Carbon Steel/Stainless Steel Boiler Fin Tube Spiral Fin Tube Heat Exchanger for Boiler System

Carbon Steel/Stainless Steel Boiler Fin Tube Spiral Fin Tube Heat Exchanger

General introduction

Spiral finned tubes are widely used in heat recovery of boiler economizer, air preheater, and waste heat boiler, as well as heat exchange equipment in chemical industry, pressure vessel and other fields. The capacity of units used in boilers has also increased from small to large, and their applications are increasing day by day. At present, many professional manufacturers in China can produce high frequency resistance welding, brazing spiral finned tubes, and the production equipment and technology of finned tubes have been developed, designed and manufactured from importation, digestion and absorption to self-development. The quality has reached the requirements of advanced foreign standards.

Advantages of using finned tubes:

1. the heat transfer area is increased in the effective space to improve the heat transfer effect.

2. Reduce the occupancy space of heat transfer surface and reduce its volume, especially for fast-loading boilers.

3. Reduce the equipment cost and improve the safety of equipment.

4. Due to the decrease of water side pressure drop, the operation cost is reduced.

5. The stiffness of finned tubes are increased, and the seismic resistance of the tube is improved.

Manufacturing method

Spiral finned tubes can be manufactured by various ways. At present, there are several main manufacturing methods for finned tubes used in heat exchangers such as boilers and pressure vessels.

High frequency resistance welding spiral finned tube

High frequency resistance welding spiral finned tube is kind of high frequency current imported into the welded parts. By using the resistance heat generated by the current through the contact surface of the welded joints and adjacent areas, the welded contact surface can reach the plastic state of melting or semi-melting, then appropriate pressure is applied to the welded contact surface, to complete welding work of finned tubes.

Brazed spiral finned tube

Brazing spiral finned tube is a kind of metal filler with a melting point lower than that of the welded part, and then heating the brazing temperature. When the welded part is not melting, the solder melting well wets and brazes, and forms the brazing joint depending on expansion and dispersion of the contact point of the welded part, thus completing the welding of the spiral finned tube.

Integral spiral finned tube

Integral spiral finned tube is formed by extrusion and tie of thick-walled tube(billet tube) under the condition of medium frequency continuous heating.It is known as the latest method of manufacturing finned tube in domestic market. It is developed by a domestic company and the researched and developed integral finned tube as well as the self-manufactured integral finned tube manufacturine equipment have been applied for patents.

Service life

High frequency resistance welding of spiral finned tube is to apply pressure while melting at the contact of two metal surfaces. The welding rate is better. The corrosion resistance of welded metal is more than twice that of brazing, and the service life of the finned tubes can be greatly improved. However, due to improper welding, long-term use is prone to weld cracking, which makes the fins and tubes detached, thus affecting their heat transfer efficiency, so finned tubes have to be replaced.

Integral spiral finned tubes do not have the problem of welding fins, so there is no need to worry about corrosion and cracking of fins, so the heat transfer efficiency will not be reduced. Moreover, because the surface hardness of integral spiral finned tube increases, the wear resistance of the finned tube is increased, and the root structure characteristics of the fins are convenient for heat transfer, the service life of integral spiral finned tubes is equal to that of the raw material of finned tubes, at least 2-3 times of that of high frequency resistance welding and brazing spiral finned tubes.

Economical efficiency

Brazing spiral finned tubes require a third kind of material-brazing filler metal. When brazing, the fins need to undergo cold winding, spraying solder, sintering and other major processes, so the manufacturing cost is high. High frequency resistance welding spiral finned tubes do not need a third material. The fin is formed by one-time welding, so the cost is relatively low. The winding end and termination end of high frequency resistance welding and brazing spiral finned tubes, should be fixed by manual welding method, then good for welding production.

Integral sprial finned tubes are made of thick-walled tubes by extrusion and rolling without the need of a second material. It eliminates the winding and welding of high frequency resistance welding fins, and high production efficiency and low cost. In addition, because the fin root of integral spiral finned tube is a small R smooth transition, it is convenient for heat transfer.

