Aluminum is the common material of finned tube. Today this article will introduce the details of all aspects of finned tube.
Development of aluminum finned tubes
Aluminum finned tube in form is the, the base tube more common with several kinds of stainless steel, carbon steel and copper material, after extrusion forming professional equipment, made into the finned tube, we need this kind of finned tube in the position of the base, is a must and the walls of the tube for a tight fit, this is to compare the obvious advantages of aluminum fin tube.
And aluminum finned tube on the heat transfer coefficient is quite high, and the heat transfer performance is good, major is its surface without burr, and wrinkle, the appearance is very bright and beautiful, also is more convenient in cleaning, main is to use the heater, or the surface of the condenser, the discharge of water effectively.
If the aluminum fin tube is used in drying and heating, it will definitely not scale and dust and other adverse phenomena, because the aluminum fin tube in the cross section is mainly trapezoidal shape, therefore, its strength will be higher, but also the heat dissipation area for diffusion, and to ensure the use of products get big talk.
Features of aluminum finned tubes
Aluminum finned tube are basically use aluminum pipe, copper and iron are or after rolling, and so on the thermal resistance is small, and the heat transfer performance is higher, and the anticorrosion performance is very strong, the main or on the flow loss is small, even in the uneven and under the condition of long-term processing, it also won’t appear deformation.
After the manufacture of aluminum finned tube using the whole aluminum tube, it will not have contact with thermal resistance, and the strength is also very high, not only mechanical vibration resistance is also very heat resistant shock, in the whole thermal expansion performance is relatively good, the main or heat transfer area can be expanded.
In addition, according to the relevant requirements of customers, aluminum finned tubes can be manufactured and produced into various pipe materials. The manufacturing technology of aluminum finned tubes should be successful and extensive in terms of development. Therefore, Murphy will focus on innovation and research and development regardless of future development and current use
Technological characteristics of aluminum finned tube
Extrusion aluminum finned tube technology features, using the form of base tube sleeve aluminum tube, (base tube can be carbon steel, stainless steel, copper) through machine extrusion, forming a fin, the fin base and tube outer wall close fitting, high heat transfer coefficient, excellent heat transfer performance.
Rolling plate finned tube fin smooth and no burr, no fold, beautiful and bright, easy cleaning, as air heater and puts forward the components easy to eliminate surface when the condensate, the drying heat and other places is not easy to dust, scale, rolling plate finned tube fin transection and a trapezoid, and fin high intensity, and expanded the cooling surface, thus make maximum use of the material.
The extruded finned tube is made of iron or copper or aluminum tube by compound rolling, which has the advantages of tight bonding, small thermal resistance, good heat transfer performance, high strength, small flow loss, strong anti-corrosion performance, not easy to deform under long cold and hot working conditions, long working life and so on.
The integral rolled fins are smooth without burring and easy to be cleaned. The fins are easy to condense water on the surface during wet cooling in heating and air conditioning engineering. The surfaces are anodized under drying heating and other hot intersections, with beautiful and elegant color, and can effectively prevent surface corrosion.
Aluminum rolled finned tube is made by rolling aluminum tube as a whole, no contact thermal resistance, high strength, heat resistance and mechanical vibration, good thermal expansion performance, and has considerable expansion heat exchange surface, the effect of this finned tube heat exchanger is ahead of the series or wound heat exchanger.
Aluminum finned tube adopts CNC L finned pipe through digital control to keep segment binding force in the best condition, rolling forming of the trapezoidal cross-section with heat flux density distribution size, aluminum finned tube on the basis of material saving, greatly improving the thermal efficiency, is apart from the uniform, good heat transfer, wing than high, base tube can be protected from air erosion. It is mainly used in air coolers, air heaters in petrochemical, electric power, papermaking, tobacco, building heating and other industries, and air heaters in spray drying systems of plant protein powder and starch in food industry.
Efficiency of aluminum finned tubes
Aluminum finned tube is usually finned on the surface of heat exchange tube to increase the outer area (or inner surface area) of the heat exchange tube, so as to improve the heat exchange efficiency. L type, double L type finned tube: working temperature: 230 ℃, aluminum finned tube adopts the most advanced CNC L finned pipe through digital control to keep segment binding force in the best condition, rolling forming of the trapezoidal cross-section with heat flux density distribution size, on the basis of material saving, greatly improving the thermal efficiency, put an end to the string type finned tube for segment gap cannot eliminate the contact thermal resistance.
Aluminium finned tubes are formed by aluminium alloy plates and aluminium tubes in a single row to form flaky fin tubes, which are separated by 100mm intervals by screw rods to form rows of different lengths and widths. The space of 100mm forms several longitudinal parallel channels. When the refrigeration system is working, the cool air sinks and the hot air rises, and the cold air in the channel forms a flue effect, which accelerates the convection, accelerates the cooling speed, and shortens the running time of the compressor.
