Pressure spray drier is a commonly used drying equipment. The following is a detailed introduction to it:

First, the working principle

Pressure spray drier sends the liquid material (filtered liquid material) into a pressure atomizer through a high pressure of 220MPa to be atomized into small droplets, and the surface area of the atomized droplets is greatly increased. Through full contact with hot air, the drying process can be quickly completed within 1030 seconds. Most of the powder particles are collected by the discharge port at the bottom of the tower, the waste gas and its tiny powder are separated by a cyclone separator, the waste gas is discharged by an exhaust fan, and the powder is collected by a pollination tube arranged at the lower end of the cyclone separator, thus obtaining the finished product of powder or tiny particles.

Second, the advantages

Fast drying speed: the surface area of the feed liquid is greatly increased after atomization. In the hot air flow, 95%~98% of water can be evaporated instantly, and the drying time is only ten seconds to tens of seconds, which is especially suitable for drying heat-sensitive materials.

High product quality: the obtained product is spherical particles with uniform particle size, good fluidity, good solubility and high product purity.

Wide application: widely used in pharmaceutical, chemical, food and other industries.

Simple operation: the equipment structure is compact and the operation is relatively simple.

Third, shortcomings

Higher equipment price: Due to its high-precision manufacturing requirements and complex technology, the equipment price is relatively high.

Large energy consumption: a lot of heat energy is needed to complete the drying process.

Fourth, the operating procedures

Necessary preparations should be made before starting the pressure spray drier. First, check whether there is looseness at the joint between the bearing and sealing part of each device, the lubricating oil condition of each mechanical part and whether the valves of each water, air and slurry pipe are in the required position.

Turn on the power supply to check whether the voltage and instrument are normal, then check the amount and concentration of slurry in the slurry mixing barrel, and eliminate any problems in time.

Turn on the blower and exhaust fan in turn, and then turn on the heating switch to start heating up.

When the outlet temperature reaches the set temperature (generally about 130℃), start the material pump and dust removal system. When the pump pressure reaches 2MPa, open the spray gun and start granulation.

After the normal operation of spray drier, the atomization situation and the working condition of the feed pump should be observed in time, and the nozzle should be cleaned or replaced immediately if the gun is blocked. At the same time, we should also receive materials regularly, check the operation of each system regularly, record the process parameters, and pay attention to cleaning the vibrating filter screen.

At the end of granulation, the heating device should be turned off first, and the gas turbine should be stopped. Then close the spray gun valve, replace the spray gun, unscrew the nozzle and rinse it clean.

When the inlet temperature drops below 100℃, the operation of the blower and exhaust fan can be stopped. Then clean up the residual materials in the drying tower and dust collector, turn off the dust collector and air hammer, and finally turn off the main power supply to complete the production operation.

V. Maintenance and maintenance

After long-term operation or improper operation, aggregate will appear in some equipment, which will affect the normal operation. At this time, it is necessary to stop working and clean.

For cleaning the aggregate in the drying tower, open the cleaning door, sweep the aggregate at the bottom of the funnel with a long broom, open the discharge valve and rinse the tower with tap water.

To remove the dust in the cyclone separator, it is also necessary to open the cyclone separator, clean the aggregate with a broom and wash it with water if necessary.

For cleaning the bag filter, turn on the control switch and knock continuously, then open the cleaning door, knock the bag filter, and finally replace the filter bag.

For cleaning the slurry pipeline system, open the drain valve of the two-way filter, clean the filter screen and pipeline, then open the material pump, replace the material with water, and clean the pump pipe, pressure stabilizing bag and pipeline.

After a period of operation, it is necessary to check and maintain the spray granulation dryer. For the feeding system, check the filters, pipes, valves, nozzles, etc. to see if there is any blockage, clean them regularly, and check the nozzle wear for timely replacement.

Check whether the material pump leaks oil, whether the pressure is normal and whether the oil level is normal. For the fan, check whether the shaft and bearing are short of oil and have heat, vibration and noise, etc. If necessary, clean the blades and check the balance of the blades.

For the heater, check whether the heat pipe is normal, and if necessary, clean the filter screens at the oil pipe, oil pump and oil nozzle. In addition, attention should also be paid to whether the motors have fever, vibration, abnormal sound, etc., and whether the instruments and electrical appliances in the control cabinet work normally.

To sum up, pressure spray drier has many advantages, but it also has some disadvantages. In the process of use, it is necessary to operate in strict accordance with the operating procedures and carry out necessary maintenance work to ensure the normal operation of the equipment and prolong its service life.