Double Pipe Heat Exchanger
Two concentric pipes, one inside the other, make up a Double Pipe Heat Exchanger (DPHE), one of the most simple but efficient heat exchanger designs. One fluid is carried by the inner pipe (tube), while the second fluid is carried by the annular space (shell) that separates the inner and outer pipes. Heat transfer takes place across the wall of the inner pipe, allowing thermal energy to flow from the hotter fluid to the cooler one without direct mixing.
Table of Contents
- Construction
- Flow Arrangements
- Working Principle
- Key Characteristics
- Industrial Applications
- Advantages
- Why Choose Our DPHEs
- Frequently Asked Questions (FAQ)
Construction
Inner Pipe (Tube):
- A smaller-diameter pipe through which one fluid flows.
- Typically made from materials with high thermal conductivity such as copper, stainless steel, or carbon steel.
Outer Pipe (Shell):
- A larger pipe enclosing the inner pipe, creating the annular flow space for the second fluid.
- Provides structural support and pressure containment.
Headers/End Connections:
- Fittings or manifolds at both ends direct the fluids into and out of the exchanger.
Support and Expansion Joints:
- To accommodate thermal expansion and ensure mechanical stability.
Flow Arrangements
Counterflow (Most Common):
- Fluids flow in opposite directions.
- permits the cold fluid to get close to the hot fluid's input temperature and provides the maximum heat transfer efficiency..
Parallel Flow:
- Fluids flow in the same direction.
- Simpler arrangement but less efficient compared to counterflow.
Working Principle
- The hot fluid enters either the inner tube or the annular space depending on design.
- The cold fluid flows either in the same direction or in the opposite way in the following tube.
- Heat transfers across the pipe wall by conduction through the metal and convection from the fluid layers.
- The temperature differential, pipe material, flow configuration, and fluid velocity all affect efficacy.
Key Characteristics
- Heat Transfer Capacity: Moderate, best for small-to-medium duties. Efficient heat transfer in counterflow arrangement.
- Operating Pressure: Can handle moderate-to-high pressures.
- Temperature Range: Suitable for wide temperature ranges depending on material (copper, stainless steel, carbon steel).
- Maintenance: Simple construction allows easy inspection and cleaning.
Industrial Applications
- Chemical Industry: Cooling/heating of process fluids and solvents.
- Oil & Gas Industry: Fuel oils, hydraulic oils, and cooling lubricants are examples of the oil and gas industry.
- Power Plants: Preheating small fluid streams, cooling turbine oils.
- Food & Beverage: Heating/cooling syrups, water, or process liquids.
- Pharmaceuticals: Temperature control of small-batch reactors.
- HVAC Systems: Used in hot water generation or small process cooling loops.
Advantages
- Compact and simple design.
- Can handle high-pressure applications.
- Easy to install, maintain, and clean.
- Flexible: Depending on the needed heat load, units can be arranged in parallel or series.
- Cost-effective for small capacities.
Why Choose Our Double Pipe Heat Exchangers?
In essence, a double pipe heat exchanger consists of two concentric pipes, one of which runs fluidly in the annular area and the other within the inner pipe. Its counterflow arrangement provides high thermal efficiency for small-to-medium process duties.
At United Heat Exchangers, our DPHEs are designed for durability, performance, and cost-effectiveness, offering:
- Proven thermal efficiency for small-to-medium process streams.
- Custom-built designs to suit your specific industry requirements.
- Long service life with robust and reliable construction.
- Cost-effective heat transfer compared to larger exchanger types.
Whether for oil cooling, preheating, batch operations, or educational labs, our DPHEs combine simplicity, reliability, and adaptability to high pressures, making them the preferred choice for industrial applications.
Frequently Asked Questions (FAQ)
1: What is a Double Pipe Heat Exchanger?
A Double Pipe Heat Exchanger (DPHE) consists of two concentric pipes, where one fluid flows through the inner pipe and the other flows through the annular space. There is no mixing of the two fluids when heat is transferred over the pipe wall.
2: Where are Double Pipe Heat Exchangers used?
They are widely used in chemical processing, oil & gas, power plants, food & beverage, pharmaceuticals, and HVAC systems, especially for small-to-medium heat loads.
3: What are the advantages of a DPHE?
- Simple, compact, and cost-effective design.
- Handles high pressure applications.
- Easy to clean and maintain.
- Flexible configuration (can be installed in series or parallel).
4: What flow arrangements are available?
Counterflow (most efficient) or parallel flow arrangements depending on application needs.
5: What materials are available for construction?
Stainless steel, copper, or carbon steel, depending on process fluid, pressure, and temperature requirements.
6: How efficient is a Double Pipe Heat Exchanger?
Counterflow DPHEs provide high thermal efficiency and can achieve close temperature approaches, making them highly effective for small process duties.
7: Can DPHEs handle corrosive fluids?
Yes, by selecting the right material (such as stainless steel), they can handle corrosive fluids and aggressive chemicals safely.
8: How do I choose the right size of DPHE?
Selection depends on heat load, flow rate, operating pressure, fluid type, and temperature range. Our team at United Heat Exchangers offers expert guidance for optimal sizing.
9: What is the maintenance requirement?
Due to their simple design, DPHEs are easy to inspect, clean, and maintain, minimizing downtime and lifecycle costs.
10: How can I get a quote for a Double Pipe Heat Exchanger?
You can easily request a quote from United Heat Exchangers by sharing your process details such as fluid type, flow rates, inlet/outlet temperatures, and operating pressure.
Get Your High-Efficiency Double Pipe Heat Exchanger Today
If you are looking for a highly efficient Double Pipe Heat Exchanger (DPHE) that combines performance, durability, and cost-effectiveness, United Heat Exchangers is your trusted partner.
Request a Quote Today and get a customized solution tailored to your industrial requirements.
