What type of screening equipment is characterized by high-frequency vibrations (1000 to 7000 Hz) and is used for a wide range of particle sizes with good separating efficiency?

Correct answer: Vibrating screens

Explanation

This question tests the ability to differentiate between various types of dynamic screening equipment based on their operational characteristics, such as frequency of motion.

Other questions

Question 1

What is the term for the ratio of an irregular particle's longest dimension (L) to its width (W)?

Question 2

Which of the following defines the Stokes diameter (dst) of a particle?

Question 3

What is the relationship between bulk density (ρb), particle density (ρp), and bed void fraction (ε)?

Question 4

In the context of the properties of granular materials, what is attrition resistance a measure of?

Question 5

According to Geldart's classification of fluidization behavior, which group of particles is characterized by bubbling at the minimum fluidization velocity (Umf) and includes materials like sand and salt?

Question 6

What type of flow pattern in a bin or hopper is characterized by slip occurring within the solid, stagnant regions, and the potential for rat-holes or bridges to form?

Question 7

Which type of feeder is also known as a rotary vane feeder or star feeder and can provide a positive seal between a gas atmosphere in the process and air in the hopper?

Question 8

What is the primary purpose of a dual hopper system, also known as a charge hopper or lock hopper?

Question 9

Which separation technique is used extensively for finely divided solids, depends on differences in surface properties, and involves air bubbles adhering to particles to bring them to the surface?

Question 10

In the context of solids mixing, which type of equipment is described as a rotating drum, often double-cone or V-shaped, suitable for gentle blending without changing particle size?

Question 11

What is the primary mechanism of separation in a gas-solid cyclone separator?

Question 12

Which type of gas-cleaning equipment consists of a number of bags supported on a frame in a chamber and is used to separate small particles down to around 1 micrometer with high efficiency?

Question 13

What is the primary difference between a thickener and a clarifier in solid-liquid separation?

Question 14

In the theory of drying, what is the term for the moisture content at the end of the constant-rate period?

Question 15

Which type of dryer is similar in operating principle to a spray dryer but disperses the product to be dried into an upward-flowing stream of hot gas, acting as a pneumatic conveyor and dryer?

Question 16

What is the primary reason for using a closed-loop, recirculating gas system with an inert gas like nitrogen for drying solids?

Question 17

Which of the following size enlargement processes is a variant of extrusion used to form fibers, such as in polymer processing?

Question 18

What is the term for the process of particle size reduction that is the first step, reducing large lumps to manageable sized pieces?

Question 19

According to the Bond (1952) model of energy consumption for grinding, if the Bond work index (Ei) is 15 kWh/ton, what is the work done (E) in kWh/ton to reduce a solid from an initial size (d1) of 400 micrometers to a final size (d2) of 100 micrometers?

Question 20

What is a primary advantage of wet grinding over dry grinding?

Question 21

Which type of comminution equipment crunches material between a vertical fixed plate and a moving plate and is used for coarse size reduction?

Question 22

What is the primary health hazard associated with inhaling fine particulate dust from materials like asbestos, silica, or coal?

Question 23

What is the most common method of explosion prevention when handling flammable dust in equipment?

Question 24

What is the typical average residence time for a process feed bin designed to compensate for short interruptions in an upstream system?

Question 25

Which type of solid-liquid centrifuge is generally used to produce a pure, dry, solid product?

Question 26

A particle has a length (L) of 15 mm, a width (W) of 5 mm, and a thickness (t) of 2 mm. What is its elongation?

Question 28

According to Table 18.2, which of the following materials has the highest Moh hardness?

Question 29

What is the defining characteristic of a pipe conveyor?

Question 30

In sedimentation centrifuges, the 'sigma theory' provides a performance value (Σ) that is independent of the solid-fluid system properties. What is the sigma value equal to?

Question 31

What is the typical work index for wet grinding as a percentage of the work index for dry grinding?

Question 32

Which of the following is NOT a mechanism of agglomeration mentioned in the text?

Question 33

What is the primary factor that causes stronger cohesive forces in particulate materials?

Question 34

In a solids-handling plant, what is the term for an uncontrollable flow of fine powder through a discharge opening that occurs when a bridge or rat-hole collapses suddenly?

Question 35

What does a Bond work index (Ei) of 11.6 kWh/ton for limestone signify?

Question 36

Which type of centrifuge is used for classifying particles in size ranges below 10 micrometers?

Question 37

For a particle with a true density (ρt) of 2500 kg/m3 and an internal pore volume fraction (χ) of 0.2, what is its particle density (ρp)?

Question 38

What is the primary engineering control used on plants susceptible to dust formation to prevent dust from escaping into the work environment?

Question 39

Which of these solid-liquid separation processes relies on passing the slurry through a porous medium to separate solids from the liquid?

Question 40

In the context of fluidization, what does the Archimedes number (Ar) represent?

Question 41

What is the typical speed for a belt conveyor used in the process industries?

Question 42

Which size enlargement process is most suitable for producing a very uniform product, such as pharmaceutical tablets, at high throughputs?

Question 43

What is a major disadvantage of fluidized beds in solids processing?

Question 44

Which of the following is NOT one of the five types of particle-to-particle interactions that give rise to cohesion?

Question 45

What is the angle of repose (β)?

Question 46

A solids stream has an average bulk density of 960 kg/m3. According to Table 18.2, which material could this be?

Question 47

What is the typical range for the ratio of fin area to bare tube area for finned tubes used in solids-handling equipment like air-cooled exchangers?

Question 48

What is the ASTM E-11 standard wire mesh sieve size that corresponds to a sieve opening of 0.250 mm?

Question 49

In a horizontal trough mixer, what is the primary mixing action produced by the rotating element?

Question 50

What is the typical range for solids concentration in the feed for filtration centrifuges to be effective, considering that for dilute slurries, preconcentration is recommended?