The double tube sheet heat exchanger avoids the insecurity caused by the leakage of the connection between the heat exchange tube and the tube sheet, but the leakage of the heat exchange tube is still unavoidable. FUNKE has developed a heat exchanger with double tube plates and double heat exchange tubes, which can completely avoid the danger caused by the leakage of the shell side and tube side media. At the same time, an alarm device is installed to constantly monitor the product operation. FUNKE puts customer needs first, endows products with life, constantly develops, challenges itself, and pursues perfection. The successful development of double tube and double tubesheet heat exchanger properly explains this concept. It is mainly used in industries where the mixing of tube side medium and shell side medium will cause serious hazards such as explosion, and industries with high requirements for environmental protection, such as chemical industry, metallurgy, food, polysilicon, etc.