Cone crushers are an important type of crushing machine that is used in many industries. They are versatile, reliable, and durable, making them ideal for use in a wide range of applications. Whether you are in the mining or construction industry, a cone crusher can help you to efficiently and effectively crush materials into smaller pieces.
The cone crusher was first developed in the s by Symons brothers, who were trying to improve the efficiency of crushing machines. The Symons cone crusher was then further developed in the s by a company called Allis-Chalmers. Today, there are many different types of cone crushers available, each with its unique features and capabilities.
One of the main advantages of cone crushers is their ability to crush materials of varying hardness. They are also able to produce a more uniform product size than other crushing machines, which makes them ideal for use in the production of asphalt and concrete.
There are two main types of cone crushers: the standard type and the short head type. The standard type is used for coarse and medium crushing, while the short head type is used for medium and fine crushing. The difference between the two types is that the short head type has a steeper crushing chamber and a smaller feed opening.
Cone crushers are also known for their reliability and durability. They are designed to withstand heavy use and are often used in harsh environments. Many cone crushers are also equipped with advanced technology, such as hydraulic systems, which can help to reduce maintenance and repair costs.
The type of material you will be processing will play a significant role in selecting a cone crusher. Different materials have different properties and characteristics that require different types of crushing equipment. For example, hard and abrasive materials such as granite and basalt require a cone crusher with a high capacity and a high reduction ratio, while softer materials like limestone and shale require a cone crusher with a moderate capacity and a lower reduction ratio.
The third factor to consider is the size of the feed material. Cone crushers have a limited maximum feed size, which is the largest piece of material that can be fed into the crusher without causing damage. If your material is too large, it may cause the crusher to jam or break down, so it is important to choose a crusher that is appropriate for the size of your material.
The capacity of the cone crusher is another important factor to consider when selecting a cone crusher. The capacity is determined by the size of the feed opening and the throughput capacity of the machine. The larger the feed opening and the higher the throughput capacity, the more material the cone crusher can process.
Standard cone crushers are used for secondary and tertiary crushing, while short head cone crushers are used for fine crushing. The choice between these two types of crushers will depend on the specific application and the desired product size.
The fifth factor to consider is automation. Cone crushers with advanced automation features can help improve productivity and reduce operating costs. Some cone crushers come with automated control systems that allow operators to adjust the settings from a remote location, reducing the need for on-site personnel.
The sixth factor to consider is mobility. If you need to move the crusher from one site to another, it is important to choose a cone crusher that is easy to transport. Some cone crushers can be mounted on wheels or tracks, making them more mobile and easier to move from one location to another.
The power and efficiency of the cone crusher are also important factors to consider. The power of the cone crusher is determined by the motor size and the hydraulic pressure. The efficiency of the cone crusher is determined by the design of the crushing chamber, the speed of the eccentric shaft, and the length of the crushing stroke.
The maintenance and service requirements of the cone crusher are also important factors to consider. The cone crusher should be easy to maintain and service, with easy access to the main components for inspection and maintenance. The wear parts should be easy to replace and readily available.
The cost of the cone crusher is also an important factor to consider. The cost of the cone crusher includes the initial purchase price, the operating cost, and the maintenance cost. While a more expensive cone crusher may have a higher initial cost, it may be more cost-effective in the long run due to lower operating costs.
Many countries have strict regulations on emissions, noise levels, and dust suppression, so it is important to choose a cone crusher that meets these regulations. Cone crushers with advanced dust suppression systems and low emissions can help ensure compliance with environmental regulations.
Crushing and screening equipment is widely used in the construction of highways, construction, water conservancy, mining, ports and other fields for processing and producing various specifications of crushed stone and sand. How to make a good decision when purchasing crushing and screening equipment? How to buy cost-effective equipment without being taken advantage of? Here are 10 factors need to be considered while purchasing crushing and screening equipment.
