Technical introduction

 Hot air furnace is a kind of heat exchange equipment which regards air as working media. It is divided into two kinds, indirect and direct type.
  In indirect hot air furnace, cold air will be blown into heat exchanger by blower. Replacement of energy will be achieved by pipe walls arranged inside and hot flue gas by convection conduction mode. there will be some hot air with certain temperature, air pressure discharged out from air outlet of furnace. Then, materials will be sent to dryers for drying or heating. Hot flue of pipe in heat exchanger. After passing by heat exchanger, hot flue gas is discharged out from induced draft fan in flue pipe to realize heat exchange process.
Applications of chain indirect hot air furnace:
Energy: coal (lignite, washed coal and coal distillation pretreatment), kerogen, briquette and coal slime;
Ceramics: ceramic powder (polishing brick), frit, crockery and kaolin;
Fertilizer: compound fertilizer, ammonium phosphate, diammonium phosphate, muriate and sulfuricum;
Chemical industry: Potassium fluoride, dyes, calcium chloride, alumina, Zinc Oxide, fluorite powder, etc. 
Forage: dregs, barley straw feed, pellet feed, dicalcium phosphate etc. 
Building materials: Ceramic fiber, thermal insulation board, thermal insulation cotton, super fine powder, desulfurization gypsum, quartz sand, etc. 
Environmental protection: Paper making black liquor (lignin), sludge drying, phosphorus gypsum, waste water treatment, solid waste residue, etc. 
Food and medicine: food, dried fruit, vegetables and medicines;
Water purifier: polymeric aluminum chloride, sulfuric acid and etc;
Others: wood, mine smelting processing, rubber powder, acetylene bottle, plastic mold and etc; 

Advantages

Structure and performance of chain indirect hot air furnace:
1. Heat exchange tube adopts vertical structure; increase pipe diameter; avoid pipe blockage of traditional hot air furnace;
2. The outer wall of heat exchange pipe is surrounded by finplates which are resistant to high temperature; increase heat exchange area; reduce manufacturing cost;
3. Dryers adopt pouring; avoid problems caused by masonry such as short service span, much cracks and top-collision.
4. Furnace body and heat exchanger are installed separately. better for long-distance transportation and maintenance;
5. Its service span is two times longer than traditional hot air furnace;
6. After many times’ circulation, the thermal efficiency of cold air sent will be increased by 100%. It adopts heat exchange measures which are
Resistant to high temperature and with long service span.
7. There is no dust accumulated on the heat exchange part which holds stable heat conduction performance.
8. This furnace can use coal, firewood and other solid fuels. It is equipped with secondary ventilation device which makes combustion more sufficient.
9. The temperature of furnace increases quickly. This furnace is with high thermal efficiency which can reach to over 85%.
10. Its operation is simple and reliable. There is no risk of explosion. The equipment has long service span.
11. The temperature can be controlled automatically; the temperature difference can be controlled with in 5 degree centigrade. The temperature of hot air can be controlled at 60 degree centigrade to 550 degree centigrade. This furnace can be divided into three types, low temperature, middle temperature and high temperature.

Working principle

Technical parameters