Causes of pulp running in vibrating screen

There will be various problems during the use of the vibrating screen. Among them, through continuous analysis and summary, the occurrence of slurry running is mainly related to the high solid content in the drilling fluid, high mud viscosity, and the dispersion of cuttings. It is related to the factors of the material; it is related to the own conditions of the vibrating screen with small vibration force, high mesh number and small screen area; it is also related to the direction and position of the liquid inlet of the vibrating screen during on-site installation. A few points can do some analysis.
1. The selected screen mesh is unreasonable. The processing capacity of each vibrating screen is 50L/s. This is because the processing capacity test conditions are based on the national standard: select a 60-mesh screen, and conduct the test in aggravated mud with a specific gravity of 1.8. The mud viscosity is that the mud contains different particle sizes. river sand. Due to the rapid drilling of the surface layer, a large amount of solid phase is produced to occupy the effective screen area, so the vibrating screen cannot use fine screens in shallow well sections. Therefore, larger screens should be used at the beginning of drilling, and finer screens should be gradually used as the drilling depth increases.
2. The formation and mud conditions affect the processing capacity. In another case, when drilling into a loose sandstone layer or a quicksand layer, the sand particles are easily stuck in the screen holes, resulting in screen plugging. Therefore, it is necessary to test several screens with different meshes to reduce the screen plugging phenomenon.
3. Check whether the rotation direction of the motor is correct. First remove the vibrator shield and check whether the eccentric weights of the two motors are rotating outward. Secondly, if the steering is wrong, please exchange any two phase wires in the incoming power supply of the electric control box. Wrong way 1 (two motors rotate inward), although it can also discharge drilling cuttings outward, but the speed is slow; wrong way 2 (two motors rotate in the same direction), the vibration force is very small, basically no sand is discharged and mud is not processed .
4. Check the vibration amplitude of the vibrating screen. The larger the vibration amplitude, the greater the processing capacity; the vibration force is adjusted to 90% when leaving the factory. In case of pulp running, you can align the angles of the inner and outer eccentric blocks, and the vibration force will be 100%. (At this time, the processing capacity of mud only increases by about 15%)
5. Check whether the liquid flow distribution on the screen frame is reasonable. For the vibrating screen with hook edge screen structure, the screen surface on both sides is lower than the middle, and the mud is easy to flow to the two sides and get lost. It should be ensured that the mud enters the screen frame from the middle. At this point, two options can be adopted. One is to adjust the front spring seat to properly raise the angle of the front of the screen box; the other is to adjust the position of the flip plate of the extension tank to control the distribution of liquid flow.