Separation of oil drops from water using stainless steel fiber bed

Abstract

Article Highlights • Separation of mineral oil droplets with stainless steel fibers bed different geometry was investigated • The separation efficiency for all operating conditions were higher than 90% • Low bed permeability is most favourable for the separation of mineral oil droplet from water • Separation of oil using stainless steel fibers is extremely sensitive to changes in oil properties Abstract This study is focused on the separation of oil droplets from water by applying a stainless steel fiber bed. The separation efficiency was followed by monitoring the oil concentration of three mineral oils that have a wide range of viscosity from 10 to 170 mP s, as well as neutralization number from 0.10 to 1.70 mg KOH/l. The bed properties were varied by altering the bulk density of the filter material, which resulted in a change of bed permeability from 0.7×10-9 to 5.389×10-9 m 2 and bed porosity from 91 to 98%. All experiments were conducted in a wide range of superficial velocity from 10 to 50 m/h. It can be concluded that high separation efficiency was achieved using stainless steel fibers, reaching values over 90%. Low bed permeability is most favorable for work at the selected conditions for the separation. The operation of stainless steel fiber bed is very sensitive to changes in the properties of oils. For lower viscosity of oily contaminants, the required efficiency of separation is achieved at lower superficial velocity through the fibrous bed. This phenomenon can be considered as a serious drawback since the bed coalescers often have to separate oils of different quality over time.

Wettability investigation of stainless steel fibers with mineral oils using the modified method for liquid penetration kinetics

“…It should be pointed out that the critical velocity was adopted as the measure of coalescence efficiency (separation of oil from oily water) being the fluid velocity when the effluent oil concentration reaches 15 mg/l at which the quality of effluent is satisfying. The critical velocity increase is extremely desirable due to the reduction of the equipment size particularly important for the coalescers that are located at platforms and ships (15,16,17). From Figure 6 it can be observed that the LLR values were in excellent agreement with the results from the separation efficiency of steady-state bed coalescence (15,16,17) considering that the critical velocity correlates with the separation efficiency and therefore LLR can also be correlated with the separation efficiency.…”

“…The critical velocity increase is extremely desirable due to the reduction of the equipment size particularly important for the coalescers that are located at platforms and ships (15,16,17). From Figure 6 it can be observed that the LLR values were in excellent agreement with the results from the separation efficiency of steady-state bed coalescence (15,16,17) considering that the critical velocity correlates with the separation efficiency and therefore LLR can also be correlated with the separation efficiency. With the increase of the LLR values the critical velocity also increased indicating that there is a possibility of separation efficiency prediction using solely LLR values obtained from the suggested modified equation [2].…”

The effect of fibre morphology on packing phenomena and bed properties in coalescers

“…Our research group extensively investigated application of different waste fibre materials as filter media in bed coalescers used for the treatment of oily wastewater [25][26][27][28]. The investigated fibre materials showed high separation efficiency of mineral oil from water.…”