Suchergebnisse

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.

Previous research on the use of "no opinion"-filters has indicated that respondents (Rs) are least likely to offer a substantive response the more strongly the filter question is worded. Here, results of 3 experiments conducted in Urbana, Ill, & Mannheim, Federal Republic of Germany (total N = 424 college students & 336 other randomly selected adults) demonstrate that filter questions influence Rs' perception of their task: the more strongly the filter question is worded, the more Rs assume that they will have to answer difficult questions, & that they may not have the required knowledge to do so; accordingly, they are discouraged from offering global opinions. In line with this assumption, all Rs who reported not having an opinion in response to a filter question subsequently provided substantive responses on a global opinion question -- presumably because the global question asked was less demanding than expected on the basis of the filter. Analyses of these substantive responses indicate that Rs who initially reported not having an opinion differed from Rs who reported having one. Methodological implications for the use of filter questions & for research on the nature of "floating" are discussed. 3 Tables, 14 References. Adapted from the source document.