Rotary dryer design calculation for wood chips

Rotary drum dryer in malaysia

Rotary Dryer Detailed Description:

Rotary Dryer from Qingdao Palet Machinery can reduce the biomass material moisture content from 40-55% to below 10% -15%, according to the customers’ request. How to choose the rotary dryer design for wood chips? We have finished a successful project for wood chips dryer in Malaysia.

rotary dryer in processing

How to calculate the dimension of the rotary dryer for wood chips?

The information as follows:

The material: wet wood chips, sawdust

The output: 3ton per hour

A:Drying intensity (35kg/m3h)

G1:Dry Material Production (3t/h)

V:Dry Space needed(m3)

W1:Initial Moisture Content(55%)

W2:Final Moisture Content(12%)

Material Calculation:

For every 1000kg wet material evaporation and moisture content:

W=1000×(0.55-0.12)/(1-0.12)=488.6kg(H20)

For every 1000kg wet material quantity after evaporate:M=1000-488.6=511.4kg

To produce 1000kg of end product need to feed in:

G=1000/511.4×1000=1955.4kg(wet raw material)

Rotary Dryer Calculation:

Volume calculation:

G1=AV÷{1000×〖W1—W2〗÷〖100—W1〗}

3=AV÷{1000×(55-12)/(100-55)}=AV/956

V=81.9m3

Provided Drum dimension:φ2.2×24m

V=πr²L=3.14x(1.1)²x24=91m>82m3(fulfill requirement)

Rotary Dryer Energy Balance

Air Flow Velocity:  v=1.5m/s,

Dry Air Density:  ρ=1.2kg/m3,

Air Humidity:  H=0.007kg/kgdry air

Ambient Air Temperature: t0=30°

Inlet Hot Air Temperature: t1=250°

Outlet Hot Air Temperature: t2=70°

Dry air consumption:

L=πr2vρ3600=3.14×12x1.5×1.2×3600=20347.2kg/h

Wet air consumption:

L1=L(1+H)=20347.2X(1+0.007)=20490kg/h

Heating value for ambient air:

Q1=L(1.01+1.88H)(t2-t0)=20347.2÷3600x(1.01+1.88×0.007)x(70-30)=231.3kw

Heating value for evaporating moisture:

Q2=W(2490+1.88t2-4.187×30°)

=955.4÷3600x(2490+1.88×70-125.61)=622.4kw

Heating value for wet material:

Q3=Gc( wood )(t2-t0)=1955.4×2.5×103x40÷3600÷1000=54.3kw

Heating value loses:

Q4=(Q1+Q2+Q3)0.22=908×0.22=199.76kw

Total Heating Value:

Q=Q1+Q2+Q3+Q4=1107.76kw

Rotary Dryer Gas Quantity Needed

For standard condition

Dry Air Density:ρ=1.29kg/m3
Air Specific Heat Capacity:c=1.0×103J/(kg.℃)

Q=V(T-t2)ρc=V(400-70)ρc

V=2303.4*3.6×106/370*1.29*103=17373m3

Single Rotary Dryer System Air Flow Rate

Evaporation=955.4kg,t1=250°,t2=70°

System Air Flow Rate=Evaporation*3000/(t1-t2)=16000m3/h

Air Flow Rate =1.3*System Air Flow Rate=20800m3/hm3/h

Provided model:4-72-8C-22kw

Rotary Dryer Draft Fan Air Flow Rate

Draft Fan Air Flow Rate=2*System Air Flow Rate=32000m3/h

Provided model:4-72-10C-45kw

Rotary dryer design pdf for biomass

Share on facebook
Facebook
Share on twitter
Twitter
Share on linkedin
LinkedIn
Share on pinterest
Pinterest
Close Menu