Pressure Spray Dryer for Malto-dextrin

300 centrifugal spray drying project：

I. Equipment design conditions

Ii. System description

Three, equipment technical parameters table

Iv. Description of equipment mechanism performance

V. Device configuration details

Vi. List of spare parts of equipment

Vii. Equipment price

Viii. Supply cycle

Ix. Engineering Description

X. Other matters

1. Equipment design conditions

material and liquid conditions

Material name:

Material solid content: ≥25%

Material handling capacity: 380kg/ hour

Dry product final moisture: ≤5% dry product yield: 100Kg/h

Water evaporation: 280Kg/h

Material liquid temperature: about 30℃

Equipment material: Material contact 304

Heat source: saturated steam 0.8mpa + electric heating compensation

Air inlet temperature of drying tower: 180-200℃

Air temperature of drying tower: 80-100℃

Exhaust temperature: 60℃

Finished particle size: 90-100 micron

Dry product recovery rate: ≥98%

2. Process conditions

Atomization method: centrifugal fog drops and hot air

Contact mode: parallel flow

Heat source and heating mode: steam + electric heating

Tower inlet air temperature: about 180-200℃

Tower exhaust temperature: 80 ~ 100℃

Product collection method: collector at the bottom of the spray tower

Product collection method: first stage + second stage cyclone collector

Equipment material: Contact with material 304

3. Design meteorological conditions (standard)

Atmospheric pressure: 101.325KPa

Ambient temperature: ~20 ° C

Relative humidity: 60-80%

4. Utilities

4.1, the power supply

Power supply: 380V, 3 phase, 50HZ

Power: 70KW;

Electric compensation heating: 150KW (automatic temperature control)

4.2, steam consumption: 218240kcal/h÷500kcal=~436kg/h

(Steam /kg calorific value utilization: 500Kcal)

4.3 Compressed air

Pressure: 0.4-0.6 MPa

Usage: 0.3 m3 / min

4.4 Water consumption (drying tower cleaning)

Pressure: Clean water gun

Dosage: 500kg/h(for cleaning)

5. Calculation process

1, per hour dry production: G dry = 100 kg/h

2, moisture evaporation per hour: W water =100×(75-5)÷(100-75)=280kg/h

3, stock solution processing capacity per hour: G wet = G dry +W water =100+280=380kg/h

4, the total heat consumption of water evaporation: Q1= 280×600=168000kcal/h

5, material and moisture temperature must heat: Q3=380×1×(100-20)=30400kcal/h

6, total energy consumption: Q total =Q1+Q2=198400kcal/h

7, drying equipment heat loss 10% : Q total =198400×1.1=218240kcal/h

Working principle of centrifugal spray drying system:

Unlike pressure spray drying systems, it uses a centrifugal disk atomizer. The centrifugal disk nebulizer is installed on the upper part of the spray tower, and the mud pump sends the mud that needs to be dried into a high trough with a certain height located on the top of the tower. Under the action of gravity, the mud flows naturally into the center of the centrifugal disk nebulizer in the tower through the slurry outlet pipe. The centrifugal disk rotates at a high speed of 4000~20000r/min driven by the motor. When the mud flows to the edge through the groove or nozzle hole on the centrifugal disk, it obtains a high tangential linear velocity. Once it leaves the centrifugal disk, it is immediately fricted and torn by air, and atomized into mud droplets. The hot AIR DISCHARGED from the air HEATER is sent to the hot air distribution chamber located at the top of the tower through the hot air pipeline, which contacts with the mud droplets in the way of downstream flow, and dries the mud into powder suitable for dry pressing molding, which falls on the lower cone of the spray tower. The dry exhaust gas is extracted from the air outlet located at the lower part of the cone, and the fine powder is recovered by the dust collector, and the purified gas is discharged into the atmosphere by the exhaust fan

Matters needing attention

Technological requirements of spray droplet size should be uniform, in order to achieve the purpose of uniform drying, to obtain a uniform droplets, must reduce the vibration of the disc rotates, enter the liquid quantity in unit time constant of the disc, the disc surface level off is smooth, the circumference of the disc rate shoulds not be too small, the circumference of 60 m/s speed is the minimum value industry can be used. For example, 100~160m/s is generally used in the dairy industry. Practice has proved that when the circumference velocity of the centrifugal plate is too small (less than 60m/s), the spray droplets obtained are not uniform. The spray distance is mainly composed of a group of coarse droplets and a group of fine droplets that sink close to the plate. The distance between the main coarse and fine droplets is also reduced. When the circumferential velocity starts to reach 60m/s, the above divergence does not occur. Industrial disk diameter is usually between 160~500mm, the speed is 3000~20000r/min, there are more than 20000r/min above, the circumference speed is generally controlled between 75~170m/s