The fundamental types A, sludge dewatering belt
1 screen
Sludge dewatering belt medium with large pore, only solid particle size is larger than the pore, they will accumulate in the sludge dewatering belt medium, and the scale is smaller than the pore particle, together with the filtrate through a medium. The sludge dewatering belt mechanism in the bar, plain woven mesh and film plays a primary effect. Because the particles are accumulated in the medium appearance, so the sludge dewatering belt representation is also known as the appearance of the sieve.
If the screening mechanism is now medium deep -- channel narrow solid particle size is smaller than the local, so the sieve filter called deep filtration. For example, felt, non-woven fabric and film media, have deep filtration mechanism.
2 deep sludge dewatering belt
The sludge dewatering belt medium has the pore distribution of three-dimensional, it can capture solid particles smaller than the pore, and even far less than pore (channel) of solid particles, but also in the deep medium arrest set.
Sludge dewatering belt has deep mixing mechanism of messy. The solid particles in the inertial force, hydraulic pressure or Brown movement (molecular motion) effect, first with the pore channel wall touch, then the particles attached to the pore channel wall, perhaps the particle in the van der Waals force or other surface force effect mutually agglomerated together.
3 sludge dewatering belt cake
In brief, followed by sludge dewatering belt, medium constitutes a cake. The cake itself plays sludge dewatering belt effect of medium, solid particles are cake appearance retention, and liquid through the sludge dewatering belt cake and the medium into the filtrate. The filter cake gradually becomes thickening, filtrate also gradually clear.
In the early stage of sludge dewatering belt, by the medium of trapping particles larger than the pore, and fine particles through a medium with filtrate clean-up. At the moment of filtrate not clear, it should be recycled to the suspension liquid bath. After certain time cycle, then collect the qualified filtrate. Medium trapped together in large particles, some less than fine particle medium pore will bridge a pore. The bridge will stop fine particles through sludge dewatering belt media, which is cut to retain large particles and small particles gradually accumulated griddle cake layer, even thick cake layer. Then, sludge dewatering belt will be transferred to the sludge dewatering belt cake. Obviously at the early stage of sludge dewatering belt, sludge dewatering belt media plays a decisive effect, and have a lasting effect on filter cake distribution and the sludge dewatering belt process.
4 cross flow sludge dewatering belt
With the expansion of sludge dewatering belt application, sludge dewatering belt material has emerged in an endless stream (such as small particles or metal hydroxide etc.). In order to improve the speed of belt sludge dewatering such material, it has been launched with the cake sludge dewatering the traditional belt method completely different cross flow sludge dewatering belt method.
Differences in cross flow sludge dewatering belt and the traditional cake sludge dewatering belt:
Sludge dewatering belt when the filter cake slurry is perpendicular to the sludge dewatering belt media appearance, solid particles are trapped in the filter cake gradually formed and thickening, sludge dewatering belt speed will gradually decline, until the filtrate suspension flow.
In the filter cake sludge dewatering belt process, sludge dewatering belt speed is gradually declining, because the sludge dewatering belt in porous media by the particle blocking and thickening of the filter cake gradually compaction caused by. About this question, we often have to filter pulp sludge dewatering belt increased flocculant (such as polyacrylamide) or filter aid agent (such as diatomaceous earth).
Cross flow sludge dewatering belt, sludge dewatering belt filter pulp is parallel to the medium appearance quickly, the filtrate to low-speed perpendicular to the medium surface outflow. These two activities are straight direction interwoven, so the cross flow sludge dewatering belt called sludge dewatering belt crossflow.
Cross flow sludge dewatering belt speed is nearly constant, sludge dewatering belt pressure also with not the time passing and quick increase. The fundamental reason for this effect is good, is the filter slurry rapid activities to accumulate in the medium on the particle shear sweep flow effect, and then restrain the cake thickness increase at any time.