SHS plus GmbH

Material Pre-Heating in Plastics
Processing
KOENST Final Conference
Dr.-Ing. Martin Spitz
06.03.2015
Agenda
Introduction
Available Waste Heat Sources
Experimental Series
Challenges
Summary
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SHS plus GmbH: Company Profile
Technology
- INGENIO Material
Pre-Heating
- autoCHILL Cooling
Section Automation
Software
- chillWARE Cooling
Simulation
- PipeSIM
- CoEXSIM
- CableSIM
- SheetSIM
- ProfileSIM
Consulting
- Process
Analysis & optimisation
- Reduction of
Set-Up Time
- Troubleshooting
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Advantages of Material Pre-Heating
Enthalpy [kJ/kg]
Reduction of energy consumption of the extruder drive
Temperature [°C]
Potential savings (ca. 20 %)
Reduction because of lower torque of the drive
 Reduction of mechanical loads and wear
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Agenda
Introduction
Available Waste Heat Sources
Experimental Series
Challenges
Summary
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Available Waste Heat Sources
© SHS plus GmbH 2015
Filmproduktion:
6 VDI-ZRE (Zentrum für Ressourceneffizienz) für Ressource-Deutschland.TV
Available Waste Heat Sources
Screw Barrel
 Idea:
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a centrally arranged suction blower (rpm-controlled)
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a continously adjustable valve at each barrel-zone for optimized temperature control
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Materialcontainer to heat up the material using air at 70°C-110°C
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Air temperatur controlled by a bypass-valve
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Available Waste Heat Sources
Inner Pipe Cooling
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Inner pipe cooling gets more and more popular
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Waste heat temperatures between 70°C and 150°C
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Thermal energy between 5kW and 15kW inside the airflow are common values
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Usually the air is blown into the production environment or out of the building via a chimney
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There are aerially paraffine in the airflow, that causes a lot of trouble (e.g. maintenance on
the suction blower, deposits in the production)
© SHS plus
GmbH
2015
Picture:
Krauss
Maffei
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Agenda
Introduction
Available Waste Heat Sources
Experimental Series
Challenges
Summary
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Experimental Series Inner Pipe Cooling
Process Data
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PE 100 Material
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700 kg/h pipe extrusion (250mm x 22,7mm)
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Air inlet-temperature into Ingenio pre-heater up to 116°C
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Air outlet temperature 19°C
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Pre-heating Temperature of 31°C
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Experimental Series Inner Pipe Cooling
1 hour
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Experimental Series Inner Pipe Cooling
Findings
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Material temperature 18°C  energy consumption of 190kW
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Material temperature of 31°C  energy consumption of 185kW
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Calculation: saving of 5kW per 13°C in that process (700kg/h)
Assumption
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Heating up from 18°C up to 75°C would cause
a saving of 20kW (ca. 10%)
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A second experimental series confirmed the
result
 PE100 at 500kg/h
 Pre heating from 18°C to 63°C
 Energy Consumption reduced from 85kW to
79kW (7%)
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Experimental Series Screw Barrel
Test Setup
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Experimental Series Screw Barrel
Findings
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Cooling of the last three zones of a srew barrel using a centrally arranged suction blower
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Ambient temperature: 24°C
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Air inlet temperature: 65-70°C (controlled using the bypass)
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Airstream of 251 kg/h
 Usable waste heat of 3,3kW
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Agenda
Introduction
Available Waste Heat Sources
Experimental Series
Challenges
Summary
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Current Challenges
Inner pipe cooling
Filtering of paraffines is a problem
Using a heat exchanger to get clean air in contact with the plastics material,
the savings are reduced because of the second blower
Current research work is done to find out, if there are materials, where the
amount of paraffins is accaptable
Screw barrel
Good temperature control using the centrally arranged suction blower
combined with continously controllable valves
Low thermal energy level inside the air
Only cost-efficient in processes, where the cooling of the barrel is high
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Agenda
Introduction
Available Waste Heat Sources
Experimental Series
Challenges
Summary
© SHS plus GmbH 2015
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Summary
Two ways to use waste heat in pipe extrusion for material pre-heating were reviewed
Waste heat from inner pipe cooling
Waste heat from screw barrel cooling
Both cases can be (economically) interesting, if the processes are chosen well
Generally: If there is an air-stream having thermal energy, approximately 50% of the
thermal energy can be saved at the extruder drive by material pre-heating.
Heating up to 70-80°C is possible using PE
No problems accured using an air temperature of 116°C to heat up the material
© SHS plus GmbH 2015
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Thank you for your kind
attention!
Dr.-Ing. Martin Spitz
SHS plus GmbH
Erlenstr. 20
46149 Oberhausen
spitz@shs-plus.de
www.shs-plus.de
+49 208 65637923