Sedimentation ,Centrifugation & extractions
21 Questions
6 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What happens to larger particles in a centrifuge compared to smaller ones?

  • They pass through with the clarified liquid.
  • They have lower settling velocities.
  • They remain suspended in the liquid.
  • They accumulate at the outer edge of the bowl. (correct)
  • Which statement best describes the inside structure of a disc stack centrifuge?

  • It contains closely spaced disks shaped like cones. (correct)
  • It operates without any central rotation axis.
  • It has a singular, flat base for solid accumulation.
  • It is a vertical cylinder with no internal components.
  • What is a feature of nozzle discharge centrifuges?

  • They only have one nozzle for liquid discharge.
  • They can only be used for solid materials with less than 10% content.
  • They enable continuous discharge of solids and liquid. (correct)
  • They require manual operation to remove solids.
  • In which industries are centrifuges commonly used?

    <p>Brewing industry and edible oil refining.</p> Signup and view all the answers

    What modification allows for controlled discharge of solids in a centrifuge?

    <p>Implementing self-opening nozzles controlled by timers.</p> Signup and view all the answers

    What is the primary mechanism of sedimentation?

    <p>Gravity allowing denser solids to settle.</p> Signup and view all the answers

    Which separation process is used to separate immiscible liquids and solids from liquids?

    <p>Centrifugation</p> Signup and view all the answers

    What type of product is typically obtained through centrifugation?

    <p>Thick paste or concentrated suspension</p> Signup and view all the answers

    What is a key characteristic of a tubular bowl centrifuge?

    <p>It consists of a narrow bowl rotating about a vertical axis.</p> Signup and view all the answers

    What determines the separation of immiscible liquids in centrifugation?

    <p>The centrifugal force applied</p> Signup and view all the answers

    Which operation is typically more expensive in terms of equipment cost?

    <p>Centrifugation</p> Signup and view all the answers

    What is the main application of centrifugation in the dairy industry?

    <p>To separate cream from skim milk</p> Signup and view all the answers

    In what scenario would centrifugation be preferred over filtration?

    <p>When filtration proves ineffective</p> Signup and view all the answers

    What is the primary role of the liquid in solid-liquid extraction?

    <p>To carry out the separation process</p> Signup and view all the answers

    Which factor does NOT control the operation of liquid-liquid extraction?

    <p>Temperature of the mixture</p> Signup and view all the answers

    What is the main product obtained when sugar is extracted from sugar beet?

    <p>Sugar crystals</p> Signup and view all the answers

    In liquid-liquid extraction, what is necessary for the liquids being separated?

    <p>They must be immiscible</p> Signup and view all the answers

    What medium is typically used to extract oil from natural products in a lab-scale liquid-liquid extraction process?

    <p>Hexane</p> Signup and view all the answers

    Why are sugar beets cut into slices during the extraction process?

    <p>To increase the surface area for extraction</p> Signup and view all the answers

    After extracting oil using hexane, what is the next step before reusing the solvent?

    <p>Distillation</p> Signup and view all the answers

    Which of the following is an example of solid-liquid extraction?

    <p>Extraction of coffee from coffee beans</p> Signup and view all the answers

    Study Notes

    Sedimentation

    • Solids in a suspension settle due to gravity.
    • Used in food processing to separate dirt, crystals, and/or dust from raw materials.

    Centrifugation

    • Accelerates settling with a centrifugal field.
    • Separates immiscible liquids based on density differences.
    • Separates solids from liquids by moving solids to the bowl wall.
    • More effective for particles than sedimentation.

    Sedimentation vs. Centrifugation Comparison

    Feature Sedimentation Centrifugation
    Separation Principal Gravity Centrifugal force
    Employment Dilute suspensions of large, rigid solids When filtration is ineffective, or in more concentrated suspensions
    Product Obtained Dry cake Paste or concentrated suspension
    Expense of Equipment Less More
    Particle Size Large particles Wide range
    Removal of Insolubles Dilute, large, and rigid insolubles Effective across a broader range of particle sizes

    Centrifugation Application

    • Immiscible liquids: Separates liquids of different densities. Example: separating milk into skim milk and cream.
    • Solids from liquids: Separates solids from liquids. Example: Fruit juice processing, clarifying cider, sugar syrups

    Tubular Bowl Centrifuge

    • Tall, narrow bowl rotating vertically.
    • Suspension fed at the bottom; clarified liquid removed from the top.
    • Suitable for feeds up to 2% solid content.
    • Solids collected as a paste.
    • Intermittent operation.

    Disc Stack Centrifuge

    • Short, wide bowl with closely spaced cones (disks).
    • Feed enters at the bottom, flows upward past disks.
    • Larger particles settle more easily.
    • Solids accumulate at the outer edge of the bowl.
    • Soluble material passes through.

    Continuous Centrifugation

    • Nozzle discharge centrifuges allow for continuous operation.
    • Continuous discharge of solids (sludge) and clear liquid.
    • Used in various industries including brewing, wine making, and edible oil refining.
    • Can handle slurries up to 25% solids content.
    • Modifications include self-opening centrifuges for controlled nozzle openings. (e.g., based on solids buildup)

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Explore the concepts of sedimentation and centrifugation, including their principles, applications, and comparisons. This quiz highlights the differences between these two methods of separation, focusing on efficiency, equipment expense, and particle size. Test your knowledge on their uses in various industries.

    More Like This

    Use Quizgecko on...
    Browser
    Browser