What are the advantages of titanium tube in seawater desalination equipment?
Titanium tubes in seawater desalination equipment will gradually replace the original copper alloy tubes. Compared with the two, titanium tubes have the following advantages
1. Under the same operating conditions, the titanium pipe has thinner wall thickness and less pipe consumption. Generally, the equal wall thickness of copper alloy pipe is 0. 9mm-1。 2mm; Use titanium tube instead. In places with low corrosivity, the wall thickness can be 0. 5 mm thin wall tube.
2. Titanium tube has good thermal conductivity. The thermal conductivity of titanium is 17W/(m · k), that of aluminum brass is lOOW/(m · k), and that of 70/30 white copper is 29W/(m · k). The thermal conductivity of titanium is small. However, with thin-walled titanium tubes, although the thermal conductivity is worse than that of aluminum brass, it is equivalent to that of 90/10 white copper and better than that of 70/30 white copper.
3. The use of titanium tube is more cost-effective. The price of titanium tube can compete with that of copper alloy tube. Because of the low density of titanium and the same wall thickness, the mass of titanium tube with the same length is only 50% of that of copper alloy tube. When the wall thickness of titanium tube is 50% of that of copper alloy tube, the mass of titanium tube with the same heat transfer area is only 1/4 of that of copper alloy tube. It can be seen that titanium tubes are competitive in terms of price.
4. The service life of titanium tube is longer. As sea water is often mixed with sediment and sea creatures, they attach to the heat transfer tubes and tube ends, which will erode copper alloy tubes, and copper alloys will also be corroded by Br - in sea water. However, the hydrogen introduced from the external environment during use is called external hydrogen, specifically, it generates active hydrogen atoms on the metal surface through the following ways, and then enters the metal:
(1) The medium where titanium equipment is located contains molecular hydrogen, such as high-temperature hydrogen atmosphere.
(2) Hydrogen generated by overall or local corrosion of titanium is absorbed by titanium. For example, crevice corrosion is often accompanied by hydrogen absorption.
(3) Hydrogen generated during galvanic corrosion or cathodic protection of titanium and negative metal.
The latter two kinds of hydrogen embrittlement caused by electrochemical corrosion cathode are more frequent and can occur without high temperature and pressure, which should be paid more attention.
