Bubble-Cap Trays
Bubble-cap tray assemblies for duties where the required operating range and hydraulic conditions justify their selection. ATTOMO fabricates to the agreed process and mechanical specification.
Process and equipment approach
Vapour passes through risers and beneath caps before entering the liquid on the tray. The arrangement can support operation at low liquid loads and a broad operating range, while pressure drop, capacity, complexity and cost must also be evaluated.
Applications and product requirements
Bubble-cap trays are considered where the liquid-seal arrangement and low-load behaviour suit the separation duty. They are used in selected distillation and absorption applications. Their suitability should be compared with valve or sieve trays using the same flows, fluid properties and allowable pressure drop.
Equipment and operating approach
Vapour rises through risers beneath caps and is directed through the cap openings into liquid on the tray. This differs from vapour passing directly through simple sieve holes. Caps, risers, weirs and downcomers form a coordinated hydraulic arrangement. Cap number and spacing, liquid depth and vapour load influence contact and pressure loss.
Simplified equipment illustration — not a fabrication drawing or project photograph.
Define the right package.
The quotation defines the included equipment, services and battery limits.
- Caps, risers and tray decks
- Liquid-handling components and supports
- Specified materials and fabrication records
- Replacement and installation interfaces
Materials and configuration
The fabrication package can define caps, risers, tray panels, downcomers, supports and fastening hardware. Materials must suit corrosion, temperature and cleaning. Existing-column replacements need confirmed cap geometry, tray spacing, support dimensions and access. Bubble-cap construction can involve more parts and maintenance access than simpler tray designs.
Utilities and operation
Specify the minimum as well as normal and maximum vapour and liquid loads. Low-load operation, fouling and the available pressure-drop budget are important selection factors. A claimed turndown or efficiency must be supported by hydraulic calculations for the actual duty.
Information for your enquiry.
Share the information you already have. Early-stage enquiries are welcome.
- Vapour and liquid operating cases
- Column geometry and tray spacing
- Allowable pressure drop
- Corrosion, fouling and maintenance constraints
Frequently asked questions
Are bubble-cap trays always better than valve trays?
No. A broad operating range may be useful, but selection must also consider capacity, pressure drop, cost and service conditions.
Can existing trays be replaced without a hydraulic review?
A review is needed when geometry, loads or tray type change. Physical fit alone does not establish equivalent performance.
Why consider bubble caps at low vapour loads?
Their riser-and-cap arrangement retains a liquid seal and can suit low-load duties. Actual operating range still depends on the complete tray design.
What information is required to quote a bubble-cap tray package?
Provide column dimensions, tray spacing, operating loads, fluid properties, materials and inspection requirements. For replacement parts, include the existing cap, riser, support and fastening details.
Can caps be replaced without replacing every tray?
Potentially, if geometry, condition, material and attachment details are compatible. Verify the existing arrangement and the reason for replacement first.