Detlev Matzdorf, Nov 2015, Sirris, Gent Welcome to Sirris workshop: Energy efficient peripherals and ancillaries in plastics processing Gent Meeting Center, Nov. 18th 2015 Subject: Energy efficient use of raw materials Speaker: Mr. Detlev Matzdorf motan-colortronic GmbH Otto-Hahn Str. 14 D-61381 Friedrichsdorf
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Detlev Matzdorf, Nov 2015, Sirris, Gent
Welcome to Sirris
workshop: Energy efficient peripherals and ancillaries
in plastics processing
Gent Meeting Center, Nov. 18th 2015
Subject: Energy efficient use of raw materials
Speaker: Mr. Detlev Matzdorf
motan-colortronic GmbH
Otto-Hahn Str. 14
D-61381 Friedrichsdorf
Detlev Matzdorf, Nov 2015, Sirris, Gent
Energie efficient use of raw materials
Where to save energy in the material handling process
- Where to save energy in the material storage process
- Where to save energy in the drying process
- Where to save energy in the conveying process
- Where to save energy in the dosing process
- Where to save energy in motor design
Detlev Matzdorf, Nov 2015, Sirris, Gent
Where to save energy in the handling process
If possible, heat the
material on the
machine material inlet Prevent the
material from
re-moisturing
Preheating the
silo with
exhaust heat
Use the right drying
parameters (airflow,
dew point, temperature
and residence time )
for your application.
Dryer Bin Bin
Octabin
M
Moulding M.
Outdoor silo
Improve the efficiency
of the screw drive
of the moulding
machine
Prevent the material
from recooling
Convey the material
energy efficient
Detlev Matzdorf, Nov 2015, Sirris, Gent
Parameters which influence energy consumption
1. Summer – Winter
changing ambient humidity
changing material temperatures
2. Changing humidity in material supply.
3. Changing drying parameters
- temperature difference between drying temperature
and return air temperature
- dew point for material drying
- material data (cp value) related to specific dry air flow
- changing demand of the connected machines
4. conveying process
5. use of right motors ( please refer to the lecture of
Kurt Muylaert, Danfoss)
Detlev Matzdorf, Nov 2015, Sirris, Gent
1. Initial moisture in granules, Summer – Winter relation
Spring Summer Winter Autumn
Moisture content of the material in relation to
the season
Required rest humidity for production
If plastic granulates are stored in ambient air, it always adapts to the moisture content of the
environment until the moisture of the material and environment is equal.
Detlev Matzdorf, Nov 2015, Sirris, Gent
The specific air flow rate must be adapted
to the material inlet temperatures!
The colder the material, the more air
and energy is needed, in order to
heat up the material to a final
temperature.
Example: In order to heat up a material in
winter time from –10 °C to 175 °C with a
constant exhaust air temperature of 62 °C,
we need a specific dry air flow of 2.7 m³/kg
and 104 Wh/kg of energy will be consumed.
Same case in summer : at 20 °C material
inlet temperature, 2.27 m³/kg air flow will be
sufficient to heat up the material to
175 °C, with an energy consumption of
88 Wh/kg with an exhaust air temperature
of 62 °C.
1.1. Material inlet temperature in relation to the
specific air flow and the energy consumption
1,8 1,92 2,05 2,18 2,30 2,43 2,55 2,68 2,80
Specific dry air flow [m³/kg]
Energy usage and specific dry air flow in relation to the material inlet
temperature
-20
-10
0
10
20
30
40
50
70 75 80 85 90 95 100 105 110
Energy usage [Wh/kg]
Mate
rial
inle
t
[°
C]
Autumn / Fall
Summer
Winter
Detlev Matzdorf, Nov 2015, Sirris, Gent
Dryer Bin Bin
Octabin
M
Processing machine
T1a T1b
T3
T4 T5
T2
0,2%
0,4%
0°
0,5%
Delivery of pre-
dried material
Winter
Summer
Re-moisturing
dependent on the
storage time and
ambient moisture
More or less drying
performace required
T2 T1 T4 T5
Re-moisturing
dependent on the
storage time on the
machine bin
Outdoor silo
T0
T3 T0
0,3%
0,1%
Note : Drying systems are always rated for the worst case of maximum material
moisture, minimum inlet temperature and maximum throughput. Solution is: ETA²
1.2. Re-moisturing of the material in a standard production
Detlev Matzdorf, Nov 2015, Sirris, Gent
- Prevent the material from re-moisturing! The material stays for hours or weeks in the outdoor silo or other storage vessels. Keep the material in a dry environment.
- For every % of moisture the material absorbs, you have to spend another 25 Watt hours/kg to
remove it!!
Dry air
generator Outdoor silo Use exhaust heat
from production
2.2. Prevent material re-moisturing in the outdoor silo or
octabin.
