Bituminous mixing plant

The invention discloses a bituminous mixing plant which comprises a main building and a negative pressure dust removal device, wherein the main building comprises a vibration sieve, a hot aggregate bin, an aggregate balance, a mixer and a finished product bin which are arranged in sequence from top to bottom; the negative pressure dust removal device communicates with the main building; the main building further comprises a material overflow pipe and a closed material overflow bin; and one end of the material overflow pipe communicates with the hot aggregate bin, and the other end of the material overflow pipe communicates with the material overflow bin. By the additional arrangement of the closed material overflow bin, the material overflow pipe is not arranged outside and connected with the atmosphere in a traditional way, but is connected with the closed material overflow bin, so that not only can the material overflow pipe be used as a material overflow channel, but also the material overflow pipe can form a closed space with the closed material overflow bin, and the closed space becomes a negative pressure channel in a replacing manner; negative pressure generated by the negative pressure dust removal device is retained in the whole main building, and communication between the negative pressure and the atmosphere via the hot aggregate bin and the material overflow pipe is avoided, so that the negative pressure loss and the operation waste of equipment are reduced to an extremely large extent; and moreover, constant negative pressure in the plant is guaranteed favorably, the influence of negative pressure fluctuation on metering is reduced, and the metering accuracy is improved.