Spray drying tower system for re-dispersible polymer powders test. Since the introduction of the Danish system, produced by Maini Lu, model Production minor / 12.5, drying tower by the high speed atomizer, hair dryer, flash dryer, cyclones, heating box, feeding systems, filling pusher, the wind system , blast doors and control cabinets.

1. Run the device suddenly smoke alarm
Smoke, is the cause of the alarm system into the combustion air filter. Off-site immediately extinguish the fire source. Inspection found that the combustion air intake filter a large amount of ashes; control cabinet inlet air temperature display normal; a damaged electric heater; tank connected in a large bulk materials.

Long-term system in the dust environment, a lot of dust adhering to the air intake filter cartridge (paper), leading into the wind speed is much lower than the process design requirements (2m3 / s), so that　Heating cabinet temperature. When the temperature reaches the filter self-ignition temperature, spontaneous combustion caused by the filter.
Signal feedback line is attached to the bottom of the heating chamber, after overheating, temperature tester lead is damaged, the temperature feedback signal can not return, heating regulator circuit, automatic adjustment can not be achieved; the heater can not be powered down, a group of high-power heater burnout; when the operator off, spray drying tower some materials can not be dry, condensation occurs, generate massive.

The heater inlet tube leads workshops, avoid heating tank filter blocked by dust adhered to, in order to ensure the heating chamber into the wind speed.

Reconstruction heated oven temperature tester installation, just place the probe in a heating cabinet, signal feedback line through insulation, fire protection, heating attached to the external tank.

The heater thermostat control circuit, the series circuit in the main control device. When the heater temperature is higher than the set temperature, the system can be powered down in time to avoid accidents.

2. High-speed atomizer severe vibration noisy
High-speed atomizer, by the high-speed motor, the material dispenser, flash dryer, the composition of the atomizer wheel, motor model VFS31.09- 24, speed 10000 ~ 30000r / min, operating current 0.47A, made in Germany. Operation, the high speed atomizer severe vibration, issued a "creak" sound, the motor running current of 0.55A. After the disintegration of the discovery, the atomizer wheel, the material dispenser are intact, the motor bearing cracks, about 8mm, the rear bearing inner ring raceway 0.5mm deep signs of wear, and there bluing phenomenon, cage broken. Also found traces of a slight friction between the rotor and the stator. Preliminary judgment, motor speed operation caused by poor lubrication.

Detection and coaxial rotor dynamic balance test, meet the technical requirements. TIG welding after the motor bearing, and correct processing. Before and after the replacement of motor bearings (type HSS7002, HSS7004, FAG). When commissioning, the speed at 20000r / min, appeared shaken vigorously and issued a "creak" sound, motor current up to 0.5A.
Scene detection Sitai Ke CMS2977 Maintenance System. Measuring point provided in the motor bearings at the front and rear, were taken radial horizontal (H) for each point, radial vertical (V) and axial (A) in three directions.

When the motor load and no-load operation, the vibration of each point value did not change significantly, indicating that has nothing to do with the atomizer wheel vibration, it has nothing to do with the material dispenser.

Motor measuring points radial and axial vibration level of the vibration is large, and the rear bearing vibration significantly greater than at the front bearing. It showed significant imbalance couple characteristics that have a great relationship with the bearing.

Since the rear end face of the bearing post welding machining motor, it is difficult to achieve the original bearing position accuracy after processing, which in terms of the separation of bearings, will cause clearance increased, resulting in severe vibration running.

The centrifugal force generated when the high-speed rotary atomizer wheel is unbalanced force of the motor rotor. Due to the presence of the bearing radial clearance, the ball in the uneven non-load zone, will appear abnormal sound and vibration.

After installation of the motor bearing at a wave spring (thickness of 0.5mm, an outer diameter of 32mm, an inner diameter of 28mm). After installation, there is a spring preload compression 1.5mm, the axial displacement of the bearing can be compensated. When the rotor heat change, bearing inner ring moves, eliminate excess bearing clearance.
After the treatment, since the motor is running, each measuring point vibration values are in good range.