Dry air quantity for blanketing
per m³ silo volume = 1m³/h dry air flow
Detlev Matzdorf, Nov 2015, Sirris, Gent
2.3.1. Efficiency of material heat up of heating with hot air
in comparison to heating up by friction by the screw.
Example: to heat up material from 40°C to 120°C we need energy:
- by using friction : 1 kg x 1,2 kJ / kg K x 80°K / 0,49 efficiency / 3,6Wh / kJ = 54,4 Wh/kg
- by using hot air heat up with electric heater : 1 kg x 1,2kJ/kg K x 80°K /0,8 Wirkungsgrad /3,6Wh/kJ = 33,3 Wh/kg
By heating the material on the machine from 40°to 120°C the energy consumption can be
reduced by 38.8 % only for this part of process.
ProcessingE-Motor
Hydro-drive
= Efficiency
E-Motor
= 0,85
Hydro pump
= 0,80
Tubes and
Valves = 0,90
Hydro drive
= 0,80
Total efficiency for
heating with electrical
heater incl. blower = 0,80
Total efficiency for
heating with friktion = 49%
( 0,8 x 0,9 x 0,8 x 0,85 = 0,49 )
Detlev Matzdorf, Nov 2015, Sirris, Gent
2.3.2 Small application of material drying on the machine
M
Moulding
Dryer Bin
Re-cooling of the
material due to
conveying and storing
in the machine hopper
Dryer
Bin
M
Moulding
Heat exchanger
Heater No loss of
heat
100°
200°
0°
250°
T1a Winter
T1a Summer
T1
T2
Cooling by
conveying
with cold
ambient air
Cooling by storing
the material in the
machine hopper
T3 T4 T5
Heating to 230° by friction and heating
LOSS
Drying
phase
100°
200°
0°
250°
T1a Winter
T1a Summer
T1
T2
Material gets hot
by drying
T4 T5
Heating to. 230° by Friction und heating
No conveying
no cooling
T2
T2
T4
T4
T5
T5
T3
T1 Winter / Summer
Drying
phase
With two conveying steps we need approx. 10% of specific energy use for
conveying
Detlev Matzdorf, Nov 2015, Sirris, Gent
2.4 Energy consumption comparison of drying Nylon PA 6
The comparison of the energy usage shows the real benefit of a conditioning process at 60°C with reduced
airflow for Nylon in relation to standard drying at 80°C and full airflow.
- No over-drying or too wet material
- only half size dryer needed and application with low air flow
Energy calculation comparison
Standard drying
at 80°C
Conditioning at
60°C
Material throughput: Kg/h 500 500 Kg/h
Dry air generator LUXOR 1200 600
Dry air fow with ETA plus 950 450 m³/h
Energy usage of a drying system for PA 6 63,2% % Savings
Energy consumption of the system 15,3 5,6 kW
Spezific energy usage = 30,5 11,3 Wh/kg
Cost in Cent / m³ dry air 0,1608 0,1250 Euro Cent / m³
Total cost in 8000 h per year 12219,44 4500,70 Euro/year
Standard drying at
80°C
only conditioning at 60°C
Blower 9,7 5,2
Heater 11,7 3,0
Regeneration 9,2 3,0
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
Standard drying at 80°C only conditioning at 60°C
En
erg
y u
sag
e [
Wh
/kg
]
Energy usage of drying or conditioning of PA 6
Regeneration
Heater
Blower
Detlev Matzdorf, Nov 2015, Sirris, Gent
3.1. Desiccant bed dryer with automatic
energy saving technology
- Preheating of regeneration air
with heat exchanger
Reduction of energy usage
- Temperature controlled
regeneration
Energy efficient load related
heating process
- Dew point control
Reduced quantity of regeneration
Cycles = energy saving
- Insulated desiccant bed Reduced heat radiation during the
heat up phase
Drying process:
- Frequency controlled process air blower
Enables load-related energy
consumption
Regeneration process:
Advantages:
- Return air controlled
dry air flow
Best way to control the energy
requirement of the drying process
- Dew point control Defined maximum process dew point
Detlev Matzdorf, Nov 2015, Sirris, Gent
3.2. Elements of ETA plus drying process
ETA plus AFC frequency
controlled drying process
blower.
Measurement of the
exhaust air °C, °F
Difference pressure
measurement
Motor valve on every
drying bin
Optional ETA plus heat exchanger
for high temperature and high
airflow solutions
Heater close to the bin air
inlet
M
Heat exchanger for
regeneration air heating up
Dew point controlled
regeneration bed switch
cycles
Separated bed switch
valve blocks for
minimum heat loss Fully insulated drying bin
Closed loop recooling with active
cooler, in order to prevent the desiccant bed from re-moisturing. Up to 30% more dehumidification
power in comparison to ambient air recooling
Fully separated process air circuits for regeneration
and material drying
motan
Detlev Matzdorf, Nov 2015, Sirris, Gent
Temperature profile in drying systems with and without ETA plus heat exchanger