AAC Blocks Manufacturing Process
Step 2 – Dosing and Mixing
After raw material preparation, next step of AAC blocks manufacturing process is dosing and mixing. Process of dosing and mixing defines the quality of final products. Maintaining ratio of all ingredients as per the selected recipe is critical to ensure consistent quality of production. This is accomplished by using various control systems to measure and release the required quantity of various raw materials.
A dosing and mixing unit is used to form the correct mix to produce Autoclaved Aerated Concrete (AAC) blocks. Fly ash/sand slurry is pumped into a separate container. Once the desired weight is poured in, pumping is stopped. Similarly lime powder, cement and gypsum are poured into individual containers using screw conveyors. Once required amount of each ingredient is filled into their individual containers control system releases all ingredients into mixing drum. Mixing drum is like a giant bowl with a stirrer rotating inside to ensure proper mixing of ingredients. Steam might also be fed to the unit to maintain temperature in range of 40-42oC. A smaller bowl type structure used for feeding Aluminium powder is also attached as a part of mixing unit. Once the mixture has been churned for set time, it is ready to be poured into molds using dosing unit. Dosing unit releases this mixture as per set quantities into molds for foaming. Dosing and mixing process is carried out continuously because if there is a long gap between charging and discharging of ingredients, residual mixture might start hardening and choke up the entire unit.
For AAC blocks manufacturing, entire dosing and mixing operation is completely automated and requires minimum human intervention. This entire operation is monitored using control systems integrated with computer and CCTV cameras. As with any industrial operation, there is provision for human intervention and emergency actions integrated inside the control system.
AAC Blocks Manufacturing Process (…contd….)