Monthly Archives: August 2016

Hydraulic coupling is an important part of decanter centrifuge

The fluid coupling has been widely used in the transmission system of the centrifuge in order to control the centrifuge overload effectively and make it start and operate smoothly, or meet the requirements of speed adjustment.

Hydraulic coupling is a kind of hydraulic transmission device, which uses the liquid dynamic pressure to transmit power and torque. The fluid coupling is made up of working wheel, shell, output shaft, bearing, sealing ring and other components.

p centrifuge

There are working fluid (mineral oil) filled in the shell. And the working wheel connected with the motor shaft will change the mechanical energy that input into kinetic energy of liquid, it is equivalent to the working wheel of centrifugal pump, and commonly known as the pump wheel.

Working wheel is equivalent to the working wheel of water turbine, commonly known as turbine. It restores the kinetic energy of the working fluid to mechanical energy, and drives the load through the output shaft. The shell is connected to the pump wheel to form a container for receiving the working fluid. The speed of the turbine is lower than the pump wheel, the relative slip rate is 3%-4% and the efficiency is 96%-98%.

Application of slurry recovery system in non excavation

With the rapid development of China’s economy, continue to push forward the process of urbanization, problems faced in the construction of urban construction is becoming more and more significant, narrow site, dense buildings, underground complex pipeline, construction difficult ground excavation obstacles. With the application of non excavation construction technology in Municipal Engineering in recent years, the above problems can be improved obviously.


Drilling mud is is an indispensable important material in non excavation construction, plays a role like “blood” in horizontal directional drilling construction, in the construction process, mud has the functions of hole cleaning, stable formation, suspended drilling cuttings, cooling and lubricating . Mud quality directly affect the construction quality, the non excavation trombone construction is often used by the quality of bentonite slurry and a small amount of polymer mixing formulated to enhance the performance of the polymer mortar.

Mud recovery system is a necessary facility for drilling mud in the process of non excavation construction. It is mainly by the use of drilling fluid vibrating screen, desander, desilter or mud cleaner or other mud solid control equipment to achieve purification, recovery and utilization of waste mud drilling, the system can recycle the waste mud, save cost for the users, and improve the economic benefits of the customers, protect the rig, but also can protect the environment from pollution.

Common underflow problems of drilling fluid cleaning Cyclone

When cyclone works, high-speed swirling movement generates the air column and low-pressure area, creating suction towards underflow outlet. Inject some water into cyclone by certain pressure and adjust the outlet till it allows no fluid flow, meaning it reaches the balance point. This cyclone is called balanced cyclone, often found in mud cleaners where solid-content fluids enters and solids leave through underflow outlet.


However, some problems may arise adjusting the underflow outlet:

1. “Dry Underflow”: Relatively smaller outlet can pile a layer of dry silt between it and the balanced point. When ultra-fine solids enter, its water goes through the layer and dewatered solids block the outlet, causing dry plug. And this is called “dry underflow” adjustment.

2. “Wet Underflow”: Relatively larger underflow outlet can discharge conical rotating liquid. And this is called “wet underflow”.

3. “Radial” Discharge: Commonly, two flows move mutually reversely at the apex, one is the air inhaled and another the solid-content slurry discharging radially, forming an annular curtain there. Inhaled air keeps the outlet open and the cyclone efficient.

4. “Rope-like Discharge”: When the solid content excessively exceeds the designed capacity, the cyclone is over-loaded and solids flow out outlet in a rope-like shape, making no air or annular curtain but a nozzle possible. Then, some solid phase within limits will turn around and out from vortex finder.

A shippment of DCZS630 linear motion shale shakers sent to Iran

This time we delivered three sets of DCZS630-3K linear motion shale shaker to Iran, the treating capacity of DCZS630-3K is about 500GPM, which can meet the client’s requirements for drilling fluid clening.

Linear motion shale shaker is the primary processing equipment of solid control system, it is used for separating the large drilling cuttings from drilling fluid, and it plays an important role in protecting drilling fluid performance. Our shale shaker has following advantages:


  1. Adopt Italy OLI brand motors which have the advantages of high strength vibration, large screening area, adjustable screen box angle, little noise and high efficiency.
  2. Heat treatment of the complete shaker deck.Surface painting with heavy anticorrosion to extend the service life of shale shaker.
  3. Use the full adhesive hookstrip rigidity screen or steel frame screen, the fixed tensioning plate can make to replace screen more convenient and easier and also can replaced into many kinds of screens.
  4. Reasonable designing the cofferdam height of shale shaker logging tank can make mud buffer is uniformity flow, reduce direct impact on screen and effective extend the screen service life.


What is the development direction of drilling mud centrifuge?

The development trend of the centrifuge is high speed, large capacity, reliability and operation automation. High speed refers to the roller speed of the centrifuge to reach 2500r/min above, the separation factor is as high as 1200-3000, in order to remove more subtle particles, the separation point can be as low as 2-5 microns. Large capacity is to continue to increase the capacity of the existing centrifuge, when the capacity is greater than or equal to 40-50 cubic meters, in order to quickly remove the harmful solids phase in drilling fluid. In addition, whether domestic or imported centrifuge, there are the problems that how to make the key parts of the centrifuge more wear and corrosion resistance.


At present, some foreign countries have strengthened the study of the centrifuge processing capacity and the speed of the centrifuge, increasing the separation factor of the centrifuge. The material of the centrifuge is made of stainless steel which can  increase the corrosion resistance. In order to increase the processing capacity of the centrifuge and improve the separation effect, they have done a lot of modification and innovation in many details.

Dachuan Machinery Co., Ltd according to characteristics of petroleum drilling fluid and after a large number of field test, design out the drilling fluid centrifuge which is special in solid-liquid separation, it can effectively reduce the drilling mud solids content, and control density and viscosity of drilling fluid to ensure drilling fluid performance and have an important role in fast drilling.

Motor heat dissipation problem of drilling fluid shale shaker

Drilling fluid shale shaker is one of the most important equipment for drilling fluid cleaning during oil drilling, it is the first stage machine for drilling fluid solid control.

There is a fan at the end of ordinary vibrating screen motor, it can make the wind direction flow along the vertical bar on the shell, by this not only heat dissipation is faster, but also can remove the dust, so that the motor can work in a good condition. But for the motor of shale shaker, due to no fan to dissipate heat, it all depends on natural cooling, coupled with the working environment is always very bad and a large amount of dust which is easy to accumulate on the motor surface, causing the internal temperature is too high and motor burning.


Heat prevention measures for vibrating motor of shale shaker:

  1. It often needs to remove the dust on surface to make it work under good conditions;
  2. In the design process, the surface of the vibration motor should be as smooth as possible, so that the dust is not easy to accumulate. If working in a dust environment, consideration should be given to minus the radiating ribs on the shell surface, because at this time, the radiating ribs will make it easy to make dust accumulation instead playing the role of heat dissipation which will block heat dissipation of shale shaker motor.