How a three-dimensional mesh packing works in a degassing, decarbonation or stripping tower — structure, features, parameters, installation and applications.
← Back to Degassing PackingDegassing packing — also written three-dimensional mesh packing — is a random tower packing made as an extruded diamond-mesh cylinder. The elements are supplied as single mesh cylinders and are charged into a tower between a support grid at the bottom and a retaining grid below the liquid distributor, forming a packed bed of the depth the process design calls for.
Its purpose is mass transfer between water and air. Dissolved gases such as carbon dioxide, hydrogen sulphide, radon and volatile organic compounds leave the water when their partial pressure in the gas phase is lower than the equilibrium value for the water being treated. Continuously replacing the air in contact with the water keeps that driving force high, which is why a degassing tower is operated counter-current: water enters at the top through a distributor and falls through the bed, while air is drawn or blown upwards from below the support grid.
The packing does not create the driving force — the airflow and the water chemistry do that. What the packing contributes is interfacial area and contact time at an acceptable pressure drop. A mesh cylinder presents a large wetted surface inside a bed that is mostly open volume, so the water arrives at the rising air as thin films and droplets rather than as a solid curtain of falling water, and the air still finds an easy path upward through the tower.
Each element is a single extruded HDPE cylinder with a diamond-shaped mesh wall, supplied in the standard size of 50 × 50 × 55 mm, with other sizes made to order. Elements are stacked loosely in the tower and locate against each other by their cylindrical shape, so the bed holds its form without any fixing between individual pieces. The bed is confined at the bottom by the support grid and at the top by a retaining grid or hold-down layer placed below the liquid distributor; the packed depth, the freeboard above the bed and the grid arrangement are confirmed with the quotation against the tower drawing.
| Parameter | Value | Remark |
|---|---|---|
| Product type | Degassing packing (three-dimensional mesh packing) | Random tower packing |
| Structure | Extruded diamond-mesh cylinder | Elements charged in a loose bed |
| Standard element size | 50 × 50 × 55 mm | Other sizes made to order |
| Material | HDPE (high-density polyethylene) | Grade confirmed for the duty |
| Colour | Black | Standard supply |
| Bulk density | On request | Depends on the element geometry |
| Specific surface area | On request | Depends on the element geometry |
| Void ratio (porosity) | On request | Depends on the element geometry |
| Packing factor / pressure drop data | On request | Issued with the tower design data |
| Service temperature | On request | Confirm the medium and the operating temperature |
| Service life | On request | Depends on the medium and operating conditions |
| Price | On request | No price is published |
| Item | Detail required |
|---|---|
| Tower geometry | Inside diameter, packed bed height, support grid and liquid distributor arrangement |
| Water side | Flow rate, water temperature, inlet concentration of the gas to be removed and the target outlet value |
| Air side | Air-to-water ratio and airflow; whether the exhaust air needs to be treated downstream |
| Water quality | pH, alkalinity, suspended solids and the risk of scaling or biological growth in the bed |
| Element selection | Preferred element size, or leave it to us against the tower and the duty |
| Commercial | Quantity, destination port and transport mode |
Price is quoted on request for every configuration; no price is published on this page.
The elements are charged into the empty tower in layers and levelled as the bed rises, up to the packed depth in the design. The bed is confined by the support grid below and by a retaining grid or hold-down layer above, and freeboard is left between the top of the bed and the liquid distributor so that the water can spread and the airflow can leave without carrying elements with it.
The water distributor has to cover the whole tower cross-section evenly. A mesh packing spreads water along its own strands, but it cannot repair a badly distributed inlet: a jet from one nozzle or a dry sector at the wall stays wet or dry all the way down the bed. Where the tower handles water liable to deposit scale or support biological growth, provision for draining, washing or lifting out part of the bed is worth agreeing at the design stage rather than after commissioning. Packed depth, grid detail and quantity are confirmed with the quotation.
This reference is compiled from the product record held for this line and from general practice for packed degassing and stripping towers. The element size of 50 × 50 × 55 mm is the standard supplied size, in HDPE, black; other sizes are produced to order. Bulk density, specific surface area, void ratio, packing factor, pressure-drop data, service temperature and service life all follow the element geometry, the water chemistry and the tower duty, so they are confirmed in writing with the quotation rather than fixed on this page.
Where a figure is not confirmed for your duty it is marked On request rather than estimated. Please send your tower diameter, packed bed depth, water flow rate and the gas to be removed and we will return the element selection, quantity and packing data with the offer.