Why bell mouth is given at heat exchanger tube ends?
Bell mouth is given at the end of Heat exchanger tubes.
If sharp edges are given then flow is separated this means it is not uniformly ditributed and turbulence is formed in flow which subsequently result in head loss and turbulence in flow decreases in heat transfer capacity of fluid
Bell mouth helps in increasing area at entry of fluid which means there is pressure drop and low turbulence result in uniform flow in tubes and no fluid separation takes place also results in no loss of head . Uniform flow of fluid results in more heat transfer and less erosion of tube surface takes place.. Although the flow doesnt stay in state of uniform flow it goes in transient region inside the tubes but still have high heat transfer property than flow in turbulence region.
Bell mouth also helps in holding the tube in end plates and it is so formed to increase the area as well as to form a seal on the plate so that there is no mixing also and hold the tubes there. Bell mouth is made by tube expander .
If sharp edges are given then flow is separated this means it is not uniformly ditributed and turbulence is formed in flow which subsequently result in head loss and turbulence in flow decreases in heat transfer capacity of fluid
Bell mouth helps in increasing area at entry of fluid which means there is pressure drop and low turbulence result in uniform flow in tubes and no fluid separation takes place also results in no loss of head . Uniform flow of fluid results in more heat transfer and less erosion of tube surface takes place.. Although the flow doesnt stay in state of uniform flow it goes in transient region inside the tubes but still have high heat transfer property than flow in turbulence region.
Bell mouth also helps in holding the tube in end plates and it is so formed to increase the area as well as to form a seal on the plate so that there is no mixing also and hold the tubes there. Bell mouth is made by tube expander .
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