Overview

In order to reduce energy consumption, air heat exchangers are installed in the flue gas of heating furnaces to recover a large amount of waste heat from the flue gas, achieve fuel savings, reduce production costs, increase combustion temperature, and increase furnace output. Air heat exchangers are suitable equipment for waste heat utilization and have been applied in various industrial furnaces such as steel rolling heating furnaces, heat treatment furnaces, and calcination heating furnaces. There are many types of air heat exchangers used in furnaces, and currently the vast majority of them both domestically and internationally are metal heat exchangers. Air heat exchangers use the heat from the exhaust gas discharged from the furnace to preheat the air to a certain temperature and return it to the furnace for combustion assistance or use in other equipment. Metal heat exchangers have the characteristics of small volume, high heat exchange efficiency, good tightness, and simple structure.

Tubular preheater

In order to reduce energy consumption, air heat exchangers are installed in the flue gas of heating furnaces to recover a large amount of waste heat from the flue gas, achieve fuel savings, reduce production costs, increase combustion temperature, and increase furnace output. Air heat exchanger is a suitable equipment for waste heat utilization. The GCJ type tubular air heat exchanger has a compact structure and can be applied to both horizontal and vertical flues. The heat transfer surface of the heat exchanger is composed of tube bundles, with flue gas (heat source) flowing outside the tubes and combustion air flowing inside the tubes. The Fried Dough Twists insert is added in the heat exchange tube to change the boundary layer of the fluid on the air heat transfer surface, increase the turbulence intensity of the flowing medium, enhance the convection heat supply on the air side, and thus improve the heat transfer efficiency of the heat exchanger. Due to the abundant supply of steel pipes and steel plates required for the production of tubular air heat exchangers, as well as the advantages of simple production and installation processes, low air leakage, and no dust accumulation, they have been widely promoted and used both domestically and internationally.

Manufacturing Inspection

1. After welding the steel pipes and tube plates of the tubular heat exchanger, remove the welding slag and conduct a leakage test with kerosene. Before leaving the factory, the heat exchanger undergoes individual or overall pressure testing. The test medium is air, with a pressure of 2000 millimeters of water column. If there is no leakage within 1 hour, it is considered qualified. For large heat exchangers, due to transportation reasons, they cannot be assembled as a whole and only undergo individual pressure tests before leaving the factory. After the equipment arrives at the construction site, it is assembled and welded, and then subjected to overall pressure testing.

2. For cylindrical heat exchangers, steel plates are used for forming, and after forming, an overall pressure test is conducted. The test medium is air, with a pressure of 2000 millimeters of water column. If there is no leakage within 1 hour, it is considered qualified.

Install

1. Install according to the requirements of the heating furnace design layout plan or heat exchanger installation diagram.

2. Lift the heat exchanger into the constructed flue, and in special circumstances, the flue can be constructed after it is in place.

3. For heat exchangers with shells, they should be directly connected to the flue after being in place.

4. Connect the inlet and outlet air ducts and wrap them with insulation.

Use

1. When the flue gas temperature reaches 400 ℃ or above, the heat exchanger must be in the air supply state. When the preheating temperature exceeds the high design value, the air volume should be increased to release the excess hot air. When the temperature of the flue gas entering the heat exchanger is too high, cold air mixing measures can be taken.

2. When the furnace is shut down, the heat exchanger should continue to supply air and the fan should not be stopped immediately. The hot air should be released. The fan can only be turned off when the temperature of the flue gas entering the heat exchanger is below 400 ℃.

3. Sudden power outages can easily cause the heat exchanger to burn out, and should be prevented as much as possible. If this situation occurs, the flue gate should be immediately closed or effective measures should be taken to reduce the flue gas temperature, so that the heat exchanger will not overheat and be damaged.

4. If any abnormal situation is found in the heat exchanger, the cause should be identified and dealt with in a timely manner.

Negotiate and place orders

In order to maximize the efficiency of the heat exchanger, customers are requested to provide the following technical parameters when selecting our products:

1. The flow rate of flue gas entering the heat exchanger.

2. The airflow entering the heat exchanger.

3. The temperature of the flue gas entering the heat exchanger.

4. The required air preheating temperature.

5. Heating furnace type.

6. Types of heating furnace fuels.

7. Smoke exhaust method.

8. Allow for the loss of flue gas resistance in the heat exchanger.

9. Allow for air resistance loss in the heat exchanger.

10. Allow for large external dimensions and interface sizes of the heat exchanger.