Coating and Resin Reactor Level Measurement in Production

Coating and resin reactors change throughout a batch: raw materials are charged, temperature rises, solvents vaporize, viscosity develops, foam may appear and cleaning follows. A level instrument must work through the required stages and identify invalid conditions. Non-contact radar can reduce wetted-probe buildup, but the antenna, nozzle and beam still need protection from condensate and splash.

Map the full batch sequence

List every feedstock, solvent, intermediate and cleaning medium with concentration, dielectric behaviour, viscosity, temperature and pressure. Record when agitation, vacuum, reflux and heating operate. The worst echo condition may occur during a short transition rather than at finished-product storage.

Define whether the measurement controls charging, heating permissives, agitator protection, high alarm or batch volume. Assign acceptance criteria and response time for each duty.

Control vapour and condensation

Solvent vapour and temperature gradients can produce heavy condensation at the roof and nozzle. Radar is not governed by acoustic velocity, but a liquid film or deposit on the antenna can attenuate the signal or create a near-field target.

Avoid cold recessed pockets and follow the antenna projection and temperature requirements. Use approved insulation, thermal extension or purge arrangements only after checking hazardous-area and product-quality constraints.

Avoid agitator and inlet interference

Plot the complete radar beam against shaft, blades, baffles, coils and charge lines. Avoid the vortex centre and direct feed stream. A wall position can be affected by climbing liquid or cured resin deposits, so confirm it while the reactor is operating.

Save echo curves with the agitator stopped and at required speeds. False-echo mapping should cover only confirmed fixed targets and must not suppress the real surface near a critical high level.

Address buildup and cleanability

Sticky coating or resin can dry on the nozzle, antenna and surrounding roof. Design a connection that can be inspected and cleaned without uncontrolled vessel entry. Any rinse or solvent wash must be compatible with seals, antenna materials and waste procedures.

Trend signal quality and record as-found deposits before cleaning. If buildup repeatedly returns, review splash, temperature and nozzle geometry before simply shortening the interval.

Verify materials and safety

Confirm process-facing antenna, flange, gasket and barrier materials against all batch and cleaning chemicals. Check pressure, vacuum and temperature cycles. Use the exact hazardous-area classification, gas group and certificate conditions for volatile solvents.

Keep process control separate from independent overfill or safety functions. Test fail-safe output, lost echo and communication loss under the approved cause-and-effect logic.

Commission with representative batches

Check low, normal and high points against a suitable reference. Verify local value, output, PLC scaling, recipe totals and alarms, including damping. Record recipe, temperature, mixer speed and vessel pressure with each curve.

Revalidate after formula, solvent, agitator, cleaning or nozzle changes. Store the accepted parameter file and operating limitations with the batch equipment record. Complete at least one heat-up and cool-down cycle before final acceptance, because vapour condensation and viscosity may expose target-selection problems absent during a static fill test.

Engineering checklist

Document every batch and cleaning stage.
Map vapour, condensation and temperature cycles.
Keep the beam clear of agitator and feeds.
Provide safe inspection and cleaning access.
Verify materials and hazardous certification.
Commission during representative production.

Frequently asked questions

Can radar ignore solvent vapour?

It is generally less affected than ultrasound, but condensation, deposits, pressure and hazardous-area requirements still matter.

Should radar be mounted at the reactor centre?

Usually not when a central agitator or vortex occupies that area.

Can one water test prove performance?

No. Representative viscosity, foam, vapour and agitation conditions must be tested.

Need a project-specific review? Send process data, drawings, cleaning conditions and acceptance criteria through our contact page.