Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas (LNG) realm.Due to efficient performance,shell-side flow in this type of vaporizers has received considerable attention and has been investigated extensively.However,the detailed flow structure in the shell needs to be determined for reliable and effective design.Therefore,the objective of this study was to clarify the flow structure in shell by particle image velocimetry (PIV).Experiments were conducted using two types of model;15% baffle cut having inlet and outlet positions in the direction of 90° to the cut and 30% baffle cut having inlet and outlet positions in the direction of 180° to the cut.Each test section is 169 mm in inner diameter and 344.6 mm in length.The flow features were characterized in different baffle cuts with regards to the velocity vector field and velocity distribution.The results show that the flow characteristics of 15% baffle cut type vaporizer are comparable to those of 30% baffle cut type vaporizer. Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas (LNG) realm. Due to efficient performance, shell-side flow in this type of vaporizers has been exhibited attached attention and has been investigated extensively.However , the detailed flow structure in the shell needs to be determined for reliable and effective design.Therefore, the objective of this study was to clarify the flow structure in shell by particle image velocimetry (PIV). Experiments were conducted using two types of model; 15% baffle cut with inlet and outlet positions in the direction of 90 ° to the cut and 30% baffle cut with inlet and outlet positions in the direction of 180 ° to the cut. Each test section is 169 mm in inner diameter and 344.6 mm in length. flow features were characterized in different baffle cuts with regards to the velocity vector field and velocity distribution. The results show that the flow characteristics of 15% baffle cut type vaporizer a re comparable to those of 30% baffle cut type vaporizer.