Energy Intake Models for Intermittent Operation of Dead-End Microfiltration Filling Line

Abstract

In filling lines equipped with membrane separation devices in the form of filters energy, consumption is only one of the important working parameters, the other being sustainable filter performance in terms of separation efficiency. As the filling line is typically equipped with a valve, intermittent operation of the filter is an important form of its use. Whereas the overall energy consumption of the filtration process is governed by the continuous operation mode, the intermittent mode, characterised by opening/closing of the valve, contributes most to problems of filter failure, i.e., the breakthrough of filtered particles through the membrane. A model for determination of the energy intake of a microfiltration membrane during the opening and closing of a valve is presented in this work. The model is based on computational analysis of the pressure wave signals recorded during the opening/closing of the valve using Fourier transform, and expressed in a nondimensional filter area specific energy intake form. The model is applied to a case of constant pressure dead-end microfiltration with three filter types: a single membrane filter, a stacked filter and a pleated filter with filtration surface areas ranging from 17.7 cm2 to 2000 cm2. Both clean filters, as well as partially clogged filter cases are taken into account. Second order polynomial models of the energy intake are developed and evaluated based on extensive analysis of the experimental data. The analysis of energy intake results show that the largest energy intake was observed for the clean filter case. When membrane fouling occurs at the constant flow rate values it leads to larger energy intake, however, due to a decreasing specific flow rate during fouling these values do not exceed the clean filter case.

Development of an Experimental Dead-End Microfiltration Layout and Process Repeatability Analysis

“…The presented system was used for flow measurements and dynamic tests. The main purpose of acquired dynamic data was the calculation of the stress acting on the filter [20]. The results are presented in Table 1.…”

“…Almost 1 s is needed for pressure stabilization after valve opening. Pressures PE0 and PE1 are in phase and almost the same in amplitude during valve closing, contributing less to the filter energy intake [20]. There are some additional oscillations in the PE1 curve caused by plunger movements.…”

“…The focus of this paper is on pressure oscillations taking place during system valve opening and closing and, consequently, the energy impact on the filter [20]. According to [20], the energy impact during valve opening is higher than during valve closing, so the article will focus on valve opening. In some cases, pressure oscillations can be used for fouling layer removal [21].…”