Closed sand conveying belt

A plurality of fixing cylinders are arranged at intervals in the length direction of a conveying belt assembly and erected above the conveying belt assembly, one end of each fixing cylinder in the length direction is provided with a mounting opening, and the outer wall of each fixing cylinder is provided with a suction window extending in the length direction of the corresponding fixing cylinder; the plurality of spraying cylinder assemblies are detachably mounted at the mounting opening, and each spraying cylinder assembly comprises a pipeline part and at least one atomizing nozzle arranged on the pipeline part; the negative pressure pipeline system comprises a plurality of sub-pipelines, and the sub-pipelines are detachably connected with the mounting opening; according to the closed sand conveying belt provided by the utility model, under the condition that the fixed cylinder is connected with the sub-pipeline, negative pressure can be generated at the suction window of the fixed cylinder; when spraying tr