Tunnel Boring Machine Slurry System of Kosun on Soft Ground

Tunnel Boring Machine Slurry  System

Tunnel Boring Machine Slurry  System of Kosun with more than 20 years experience.
Three main types of tunnel boring machine separators are used in soft ground excavations-
–    Slurry shield TBMs
–    Earth pressure balance machine
–    Open – face type
In soft grounds with pressure less than 7bar, earth pressure balance machines are used. These along with cutting head also comprises tungsten carbide disc cutters, cutting bits and hard disk cutters.

Machine derives its name from the fact that it balances the pressure in tunnel head by use of excavated earth. Rate of excavation and advances through Archimedes screw controls pressure in the cutterhead. Some additives like bentonite may have to be injected to increase the stability.

Kosun Tunnel Boring Machine Slurry System
Tunnel Boring Machine Slurry System

These are also added to make sure that the earth is sufficiently attached to the Archimedes screw thus marinating the pressure in the head and prevent seepage of water in the tunnel.

Slurry shield TMBs are used in cases where the ground is so granular in nature that it cannot form plug in Archimedes screw. The cutting head is feeded with slurry which in turn applies pressure. This even acts as transporting medium as it mixes with excavated earth and is being pumped out in slurry separation units usually located out of tunnel. In this separation unit slurry is processed so that it is recycled and can be used again. This filtration is a multi- staged process. However, filtration of slurry depends on the size of excavated particles.

Thus making this slurry shield tunnel boring machine separation units suit able for clays and silts sized particles as they are smaller than bentonite particle, which makes the slurry. In these instances separation with water can be done which will help form clay cake thus filtering the slurry in the end.

In grounds where the excavated tunnels can stand without support for a little period, open face TMBs can be used. These tunnel boring machine separators are generally used where strength is more than 10Mpa and seepage of water is low. Cross sections of sizes up to 10 meters can excavated with these TMBs.

Cutter head excavates within 150mm of the shield edge. This shield is moved forwards and cut the ground in same circular manner. Pre-casted concretes or graphite iron segments provide ground support. The key spreads the rings until it is tightly fitted against the tunnel made by tunnel boring machine separators shields. Open face TMBs comes in many variations.

Slurry Separation Units in Slurry Treatment by Kosun

Slurry Separation Units

Slurry Separation Units in Slurry Treatment were mainly refer to mechanical system used during oilfield drilling work, just like TBM separation units – the slurry separation units(or Slurry Separation stations, Slurry Separation plants)are often been called mud separation units(or Mud Separation stations/mud Separation plants). The main component of the system are consisting by shale shaker(or vertical dryer), centrifuge and mud cleaner in general. And these units are just helping the engineers in real projection solving the problem about mud clean and recycle of the slurry.

Here you can find sample picture of Slurry Separation Units like the following:

Slurry Separation Units
Slurry Separation Units by Kosun

Although the main application area is in oilfield drilling, in the following industry or circumstances, the slurry separation units also take tribute in the work: Infrastructure construction, environmental protection industry.

For example, in trenchless HDD projection, trenching mechanics need special mud in working for many functions like lubrication and keep tunnel wall “strong” enough for preventing collapse. Or in pile foundation engineering work, these mud or slurry are very important in different functions, and all these mud need reuse or make it can be recycling again, then the slurry separation units by Kosun give the good solution. All the units are manufactured by Kosun’s own factory and serving clients well by 24 years experience.

To separate the solid material from the slurry water, the slurry separation unit be deployed to the projection site. The unit uses a series of sieve screens and hyrdocyclones and will remove solids from the slurry water down to about 60 microns particle size, and this parameters are different from project to project and only the customized slurry treatment system by specialists can meet the real needs in construction site.

If you are interested or looking for the required slurry/mud separation units, just contact Kosun for the detailed solutions.