For the fresh concrete concentrating machine with an average temperature above 25 °C and the requirement to produce below 10 °C, there is no single, single-stage cooling method that can meet the requirements of large-scale concrete production. It must be adapted according to different cooling ranges according to local conditions. The combination of cooling measures, generally preferred ice cold (of course, including cold water mixing); when the ice cold can not meet the requirements, then increase the mixing building air cooling; when the ice cold, mixing building air cooling can not meet the requirements, then use two-stage relay cooling. In addition to cold and liquid nitrogen cooling can be "cool and ready to use", water cooling and air cooling need to start the cooling equipment after the aggregate into the mixer 1 ~ 2h cooling, if the aggregate can not be immediately mixed into concrete, it must be insulated For storage, the best way to keep warm is to keep it cool. Therefore, as long as the coarse aggregate is pre-cooled, the air-cooling measures should be taken to stir the building, so that it can cool down and keep warm. Due to the space limitation of the silo section, height, capacity and high-altitude configuration of the mixing plant, the cooling is not sufficient or the first-level ground cooling is required for economic and energy reduction.
The so-called water cooling or air cooling outside the building, which is mostly located on the ground, is the first stage in two-stage cooling. The concrete distributing machine adopts the air cooling of the mixing building. Whether it needs to be cooled on the ground, not only depends on the cooling range, but also the production capacity of the cold concrete. If the production capacity of the cold concrete is not high, it is not necessary to use two-stage cooling when appropriate measures are taken in the cooling silo and there is sufficient time or air volume to lower the temperature of the aggregate; otherwise, even if the temperature is not high, the production is not The scale is huge, limited by the capacity of equipment and aggregate storage, unable to provide enough cold or cooling time, often requires two levels of cooling. In this case, it is economical to use the main cooling load because the ground cooling is relatively small due to the relatively small plane and space constraints, while the upstairs air cooling is only used for thermal insulation and auxiliary cooling. 10% of the total cooling load, because the cold air temperature of the agitated building is lower, the cooling coefficient is lower, and the ground level is cooled, working in the higher temperature zone, and the refrigeration coefficient is higher. The combined scheme of pre-cooling of concrete distributors needs to be optimally configured according to the production scale and cooling rate of cold concrete.