dry-type shotcrete machine safety

Working Theory

Shotcrete Machine mainly includes drive device, rotor assy., air conveying system, spraying system

and electric control casing etc.

1 Drive Device

Full sealing, Oil-immersed gear box 11 is mounted on the machine bottom and is transferred

by three pairs gears. Its overall reduction ratio is 72 and efficiency is about 92%. A 3kW motor

provides power supply.

Motor drive 13 is vertically installed on the gearbox, Paralleling with rotor axle.

Motor type: Y100L2-4

Motor power: 3kW Motor speed: 1420r/min

Voltage: 3 phases 380V Cycles: 50Hz

2 Rotor Assy.

This shotcrete machine adopts non-adhesive, through-going rotor with lining plastic chamber in its each hole. With this special rotor, it can improve the capacity to handle wet mixture and reduce clearing and maintenance work.

Rotor Plate 8: There are two rotor plates on the opposite sides of rotor, it is made of high-qualified alloy steel and can handle concrete more than 4000m3 during its working period.

Rubber Sealing Plate 5: There are two plates (upper and lower). Both of the upper and lower plates are made of anti-abrasive special rubber and can handle concrete 300-400m3 during its working period.

Clamping Device 16: By this device, the force is acted through the screws and cylindrical springs, which works as elastic auto-clamping device. Tight clamping by the turnover frame floating can provide a constantly

uniform pressure at the sealing surfaces with a high tightening effect and low dust emission, and can avoid rubber plate over-worn, too.

3 Air Conveying System

There are three ball valves separately to control main air pipe, upper air pipe leading to rotor and lower air pipe leading to Vortex Stream Implement. There is another small air pipe leading to hopper vibrator. A pressure gauge is mounted on the lower air pipe to monitor the operating pressure of conveying hose.

4 Spraying System

It consists of conveying hose and nozzle unit. Conveying hose is made of anti-abrasive rubber, nozzle unit is made of high polymer. Water pipe, water valve and water ring are fixed on the nozzle unit.

Operation Manual

Operators must be trained and be familiar with this manual and the machine structure before operating the machine.

1 Preparation

A. Connect the machine to air supply.

B. Check the oil indicator of Reducer to see lubricating oil enough or not.

C. Check all part being fastened or not.

D. If there is no problem, start the machine and make it working for a short time checking its working condition. (Note: machine running should be the same with the arrow marked on the machine. Do not race the machine for a long time)

E. Check the clamping degree on rubber sealing plate. Tighten the clamping nut until there is no air leakage

from rubber sealing plate. Check the tightness in two ways as follow:

(1) Bend up Conveying Hose and open the air valve with a pressure of about 0.3MPa .If there is no air leakage, it will be OK.

(2) Start the machine with running about 1/2 circle and stop it, if rotor stop instantly and run reversibly a bit, the tightness can be considered ok.

2. Shotcreting Operation

After the above mentioned preparation completed, fill the mixture to vibrating hopper, open the main valve completely and open upper air valve with 1/3 circle, then adjust lower air pressure (to Vortex Stream Implement) to about 0.05-0.1MPa (proportional to conveying distance). In the meantime, open the water valve of Nozzle

Assy.to pre-damp the spraying surface, and then the operator can start the machine to shotcrete.

The working pressure is about 0.2-0.4Mpa. Subject to the conveying distance and water/cement ratio,

adjust the air pressure of Vortex Stream Implement till a spraying speed is suitable(spraying distance is

about 0.6-1m), then adjust upper air pressure till there is no much material goes out from the air overflow

opening.

3. Stop Shotcreting

A. Stop the machine and blow the remaining material out.

B. After the hose being cleared, close the water valve on Nozzle Assy.

C. At last, close the main air valve.

If shotcreting will be stopped for a long time, at first, stop filling material, and then keep the machine working till the material in the hopper and chambers is sprayed out thoroughly. Add a bit of wet aggregate to clean the hopper and chambers.