieve, valve (fixed and floating), bubble cap, dual-flow

Packing supports: Beam-type, gas-injection, structured-packing supports

Distributors: Pan, trough, drip-pipe, and high-performance gravity distributors

Demisters: Mesh pads, vane packs, multi-stage

Materials: Stainless steel (304/316L), Hastelloy, Inconel, Monel, FRP

Tolerances: Tray flatness ≤ 1/8 in., weir height ±1/16 in., support ring level ≤ 1/8 in.

Certifications and Codes

ASME Section VIII Division 1 — U-stamp

ASME Section VIII Division 2 — available on request

National Board registration — R-stamp

PED 2014/68/EU — CE marking with Notified Body coordination

CRN — registered for all Canadian provinces

NACE MR0175 / ISO 15156 — sour-service compliance

AWS D1.1 / ASME Section IX — qualified welding procedures and welders

Frequently Asked Questions About Design of Internals: Trays, Supports and Other

Does Roben Mfg. design the column internals or just fabricate them?

Both. Our engineers will design the internals from the process requirements (vapor and liquid loads, fouling potential, turndown), or fabricate to a process licensor's design (UOP, Sulzer, Koch-Glitsch, Shell, etc.).

What tolerance does Roben Mfg. hold on tray fabrication?

Tray flatness ≤ 1/8 in. across the diameter, weir height to ±1/16 in., downcomer geometry to ±1/16 in. We measure during fabrication and at installation.

Can Roben Mfg. install internals at the column site?

Yes. We coordinate field installation through site-services partners, with our engineers available for technical support during tray-by-tray installation and inspection.

What is a distributor and why does it matter?

A distributor evenly distributes liquid across the cross-section of a packed bed at the top of the column or at intermediate elevations. Poor distribution kills column efficiency. Distributor design is critical for packed columns.

What is a demister and where is it used?

A demister (mist eliminator) removes entrained liquid droplets from a vapor stream, typically at the column overhead. We supply mesh pads, vane packs, and combinations sized for the K-factor and droplet-removal target.

Request a Quote on This Project

Contact Roben Mfg., Inc. to discuss your project specifications, timeline, and material requirements.

📞 (732) 364-6000 ✉ sales@robenmfg.com 📍 760 Vassar Ave, Lakewood, NJ 08701

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Custom Design of Column Internals — Trays, Supports, Distributors