The crushing equipment is divided into jaw crusher, gyratory crusher, cone crusher, roller crusher, rotary disc crusher, impact crusher and hammer crusher. The first 5 types are called compression type crushers, and the last 2 types are called impact type crushers.
Jaw crusher: It has large crushing ratio, uniform product size, simple structure, reliable operation, easy maintenance, and economical operating costs and some other features. It is generally used for coarse and medium crushing of hard and medium-hard rocks with compressive strength does not exceed 320MPa.
Cone crusher: large crushing ratio, high efficiency, uniform product particle size, mainly used for medium and fine crushing of medium-hard rocks.
Impact crusher: can crush materials with a side length of 100-500mm, and its compressive strength can reach up to 350MPa, large crushing ratio and the crushed products are cubical with uniform particle size. Impact crusher is widely used in rock crushing in highway engineering.
Hammer crusher: suitable for crushing various brittle minerals. The crushed materials are coal, salt, gypsum, alum, bricks, tiles, limestone, etc. The compressive strength of the material is not more than 100MPa, and the moisture content should below 15%.
The screening machinery is divided into eccentric vibrating screen, inertial vibrating screen, resonance screen and electromagnetic vibrating screen, which are called vibrating screen; drum screen, fixed grid screen, arc screen and cyclone screen are called fixed screen. Due to their large production capacity, high screening efficiency and the ability to form a combined crushing and screening equipment with crushing machinery, Vibrating screens are widely used in highway and bridge engineering.
Construction period
For projects with a long construction period and relatively concentrated amount of crushed materials, fixed combined crushing and screening equipment should be selected; and for projects with short construction period and relatively scattered amount of crushed materials, especially long linear projects such as highways, portable combined crushing and screening equipment should be selected.
Raw material size
If the size of raw material is large, adopt jaw crusher as primary crushing equipment; when the size of the final products is strict and need to be composed of a certain grade of particles, it is necessary to use a combined crushing and screening equipment, such as combined crushing equipment composed by jaw crusher, cone crusher or impact crusher hammer and screening equipment with a certain size.
Properties of raw material
To crush hard or medium hard rocks, we should adopt jaw crusher as primary crushing equipment; to crush medium hard or soft rocks, we can directly adopt cone crusher, impact crusher or hammer crusher.
While choosing crushing and screening equipment, customers should consider all the indicators comprehensively.
1. Preliminary expenditures
Preliminary expenditures refer to the necessary early investment for the normal operation of the equipment, such as the recruitment and training of relevant personnel, equipment packaging, calibration, certification, and so on.
2. Equipment total price and payment method
The equipment price and payment method are often key considerations for companies with tight funds, which are directly related to the continuity of the project.
3. Installation and relocation costs
The total cost of equipment entry, installation and relocation plus the cost of removal, relocation and clearance. The installation costs include the cost of steel bars and concrete materials used in the foundation, labor costs, and costs for hoisting and coordinating equipment.
4. Operating costs
In addition to the cost of working shift, stopping shift and equipment maintenance of the crushing and screening system, the corresponding blasting production and operation costs should also be included.
1. Reliability of equipment
The reliability of equipment is one of the most important factors in evaluating the technical performance of equipment. Generally, foreign countries require that such products can be used continuously for h without mechanical failure after leaving the factory; according to the requirements of most Chinese manufacturers for the reliability of mechanical equipment, the continuous use period of such machinery in China should be guaranteed within h.
2. Manufacturing process
The manufacturing process is an important prerequisite to ensure the reliability of the equipment. It reflects and measures the technology and management level of the manufacturer.
3. Production efficiency
Production efficiency is an important control parameter in equipment selection. Generally, the upper and lower limits of equipment production capacity suitable for the project can be determined according to the characteristics of the project. There is a certain gap between the actual production capacity of the equipment and the production capacity of the nameplate, which changes with the change of the type, strength, hardness, specification and other factors of the crushed material.
