November 09 2017

Tunnel boring machine is an important machine in the city construction project like subway and pipe laying. In order to bring out the cutting and lubricate the drill bit of the tunneling machine, the operators need to add large quantity water or drilling fluids into the drilling well. For cost saving, the operators also have to think about reusing of the drilling fluids.
Mud recycling equipment is mainly used to recycle the drilling fluids and remove the cuttings. Shale shaker, de-sander and de-silter could respectively separate the coarse solids, sand and silt. For fine solids, the decanter centrifuge would be needed.

After several time recycling, the specific gravity of the drilling fluids would be higher and higher due to the built up of ultrafine solids that even cannot be removed out by using only the centrifuge unit. Operators need to add chemicals into the drilling fluids and then do the dewatering process.
Dewatering centrifugepackage includes 2 parts: chemical dosing system and big bowl decanter centrifuge unit. The units ready for shipping to Singapore is designed containerized with both the centrifuge and dosing unit are put into the 20 feed container for easy transportation and jobsite safety purpose.

GN’sdosing system is consisting of powder feeding hopper, powder transferring screw, mixing tank and discharge pump. The screw is PLC for accurate metering of the powder. Mixing tank is divided into 3 departments for flocculation powder mixing, curing and storing. The mixing procedure is also PLC for automatic convenience. Before the drilling fluids fed into the decanter centrifuge, the flocculation agent is firstly mixed into the fluids to gather the ultrafine solids. Thus the decanter centrifuge would remove the floccule from the drilling fluids.

Removing the ultrafine solids from the drilling fluids greatly reduces the consumption of water and increase the drilling efficiency. The dewatering centrifuge package can also be used inoil sludge treatment project for oil recovery.