I just purchased a vent for my dryer however it keeps coming off i have a very clamp although not certain whats incorrect. make sure you guide?

Qusetions: i duct taped mine

Answers:Is the vent outlet plugged up with some thing, seems like it truly is. does it go out the wall, when the vent is off is it possible to go out aspect and start looking, some persons stick rags or some thing in them to continue to keep out cold climate, when the vent is off.???