Thirsty Dog Brewing Co. is adding an Italian-built bottling line to its Akron plant.Two truckloads of new equipment arrived Thursday at the Akron brewery, and more are on the way.Co-owner John Najeway estimated that the new line and other equipment upgrades represent about a $2 million investment by the company.The 86-foot bottling line, made by Krones Kosme in Verona, will be able to fill 2,400 bottles an hour, compared with the brewery’s current line that can produce 300 bottles an hour.“It’s a huge step in efficiency in the manufacturing process and, no pun intended, that’s our bottleneck right now,” Najeway said.The brewery, which produces such brands as Wulver, 12 Dogs of Christmas and Citra Dog, said the new line also will boost quality because of improved technology that will remove more oxygen from the bottle.