1. condition of blasting rocks
Chunlei Product Page
(1) Type
Select representative rocks for petrographic and chemical composition analysis to identify the types of blasting materials, such as limestone, granite, basalt, etc., and the types and contents of main minerals, accessory minerals, and secondary minerals in the rock.
(2) Strength
Generally refers to uniaxial compressive strength. According to the uniaxial compressive strength of the rock, the rock can be divided into extra-hard rock (250-160MPa), hard rock (160-100MPa), sub-hard rock (100-140MPa) and soft rock (<40MPa).
(3) Hardness
Generally refers to Mohs hardness, which indicates the ability of minerals to resist external mechanical action. It is also a common standard used to identify the relative hardness of minerals. The standard is composed of 10 common minerals, talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum, and diamond, with hardness from 1 to 10.
(4) Moisture content
The general requirement is 2, and the highest is not more than 5%.
(5) Mud content
The general requirement is 1, and the highest is not more than 2%.
(6) Maximum size of side length
Generally, the size of blasting material is not the main parameter of equipment selection. When the main parameters such as production efficiency, product specifications and shape requirements are determined, the maximum size limit of the complete set of crushing and screening system can be determined accordingly. We can control the size of the blasting material by selecting the blasting method and adjusting the blasting parameters to meet the requirements of the crushing and screening system.
(7) Feeding method
Which feeding method is to be selected, such as loading by loader or direct feeding by dump truck, etc.
2. finished products
(1) Total production capacity
Generally, adopt the production capacity per hour as standard. If customers adopt the production capacity per year or month as standard, it is required to determine the annual working days and daily operating hours in order to determine the capacity per hour.
(2) Grading requirements
Generally, there are several specifications such as 05mm, 515mm, 1525mm, 2540mm. According to the construction requirements of the project, determine the engineering quantity of various graduations of aggregates, select the required screen type, aperture and mesh form, such as steel screen or resin screen, square hole or round hole, etc.
(3) Granular requirements
Determine the allowable percentages of needles and flakes for products of various specifications according to the requirements of construction specifications.
(4) Other requirements
For example, whether it is necessary to wash the crushed materials on the vibrating screen.
1. Site topography
Choosing a site with a certain slope to install crushing and screening equipment will help reduce the amount of earthwork. When selecting equipment, pay attention to factors such as the height of the natural drop between the feed opening grade floor and the equipment installation floor, as well as the shape and footprint of the equipment installation floor.
2. Site area
The area of the installation site is generally determined by factors such as the equipment installation area, the location of the feed and discharge opening, the entry and exit of the site and the transportation and traffic in the site, the product storage method, the product specification and storage volume, the generator room, the warehouse, the living facilities, the guard room, etc. .
The prop form of the crushing and screening equipment, the ease of installation, and the amount of foundation steel and concrete are also important factors should be considered in the selection. The movable steel structure support has simple construction, easy assembly and disassembly, rapid transfer, and small foundation reinforced concrete engineering volume and some other advantages. It is suitable for long linear highway projects with scattered demand for raw materials.
1. Source of equipment
Equipment selection should be based on the regional differences in the use environment (such as Asia or Africa), the degree of market development, the versatility of maintenance parts in construction and supply channels, and different sources of equipment should be fully demonstrated and carefully selected.
2. Supply or delivery cycle
In principle, the shorter the supply or arrival period is, the better. However, for the equipment selected or ordered, the manufacturer should have enough time to produce without affecting the progress of the entire project, so as to avoid rushing and affecting the quality of equipment manufacturing.
3. Transportation methods and requirements
Different methods of transportation bear different costs and different risks. Whether there are special requirements for transportation, this indicator also reflects the design level of the manufacturer.
4. After-sales service
After-sales service includes professional technical training, supply, location& price of spare parts, technical testing and equipment maintenance, etc.
