21st Century Building Blocks Technology

Production Parameters

Production Parameters

  • Basic mix ratio
    • Fly ash or Sand: Lime: Cement: Gypsum=69: 20: 8: 3
    • Aluminum is about 0.08% of total of dry material
    • Water ratio: 0.6~0.65
    • Note: special reference should be adjust according with actual situation of raw material
  • Cycle of mixing and pouring: The cycle of mixing and pouring is 5.0minutes
  • The complete rest of blocks
    • Time: 2-3 h
    • Temperature: about 40 C
    • Pressure :0.3~0.5 Mpa
  • Cycle of cutting: 5.0 minutes
  • Autoclave system
    • Evacuation: 0~-0.06 Mpa 0.5h
    • Boost pressure: -0.06~1.3 Mpa 1.25h
    • Isopiestic pressure: 1.3 Mpa (temperature is about 183) 7.0h
    • Depressurization: 1.3 Mpa~0 1.25h
    • Total: 10h
    • Coal consumption: 24kg/ m3

AAC manufacturing plants are simple in operation

  • Preparation of the raw material
    • Fly ash(sand), gypsum: The slurry is the admixture of fly ash (sand) and gypsum. Mixed fly ash (sand) and gypsum in a certain proportion in the slurry mixer tank, and then add water into the slurry; finally, we can get the appropriate concentration slurry, and then it will be pumped by a slurry pump into slurry tanks for pouring.
    • Quicklime: Massive Powdered quicklime is transported and stacked in the lime Silo.
    • Cement: Use of bulk cement. Bulk cement is transported to the plant site by Bulker  and then pumped directly into cement silos for Use.
    • Aluminum Powder: Aluminum powder or aluminum powder (paste) in barrels purchased from the market are stored in aluminum powder warehouses. The worker will weigh it, and then put it into an aluminum mixer, then make a 5% suspension for use.
    • Return slurry: Trims and scraps from cutting will fall into the chute under the cutting machine. The water washes the scrap into the waste slurry tank. After mixing to a certain concentration, the waste slurry pump will pump it into the waste slurry tank.
  • Batching, Mixing, Pouring and Pre-curing
    • Lime and cement are Sent into electronic powder scales by screw conveyors. Through cumulative measurement, the unloading devices will send them into the pouring mixer Automatically.
    • The fly ash (sand) Slurry from slurry tank, is  then pumped into measurement by Automatic electronic scale hopper, by  automatic control system.The measured slurry is then sent  into pouring mixer
    • Aluminum is measured manually, and then put into an aluminum mixer for making a water mixed suspension which is poured  into the pouring mixer directly.
    • The temperature of slurry should be reached to the process requirement as per local weather before pouring and If the temperature is not enough, it could be reached by adding steam.
    • Ferry cart carries  the mould to the position under the pouring mixer, and then the pouring mixer puts slurry into the mould for pouring. After pouring, the mould with slurry will stay in the pre-curing room for 2-3 hours. During this period, the aluminum powder will react, and the hydrogen will be released under the action of Si and Ca material. The slurry will become the Green solid cake, as  volume expands.
  • Cutting and Grouping
    • After pre-curing when the cake reaches the cutting density  (tested by special instrument or determined by production experience), the cake is transported to the cutting position through Demoulding crane. Green cake will stand on the side plate. Finally, the Horizontal & Side cutters and Vertical cutter will cut the cake.
    • After the cake is cut, the crane Carries it to the hardening carriage and group them in front of the autoclave.
  • Curing and Leaving autoclave
    • The low speed Ferry cart will load grouped cake inside the autoclave for curing. The cake will be in an isopiestic pressure environment for approximately 10 hours, and the steam pressure of 1.3Mpa. The temperature of the autoclave is about 190–210c.
    • Cured cake is pulled out of the autoclave by Ferry cart, and Final product is segregated and transported on pallets by Forklift to the storage yard.
    • The Bottom plate is returned after cleaning and re oiling with demoulding oil for reassembling with moulds for recycling.
  • Reclamation system of waste slurry
    • After cutting, the wet waste falls into the carriage  under the cutting machine. The water washes it into a waste slurry mixer. It is Then mixed until it reaches the required density concentration, and then pumped into the Return slurry tank for storage and subsequent uses.

Autoclave is large pressurized steam equipment, which can be used for  Curing Sand-Lime brick, Fly Ash brick, slag brick, the aerated concrete block, cement pole, and other cement products. Our company can manufacture all kinds of autoclaves according to requirements of users to meet the demands of application.

Autoclaves of our company have been developed with the best features of similar products in India and abroad. The design of main pressure equipment  has been done according to finite element analysis and all kinds of stress tests to improve strength calculation.

Autoclave structure is special steel horizontal cylinder design, and the whole autoclave body is made with Q345R steel plate. Autoclave body flange, autoclave cover flange both are manufactured with 16MnII forge pieces.

Welding of pressure parts is inspected with X-ray non-destructive testing and heat treatment is done according to GB150-2011(Pressure Vessel) industrial standard.

Sealing of the autoclave door is done with a rubber seal ring which is produced by professional manufacturers.

It features easy installation, good sealing and long service life. According to different parts of autoclave body bearing, we set up hold-down support, movable bearing support and customization according to geographical requirements. It adapts expansion and contraction of the autoclave body well and ensures steam distribution pipes and rails. Besides this, we also specially install sealing gas mask, hydrophobic covers.

Products are available with manual control and computer control. Autoclave door adopts active-opening structure, and opens and closes by hand speed reducer or can be electric driven, aerodynamic driven and hydraulic driven. The equipment deploys a perfect safety chain protection device, which avoids any mistaken operation during high pressure limit, it  ensures safe operation of autoclave and safe protection of operating staff. We produce both way of opening the door, side-opening door and up-sliding door depending on users selection. Side-opening adopts rotating arm type opening structure, flexible turning, low operating, and easy opening. Up-sliding door adopts lever-type opening structure, leverage bottom connects with autoclave door. At the top of the door, there is a counterweight device, and this type opens easily, Un This way the Autoclave  side occupies a smaller space.

Autoclave deploy safety valve, pressure gauge, temperature element air release valve, seal ball valve, traps. We have drainage pipe connectors for the user matching their use.