BUCHI Nano Spray Dryer B-90 - Manual (Page 90)

8 Troubleshooting
90 B-90 Operation Manual, Version B
Table 8-2: Malfunctions and their remedy (cont.)
Spray head blocked
Product is too concentrated Use a lower sample concentration
Change to a bigger spray cap / mesh
Clean the spray head and spray cap
Product drips in spray cylinder No spray flow Turn on spray
Insufficient spray flow Inspect inside gas pressure
(20-50 mbar) and gas supply
Deposits on the spray cylinder Spray head is not clean Completely dismantle the spray head
and clean with water
Spray head is defective (bent PEEK
tubing, washer or mesh) Replace spray cap or defective
element
Product will not dry Increase inlet temperature
Inlet temperature is above the
melting point of the product Reduce inlet temperature
Product related deposits No action possible
Irregular or pulsed spraying Leaks in the spray head Check seal in the spray head and
replace if necessary
Deposits in the particle collector Product too moist Increase inlet temperature to dry the
product
Increase residence time of product in
drying cylinders
Increase gas flow rate to increase
the energy input for drying
Inlet temperature falls Heating is switched off Switch on heating
Heater plug is unplugged Insert heater plug
Outlet temperature falls No heating Follow measures under “Fall of entry
temperature”
Spraying too powerful Reduce production rate of spray
Outlet temperature rises System has not reached stationary
temperature conditions Warm up the system with hot drying
gas for about 30 minutes.
Spray head blocked Clean the spray head
Feed tubing not dipped into sample
solution Dip feed tubing into product
Change of concentration in sample
solution Agitate product (magnetic stirrer) to
obtain uniform concentration
No feed of product Switch on peristaltic pump