1. Maintainability
This refers to the accessibility of maintenance, the interchangeability of spare parts, and the error-proof design for maintenance, etc. It is realized by scientific and reasonable design and good processing technology. In the production process of project, in order to improve the utilization rate of machinery, it is often required that machinery failures can be handled on-site. This requires that the machinery must be convenient to disassemble and assemble, the supply of spare parts must be reliable and interchangeable, and there should be specialized tools for special parts.
2. Spare parts supply
Spare parts supply not only refers to the supply of spare parts in the after-sales service, it also includes the difficulty of obtaining repair parts in addition to the after-sales service organization.
main spare parts of jaw crusher
Project compatibility: refers to the applicability of the introduced equipment and project engineering features.
Fleet compatibility: refers to the degree of matching of the introduced equipment with the existing equipment of the project, such as loaders, dump trucks, etc., and the impact on the matching of existing equipment.
Operational safety: refers to the completeness of equipment safety protection devices.
Operating comfort: refers to the operating conditions of the operator.
Related supporting number: This indicator reflects the degree of equipment operation and automation.
Environmental requirements mean the degree of environmental pollution. The degree of environmental pollution also refers to the influence of equipment installation and operation on the surrounding environment, which mainly reflected in two aspects, dust and noise.
Cone crushers are an important type of crushing machine that is used in many industries. They are versatile, reliable, and durable, making them ideal for use in a wide range of applications. Whether you are in the mining or construction industry, a cone crusher can help you to efficiently and effectively crush materials into smaller pieces.
The cone crusher was first developed in the s by Symons brothers, who were trying to improve the efficiency of crushing machines. The Symons cone crusher was then further developed in the s by a company called Allis-Chalmers. Today, there are many different types of cone crushers available, each with its unique features and capabilities.
One of the main advantages of cone crushers is their ability to crush materials of varying hardness. They are also able to produce a more uniform product size than other crushing machines, which makes them ideal for use in the production of asphalt and concrete.
There are two main types of cone crushers: the standard type and the short head type. The standard type is used for coarse and medium crushing, while the short head type is used for medium and fine crushing. The difference between the two types is that the short head type has a steeper crushing chamber and a smaller feed opening.
Cone crushers are also known for their reliability and durability. They are designed to withstand heavy use and are often used in harsh environments. Many cone crushers are also equipped with advanced technology, such as hydraulic systems, which can help to reduce maintenance and repair costs.
The type of material you will be processing will play a significant role in selecting a cone crusher. Different materials have different properties and characteristics that require different types of crushing equipmentcrushing equipment. For example, hard and abrasive materials such as granite and basalt require a cone crusher with a high capacity and a high reduction ratio, while softer materials like limestone and shale require a cone crusher with a moderate capacity and a lower reduction ratio.
The third factor to consider is the size of the feed material. Cone crushers have a limited maximum feed size, which is the largest piece of material that can be fed into the crusher without causing damage. If your material is too large, it may cause the crusher to jam or break down, so it is important to choose a crusher that is appropriate for the size of your material.
The capacity of the cone crusher is another important factor to consider when selecting a cone crusher. The capacity is determined by the size of the feed opening and the throughput capacity of the machine. The larger the feed opening and the higher the throughput capacity, the more material the cone crusher can process.
Standard cone crushers are used for secondary and tertiary crushing, while short head cone crushers are used for fine crushing. The choice between these two types of crushers will depend on the specific application and the desired product size.
The fifth factor to consider is automation. Cone crushers with advanced automation features can help improve productivity and reduce operating costs. Some cone crushers come with automated control systems that allow operators to adjust the settings from a remote location, reducing the need for on-site personnel.
The sixth factor to consider is mobility. If you need to move the crusher from one site to another, it is important to choose a cone crusher that is easy to transport. Some cone crushers can be mounted on wheels or tracks, making them more mobile and easier to move from one location to another.
The power and efficiency of the cone crusher are also important factors to consider. The power of the cone crusher is determined by the motor size and the hydraulic pressure. The efficiency of the cone crusher is determined by the design of the crushing chamber, the speed of the eccentric shaft, and the length of the crushing stroke.
