The GRL series hot-air furnace is a high-efficiency, energy-saving, new-type heat-exchange device independently developed by our factory. It uses coal, biomass, gas, or oil as fuel and delivers clean, pollution-free hot air through radiation heat transfer, conduction heat transfer, and convection heat transfer.

Product Introduction

The GRL series hot-air furnace is a high-efficiency, energy-saving, new-type heat-exchange device independently developed by our factory. It uses coal, biomass, gas, or oil as fuel and delivers clean, pollution-free hot air through radiation heat transfer, conduction heat transfer, and convection heat transfer. The clean hot-air furnace designed and manufactured by our company has been granted a national patent.

Thanks to the optimization measures and innovative design adopted in this series of hot-air furnaces, heat transfer and heat exchange performance have been significantly enhanced, resulting in a high overall heat-transfer coefficient, rapid temperature rise, and substantial thermal storage capacity for the entire unit.

The GRL series hot-air furnace, as a new type of heat-source equipment, can replace steam heat exchangers, thermal-oil heat exchangers, and electric air heaters, offering advantages such as compact size, easy installation and transportation, and low energy consumption. It is widely applicable in various operations including drying, heating, heat preservation, and dehumidification, and when paired with drying equipment such as cyclone flash dryers, pressure spray dryers, and vibratory fluidized-bed dryers, it can maximize the performance of the entire system.

Working Principle

The GRL series hot-air furnaces are available in two configurations: vertical and horizontal. The vertical coal-fired (or biomass-pellet-fired) hot-air furnace can, according to customer requirements, be further classified as either a manual-firing unit or an mechanically-firing unit. It consists of two main components: the combustion chamber and the heat-exchange section. High-temperature flue gases generated in the combustion chamber enter the heat-exchange section, where they undergo multi-pass counterflow heat exchange with cold air supplied by a blower through both radiation and convection. After the cold air is heated to a specified temperature, it is discharged through the hot-air outlet of the furnace and delivered to the heat-consuming equipment. The flue gases are drawn out by an induced-draft fan and then passed through a flue-gas separator and a dust collector before being vented to the atmosphere.

The hot air does not come into direct contact with the material, thereby preventing flue-gas contamination; this makes it suitable for materials with stringent requirements regarding whiteness and freedom from impurities.

Product Features

• Pure and contamination-free: Hot air is separated from combustion products, ensuring that the material remains uncontaminated.
• High efficiency and energy savings: large heat-exchange area and high heat-transfer efficiency, with some models achieving thermal efficiencies of 85% or higher.
• Temperature control: The hot-air temperature is precisely regulated via an intelligent PLC control system, with an output range of 100–450°C.
• Special Note: Our equipment features a multi-layer, sleeve-type all-metal construction (without refractory materials), thereby eliminating common issues associated with traditional equipment—such as cracking and spalling caused by differential thermal expansion and contraction due to varying material coefficients of thermal expansion. Each air-gap sleeve is densely fitted with metal fins, maximizing heat-exchange efficiency. The high-temperature zone is constructed from high-temperature-resistant stainless steel (310S), ensuring a long service life.

Application Fields

• Food industry: drying of milk powder, bread, biscuits, and other products.
• Pharmaceuticals and chemicals: drying of pharmaceuticals, synthetic resins, and other materials.
• Other fields: grain drying, wood processing, industrial heating, and more.

Strengths and Weaknesses

• Advantages: high-quality manufactured materials, wide applicability, and excellent environmental performance.
• Disadvantage: High equipment costs.

Selection Recommendations

• Select the appropriate type based on material characteristics, such as requirements for whiteness, impurities, and contamination.
• Considering fuel type (coal, natural gas, etc.) and thermal efficiency, natural-gas-fired systems are cleaner but more expensive.
• Pay close attention to the material and design of the heat exchanger to ensure long-term stable operation.

The Hot Air Furnace is an advanced heating system designed to provide stable, efficient, and energy-saving thermal solutions for industrial processes. With reliable heat circulation and precise temperature control, the Hot Air Furnace is widely used in drying, chemical processing, food production, and manufacturing industries. It helps businesses improve production efficiency while maintaining consistent product quality.

Built with durable materials and optimized heating technology, the Hot Air Furnace offers excellent thermal performance, low energy consumption, and long service life. Its intelligent design ensures uniform hot air distribution, reducing heat loss and solving common problems such as uneven heating, high operating costs, and unstable production results.

In practical applications, the Hot Air Furnace supports factories in achieving faster and more reliable production. For example, manufacturers use it for material drying and industrial heating processes to improve efficiency and reduce downtime. Choosing a high-quality Hot Air Furnace provides customers with safer operation, lower maintenance costs, and continuous production advantages.

Every Hot Air Furnace is manufactured with strict quality control and can be customized according to different industrial requirements. With professional design and reliable performance, the Hot Air Furnace becomes an ideal heating solution for companies seeking efficient and sustainable development.