ASPHALT BATCH PLANT

The Asphalt Batch Plant is mainly composed of cold aggregate supply system, drum dryer, burner, dust collector, hot aggregate elevator, vibrating screen, hot storage bins, filler supply system, weighing and mixing system, asphalt storage, bitumen supply system etc. The cold feed bins where the aggregates are temporarily stored before processing. Closely associated with collecting (feeder and gathering) conveyors under each bin and the incline or charging conveyor which carries the combined aggregates to the dryer. In dryer where moisture is removed from the aggregates and the aggregates are heated to the proper mixing temperature. The hot, dry aggregates are then carried to the top of the batch plant tower by means of a hot elevator. At the top of the plant, the material is passed through a set of screens which divide the aggregate into several different sizes, typically four. The heated aggregates are then temporarily stored in the plant hot bins, located directly under the screen deck. From these bins, the various sizes are proportioned, by weight, into the weigh hopper. At the same time that the aggregate & cement is being weighed separately in separate hopper, bitumen is pumped from a storage tank to the asphalt weigh bucket on the plant. The correct blend of material is next dropped into the plant mixer, a twin-shaft pugmill. After the aggregate is introduced into the pugmill. the bitumen sprayed into the mixing unit. All materials are blended together by the shearing action of the pugmill blades or paddles. The completed mixture is then discharged from the plant, either into a haul truck or into a conveying device to temporary storage in a surge silo for subsequent delivery to the paving site. Reclaimed or Recycled unused mix material can be introduced into the plant at the following points: (1) at the bottom of the hot elevator (2) into the hot bins (3) more commonly into the weigh hopper. Due to environmental requirements, each batch plant is equipped with an air pollution control device. This equipment can consist of a dry collector, a wet collector, a fabric filter (baghouse), or a combination of devices. In some cases, the fines collected in the pollution control equipment are wasted in other cases the dust is returned to the plant for incorporation into the mixture. Sometimes the dust is reintroduced into the bottom of the hot elevator. More often it is fed into the aggregate weigh hopper as mineral filler. All these components have characteristics that impact not only the overall quality of the asphalt but also the effect on the environment. The Asphalt Batch Plant is almost completely automated. After mix proportions and timers are set and the plant is started, the plant repeats the weighing and mixing cycles until stopped by the operator or until a shortage of material or some unexpected malfunction causes the plant to shut down itself. The plant operation's manual provided by Moon Engineering provides details on the setup and adjustment of the automatic equipment. You must check the accuracy and adjustment of this equipment, particularly the aggregate scales, asphalt scales or meters, batching controls, and recording equipment (if used). This should result in trouble-free production; moreover, you should check the entire plant periodically to ensure the finished product meets specifications.