Vacuum Distillation Furnace
for Refinery
A vacuum distillation furnace heats atmospheric residue before it enters the vacuum tower for further separation.
At Gelan, we design and manufacture vacuum distillation furnaces for refinery projects, with a focus on uniform heat flux, reduced coking risk, and stable operation under vacuum conditions.
- Uniform heat flux design to minimize coking risk
- ≤ ±10–15°C tube wall temperature deviation
- Long-cycle operation under heavy residue service
- ASME and API 560 compliant
What Does a Vacuum Distillation Furnace Do in a Refinery
A vacuum distillation furnace heats atmospheric residue before it enters the vacuum tower for further separation. In a refinery VDU system, it provides the heat needed for vacuum distillation while helping control thermal cracking and coking risk.
Where the Vacuum Furnace Fits in the VDU Process
In a vacuum distillation unit (VDU), the vacuum distillation furnace is located upstream of the vacuum tower and provides the required heat for the separation process.
After atmospheric distillation, residue is heated in the vacuum furnace before entering the vacuum tower for separation under reduced pressure.
How to Choose the Right VDU Furnace for Your Refinery Project
Cylindrical Furnace
- Lower pressure drop design
- More uniform heat flux distribution
- Suitable for heavy residue heating
Box-Type Furnace
- Flexible tube layout for process optimization
- Easier access for inspection and maintenance
- Suitable for space-constrained installations
Vacuum Distillation Furnace Technical Specifications
| Parameter | Typical Range |
|---|---|
| Tube Wall Temperature Deviation | ≤ ±10–15°C |
| Operating Temperature | ~380–420°C |
| Heat Duty | Based on process design |
| Run Length (Design Consideration) | Project-dependent |
| Fuel Type | Gas / Oil / Dual fuel |
| Thermal Efficiency | Up to ~90% (design-dependent) |
| Furnace Type | Box-type / Cylindrical |
| Applicable Standards | ASME, API 560 |
*All specifications are customized based on feedstock type, process conditions, and project requirements.
How Gelan Improves Vacuum Distillation Heater
Heat Flux Control and Coking Reduction
Uniform heat distribution is critical when heating heavy residue under vacuum conditions. Poor heat flux control can lead to local overheating and rapid coking.
Gelan approach:
- Optimized burner layout for more uniform radiant heat distribution
- Tube arrangement designed to reduce local hotspots
- ≤ ±10–15°C tube wall temperature deviation
- Reduced coking tendency under heavy residue service
Heavy Residue Handling Capability
VDU furnaces must handle high-viscosity, high-asphaltene feed, which increases fouling risk and affects heat transfer performance.
Gelan approach:
- Design adjusted based on residue properties and viscosity
- Heat intensity and residence time optimized for heavy feed
- Stable heating under heavy residue conditions
- Lower fouling rate during operation
Long-Cycle Operation and Fouling Control
Frequent shutdown for decoking can significantly increase maintenance cost and reduce plant availability.
Gelan approach: :
- Tube layout and spacing optimized to limit fouling buildup
- Material selection adapted for high temperature and long-term operation
- Extended run length between maintenance cycles
- Improved overall unit availability
VDU System Integration and Stability
The furnace must be properly matched with the vacuum tower and upstream systems to ensure stable separation performance.
Gelan approach:
- Design based on actual VDU operating data and process requirements
- Temperature and flow conditions optimized for system compatibility
- Stable operation under vacuum conditions
- Improved separation efficiency in the VDU system
Where Vacuum Distillation Furnaces Are Used
Typically applied in refinery CDU systems and integrated processing units.
Vacuum Distillation Furnace Projects Delivered by Gelan
Vacuum Furnace Application in 80,000 BPD Refinery VDU Upgrade
Project Background:
Vacuum distillation furnace supplied for a refinery upgrade project supporting an 80,000 BPD unit, processing atmospheric residue in the VDU section.
Key requirement:
Stable heating of heavy residue under vacuum with controlled coking risk.
Gelan support:
- Customized furnace design for heavy residue service
- Heat flux and tube layout optimization
Result:
- Tube wall temperature deviation controlled within ≤ ±10–15°C
- Noticeable reduction in coking and fouling tendency
- Stable operation during initial run cycle after commissioning
Related Equipment in the Vacuum Distillation Process
Atmospheric Furnace
Heats crude oil before distillation and provides atmospheric residue feed for the vacuum distillation unit.
Distillation Column
Separates heated residue into different fractions under vacuum conditions.
Shell & Tube Heat Exchanger
Recovers heat from process streams to improve overall energy efficiency.
FAQs About Vacuum Distillation Furnaces
What does a vacuum distillation furnace do in a refinery?
A vacuum distillation furnace heats atmospheric residue before it enters the vacuum tower, enabling separation of heavy fractions under reduced pressure.
Why is vacuum required in a distillation unit?
Vacuum lowers the boiling point of heavy fractions, allowing separation at lower temperatures and helping reduce thermal cracking and coking risk.
What is the typical operating temperature of a VDU furnace?
Typical furnace outlet temperature is around 380–420°C, depending on feedstock and process requirements.
What causes coking in a vacuum furnace?
Coking is mainly caused by high tube metal temperature and long residence time, especially when processing heavy residue.
How can coking be reduced in VDU furnaces?
At Gelan, furnace design focuses on heat flux control and tube layout optimization to help reduce fouling risk under heavy residue conditions.
Is a vacuum distillation furnace a standard product?
Gelan supports refinery and EPC projects with tailored furnace design based on actual process data.
What are the main products of a vacuum distillation unit?
Typical products include light vacuum gas oil (LVGO), heavy vacuum gas oil (HVGO), and vacuum residue (VR).
How does furnace performance affect the VDU system?
A well-designed furnace helps improve temperature control, reduce fouling, and support stable VDU operation.
Get a Quote for Your VDU furnace Project
Get a customized vacuum distillation furnace solution from Gelan based on your actual operating conditions.