ABEL EM – Filter Press Feed
Our customer processes silica flour into a variety of Silica and Silicate products used in the Rubber, Paper, Chemical and Dental markets. As part of the silicate process, a wastewater stream is generated containing unreacted silica which is reusable, as well as waste solids. The effluent treatment system employs a variety of filters to separate the solids from the liquid streams. One of the filters was an aged vacuum belt filter used to separate solids and recover silicate water for reuse in the process. The resultant filter cake solids were then further processed as a waste stream. After a review of the separation system, the decision was made to replace the vacuum belt press with a recessed plate type filter press. The filter press, which is a known technology for the plant, would provide more effective separation, yield improved cake dryness, and therefore maximize the amount of silicate water recovered for reuse.
The ABEL solution
The new filter press system would include two diaphragm pumps. Our customer has typically used Air Operated Diaphragm (AOD) and centrifugal pumps within the process, and so these were evaluated. In conjunction with the press OEM, diaphragm pumps were selected as the best applied
technology for the process. However, air usage and the subsequent cost were also of concern and so our customer explored the possibility of using electric driven diaphragm pumps in lieu of the AODs. As a result, ABEL model EM pumps were chosen and installed in the process.
A year after start-up, the ABEL model EM electric diaphragm pumps perform well with minimal wear part replacement. Along with the recessed plate filter press, the EM positive displacement pumps remove nearly two times more silicate water for reuse than the previous belt press
system (I.e. an improvement of the filter press cake from 44% solids by weight to 72% solids by weight). The new system also promotes a cleaner environment around the process equipment, free from uncontained mud.