Technical advantages

At present, spiral finned steel tubes are mostly winding, high frequency welding and brazing spiral finned steel tubes. The intergal spiral finned steel tubes have become t renewal product of the above three types of spiral finned steel tubes because of its long service life, stable heat transfer performance and obvious every saving effect. Their advantages are shown in the following aspects:

1. Long service life, more than 3 times as long as that of winding welded finned steel tubes.

2. Arc cutting of fin root and tube and smooth surface of fins completely eliminate the phenomenon of ash accumulation, ash plugging and slagging of other forms of fin tubes due to the uneven folding of fin root.

3. Hot rolling technology is sued to improve the density, yield strength, tensile strength and wear resistance of metal structure.

4. Because the fin and tube are integral and distributed in spiral band, the pressure bearing capacity of integral spiral finned tubes is more than 3 times of that of seamless steel tube with the same thickness and inner diameter.

5. Wear resistance, which solves the problem of serious wear of convective heating surface of coal-fired boiler due to high wind speed and high ash concentration (especially circulating fluidized bed boilers).

6. The integral fin-tube structure completely eliminates the contact thermal resistance that other fin-tube structure can not overcome. In addition, the longitudinal section of fin is trapezoidal structure, so the heat transfer efficiency is improved to the greatest extent.

7. The expanded surface heat exchange of integral spiral fin is adopted. Under the same working conditions, the heat transfer coefficient of tube bundle is 3.5-5.5 times of that of seamless steel tube with the same thickness and inner diameter, and twice of that of welded spiral fin steel tube with the same specification.

8. Fins and tubes are integral structure, so they can be used in high temperature and harsh environment. There will be no instability of heat transfer performance caused by the relaxation and shedding of fins in other forms of finned steel tubes.

Hua Dong Boiler Co., Ltd. is a high-tech enterprise specialized in manufacturing boilers. Established in early 1985s, has two manufacturing bases, this company covers 400,000㎡ with fixed assets amounting to USD 110,000,000. There are 1100 employees including 150 technicians and 600 coded welders. Hua Dong holds the manufacturing licenses for Grade A boilers and Grade A1&A2 pressure vessels issued by Chinese General Administration of Quality Supervision, Inspection and Quarantine; also it holds the "S" and "U" "NB" stamps issued by American Society of Mechanical Engineers; meanwhile, this Company has passed the certification of ISO9001, SO3834, EN12952 Quality Management System.

"Hua Dong" boilers include Utility Boiler, HRSG Boiler, coal-fired , oil(gas) -fired, coal-water-slurry-fired and garbage-fired steam/hot water boilers, organic heat carrier boilers, etc., and Boiler spare parts (Economizer, Finned tube, Header, Steam drum, Superheater, Water wall panel, Air preheater, Cyclone separator, etc., which are widely used in power generation, heat supply, chemical engineering, textile, food, paper, road building, plastic, rubber and wood working industries. "HD" boilers are honored as "Famous Production in Jiangsu Province", " Jiangsu High-Tech Product" and "Jiangsu Energy-Saving Product". "HD" brand is a "Famous Brand in Jiangsu Province". We are a qualified supplier for the top three boiler manufacturers in China(Harbin Boiler Co., Ltd., Dong Fang Boiler Group Co., Ltd., Shanghai Boiler Works Ltd.,). So far, Hua Dong Boilers have served 10000 customers, which sell well all over China and are exported to USA, Australia, Russia, Kazakhstan, India, Indonesia, South Africa, Brazil, and Southeast Asia.

We strive to manufacture "Safe, Efficient, Energy-Saving and Environment-Friendly" boilers, provide new-type products in excellent quality, serve users sincerely to their satisfaction, and be a top supplier of boilers in China.

Declaration

Zhangjiagang Hua Dong Boiler Co.,Ltd has no subsidiaries. 

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Our products have been wildly used in power plants and large international companies overseas.