| Application and Product Fit | Confirm that the supplier has experience with the product category, including heat sensitivity, stickiness, viscosity, foaming, and hygroscopicity. | Suitable design depends on feed solids, viscosity, target moisture, particle size, bulk density, and thermal sensitivity. No single spray-dryer configuration fits every product. | Application questionnaire, comparable test results, product specifications, and a signed process guarantee. | Poor yield, wall deposition, unstable powder properties, or product quality loss. |
| Capacity and Throughput | Evaluate feed rate, evaporation capacity, operating hours, required availability, and future expansion requirements. | Capacity should be stated in both feed rate and water-evaporation rate, because feed solids can significantly change actual powder output. | Mass-balance calculation, utility balance, guaranteed production rate, and design-basis document. | A nominal capacity may not be achievable with the buyer’s actual formulation. |
| Thermal Process Control | Check independent control of inlet temperature, outlet temperature, feed flow, atomization conditions, and exhaust humidity. | Inlet and outlet temperatures must be selected through product trials. Outlet temperature is often a key indicator of final moisture, but it is not a universal fixed setpoint. | Control philosophy, instrument list, calibration plan, process trend records, and acceptance-test criteria. | Overheating, excessive residual moisture, inconsistent batches, or loss of active ingredients. |
| Atomization System | Compare rotary atomizer, pressure nozzle, and two-fluid nozzle options according to feed properties and desired particle size. | Particle size is affected by atomizer type, feed properties, atomization energy, drying-air conditions, and solids concentration. The supplier should provide a measurable particle-size target. | Atomizer specifications, nozzle materials, spare-parts list, droplet or particle-size test data, and cleaning instructions. | Unstable particle size, nozzle blockage, excessive fines, or high maintenance frequency. |
| Powder Recovery and Yield | Review the drying chamber, cyclone or filter arrangement, fines return, powder discharge, and expected product recovery. | Recovery varies with powder stickiness, particle size, density, chamber design, and separation efficiency. The guarantee must define the test product and measurement method. | Process flow diagram, recovery calculation, mass-balance report, and factory or site acceptance-test procedure. | Hidden product losses, frequent cleaning, and higher operating costs. |
| Materials and Hygienic Design | Verify wetted-part materials, surface finish, weld quality, dead-leg control, drainability, accessibility, and product-contact seals. | For food and pharmaceutical applications, product-contact materials are commonly specified as stainless steel, with the exact grade and surface finish defined by the process and regulations. | Material certificates, weld and surface-finish records, gasket specifications, hygienic-design drawings, and cleaning validation support. | Cross-contamination, corrosion, difficult cleaning, or failure to meet regulatory expectations. |
| Safety and Explosion Protection | Assess combustible-dust hazards, solvent use, oxygen concentration, pressure relief, spark detection, grounding, and classified-area requirements. | Powder explosibility depends on the specific material. Testing may include Kst, Pmax, minimum ignition energy, and minimum ignition temperature where relevant. | Hazardous-area assessment, explosion-protection concept, risk assessment, electrical certificates, interlock list, and operating instructions. | Fire, dust explosion, equipment damage, injury, or non-compliance with local safety law. |
| Air Treatment and Utilities | Check air filtration, heating source, compressed-air quality, cooling-water needs, exhaust treatment, power demand, and installation conditions. | Utility consumption should be calculated from the required evaporation load, inlet-air conditions, operating schedule, and local energy prices. | Utility list, airflow and pressure-drop data, energy calculation, filter grades, layout drawings, and installation requirements. | Insufficient plant utilities, higher energy costs, unstable operation, or expensive site modifications. |
| Automation and Data Integrity | Review PLC, HMI, alarms, recipe management, access control, electronic records, remote support, and integration with plant systems. | Critical process variables should be recorded with time stamps, user access controls, alarm history, and traceable calibration status where regulated production is involved. | Functional design specification, software backup policy, I/O list, alarm matrix, cybersecurity controls, and validation documents. | Weak traceability, difficult troubleshooting, and higher validation or compliance costs. |
| Testing and Acceptance | Require a documented factory acceptance test and, where practical, a product-representative trial before final approval. | Acceptance criteria should cover capacity, final moisture, particle-size distribution, recovery, utility consumption, noise, safety functions, and cleanability. | FAT and SAT protocols, test reports, calibrated instruments, deviation list, and signed performance guarantee. | Disputes over performance and costly corrective work after delivery. |
| Service, Spares and Training | Evaluate commissioning support, operator training, preventive-maintenance procedures, critical spares, response time, and technical documentation. | Critical spares commonly include atomizer or nozzle components, seals, filters, sensors, bearings, and control-system parts; the exact list depends on the configuration. | Spare-parts price list, recommended inventory, service-level terms, training plan, manuals, drawings, and warranty conditions. | Long downtime, dependence on a single service channel, and unexpected lifecycle costs. |
| Compliance and Quality System | Confirm the supplier’s quality controls, manufacturing traceability, inspection procedures, and ability to provide region-specific conformity documentation. | ISO 9001 certification can indicate a documented quality-management system, but it does not by itself prove process performance or hygienic compliance. | Valid certificates, quality manual, inspection and test plan, welding records, calibration certificates, and declaration of conformity where applicable. | Documentation gaps, customs delays, failed audits, or costly redesign. |
| Commercial Terms and Total Cost | Compare equipment price together with freight, installation, validation, utilities, consumables, spare parts, maintenance, and training. | The lowest purchase price does not necessarily provide the lowest total cost of ownership. Use the same technical scope and acceptance criteria for every quotation. | Itemized quotation, Incoterms, payment schedule, delivery schedule, warranty terms, liquidated damages, and change-order procedure. | Budget overruns, unclear responsibility, delayed delivery, or poor post-sale support. |
| Recommended Supplier-Selection Method | Use a weighted technical-commercial scorecard rather than choosing solely on price, product photographs, or general capacity claims. | A practical approach is to score process performance, safety, hygienic design, documentation, service capability, delivery risk, and total cost separately. | Completed compliance matrix, reference checks, audited drawings, trial data, signed guarantees, and final contract scope. | A visually attractive quotation may conceal technical exclusions or unpriced integration work. |