Awareness: "Concrete Jet Machine"

Shotcrete machine (concrete sprayer): A machine that uses compressed air to continuously transport concrete along a pipeline and spray it onto a construction surface. There are two types of sub-dry sprayer and wet sprayer. The former is pneumatically conveyed dry mix material and mixed with pressurized water at the nozzle. The latter is sprayed by a pneumatic or concrete pump conveying concrete mixture through nozzles. It is widely used for lining construction of underground works, wells, tunnels, culverts, etc.

Dry jet machine

1. Double tank concrete dry jet

It consists of upper tank storage chamber, lower tank feeder, feeding impeller, bell-shaped door, compressed air pipeline, and motor. Close the lower bell door between the upper and lower tanks, and pass the compressed air into the lower tank. The dry mix is ​​continuously and uniformly delivered to the discharge port by the feed impeller and is blown by the compressed air along the feed pipe to the nozzle.

2. Screw concrete spraying machine

The dry mix discharged from the hopper by the screw feeder is evenly pushed to the blowing chamber, and the tank is filled with agitated concrete. The compressed air introduced by the hollow shaft of the screw feeder and the blowing pipe then blows the dry mix along the conveying pipe to the nozzle.

3. Rotor concrete jet machine

There are many holes in the vertical rotor. During the rotation of the rotor, when the feed hole is aligned with the discharge port of the upper hopper, the feed hole is fed; when the feed hole is aligned with the upper blow port, the compressed air blows the dry mix along the transport pipe to the nozzle.

4. Drum type concrete spraying machine

Eight V-grooves are uniformly distributed around the circumference of the circular drum. The drum rotates at a low speed and the dry mix in the hopper passes through the sifter and falls into the V-shaped groove. When the V-shaped groove filled with the mixture goes to the bottom, the mixture enters the blowing chamber and the compressed air is along the conveying pipe. Blow to the nozzle.

Wet concrete jet machine

Various materials (including water) are fully stirred according to the design ratio requirements, and the wet mixed materials are added to the wet concrete sprayer, and then the concrete is sprayed onto the sprayed surface by the sprayer.

The wet injection can be used for dense flow delivery and lean flow delivery, depending on how the concrete is transported on the jet.

Dense flow delivery

The dense flow transport is to pump the mixed wet concrete to the spray head through a pump. The compressed air and accelerator are added to the spray head, and the concrete is sprayed onto the sprayed surface at a high speed. This type of engineering method is recommended for Ruishen RPB7 concrete wet spraying machine.

RPB7 concrete wet sprayer

Thin flow delivery

The thin flow conveying is to add the mixed wet concrete to the hopper of the concrete spraying machine. The spraying machine distributes the material evenly to the feeding port, and then the compressed air wrapping material is transported to the spraying head through the feeding pipe at the nozzle. The accelerator was added to the mouth and the concrete was sprayed onto the sprayed surface at high speed. This method is recommended to use Ruishen PZS3000 wet concrete sprayer.

PZS3000 wet concrete sprayer

Advantages of dense flow delivery (compared to lean flow):

Transmission distance is long (maximum distance 100m, maximum delivery height 40m; thin stream transmission distance ≤ 20m)

Gas consumption is small (air consumption 3-4m3/min).

Jet rebound is small (≤8%)

Disadvantages of dense flow delivery (compared to lean flow):

Large equipment investment

Concrete needs to add pumping agent, etc.

Need to consider equipment cleaning.