Difference between revisions of "Assignment 3 - 2013"

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:grading: 12
:grading: 12
The following is laboratory size distribution data for the feed, oversize and undersize of an industrial sieve stack are given.
The following is laboratory size distribution data for the feed, oversize and undersize of an industrial sieve stack are given. (See the PDF for the data).
.. image:: ../figures/separations/screens/particle-size-results.png
:align: center
:scale: 55x%
:width: 750px
#. Calculate the overall efficiency.
#. Calculate the overall efficiency.

Revision as of 21:54, 4 October 2013

Due date(s): 11 October 2013 (at class)
Nuvola mimetypes pdf.png (PDF) Assignment questions

<rst> <rst-options: 'toc' = False/> <rst-options: 'reset-figures' = False/>

Assignment objectives

=========

To use ideas and formulas related to mechanical separation units.

.. |micron| replace:: :math:`\mu \text{m}`

.. question:: :grading: 8

#. Prove that for a spherical particle, :math:`S = \displaystyle \frac{6}{d}` = specific surface area of particle per volume of solid particle, with units of :math:`\text{m}^{-1}`.

#. Calculate this value for spherical particles of 50 |micron| and 100 |micron|.

#. What is the theoretical value(s) of voidage for spheres?

#. Calculate :math:`\alpha`, the specific cake resistance value in a filtration system for spherical particles of 50 |micron| and 100 |micron|, where the solids have a density of 2500 :math:`\text{kg.m}^{-3}`.

.. question:: :grading: 4

.. From Seader, 3rd edition

#. Under what assumptions do filtration data from lab equipment plot as a straight line for :math:`V` versus :math:`\dfrac{t}{V}` axes?

#. Look up the terms "precoat" and "filter aids" in the context of solid-liquid plate-and-frame or vacuum rotary-drum filtration. Explain in an unambiguous manner the purpose they serve.


.. question:: :grading: 5

Your sister company seems to have no problem at their site with particulate pollutant discharge. Your site however experiences continual problems, despite using a similar process.

You request their flowsheet and notice an arrangement of cyclones as shown below. Explain what this sequence might do to help you achieve pollutant reduction.

.. image:: ../figures/separations/cyclones/clarifying-sequence.png :align: center :scale: 90% :width: 750px

.. question:: :grading: 20

The following filtration data are collected from a laboratory unit, using the same filter medium for all experiments. The objective is to determine the constants :math:`\alpha_0` and :math:`f` in the equation for specific cake resistance, :math:`\alpha = \alpha_0 \left(- \Delta P \right)^f`, where :math:`\alpha` and :math:`\alpha_0` are in units of :math:`\text{m.kg}^{-1}`, and :math:`- \Delta P` is in Pascals.

.. list-table:: :widths: 15 10 10 10 :header-rows: 1

* - Filtrate volume [L] - Test 1, Time [s] - Test 2, Time [s] - Test 3, Time [s] * - 0.25 - 20 - 13 - 4 * - 0.5 - 39 - 29 - 9 * - 1.0 - 99 - 70 - 26 * - 1.5 - 175 - 123 - 53 * - 2.0 - 276 - 207 - 83 * - 2.5 - -- - 365 - 128 * - 3.0 - -- - 399 - 182

Show all calculations made, including your assumptions. Work in a systematic manner.

.. question:: :grading: 12

The following is laboratory size distribution data for the feed, oversize and undersize of an industrial sieve stack are given. (See the PDF for the data).

#. Calculate the overall efficiency. #. Calculate the cut size.


.. question:: :grading: 8

After reading this article `on the course website <http://learnche.mcmaster.ca/media/mcmaster/Hanly-Petchonka--Equipment-selection-for-Solid-Gas-Separation.pdf>`_, describe

#. what a venturi scrubber does #. draw a sketch of how it looks #. give an advantage relative to another separation unit that achieves a similar purpose #. give a disadvantage relative to another separation unit that achieves a similar purpose.

</rst>