01 / TOWER INTERNALS
Tower Internals
Packed and tray column internals for distillation, absorption and stripping — the components that control gas–liquid contact, distribution and separation inside the column.
Tower internals for gas–liquid contact
Tower internals are the working components fitted inside a packed or tray column to bring gas and liquid into close, controlled contact — the mechanism behind distillation, absorption, stripping and gas scrubbing. In a packed column, internals distribute liquid evenly over the packing bed, support and retain the packing, and remove entrained droplets from the rising gas. In a tray column, internals form the tray deck itself — the surface where gas bubbles through a flowing liquid layer at each stage.
Packed and tray are two alternative ways to achieve that contact, and a given column is usually one or the other. PCX sources both families of internals (อุปกรณ์ภายในหอกลั่น) from qualified international manufacturing partners — for new column design, revamps and internals replacement.
Packed vs. tray — selection guide
| Factor | Packed Column Internals | Tray Column Internals |
|---|---|---|
| Gas–liquid contact efficiency | High, especially with structured packing. | Good; set by the tray type and number of trays. |
| Pressure drop (lower is better) | Low — well suited to vacuum service. | Higher; varies with tray type. |
| Operating flexibility / turndown | Moderate; depends on good liquid distribution. | Wide, especially bubble cap and valve trays. |
| Resistance to fouling & plugging | Lower; packing and distributors can foul. | Higher; trays cope better with dirty service. |
| Maintenance & inspection | Beds generally removed to inspect. | Trays can be inspected and cleaned in place. |
| Best suited to | Small–medium diameter, vacuum / low ΔP, corrosive or high-purity duty. | Large diameter, high liquid loads, fouling service, wide turndown. |
Relative guidance only; actual performance depends on the specific packing or tray type, materials and design selected. Contact PCX for engineering support in matching internals to your process.
Two families of internals
Internals divide into two families by the type of column they go into — packed-column internals that serve a packing bed, and tray-column internals that form the tray decks.
PACKED · DISTRIBUTORS, SUPPORTS, DEMISTERS
Packed Column Internals
Liquid distributors and redistributors, packing support and hold-down devices, and demisters — the components that distribute, support and protect a packing bed.
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TRAY · BUBBLE CAP, SIEVE, VALVE, TONGUE
Tray Column Internals
Bubble cap, sieve, floating valve and tongue trays — each creating the gas–liquid contact stage across a tray deck in a different way, compared and supplied to your loads.
View rangeFrequently Asked Questions
What are tower internals?
Tower internals are the working components fitted inside a packed or tray column to bring gas and liquid into close, controlled contact — the mechanism behind distillation, absorption, stripping and gas scrubbing. A column shell on its own does very little; separation performance is set largely by what is installed inside it. Because the internals control how uniformly fluids move through the column, their design has a direct effect on separation efficiency, pressure drop and turndown.
Packed column vs tray column — which should I use?
They are two alternative ways to achieve gas–liquid contact, and a given column is usually one or the other. Packed columns favour low pressure drop and are common for small-to-medium diameters, vacuum service, corrosive duty and high-purity separation. Tray columns handle large diameters, high liquid loads, fouling service and wide turndown well, and are easier to inspect and clean in place. Selection also depends on operating temperature and pressure, and how far the column must turn down — see the comparison table above, and contact us for engineering support.
Can one column use both packed and tray internals?
Usually a column uses one contacting method, but hybrid columns do exist — for example trays in one section and packing in another within the same shell. Some internals are also common to both: a demister (mist eliminator) is fitted at the top of packed and tray columns alike, and a plant will often run some packed columns and some tray columns side by side. The two families in this catalog are grouped by which column type each component belongs to.
Do you supply tower internals to a drawing or specification?
Yes. Tower internals are engineered to each column — packing supports, hold-downs, distributors, tray decks, hole / valve layout and downcomer sizing are matched to the packing or tray type, column diameter and process duty, so there is no fixed size table. PCX sources both packed and tray internals from qualified international manufacturing partners and supplies them to your drawing or specification, for new column design, revamps and internals replacement.
Do you supply tower internals in Thailand, and how do I get a quotation?
Yes. PCX supplies packed and tray column internals across Thailand. When requesting a quotation, please specify the internals type, column diameter, packing or tray details, operating conditions, and delivery location — and we will return a quotation.
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