Evaporator for recovering methacrylic acid in methacrylic acid heavy components

The utility model provides an evaporator for recycling methacrylic acid in methacrylic acid heavy components. The evaporator comprises a middle barrel, an upper end cover connected to the upper portion of the middle barrel, a lower barrel connected to the lower portion of the middle barrel and a kettle type barrel connected to the lower portion of the lower barrel. An MAA heavy component feeding hole and an MAA residual liquid circulating inlet are formed in the upper end cover; an MAA gas phase outlet is formed in the upper end of the middle cylinder, the side wall of the middle cylinder is wrapped with three sections of jackets which are not communicated with one another, and a water vapor inlet and a condensate outlet are formed in each section of jacket; a polymerization inhibition airinlet is formed in the side wall of the kettle type barrel, and an MAA residual liquid outlet is formed in the bottom of the kettle type barrel and connected with an MAA residual liquid circulating inlet and an MAA waste tre