This paper presents experimentally obtained flow characteristics inside the vane passage of a vented brake disc and at the brake disc exit. The flow conditions of three different brake discs were compared: a basic design with straight vanes and two prototypes with different vane heights, shapes (airfoil shape) and numbers. The possible effect on brake disc cooling performance was studies. Hot-wire anemometry was applied to measure the pumping performance of different discs, and particle imaging velocimetry was used to map the velocity field. All three discs were tested on a brake disc dynamometer according to the SAE J2522 standard, and the maximum temperature was measured during the thermal capacity test. No prototype outperformed the original brake disc. Moreover, the brake disc with the increased vane thickness and reduced vane height (prototype C) performed significantly worse, whereas prototype B, designed with an increased vane height and increased number of vanes, performed similarly to the original brake disc. A comparison of the flow characteristics of the three discs indicated that the significant decrease in the cooling airflow rate deteriorated the cooling performance of prototype C the most. On the other hand, the improved pumping performance did not improve the cooling performance of prototype B. Only the comparison of the internal cooling air flow pattern of the original and prototype B brake discs revealed the reason. While the characteristic jet-wake flow structure formed within the vane passage of the original brake disc, the inter-vane channel flow within brake disc B was distributed much more uniformly in a circumferential direction, with significantly lower flow velocities near the pressure vane side. This reduced the convective heat transfer on the brake disc vanes, which number, as well as the heat transfer surface area increased without the desired cooling effect.

The objective of this study was to determine the density of anaerobic granules on different heights of a full-scale Upflow Anaerobic Sludge Bed reactor. The density was defined through the settling velocities of anaerobic granules, measured in a full-scale Upflow Anaerobic Sludge Bed reactor. In this study, granular density was calculated with the measured settling velocities and developed mathematical model. The developed mathematical model is based on the Stokes model. In the experiment, granules were taken from different heights of an Upflow Anaerobic Sludge Bed reactor, from 0.6 to 7.6 m. The granules’ diameters varied between 1 and 5 mm. The granules were taken from six different heights through the reactor. The settling velocity of the active granules (with gas in the granule pore and on the surface of the granule) was measured first. After the active granules’ settling velocity measurement, the granules were placed in a vortex to obtain degassed granules (granules without any gas in the pores or on the surface), for which the settling velocities were also measured later. It is shown that granules’ densities at different heights are independent of the reactor height.

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.

Microfiltration is an important process in the pharmaceutical industry. Filter selection and validation is a time-consuming and expensive process. Quality by design approach is important for product safety. The article covers the instrumentalization and process control of a laboratory-scale dead-end microfiltration layout. The layout is a downscale model of the actual production line, and the goal is filter validation and analysis of process parameters, which may influence filter operation. Filter size, fluid pressure, valve plunger speed, and timing issues were considered. The focus is on the identification of the most influential process parameters and their influence on the repeatability of pressure oscillations caused by valve opening. The goal was to find the worst-case scenario regarding pressure oscillations and, consequently, filter energy intake. The layout was designed as compact as possible to reduce pressure losses between the filter and valve. Valve-induced pressure oscillations proved to be prevailing over the water hammer effect. Several filters in sizes between 3.5 cm² and 6900 cm² were tested, and some recommendations were suggested for the reduction of energy intake of the filter and to improve the repeatability of the process.