Experimental Study On Connectiong About Graphite Tube To Fiberglass Tube-Sheet

There are expansion, welding, expansion and welding, sealant connection, high elasticity rubber connection, integrity in tube to tube-sheet connection. For FRP combinatorial heat exchanger, expansion, welding, expansion and welding are hardly used in the tube to tube-sheet connection. Sealant connection has many obvious shortcomings such as high thermal stress and maintenance inconvenience. Integrity connection technology has disadvantage in manufacture . In these reasons, this article experimental study on a new nonmetal active connection in different material .According to heat exchanger factory's manufacturing capacity, two kind of different structure tube plate hole structure, namely penetration threaded hole structure and half penetration threaded hole structure, had been designed.Designed a set of test equipment, and established three kinds of pressure resistance model: packing sealing model, O-ring sealing model and V-ring sealing model. Then, the author took soft packing, rubber O-ring, silica gel O-ring, rubber V-ring and asbestos rope as padding, did press experiment and studied on four factors: pre-tightening stress, thickness of packing, medium's temperature and packing's performance which influenced the sealing capability.The experimental results indicate that: this sealing technology can be used in these two tube-sheet structures, and the sealing effect of stepped tube-sheet hole structure is better than the worm tube-sheet hole structure. V-ring is the most best packing in these packings, it can bear 1.0MPa in 20N·m. Pre-tightening stress is the crucial influencing factor. Increase the pre-tightening stress can enhance the sealing effect. Increase the packing's thickness can greatly improve the sealing effect when the packing thickness is thin. Medium temperature can hardly influence the effect of sealing when the temperature is below 95℃. The material's performance can influence the effect of sealing, the material with high resilience, low elastic modulus and high density has better effect of sealing than the other.