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Types of Oil Heating Technologies for Industrial Presses
Based on the research conducted from multiple sources, this document categorizes and analyzes the different types of oil heating technologies used for industrial presses.
1. Thermal Fluid (Hot Oil) Heating Systems
Basic Operation Principle
Thermal fluid heating systems use a heat transfer fluid (typically mineral oil or synthetic oil) that is heated by a heat source and then circulated through a closed loop system. The heated fluid transfers heat to the press platens through channels or coils embedded within the platens.
Heat Source Variations
- Gas-fired burners: Most common heat source for thermal fluid systems
- Electric heating elements: Used in some applications where gas is not available
- Biomass-fired systems: Environmentally friendly option using renewable fuel sources
- Liquid fuel burners: Alternative to gas in some applications
Coil Design Technologies
-
Serpentine Coil Technology
- Features even heat distribution
- Reduces oil degradation
- Provides longer tube life
- Enables higher operating oil temperature
- Offers easier maintenance
- Higher fuel efficiency (up to 90% with economizer)
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Helical Coil Design
- Traditional design
- Generally less efficient than serpentine coil
- May have less uniform heat distribution
Circulation Systems
- Primary Circulation: Main loop between heater and process
- Secondary Recirculation Groups: Separate loops for each platen to ensure temperature uniformity
- High Flow Secondary Circulation Loops: Used to minimize platen thermal gradients
2. Electric Heating Systems for Platens
While not oil-based, electric heating is a common alternative that was mentioned in several sources:
Features
- Direct heating using cartridge-type heating elements
- Standard designs heat to operating temperature of 550°F (optional up to 1200°F)
- Multi-zone configurations for temperature control
- PID control systems for temperature regulation
Limitations (compared to oil heating)
- Areas near electric coils typically at higher temperature (less uniform)
- Potential electrical earthing issues posing safety concerns
- Heating elements can melt, leading to cold areas and product defects
- Generally higher energy consumption
3. Steam Heating Systems for Platens
Another alternative to oil heating mentioned in the research:
Features
- Cost-effective heating solution for lower temperature applications
- Engineered to match existing or new steam sources
- Heating up to 400°F
- Individual steam traps for each platen or zone
- Can be used for hot water heating and cooling applications
4. Implementation Configurations
Location Options
- Boilers placed on top of the press
- Boilers placed to the side of the press
System Architecture
- Individual Systems: Customized for each press
- Centralized Systems: Central boiler room with general circuit supplying multiple presses
Temperature Control Methods
- 3-way valves for temperature regulation
- Separate secondary recirculation groups in each plate
- Computer control programs for uniform and accurate temperature control
- Multi-zone temperature control with PID controllers
5. Cooling Integration
Many modern systems incorporate both heating and cooling capabilities:
- Controlled cooling with properly designed heating/cooling thermal fluid transfer systems
- Water cooling options integrated with heating systems
- Steam heated platen designs that can be used for hot water heating and cooling applications
6. Low NOx Options
Environmental considerations in modern systems:
- Less than 30 PPM emissions with upgraded burner and flue gas recirculation
- Less than 9 PPM emissions with ultra-low NOx mesh head burner
- Biomass-fired systems as environmentally friendly alternatives
7. Specialized Applications
Different industries have specific requirements for their press heating systems:
- Wood Products: OSB, MDF, and melamine line presses
- Rubber Industry: Pre-heating rubber for injection molding
- Composites: High temperature requirements for forming
- Electronics: Printed circuit board manufacturing
- Graphics/Printing: Imprinting designs using controlled heat and pressure