The maintenance and service requirements of the cone crusher are also important factors to consider. The cone crusher should be easy to maintain and service, with easy access to the main components for inspection and maintenance. The wear parts should be easy to replace and readily available.
The cost of the cone crusher is also an important factor to consider. The cost of the cone crusher includes the initial purchase price, the operating cost, and the maintenance cost. While a more expensive cone crusher may have a higher initial cost, it may be more cost-effective in the long run due to lower operating costs.
Many countries have strict regulations on emissions, noise levels, and dust suppression, so it is important to choose a cone crusher that meets these regulations. Cone crushers with advanced dust suppression systems and low emissions can help ensure compliance with environmental regulations.
Crushing and screening equipment is widely used in the construction of highways, construction, water conservancy, mining, ports and other fields for processing and producing various specifications of crushed stone and sand. How to make a good decision when purchasing crushing and screening equipment? How to buy cost-effective equipment without being taken advantage of? Here are 10 factors need to be considered while purchasing crushing and screening equipment.
The crushing equipment is divided into jaw crusher, gyratory crusher, cone crusher, roller crusher, rotary disc crusher, impact crusher and hammer crusher. The first 5 types are called compression type crushers, and the last 2 types are called impact type crushers.
Jaw crusher: It has large crushing ratio, uniform product size, simple structure, reliable operation, easy maintenance, and economical operating costs and some other features. It is generally used for coarse and medium crushing of hard and medium-hard rocks with compressive strength does not exceed 320MPa.
Cone crusher: large crushing ratio, high efficiency, uniform product particle size, mainly used for medium and fine crushing of medium-hard rocks.
Impact crusher: can crush materials with a side length of 100-500mm, and its compressive strength can reach up to 350MPa, large crushing ratio and the crushed products are cubical with uniform particle size. Impact crusher is widely used in rock crushing in highway engineering.
Hammer crusher: suitable for crushing various brittle minerals. The crushed materials are coal, salt, gypsum, alum, bricks, tiles, limestone, etc. The compressive strength of the material is not more than 100MPa, and the moisture content should below 15%.
The screening machinery is divided into eccentric vibrating screen, inertial vibrating screen, resonance screen and electromagnetic vibrating screen, which are called vibrating screen; drum screen, fixed grid screen, arc screen and cyclone screen are called fixed screen. Due to their large production capacity, high screening efficiency and the ability to form a combined crushing and screening equipment with crushing machinery, Vibrating screens are widely used in highway and bridge engineering.
Construction period
For projects with a long construction period and relatively concentrated amount of crushed materials, fixed combined crushing and screening equipment should be selected; and for projects with short construction period and relatively scattered amount of crushed materials, especially long linear projects such as highways, portable combined crushing and screening equipment should be selected.
Raw material size
If the size of raw material is large, adopt jaw crusher as primary crushing equipment; when the size of the final products is strict and need to be composed of a certain grade of particles, it is necessary to use a combined crushing and screening equipment, such as combined crushing equipment composed by jaw crusher, cone crusher or impact crusher hammer and screening equipment with a certain size.
Properties of raw material
To crush hard or medium hard rocks, we should adopt jaw crusher as primary crushing equipment; to crush medium hard or soft rocks, we can directly adopt cone crusher, impact crusher or hammer crusher.
While choosing crushing and screening equipment, customers should consider all the indicators comprehensively.
1. Preliminary expenditures
Preliminary expenditures refer to the necessary early investment for the normal operation of the equipment, such as the recruitment and training of relevant personnel, equipment packaging, calibration, certification, and so on.
2. Equipment total price and payment method
The equipment price and payment method are often key considerations for companies with tight funds, which are directly related to the continuity of the project.