Compared with traditional steel tube direct-cold evaporator, aluminum alloy fin tube has much higher thermal conductivity than steel tube. The evaporation temperature of refrigerant in the tube and the temperature in the warehouse decrease, which increases the energy efficiency ratio in the compressor. If it is applied in the construction of cold storage, the load on the roof of the storage can be greatly reduced, the construction cost can be saved, a large number of supporting pipe fittings and steel needed in the hoisting of steel row can be reduced, the cost of hoisting materials and labor cost can be reduced, and the installation efficiency can be improved.
The steel and aluminum composite finned tube is formed by cold rolling of the pressure-resistant base tube and aluminum tube on the special machine tool, which overcomes the defect that aluminum and other metals cannot be welded. Also known as heat exchange tube, heat transfer tube, rolled sheet tube. It makes use of the pressure resistance of the base tube and the high efficiency of aluminum heat transfer, plasticity, highlighting the characteristics of the two materials in the process.
Because the specific gravity of aluminum is the smallest of the commonly used nonferrous and ferrous metals, the finned material of light metals determines the lightweight nature of the heat exchanger manufactured with it.
Steel-aluminum composite finned tube has the advantages that other types of finned tube can not compare.
Steel – aluminum composite finned tube
Steel – aluminum composite finned tube has high heat transfer performance. The thermal conductivity of aluminum is about 211.9W/m.K, which is lower in cost and higher in cost performance compared with silver and copper. Objects with good thermal conductivity tend to absorb heat quickly and dissipate heat quickly.
The steel – aluminum composite finned tube also has low air resistance. The finned surface of steel – aluminum composite finned tube is smooth without fold. Air can be easily penetrated between the fins; Low contact thermal resistance; With a large heat dissipation area, the finning ratio of steel-aluminum composite finned tube can reach up to 22.7, and the unit heat dissipation area is much larger than that of conventional wound heat dissipation tube. Long service life, steel and aluminum composite finned tube in the process of processing, the base tube and aluminum finned into a compact composite.
A 0.5mm thick coating layer is formed on the surface of the base pipe to protect the base pipe from contact with the ambient air, which can improve its service life. ; Steel-aluminum composite finned tube is also not easy to dust, not easy to scale. Easy to clean and remove surface water, has a good resistance to temperature changes, can maintain good heat transfer performance for a long time.
Cleaning and maintenance of aluminum finned tube
In order to extend the service life of aluminum finned tubes, it is necessary to regularly check whether all aluminum finned tubes are intact, whether there are deposits, coking, rust layer and other scale adhesion, and immediately clean them. At the same time must also check whether the finned tube and rubber gasket adhesion is precise, whether the rubber gasket itself is ready, in order to avoid rubber gasket degumentation and damage caused by leakage.
As a heat exchange element, finned tube works under the condition of high temperature flue gas for a long time. Finned tube is divided into integral finned tube, welded finned tube, high-frequency finned tube and mechanically connected finned tube. Plate heat exchanger pressing nut and up and down guide rod, should be lubricated frequently with lubricating grease.
The adjustment of each instrument should be operated by a special person, and the operation and maintenance should be carried out in strict accordance with the operating rules; Each time the finned tube is pressed again, the scale position of the last pressing should be recorded. Do not make the rubber gasket press too much, which will reduce the service life of the rubber ring.
When replacing the finned tube rubber gasket, the whole section should be updated to avoid uneven clearance of each piece, affecting the heat transfer result. In short, gas furnace special finned tube in use to pay attention to maintenance and maintenance, will reduce the occurrence of early failure, extend the service life, improve the effectiveness of the operation, bring more benefits.
Aluminum finned tube has been widely used in the major fan heating equipment, it is mainly on the steel pipe to pre-process a certain width and depth of the spiral groove, and then the steel strip embedded in the steel pipe on the lathe. During the winding process, due to a certain pretension force, the steel strip of high-frequency aluminum fin tube will be tightly squeezed in the spiral groove, thus ensuring a certain contact area between the steel strip and the steel tube.
In order to prevent the steel strip from springback and falling off, the two ends of the steel strip should be welded to the steel tube, and there should be a certain side gap between the steel strip and the spiral groove for easy enchase. If the side gap is too small and interference is formed, the Mosaic process is difficult to proceed smoothly. In addition, the wound steel strip always springs back to a certain extent, so that the steel strip and the bottom of the spiral groove can not be well joined.
The main application of aluminum finned tube is these, I believe that with the continuous improvement of our technology, the performance of aluminum finned tube will continue to increase, its application range will be more extensive. For more information, contact us!