FRP profiles inside scrubbers and mist eliminators

Pultrusion can form a repeatable cross-section along the member's length. A curved or zigzag cross-section can therefore be a candidate if it remains unchanged along that length and the reinforcement, thickness and tooling are feasible. Three-dimensional transitions, changing drainage pockets and integral end fittings can call for molding, assembly or another process. Review each feature before labeling an entire demister module as pultruded.

For a replacement vane, establish which dimensions control the flow passage and which simply locate the part. Thickness variation, twist or accumulated pitch error can change a bank even when individual pieces appear similar. Agree on inspection datums and a representative assembled-module trial. For support rails, define the bearing face and the vessel attachment independently from the vane geometry.

A sample records the existing installation but may also contain wear, permanent deformation or an undocumented repair. Pair it with the approved drawing and a measured survey. Any geometry change that alters open area, drainage or edge sealing goes back to the equipment designer for review before tooling release.

Supply minimum, normal and maximum gas volume at the actual pressure and temperature, together with gas density and the expected liquid loading and droplet distribution. The separator specialist uses these inputs to select flow area, vane or mesh arrangement and pressure-loss allowance. A generic face velocity copied from another process cannot account for different liquid properties, orientation or fouling behavior.

Check the full route into and out of the bank. Inlet bends, partial obstruction, support beams and a short approach can create an uneven velocity field. The OEM should identify when a distribution survey, physical testing or CFD is needed. Model results should document boundary conditions and be reconciled with the real geometry; they do not replace the agreed performance test.

Drain channels, sumps, module joints and wall seals are functional features. Collected liquid needs an unobstructed exit without being swept back into the gas. Investigate carryover by checking drainage and bypass as well as blade condition. An average pressure drop can look acceptable while part of the bank is overloaded or gas passes around an unsealed edge.

Ask the operator which deposits develop, where they accumulate and what removes them. Gypsum, salts or sticky solids can narrow passages and increase retained mass. Work with the OEM on nozzle coverage, upstream and downstream access, available wash-water quality and the required cleaning sequence. A wash line that cannot reach the rear of a module leaves a predictable maintenance problem.

Agree on compatible cleaning chemicals and the permitted mechanical cleaning method for the actual laminate. Specify any limits on jet pressure, stand-off, temperature and tools through a supplier-approved procedure or representative trial; this page provides no universal pressure-washing setting. Inspect for exposed reinforcement, chipped edges, loosened locators and obstructed drains after cleaning rather than judging success only by surface appearance.

Survey manways, lifting routes and module dimensions before ordering. Plan how a damaged section can be removed without cutting neighboring members. Internal work requires the plant's isolation and entry arrangements, including control of fans, pumps, automatic wash cycles and connected process flows. Record module positions and material batches so replacement parts can be matched to the approved configuration.

Component acceptance starts with the approved drawing revision, traceable laminate, dimensional report and agreed appearance criteria. Inspect critical fits in a sample module, including vane pitch, frame alignment, hardware, drainage openings and edge seals. Record the chemical and mechanical qualification evidence separately from routine batch checks. Resolve nonconformities before the parts enter a restricted-access vessel.

After installation, establish an operating baseline at recorded process conditions. The OEM's commissioning plan should define pressure-drop measurement points, gas and liquid flow checks, wash operation and the agreed carryover or emissions test. Droplet measurement requires a defined method and sampling arrangement; a visible plume alone is not a quantified measure of liquid carryover.

Trend pressure differential with throughput, liquid flow and relevant liquor condition rather than interpreting a single reading in isolation. An increase can justify inspection for deposits; a decrease can require checks for changed flow, bypass or damage. Use alarm and intervention limits established for the system. Keep cleaning observations and replacement history alongside the process trends so repeated failures trigger a cause review instead of another identical part order.