E-LINE

Specification

Hexonic's condensing economizers are modern solutions supporting the energy transition in industry and district heating.

The HEXONIC E-LINE is a condensing economizer designed to increase boiler efficiency by recovering heat from flue gases. It is a modern solution supporting the energy transition in industry and district heating, helping modernize boiler plants by turning standard boilers into efficient condensing units.

Thanks to its advanced design, the E-LINE recovers both sensible and latent heat normally lost in traditional systems and redirects the recovered energy to feedwater or air preheaters. As a result, overall system efficiency is approximately 9% higher than with traditional solutions, while heat and steam recovery efficiency can improve by up to 20% in typical applications. This leads to lower fuel consumption, reduced emissions, and measurable operating-cost savings, especially in large industrial installations.

Key Features

• Product Type: Condensing economizer heat exchanger
• Primary Function: Recovery of sensible and latent heat from boiler flue gases
• Efficiency Gain: ~9% higher than traditional solutions
• Recovery Improvement: Up to 20% better heat and steam recovery in typical applications
• Tube Design: Teardrop-shaped horizontal tube pattern
• Gas-Side Material: Stainless steel 316L for corrosion resistance
• Frame Material: Galvanized steel
• Housing Material: Galvanized steel with powder-coated finish
• Housing Feature: Insulated modular design for easier assembly, disassembly, and maintenance
• Flow Arrangement: Flue gas outside tubes, cold feedwater inside tubes (counterflow)
• Pressure Drop: Low flow resistance and minimal pressure drops
• Connection Flexibility: Adapted to site requirements

Construction

• FLUE GAS INLET

  A gas duct for distributing flue gases
• WATER INLET

  Water system for water distribution
• WATER OUTLET

  Water system for water distribution
• FLUE GAS OUTLET

  A gas duct for distributing flue gases
• 

  HEAT EXCHANGER WITH A UNIQUE “TEARDROP” TUBE PATTERN

  Specially shaped tube arrangement maximizes the contact surface for heat exchange with the gases, enhancing energy recovery efficiency.
  

E-LINE

Frame

The frame is made of galvanized steel, providing corrosion resistance and solid, stable support for the heat exchanger. This structure facilitates installation and transportation and protects the device from mechanical damage and harsh environmental conditions.

Housing

The housing is made of galvanized steel with a powder-coated finish, combining effective anti-corrosion protection with a modern appearance. The housing is additionally insulated to prevent excessive heating of its walls, while the modular design allows for easy assembly, disassembly, and maintenance.

Operating Principle

Condensing economizers are heat exchangers that improve heating system efficiency by recovering energy from boiler flue gases. They operate by cooling the flue gases to a temperature at which the water vapor contained within condenses, releasing both sensible and latent heat. This allows for more efficient fuel utilization, reducing operating costs and emissions.
Flue gases flow on the outside of the exchanger tubes, while cold feedwater for the boiler flows inside. Heat is transferred through the tube walls, and the counterflow configuration of media ensures maximum energy recovery. Due to the acidic nature of the condensate, all components in contact with flue gases are made from corrosion-resistant stainless steel.

 

Technical Specifications

Parameter	Specification
Design Standards	ASME, PED
Max Design Pressure	tube side: 11 bar
Max Design Temperature	tube side: 110°C; shell side: 350°C
Tube Materials	stainless steel 316L (1.4404)
Shell Materials	stainless steel 316L (1.4404)
Design Types	condensing economizers / gas boiler economizers / E-LINE condensing economizers
Connection Types	exhaust / flue gas connections: Ø200–900 mm water inlet / outlet connections: DN65–DN150 drain connections: DN20–DN50
Certification	ASME, PED

Applications

HVAC

Heating

A division of the energy industry, supplying heat from a heat generating plant or a combined heat and power plant […]

Heat Exchangers for the Food Industry

A part of the economy that handles the manufacturing of products and intermediate products for consumption.

Food industry

Dairy

Production of milk involves cooling, pasteurizing, fermenting, drying and storing products in a suitable temperature.

Pharmaceutical industry

Water is material used most frequently in the pharmaceutical industry.

Refrigeration

Heat recovery

Re-use of heat (thermal energy) from hot waste water, gases, ventilation or sewage is called heat recovery.

Frequently Asked Questions

What is the E-LINE designed for?

The HEXONIC E-LINE is designed to recover heat from boiler flue gases and improve boiler plant efficiency. It supports modernization of industrial and district-heating boiler systems by converting standard boilers into condensing units.

How does the E-LINE improve boiler efficiency?

The E-LINE cools flue gases to the point where the water vapor inside them condenses. This allows the exchanger to recover both sensible and latent heat, which is then redirected to feedwater or air preheaters. According to HEXONIC, this raises system efficiency by about 9% compared with traditional solutions.

Why is stainless steel 316L used in the E-LINE?

Because condensate formed from flue gases is acidic, all components in contact with flue gases are made from corrosion-resistant stainless steel 316L to ensure long-term durability and reliability.

What design feature makes the E-LINE efficient?

The exchanger uses a unique teardrop-shaped horizontal tube pattern, which increases the contact surface for heat exchange with the gases and enhances energy recovery efficiency while maintaining low flow resistance.

What is the expected payback period?

The return on investment for the E-LINE can be less than 3 years, depending on the application and operating conditions.