The invention provides a single-
tower dual-cycle wet 
flue gas desulfurization 
tower and a tube groove type liquid collection device, and belongs to the technical field of 
flue gas desulfurization. The desulfurization 
tower comprises a tower body, the bottom of the tower body is provided with a 
flue gas inlet, the top of the tower body is provided with a 
flue gas outlet, an upper spray layer and a lower spray layer are arranged on the portion, between the 
flue gas inlet and the 
flue gas outlet, inside the tower body, and the tube groove type liquid collection device is installed between the upper spray layer and the lower spray layer and separates 
slurry of the upper spray layer from 
slurry of the lower spray layer; the tube groove type liquid collection device comprises multiple liquid collection tube grooves which are formed for multiple 
layers in the longitudinal direction, the two adjacent 
layers of the liquid collection tube grooves are arranged in a staggered mode, the liquid collection tube grooves are arranged in an inclined mode, and the lower ends of the liquid collection tube grooves are communicated with a diversion groove. According to the single-tower dual-cycle wet 
flue gas desulfurization tower and the tube groove type liquid collection device, the flow field is uniformly distributed, the resistance loss of the structural design is small, and the contact effect between the gas and liquid is good. Therefore, the 
slurry of the upper spray layer can be collected, the 
system resistance can be reduced, and the desulphurization efficiency is improved.