Gyratory Crushers

Play an AI-generated podcast conversation about this lesson

What is the primary function of a primary crusher?

To separate the aggregate into different size ranges

To eliminate undesirable materials from the aggregate

To reduce the particle size of the stone (correct)

To handle and move the crushed materials

What is the primary advantage of true gyratories as primary crushers?

They can handle slabby material well

They are less expensive than jaw crushers

They have high mechanical advantage

They provide continuous crushing (correct)

What is the purpose of screening in aggregate production?

To reduce the particle size of the stone

To handle and move the crushed materials

To eliminate undesirable materials from the aggregate

To separate the aggregate into different size ranges (correct)

What is the main difference between jaw crushers and true gyratories?

Jaw crushers can handle slabby material well Signup and view all the answers

What is the final step in the aggregate production process?

Handling and moving the crushed materials Signup and view all the answers

What is the purpose of washing in aggregate production?

To eliminate undesirable materials from the aggregate Signup and view all the answers

What type of crusher is commonly used for primary crushing by hurling the stone against interior steel apron walls?

Impact crusher Signup and view all the answers

How many crushers may the stone pass through before it is reduced to the desired size?

Four or more Signup and view all the answers

What is the purpose of the eccentric bushing in a cone crusher?

To produce the gyratory effect as the shaft rotates Signup and view all the answers

What is the unit weight of the material used in Table 13.5?

100 lb/cf Signup and view all the answers

What is the main function of roll crushers?

To produce additional reductions in the sizes of stone Signup and view all the answers

What is the advantage of single roll crushers?

Simplicity in design and operation, compact size, and ease of maintenance Signup and view all the answers

What is a limitation of single roll crushers?

They are not suitable for materials that are very hard or abrasive Signup and view all the answers

What is the main difference between a single roll crusher and a double roll crusher?

The number of rolls Signup and view all the answers

What is an advantage of double roll crushers?

They are compact in design and have high capacity Signup and view all the answers

What is the surface of the rolls in a roll crusher?

Either smooth or textured with narrow beads Signup and view all the answers

What characterizes gyratory crushers?

Gyrating mantle within a deep bowl Signup and view all the answers

What is one of the major advantages of gyratory crushers compared to jaw crushers?

Higher capacity and uniform product size Signup and view all the answers

What function does the spring-loading or hydraulic adjustment serve in gyratory crushers?

To protect from uncrushable objects and overload Signup and view all the answers

What indicates an excessive feed rate in a gyratory crusher?

Surge of aggregate at the top of the shaft Signup and view all the answers

What distinguishes a cone crusher from a true gyratory crusher?

Shorter cone and higher speed Signup and view all the answers

What is a notable disadvantage of gyratory crushers?

More complex maintenance requirements Signup and view all the answers

What is the material of the conical head on a cone crusher typically made of?

Manganese steel Signup and view all the answers

What is a balance goal for optimizing gyratory crusher performance?

Highest allowable feed rate and closed setting for required product size Signup and view all the answers

What size of finished product is achieved with a roll setting of 20 in. in roll crushers?

Finished product size of 20 in. Signup and view all the answers

What is the key difference between horizontal shaft impactors (HSI) and vertical shaft impactors (VSI)?

Rotor orientation Signup and view all the answers

What are the two main configurations for the number of rotors in impact crushers?

Single and double Signup and view all the answers

Which is NOT an advantage of impact crushers?

Suitability for high-abrasiveness materials Signup and view all the answers

What production rate can primary and secondary phase models of impact crushers achieve?

Over 800 tph Signup and view all the answers

Which materials are commonly reduced using impact crushers?

Limestone, concrete, and asphalt Signup and view all the answers

How do single-rotor impact crushers break down stones?

By impact action and striking against aprons Signup and view all the answers

What factors affect the production rate of single-rotor impact crushers?

Rotor speed Signup and view all the answers

What is a key disadvantage of double roll crushers?

They are not suitable for very hard or abrasive materials. Signup and view all the answers

What is a distinct feature of triple roll crushers?

They provide two-stage reduction in one crusher assembly. Signup and view all the answers

What is the relationship between feed size and roll diameter in roll crushers?

Feed size is directly proportional to the roll diameter. Signup and view all the answers

How do triple roll crushers handle stone differently than double roll crushers?

They use a two-stage reduction process within one crusher. Signup and view all the answers

What is one advantage of triple roll crushers?

They offer high capacity and efficient crushing performance. Signup and view all the answers

What angle is defined as the angle of nip?

16°45′ Signup and view all the answers

What does the equation $D = R ext{cos} B = 0.9575R$ represent in roll crushers?

The maximum feed size. Signup and view all the answers

What limitation is associated with triple roll crushers in terms of installation?

They may have a larger footprint and require more space for installation. Signup and view all the answers