subject: Water Heater, "copper And Aluminum War" Unfinished: True Nor Pure Copper Water Tanks [print this page] Recently, stirred widespread controversy in the market for gas Water heater Tank material from the "aluminum" instead of "copper", will the recent new developments have emerged. From the source was informed, individual water heaters currently on the market used by enterprises, "pure copper water tank," and vigorously engaged in the stores, "pure copper" tank show, in fact most of the use of a "Baptist Lead and Copper", not pure copper. Currently this "Baptist Lead and Copper," the production process has been in Europe and the United States and other developed countries is strictly prohibits the use, in our country also belongs to backward technology, phased out.
It is understood, "lead and copper leaching" tank welding method is to immerse the lead content of copper up to 95% of high-temperature tin alloy solution, to be Cooling Formed after the solidification. Some enterprises to avoid the lead, known as "dip tin copper," in fact essentially the same. An industry that the use of "dip galvanized copper" made of water tanks, tin content of about 15%, there can not be called true copper. And the water heater is used in high temperature Environment , The "lead and copper leaching" of lead metal waste water tank volatile smoke.
This copper nor that of copper
National Gas Appliance Product Quality Supervision and Inspection Center (Foshan) test referred to the Minister ZHANG Ming-wei, currently on the market Sell Gas water heater in the "Copper" water tank, the main use of "oxygen-free copper" and "dip lead and copper," the two technologies. However, only "free copper" closest to pure copper, copper content of up to 99%, without the use of lead solder, but the relatively high cost of manufacturing and technology.
Dip galvanized copper technology started in the early 80s of last century, due to relatively simple production technology, product material cost is relatively low, the production technology still in use. However, lead pollution in recent years has plagued the production technology application and development of the market.
Before Fengxiang in Shaanxi, Hunan and other places Wugang recurrence of child lead poisoning, lead in the production process so that the application of much community attention. Earlier, the EU has special out "WEEE", "ROHS" double green directive stated that the Home Appliances And other consumer Electronic Products, do not use lead products and lead welding. In China, the subsequent introduction of the green also instructions on appliances, particularly closely related to people's daily lives and microwave ovens, water heaters and other products made of lead content in specific requirements and regulations.
However, in recent years, some enterprises in the market to reflect the price competitiveness of products, still water heater products, extensive use of "lead and copper leaching" tank. Meanwhile, in the end the process of marketing and sales is not clear to consumers the "Baptist Lead and Copper" or "oxygen-free copper," but rather fuzzy concept, unity of "copper water tank" to mislead the audience.
In the end what good? Currently, the market for gas water heater, the tank material in addition to oxygen-free copper, lead and copper leaching, there are aluminum. Among them, the oxygen-free copper is mainly used for products with a higher market price, while leaching of lead and copper are used in many low-end products, aluminum alloy is used in just-to-market of new products.
Previously, some businesses in order to promote sales, upset the market competition, have been reported by insiders, and other means of exposing shady operation, publicly questioned the aluminum alloy gas water heater. A Tsinghua University professor of engineering materials mentioned, is from the thermal conductivity, preferably copper, aluminum and better lead the worst, "the Baptist lead and copper," As the copper in the molten lead will be immersed in liquid to form a curing effect , thermal conductivity copper completely covered by the package lead, will simply not a good thermal conductivity of copper.
Took the lead in "Al" material used in the water tank in the million and the Group, its related responsible person admitted in an interview, 10 000 and the use of "aluminum" material purpose is to replace the "dip lead and copper." In addition, the million is mostly oxygen-free copper and water heaters. The forest, A? O? Smith's products are already out of business "lead and copper leaching," the use of oxygen-free copper material.
Several stores in Beijing, visited and found that there are still some companies selling products using water heater "dip lead and copper." Some consumers interviewed in the store when frankly, did not know gas water heater has used the "dip lead and copper," material, business is copper only, and not in detail. A water heater manufacturer in Guangdong, compared with oxygen-free copper, lead and copper leaching costs about 15% cheaper.
ZHANG Ming-wei mentioned in the "dip lead and copper" products, fin-tube fins and pipes, combustion chamber wall and the coil connection is accomplished through leaching of lead, solder, and the gap between the two , while lead and air lower thermal conductivity than aluminum, therefore, greatly affected the heat transfer rate, while the aluminum tank Heat exchanger As the improved brazing process used, fin-tube fins and no gap between the pipes, making heat transfer area significantly increase the thermal efficiency of naturally increased.
Present, the national standard gas water heater products, the requirements on the melting point of 500 degrees. The "Lead and Copper dip" in the highest melting point of lead less than 350 degrees, but the melting point of aluminum alloy is as high as 700 degrees.
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Water Heater, "copper And Aluminum War" Unfinished: True Nor Pure Copper Water Tanks
