In the field of industrial energy conservation, air preheaters are generally perceived as large and bulky equipment, mostly associated with large utility boilers. However, with the popularization of energy-saving technologies and the refinement of industrial scenarios, air preheaters are playing an indispensable role in a growing number of sectors.

What Is a Small Air Preheater?

Generally, a small air preheater refers to a waste heat recovery device featuring a small heat exchange area and compact structure, suitable for working conditions with low flue gas volume or low thermal load. It can be a small tubular heat exchanger, a heat pipe exchanger, or even an integrated flue gas waste heat recovery unit.

Application Scenario 1: Industrial Boilers and Heating Furnaces

Small and mediumsized factories, hotels and schools are commonly equipped with 4 t/h or 6 t/h industrial boilers and hot water heating furnaces. The exhaust gas temperature of such boilers usually ranges from 150℃ to 200℃, resulting in massive waste of residual heat.After installing a small air preheater, combustion-supporting air can be preheated to 80℃–100℃ by utilizing flue gas waste heat. This directly improves boiler combustion efficiency and reduces fuel costs by approximately 3%–5%. For heating systems operating throughout the year, the energy-saving benefits can quickly offset the equipment investment.

Application Scenario 2: Drying and Coating Industry

Wood drying, food dehydration and automobile spraying workshops require a large supply of hot air. The traditional method relies on direct air heating by burners, which leads to high energy consumption.Small air preheaters can be installed on the exhaust ducts of drying equipment to preheat fresh cold air with high-temperature waste gas. The preheated air is then sent to burners or hot blast stoves. This measure greatly reduces burner load, cuts fuel consumption, and lowers carbon emissions simultaneously.

Application Scenario 3: Catering and Commercial Kitchens

This is an easily overlooked application field. Stoves and steam cabinets in large commercial kitchens generate high-temperature flue gas.In recent years, energy-saving renovation projects have widely adopted small air preheaters on smoke exhaust pipelines, to heat domestic hot water for dishwashing or circulating water for space heating. Although such equipment functions similarly to waste heat recovery water heaters, it shares the same working principle as air preheaters — maximizing the full utilization of residual heat resources.

Application Scenario 4: Laboratories and Scientific Research Facilities

University laboratories and pilot-scale research devices often need to simulate specific process conditions. Compact small air preheaters with precise temperature control have become essential supporting equipment.Adopting a combined mode of electric heating and flue gas waste heat recovery, these preheaters feature small footprint and high control accuracy, widely applied in catalyst performance evaluation, combustion characteristic research and other scientific research fields.

Application Scenario 5: Agriculture and Greenhouse Planting

The heating cost of modern glass greenhouses remains high in winter. Many new energy-saving greenhouses integrate small air preheaters at the tail of boilers or hot blast stoves.In some biogas projects, both jacket cooling water and exhaust gas from biogas generators are recycled through small preheaters to supply hot air for greenhouses. This scheme solves the problem of greenhouse thermal insulation in winter and realizes cascaded utilization of energy.

For enterprises, selecting a suitable small air preheater is not merely simple equipment procurement, but also a stable and rewarding energy-saving investment.

Shanghai Rivbay Chemical Equipment Co., Ltd. specializes in the R&D and production of non-standard pressure vessels, including reaction kettles, heat exchangers, tower equipment, modular units, freeze dryers and cold traps. The company holds ASME U-stamp certification, EU PED certification, Korea Kosha certification and EAC certification. Its products serve chemical, petrochemical, pharmaceutical, food, light industry, environmental protection and other industries. Customized, highly compatible equipment solutions are available for clients. For inquiries and cooperation, please feel free to contact us.