Negative pressure suction device

The utility model discloses a negative pressure suction device, including negative pressure cover, valve and negative pressure pump, the hourglass hopper -shaped of negative pressure cover for invering, its characterized in that at negative pressure cover's open -top and be connected with the pipeline at the opening part, is provided with the valve on the pipeline, still be fixed with the back flow that all is linked together with the pipeline with both ends on the outer wall of the pipeline above the valve, is provided with one way check valve on the back flow, still be provided with the negative pressure pump and the negative pressure pump is located the pipeline between the back flow both ends on the pipeline, the negative pressure cover that sets up can be quick high temperature wastegas releases, prevent the production of leaking, also prevented to lead to because high -temperature gas is detained in negative pressure cover high temperature on every side simultaneously, be provided with the sealing washe