The core pain point of the unformed sludge in the plate and frame filter press
As the mainstream equipment for sludge dewatering, the plate and frame filter press's sludge pressing and shaping effect directly affects the efficiency and cost of subsequent disposal. However, in actual operation, the following problems are often encountered:
Youdaoplaceholder0 Loose or runny mud cake : The rigidity of sludge flocs is insufficient. Under high pressure, they deform and clog the filter cloth, resulting in water retention.
Youdaoplaceholder0 Extended pressing cycle : The filling degree of the filter chamber is low, requiring repeated feeding, and the single cycle takes more than 8 hours.
Frequent clogging of the filter cloth : false flocs form a waterproof film in the filter cloth channels, resulting in poor backwashing effect.
The moisture content remains high : Even after dewatering with traditional agents, the moisture content of the mud cake still reaches 80%-85%, which is difficult to meet the requirements for reduction.
Ii. In-depth Analysis of the Causes of Unformed Clay Pressing
Youdaoplaceholder0 incorrect selection of sludge conditioner
False flocs problem: The appropriate chemicals were not selected based on the nature of the sludge (such as the EPS content of biochemical sludge), resulting in the deformation of flocs under pressure.
Case: A printing and dyeing factory used general-purpose PAM. Under a pressure of 1.2MPa, the deformation rate of the flocs exceeded 40%, and the moisture content of the mud cake was 82%.
Youdaoplaceholder0 process parameters out of control
Insufficient feed pressure: Low-pressure start-up causes the filter chamber filling degree to be less than 60%, and the pressing efficiency decreases.
The pressing rate is too fast: The pressure increase rate is greater than 0.5MPa/min, and the water is squeezed out before the flocs are fully compacted.
Youdaoplaceholder0 equipment maintenance is missing
The pore size of the filter cloth does not match the particle size of the flocs: When the mesh count of the filter cloth is greater than 200 mesh, fine flocs are prone to clogging the channels.
Clogging of drainage holes: Failure to clean the drainage channels regularly leads to an increase in back pressure.
Iii. Breakthrough in Chemical Conditioning of Sludge Efficiency Enhancers
The sludge enhancer achieves deep dewatering of sludge through the combined effect of surface structure modification + charge neutralization + colloid destabilization . Its core advantages are as follows:
Youdaoplaceholder0 enhance the rigidity of flocs
Component analysis: It contains inorganic compounds (such as silicoaluminates) and cell wall disruptors, which can break down the bacterial cell walls and release bound water.
Effect: The compressive strength of the flocs has been increased to over 0.8MPa, and the deformation rate is less than 15%.
Youdaoplaceholder0 reduce the specific resistance of sludge
Mechanism: By using surface treatment agents to reduce the specific surface area of sludge particles, the specific resistance decreased from 1.0×10¹² m/kg to 0.3×10¹² m/kg.
Case: After a municipal factory used an enhancer, the filtration speed increased threefold, and the single-cycle processing capacity rose from 15 tons to 40 tons.
Youdaoplaceholder0 optimize the pressing process
High-pressure adaptability: When combined with a pressing pressure of 1.5-2.0MPa, the final dryness of the mud cake can reach 55%-60%.
Automation support: In combination with diaphragm pressing technology, it realizes the full-process automation of "feeding - pressing - unloading".
Iv. Economic and Environmental Benefits of Enhancer Application
Youdaoplaceholder0 Cost savings
Chemical cost: It saves 30% to 50% compared with the lime solution, with an annual savings of over 500,000 yuan in chemical costs (based on a sludge treatment plant with a daily processing capacity of 200 tons).
Disposal cost: The volume of the mud cake is reduced by 60%, and transportation and incineration costs are lowered by 40%.
Youdaoplaceholder0 environmental benefits
No secondary pollution: Free of aluminum ions and acrylamide, in compliance with the GB 4284-2018 sludge disposal standard.
Resource utilization support: The calorific value of the mud cake has been increased to 1800kcal/kg, which can be directly used for brick-making or incineration for power generation.