Type of filter #7
Description
We have to decide on the kind of filter that we will use. We had thought that the filter could be inside the reactor, so we need to make sure it has:
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Mechanical resistance
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Chemical resistance
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Ability to filter different particle sizes
In order to evaluate this, we conducted experiments with two type of filters: a commercial blue ribbon 5893 Blauband filter (filter paper) and a filter made out of a synthetic fabric.
In both experiments, a wire was used to form a ring and the filter was attached. Then the filters were submerged in a saturated tartaric acid solution (a weak acid) at 75 °C (348 K), with stirring for 30 min. The reactor was set inside a water bath to keep temperature constant.
Figure 1. Filter paper experiment.
Figure 2. Synthetic fabric experiment.
Results
Regarding the filter paper, we arrived to the following conclusions:
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It has enough mechanical resistance. There were some minor breakages in the edges but those were because of the poor attachment, which we will have to improve.
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It was resistant to the chemical attack by a weak acid.
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According to specifications, it should be able to retain even smaller particles.
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It is hard to manipulate when it is wet.
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If too close to the bottom, it limits the speed of the stirring because the magnetic piece collides with it.
Regarding the synthetic fabric filter, we arrived to the following conclusions:
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It has good mechanical and chemical resistance (better than the filter paper).
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It is cheap and widely available.
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It might not filter the smallest particles.
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It is easier to manipulate when it is wet.
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The same limitations regarding the speed of the stirring are present but it is easier to adjust the height of the filter.
On the whole, both filters are good enough regarding the purposes of having mechanical and chemical resistance to weak acids. Next, we should proceed carrying out experiments with the solid.