The drying requirements of the vacuum spiral dryer cover four core areas: material characteristic adaptation, equipment operation parameter control, environmental condition guarantee, and safety operation specifications. The specific requirements are as follows:

1、 Requirements for adapting material characteristics

• ‌Thermal sensitivity and brittleness protectionVacuum environment reduces the boiling point of solvents, avoiding protein denaturation, fat oxidation, or crystal structure damage caused by high temperature.

• ‌Handling of viscous materialsThe spiral blades adopt a variable pitch design to form a material propulsion gradient, effectively crushing viscous agglomerates; Equipped with a spiral scraping structure to ensure residual content<0.3% and avoid uneven drying caused by wall sticking.

• ‌Solvent recovery and explosion preventionFor materials containing organic solvents (such as pesticide intermediates), a condenser and a recovery liquid storage tank need to be installed to achieve closed-loop solvent recovery; The equipment material should be 316L stainless steel to prevent solvent corrosion, and equipped with safety devices such as explosion-proof sight lights and pressure gauges.

2、 Requirements for Control of Equipment Operating Parameters

• ‌Vacuum degree and temperature synergyMaintain a vacuum degree at a working pressure of 5-1000Pa, and promote water evaporation by reducing the saturated vapor pressure; The temperature is heated using jacket steam (0.3-0.8MPa) or thermal oil (200 ℃), with a control accuracy of ± 2 ℃, to avoid material agglomeration caused by sudden heating.

• ‌Mixing and heat transfer efficiencyThe spiral shaft rotates at low speed (usually 10-30rpm) to drive the blades to evenly flip the material, ensuring sufficient contact with the heating surface; The heating area of the equipment is 40% larger than that of the traditional double cone dryer. By passing heat medium through the hollow spiral belt, forced heat transfer is achieved, and the material loading rate can still maintain 100% heating utilization at 40% -100%.

• ‌Drying time and residual controlThe drying time depends on the thermal conductivity, pressure, and stirring speed of the material, and generally takes 30-50 minutes to achieve the target of moisture content ≤ 2%; The bottom discharge valve adopts a suction valve design to ensure that there is no residue in the discharge and avoid cross contamination between batches.

3、 Environmental condition guarantee requirements

• ‌Operating environmentRelative humidity ≤ 85% RH, avoid humid air affecting the performance of the vacuum pump; There are no corrosive gases, strong vibration sources, or strong electromagnetic fields around to prevent equipment electrical system failures.

• ‌Cleaning and maintenanceRegular cleaning is required inside the equipment to prevent residue from blocking the spiral blades or vacuum channels; The dust filter in the vacuum pipeline needs to be cleaned weekly, and the metal sintered mesh filter needs to be backwashed and regenerated monthly to ensure smooth airflow.

• ‌Rust and corrosion preventionWhen not in use for a long time, the heating medium should be drained and the spiral components should be coated with anti rust oil for protection; The parts in contact with the material, such as the mixing shaft and cylinder, should be made of 316L stainless steel and polished (Ra ≤ 0.8 μ m) to reduce material adhesion.

4、 Requirements for Safety Operation Standards

• ‌Electrical safetyThe equipment casing must be effectively grounded to prevent the risk of electrical leakage; The control system power supply needs to be equipped with overload protection devices to prevent motor burnout.

• ‌Vacuum system protectionThe vacuum pump cannot work continuously for a long time. When the vacuum degree reaches the required level, the vacuum valve should be closed first, and then the power supply of the vacuum pump should be turned off to prevent oil backflow; When drying wet materials, a filter should be installed between the vacuum box and the vacuum pump to prevent water vapor from damaging the pump body.

• ‌Explosion proof and pollution preventionFlammable and explosive materials are strictly prohibited from being placed. The studio must maintain a negative pressure state to prevent gas leaks from causing accidents; The top drive design eliminates shaft seal contamination and ensures the drying quality of high-purity materials such as drugs.

• ‌emergency responseIf any abnormalities are found during the drying process (such as sudden temperature rise or decrease in vacuum degree), the machine should be stopped immediately for maintenance to avoid equipment damage or material scrap; Before discharging, slowly open the pressure relief valve and wait for the pressure to return to normal before opening the discharge port to prevent material splashing.