Industrial Cyclone Separators Quiz

Cyclone separators offer several advantages, including low capital cost, the ability to operate at high temperatures, and minimal maintenance requirements due to the absence of moving parts.

Cyclone efficiency is significantly influenced by particle size. Larger particles are more easily captured by the centrifugal force generated within the cyclone. Smaller particles are more likely to escape due to their lower inertia.

Operating costs for cyclones tend to increase with efficiency. Achieving higher efficiency typically requires higher inflow pressure, leading to increased energy consumption.

<p>The three primary categories of cyclone separators are high efficiency, conventional, and high throughput.</p> Signup and view all the answers

<p>Cyclones are frequently used as pre-cleaners because they can effectively remove larger particles, reducing the load on downstream control devices like baghouses or electrostatic precipitators.</p> Signup and view all the answers

<p>The primary drawbacks of cyclones include their relatively low efficiency, especially for very small particles, and their high operating costs due to the energy required to overcome pressure drop.</p> Signup and view all the answers

<p>The gas from one small cyclone can pass up the exit of an adjoining cyclone, leading to &quot;cross-talk&quot; and reduced efficiency.</p> Signup and view all the answers

<p>Shepherd and Lapple's work established &quot;optimum&quot; dimensions for cyclones, defining relationships between various dimensions and the overall diameter of the cyclone. This work laid the foundation for the design of many standard cyclones still used today.</p> Signup and view all the answers

<p>The design of a cyclone system involves a trade-off between maximizing dust collection efficiency and minimizing system complexity. More complex systems may offer better dust collection, but may also be more expensive and difficult to maintain.</p> Signup and view all the answers

<p>Relating cyclone dimensions to the body diameter makes their findings generally applicable, allowing for scalable design. This means their results can be applied to cyclones of different sizes, ensuring consistent performance.</p> Signup and view all the answers

<p>The initial design strategy is to aim for a single cyclone unit. Multiple cyclones are only considered if the predicted performance of a single unit is insufficient for the required capacity.</p> Signup and view all the answers

<p>It can be challenging to evenly distribute the gas flow among the multiple cyclones, leading to inefficiencies.</p> Signup and view all the answers

<p>The Kalen-Zenz formula is utilized as an initial estimate for the cyclone body diameter.</p> Signup and view all the answers

<p>The tangential velocity of the gas within the cyclone should be compared to typical ranges to ensure optimal performance.</p> Signup and view all the answers

<p>Size-dependent efficiency and total efficiency are the two types of efficiency calculations used to evaluate the cyclone's performance.</p> Signup and view all the answers

<p>The procedure involves repeatedly calculating efficiency, adjusting design parameters like cyclone configuration, number of cyclones, or body diameter, and re-evaluating efficiency until the required efficiency is achieved.</p> Signup and view all the answers

<p>Key factors include particle size distribution, gas viscosity, cyclone dimensions, and flow rate.</p> Signup and view all the answers

<p>The design parameters would require optimizing dimensions, reducing the cut size, and possibly increasing the gas flow velocity.</p> Signup and view all the answers

<p>A wider particle size distribution necessitates a design that can capture both small and large particles efficiently, focusing on the ranges with higher mass percentages.</p> Signup and view all the answers

<p>Gas viscosity affects the drag forces acting on particles, influencing their ability to be separated from the gas stream.</p> Signup and view all the answers

<p>The body diameter of 1.2 m and the flow rate of 150 m³ min⁻¹ should remain unchanged.</p> Signup and view all the answers

<p>The dimensions are inlet height (a), inlet width (b), cyclone body diameter (D), cyclone body height (h), cone height (hc), cone bottom diameter (B), vortex finder length (S), and outlet diameter (De).</p> Signup and view all the answers

<p>The reverse flow with tangential inlet cyclone design is the most commonly used in industry.</p> Signup and view all the answers

<p>The cut diameter (d50%) is the size of particles collected with 50% efficiency, indicating the effectiveness of the cyclone in removing particles.</p> Signup and view all the answers

<p>Collection efficiency decreases for particles with diameters smaller than about 5 μm due to diminishing centrifugal forces.</p> Signup and view all the answers

<p>The geometric ratios include a/D, b/D, De/D, S/D, h/D, H/D, and B/D.</p> Signup and view all the answers

<p>The three important parameters are cut diameter, pressure drop, and collection efficiency.</p> Signup and view all the answers

<p>The collected particles precipitate to the bottom and are led to an outside receiver.</p> Signup and view all the answers

<p>The principal diameter (D) characterizes the size of the cyclone, influencing various performance parameters.</p> Signup and view all the answers

<p>Increasing temperature raises the flue gas flow rate, which increases inlet and particle velocities; however, higher viscosity reduces particle velocity due to increased drag force.</p> Signup and view all the answers

<p>Generally, collection efficiency increases with higher gas flow rates due to increased inlet velocities, but excessively high velocities can lead to particle breakup.</p> Signup and view all the answers

