Compression Pads and Hold Down Mats

Preventing Fluidisation During Pressurisation

SorbiTech Compression Pads and Hold Down Mats are installed at the top of the adsorber bed to prevent fluidisation during the upward pressurisation that opens every cycle. Without a hold down, the bed top lifts a few millimetres on each pressurisation, the particles grind against each other, and the resulting fines accumulate in the downstream piping and seals.

SorbiTech supplies two main forms: a ceramic fibre pad for moderate temperature service and a stainless wire mesh assembly for high temperature or aggressive chemistry duty. The form is selected by the operating temperature, the chemistry, and the magnitude of the pressurisation step.

Ceramic Fibre Pad Construction

The ceramic fibre pad is a compressed mat of alumina silicate fibres cut to the vessel internal diameter and to a thickness that takes up the void between the bed surface and the vessel internal hold down plate. The pad compresses by 30 to 50 percent under the hold down load and exerts a uniform back pressure on the bed top, holding it in place without crushing the active media.

SorbiTech specifies the pad thickness from the vessel internal drawing during the design phase, and SorbiTech ships the pre cut SorbiTech assembly with the matching adsorbent charge ready for loading.

Wire Mesh Assemblies for High Temperature Duty

In high temperature regeneration loops, in Claus tail gas units, and in aggressive chemistry duty where the ceramic fibre would degrade, the SorbiTech hold down is a stainless wire mesh assembly fabricated from 316L or 321 stainless wire. The mesh is layered to give the same compression behaviour as the fibre pad while tolerating temperatures above 600 °C and aggressive chemistries.

Mesh assemblies are also used where the operator wants to clean and re install the same hold down across multiple media changeouts, since the mesh can be removed, cleaned, and re used where the fibre pad must be discarded with the spent media.

Service Life and Replacement

A ceramic fibre pad is single use and is replaced at every adsorbent changeout. A wire mesh assembly is cleaned and re used across 3 to 5 media changeouts before mechanical fatigue forces a replacement. Both forms are tracked against the operator turnaround schedule by the SorbiTech service team.

Forms and Supply

Cut and assembled by SorbiTech to the vessel drawing, with the pad or mesh assembly shipped with the matching adsorbent charge or as a standalone replacement spare. Standard delivery time is 4 to 8 weeks against the operator turnaround window. SorbiTech delivers compression pads with the matching adsorbent loading; see the ceramic support balls for the cover layer below, the parent support media family, and applications under the oil & gas sector.