The present disclosure relates to a fabric filter system, which may be used for removing particulate matter from a gas, such as a combustion process gas. The filter system includes a fabric filter (3) which is placed in a filter compartment. From the filter, gas flows via a filter plenary space (5) to an outlet duct (7), where the gas exits. A flow control device controls the amount of air exiting through the outlet duct. The flow control device comprises a louver-type damper (17). This provides reliable and efficient control of the gas flow. A collar (21), connecting the plenary space (5) with the outlet duct (7), improves the gas flow into the duct.