<p>At higher dust loadings, fine particles are trapped in the interstices of larger particles, enhancing the overall collection efficiency.</p> Signup and view all the answers

<p>A smaller-diameter cyclone typically has higher efficiency because it can generate greater centrifugal forces to capture smaller particles.</p> Signup and view all the answers

<p>Saltation refers to the condition where dust particles are re-entrained or fail to deposit due to insufficient tangential velocity, potentially reducing efficiency.</p> Signup and view all the answers

<p>The terminal velocity of a particle in a cyclone is determined by the balance between centrifugal force, which pulls the particle outward, and drag force, which opposes motion.</p> Signup and view all the answers

<p>Agglomerated or friable dust can break up at high gas velocities, potentially offsetting the efficiency gains from increased velocity and leading to a higher number of finer particles that are harder to collect.</p> Signup and view all the answers

<p>Experiments show that the pressure drop in a cyclone decreases as dust loading increases.</p> Signup and view all the answers

<p>Cumulative size fractions help in determining the percentage of particles below a specific diameter, aiding in the analysis of particle size distribution and its impact on filtration efficiency.</p> Signup and view all the answers

<p>Increased flow rates generally lead to lower separation efficiency due to insufficient residence time for particle collection, thereby requiring careful optimization.</p> Signup and view all the answers

<p>Gas viscosity influences resistance to flow and particle motion, significantly affecting the performance and efficiency of particle removal in cyclone systems.</p> Signup and view all the answers

<p>Higher particle density enhances their inertia, improving separation efficiency as denser particles are more likely to overcome drag forces and settle out.</p> Signup and view all the answers

<p>Lognormal size distributions provide a realistic representation of most particulate matter, allowing engineers to predict performance in cyclone separators more accurately.</p> Signup and view all the answers

<p>Maintaining 94.5% operational efficiency minimizes emissions and enhances overall process performance, ensuring compliance with environmental regulations.</p> Signup and view all the answers

<p>Parameters such as gas flow rate, particle size, and inlet velocity can be plotted against size dependent efficiency to visualize their influences on separation performance.</p> Signup and view all the answers

<p>Higher particle concentrations can lead to increased interactions among particles and reduced separation efficiency due to enhanced turbulence and clustering effects.</p> Signup and view all the answers

Eight dimensions define the configuration of a tangential flow cyclone.

Ratios like a/D and b/D characterize the cyclone's shape and efficiency.

Size of particles collected with 50% efficiency by the cyclone.

A device used to separate particles from gas streams using centrifugal force.

The difference in air pressure across the cyclone, affecting performance.

The percentage of particles collected by the cyclone based on size.

The efficiency of cyclones varies based on particle size and cyclone design.

Cyclones are more efficient for larger particles (>5 microns).

An inlet design that enhances the spinning motion of gas in the cyclone.

Three main categories: high efficiency, conventional, high throughput.

Models that use geometrical and operational parameters to predict cyclone behavior.

Low cost, high temperature tolerance, low maintenance requirements.

Forces that push particles outward in the cyclone, aiding in their collection.

Low efficiency for small particles and high operating costs.

Costs increase with cyclone efficiency due to higher inflow pressure required.

Key dimensions affect cyclone performance, originally studied by Shepherd and Lapple.

A theoretical model used to estimate collection efficiency of cyclones.

A method for estimating cyclone efficiency based on particle size distribution.

The effectiveness of a cyclone in removing particles from a gas stream.

Specific ratios and dimensions used in cyclone design for optimal performance.

The maximum allowable concentration of pollutants in a gas stream.

The mass of gas per unit volume, negligible compared to particle density.

The volume of exhaust gas moving through a system, increasing with temperature.

A measure of a fluid's resistance to flow, affects particle velocity.

The constant speed of a particle when the force of gravity equals drag force.

The concentration of particulate matter entering a cyclone, affects efficiency.

The size of the cyclone, influencing its ability to collect particles.

Larger particles formed by the clumping of smaller particles, can impact efficiency.

Process where smaller cyclones release dust into a common hopper.

Interference caused by gas from one cyclone affecting another.

Balancing between collection efficiency and equipment complexity.

Designing for one cyclone unless performance is insufficient.

Evenly distributing airflow to all cyclones for efficiency.

A formula used to estimate cyclone body diameter.

The speed at which gas moves at the cyclone's edge.

Verifying if the required efficiency of cyclone design is met.

The volume of fluid that passes a point in a system per unit time.

The amount of particles in a given volume of fluid, typically expressed in mg/m3.

A measure of a fluid's resistance to flow, affecting how easily it moves.

The ratio of the amount of particles removed to the total amount of particles in the gas.

A statistical distribution of particle sizes often seen in natural processes.

The total percentage of particles smaller than a specific diameter.

Variables that influence the performance of the cyclone separator, like flow rate and temperature.