Minimum wetting and turndown review
Connect the lowest liquid load, final concentrate properties and operating transitions to a documented wetting assessment.
Start at the concentrated end
The liquid mass rate decreases as water leaves. List the liquid rate entering each pass at the final concentration, with viscosity at actual operating temperature. Minimum feed to the whole plant is a different quantity from the liquid available to wet a particular pass.
Keep the geometry visible
Ask for active tube count, diameter, pass arrangement and the basis for the supplier’s proposed minimum load. Confirm whether quoted turndown assumes recirculation or a changed operating configuration. No universal viscosity or wetting threshold is published here.
Record a controlled low-load test
Agree the method for approaching minimum load and the conditions that stop the test. Record feed, pressure, temperature, concentration, visual inspection where available and product quality. Retain start-up and shutdown records alongside steady-state points.
Modules and record to prepare
Download a blank operating and evidence record. It contains no measured project results.
Discuss the actual duty or return to the suitability matrix.