Technical discussion: When using a plate and frame filter press to compress the sludge, the results are poor; the sludge cake on the filter cloth is very sticky and difficult to remove
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This post was last edited by hesonchang214 on 2013-5-27 at 22:44. The sludge used in our sludge thickening tank comes mainly from the activated sludge discharged from the secondary sedimentation tank; its viscosity is somewhat high. When the filter cloth was first replaced, the performance was good – the sludge cakes were relatively dry. After about 4 months of use, the viscosity of the sludge on the filter cloth has increased significantly, and sometimes it becomes thin in consistency. I’ve read on various forums that lime milk can be added to address this issue, but I’m not sure about the underlying principle. If there are any other better solutions, please feel free to share them
High-pressure cleaning of the filter cloth can be carried out using rinse water.
1. Choose the appropriate type of flocculant; it may be that the flocculant is not suitable for the current properties of the sludge, or the amount of flocculant used is inappropriate. 2. Did the rinse water fail to clean the filter cloth properly, resulting in sludge leakage? 3. Is the sludge concentration too low?
1. Choose the appropriate type of flocculant; it may be that the flocculant is not suitable for the current properties of the sludge, or the amount of flocculant used is inappropriate. 2. Did the rinse water fail to clean the filter cloth properly, resulting in sludge leakage? 3. Is the sludge concentration too low?
The sludge needs to be conditioned before dewatering! This is a problem that is often overlooked but is of great significance! Getting things in order can achieve twice the result with half the effort and save costs! Specifically, this includes but is not limited to – mixing and homogenization, concentration and stabilization, as well as property adjustment (pH value, hydrophobicity, coagulation), and so on. Regarding the principle of adding lime, it is reasonable to consider it from three aspects: adjusting the pH value, coagulation, and hydrophobicity. It is recommended to closely monitor the preparation process of lime slurry to prevent the filter cloth from being damaged by excessively large particles of lime residue!
1. The filter cloth needs to be replaced; it may have stuck together, resulting in poor filtration. 2. The flocculant does not perform well in facilitating flocculation; using too much of it is not good either, and using too little results in poor filtration efficiency. 3. There are now some high-pressure filter presses that are quite good; the moisture content of the sludge cake produced by them is only around 50%. You can contact 13864009543
This post was last edited by hesonchang214 on 2013-5-27 22:45. The 7.5kg industrial water used in public works cannot be washed away easily; even after scraping it with an iron plate and then trying to wash it, it still doesn’t get clean!
This post was last edited by hesonchang214 on 2013-5-27 22:46. The filter cloth is likely to have the greatest impact; after the pressure is released from the plate and frame structure, a large amount of water splashes out between them. The key considerations are extending the service life of the filter cloth, as well as whether it can be cleaned with acids or bases after being removed and then reused!
This post was last edited by hesonchang214 on 2013-5-27 at 22:47. We don’t use flocculants these days; the person in charge before said that using flocculants doesn’t yield significant results and is also troublesome!
This post was last edited by hesonchang214 on 2013-5-27 22:48. The key issue is that the filter cloth needs to be replaced; either its pores are no longer functional or it has become clogged. It must be difficult to filter. It depends on the service life of the filter cloth, the requirements, and how backwashing is utilized!
After the filter cloth is removed, as long as it is not damaged, it can be washed and reused; many manufacturers use it this way.