| Feed Evaporation Capacity | Laboratory and pilot units commonly process approximately 0.5–50 kg/h of feed. Industrial systems may range from about 50 kg/h to several tonnes per hour, depending on product concentration and moisture removal. | A mass-balance calculation showing feed rate, feed solids, inlet moisture, target powder moisture, and expected evaporation rate. | Compare suppliers by evaporation capacity rather than only by nominal feed-flow capacity. |
| Atomizer Type and Speed | High-speed rotary atomizers are often designed for approximately 10,000–30,000 rpm. The correct range depends on liquid viscosity, feed rate, and required particle size. | Atomizer datasheet, speed-control range, wheel or disc material, balance certificate, bearing arrangement, and maintenance procedure. | Choose a variable-speed system that can be adjusted during product trials. |
| Particle-Size Control | Spray-dried powders may commonly fall within approximately 10–150 μm, although the actual distribution depends on feed properties, atomizer speed, and drying conditions. | Particle-size distribution from laser diffraction or another stated test method, including D10, D50, D90, and test conditions. | Require product-specific test results instead of accepting a generic particle-size claim. |
| Inlet and Outlet Temperature | Many heat-sensitive products operate with inlet temperatures around 140–250°C and outlet temperatures around 70–110°C. Exact settings depend on feed composition and thermal sensitivity. | Temperature-control accuracy, sensor locations, alarm limits, and a product-specific drying curve. | The supplier should demonstrate stable outlet-temperature control during a continuous test. |
| Powder Moisture and Yield | A final moisture level of approximately 1–5% is common for many spray-dried powders, while collection efficiency can often reach about 95–99% when cyclone and filtration systems are correctly designed. | Independent moisture test results, powder recovery calculation, exhaust-loss data, and the precise definition of yield. | Confirm whether the quoted yield includes material retained in the chamber, cyclone, ductwork, and filter. |
| Product-Contact Materials | Food and pharmaceutical applications commonly specify stainless steel for product-contact surfaces; 316L is frequently selected where higher corrosion resistance or hygienic processing is required. | Material certificates, weld records, surface-finish specification, gasket materials, and a product-contact parts list. | Do not rely only on the phrase “stainless steel”; verify grade and contact locations. |
| Hygienic Design and Cleanability | Suitable systems should minimize dead zones, use accessible inspection points, provide smooth product-contact surfaces, and support dry or wet cleaning according to the process. | Equipment drawings, cleaning procedure, drainability review, surface-finish data, and cleaning-validation support where required. | For food or pharmaceutical use, assess the complete powder path rather than only the drying chamber. |
| Air-Handling System | The system should include appropriately sized air filters, heater, fan, ducts, exhaust treatment, and pressure-control devices matched to the required airflow and evaporation duty. | Airflow calculation, fan curve, filter specification, pressure-drop calculation, and heat-source details. | Review energy consumption and pressure drop, not just the advertised drying capacity. |
| Control and Automation | A modern system normally monitors inlet temperature, outlet temperature, feed-pump rate, atomizer speed, fan status, alarms, and key pressure values. | Control-system architecture, instrument list, alarm matrix, data-logging capability, user-access levels, and electrical drawings. | Prioritize traceable data records and stable automatic control for repeat production. |
| Safety and Explosion Protection | Powder processes may create combustible-dust risks. Protection requirements depend on the powder’s explosibility, dust concentration, oxygen level, and local regulations. | Dust-hazard assessment, safety risk assessment, grounding plan, temperature interlocks, pressure-relief or suppression design, and applicable conformity documents. | Obtain powder explosibility data before finalizing the chamber, filter, and exhaust design. |
| Quality Management | A documented quality system should control incoming materials, welding, machining, assembly, calibration, inspection, and nonconformities. | Quality certificate, inspection and test plan, calibration records, welding qualifications, and sample factory-acceptance documents. | Verify that the quality system applies to the actual production site and equipment scope. |
| Factory Acceptance Testing | A meaningful FAT should check mechanical operation, electrical functions, alarms, atomizer performance, temperature stability, leakage, and agreed process targets. | Signed FAT protocol with acceptance criteria, test materials, instruments, deviations, corrective actions, and final approval procedure. | Link milestone payments to documented FAT results wherever commercially practical. |
| Installation and Commissioning | A complete installation plan should cover utilities, foundations, duct routing, electrical supply, ventilation, commissioning sequence, and operator training. | General arrangement drawing, utility list, foundation loads, installation manual, commissioning schedule, and training plan. | Clarify which installation tasks are included and which costs remain with the buyer. |
| Spare Parts and Maintenance | Critical spare parts commonly include atomizer components, bearings, seals, filters, temperature sensors, pump parts, and electrical control components. | Recommended-spares list, part numbers, expected service intervals, lubrication plan, replacement procedures, and availability commitments. | Evaluate total operating cost and lead time for critical parts, not only the purchase price. |
| Export Documentation | A professional export package normally includes commercial invoice, packing list, technical manual, electrical documents, certificates, inspection records, and shipping details. | Sample document package, equipment classification, country-specific conformity requirements, and export-packing specification. | Confirm documentation requirements before signing the purchase contract. |
| Commercial and Supplier Risk | A reliable procurement process should define scope, performance guarantees, delivery milestones, warranty period, payment stages, training, after-sales response, and dispute terms. | Detailed quotation, contract terms, warranty policy, references for comparable applications, production schedule, and financial or legal due-diligence documents. | Select the supplier offering the lowest verified lifecycle risk, not necessarily the lowest initial quotation. |
