Device for eliminating floating crust formed during straw fermentation for producing marsh gas

The utility model belongs to the technical field of fermentation for producing marsh gas and relates to an anaerobic fermentation matching device for producing marsh gas energy by using biomass wastes such as crop straw, feces of livestock and poultry and organic household garbage, in particular to a device for eliminating floating crust formed during straw fermentation for producing marsh gas. The device consists of a liquid backflow system and an agitation system. The liquid backflow system comprises a leaking tank (2), a liquid circulating pipe (3) and a negative-pressure port (4), wherein the leaking tank (2) is connected with the liquid circulating pipe (3) and the negative-pressure port (4) is connected with the straight pipe of the liquid circulating pipe (3). The agitation system comprises a motor (5) which is provided with a fixed bracket (6) and agitating blades (9) which are connected with a transmission rod (7), wherein the motor (5) is fixedly arranged on the fixed bracket (6) and is connected wi