3. Installation and relocation costs
The total cost of equipment entry, installation and relocation plus the cost of removal, relocation and clearance. The installation costs include the cost of steel bars and concrete materials used in the foundation, labor costs, and costs for hoisting and coordinating equipment.
4. Operating costs
In addition to the cost of working shift, stopping shift and equipment maintenance of the crushing and screening system, the corresponding blasting production and operation costs should also be included.
1. Reliability of equipment
The reliability of equipment is one of the most important factors in evaluating the technical performance of equipment. Generally, foreign countries require that such products can be used continuously for h without mechanical failure after leaving the factory; according to the requirements of most Chinese manufacturers for the reliability of mechanical equipment, the continuous use period of such machinery in China should be guaranteed within h.
2. Manufacturing process
The manufacturing process is an important prerequisite to ensure the reliability of the equipment. It reflects and measures the technology and management level of the manufacturer.
3. Production efficiency
Production efficiency is an important control parameter in equipment selection. Generally, the upper and lower limits of equipment production capacity suitable for the project can be determined according to the characteristics of the project. There is a certain gap between the actual production capacity of the equipment and the production capacity of the nameplate, which changes with the change of the type, strength, hardness, specification and other factors of the crushed material.
1. condition of blasting rocks
(1) Type
Select representative rocks for petrographic and chemical composition analysis to identify the types of blasting materials, such as limestone, granite, basalt, etc., and the types and contents of main minerals, accessory minerals, and secondary minerals in the rock.
(2) Strength
Generally refers to uniaxial compressive strength. According to the uniaxial compressive strength of the rock, the rock can be divided into extra-hard rock (250-160MPa), hard rock (160-100MPa), sub-hard rock (100-140MPa) and soft rock (<40MPa).
(3) Hardness
Generally refers to Mohs hardness, which indicates the ability of minerals to resist external mechanical action. It is also a common standard used to identify the relative hardness of minerals. The standard is composed of 10 common minerals, talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum, and diamond, with hardness from 1 to 10.
(4) Moisture content
The general requirement is 2, and the highest is not more than 5%.
(5) Mud content
The general requirement is 1, and the highest is not more than 2%.
(6) Maximum size of side length
Generally, the size of blasting material is not the main parameter of equipment selection. When the main parameters such as production efficiency, product specifications and shape requirements are determined, the maximum size limit of the complete set of crushing and screening system can be determined accordingly. We can control the size of the blasting material by selecting the blasting method and adjusting the blasting parameters to meet the requirements of the crushing and screening system.
(7) Feeding method
Which feeding method is to be selected, such as loading by loader or direct feeding by dump truck, etc.
2. finished products
(1) Total production capacity
Generally, adopt the production capacity per hour as standard. If customers adopt the production capacity per year or month as standard, it is required to determine the annual working days and daily operating hours in order to determine the capacity per hour.
(2) Grading requirements
Generally, there are several specifications such as 05mm, 515mm, 1525mm, 2540mm. According to the construction requirements of the project, determine the engineering quantity of various graduations of aggregates, select the required screen type, aperture and mesh form, such as steel screen or resin screen, square hole or round hole, etc.
(3) Granular requirements
Determine the allowable percentages of needles and flakes for products of various specifications according to the requirements of construction specifications.
(4) Other requirements
For example, whether it is necessary to wash the crushed materials on the vibrating screen.
1. Site topography
Choosing a site with a certain slope to install crushing and screening equipment will help reduce the amount of earthwork. When selecting equipment, pay attention to factors such as the height of the natural drop between the feed opening grade floor and the equipment installation floor, as well as the shape and footprint of the equipment installation floor.
2. Site area
The area of the installation site is generally determined by factors such as the equipment installation area, the location of the feed and discharge opening, the entry and exit of the site and the transportation and traffic in the site, the product storage method, the product specification and storage volume, the generator room, the warehouse, the living facilities, the guard room, etc. .
The prop form of the crushing and screening equipment, the ease of installation, and the amount of foundation steel and concrete are also important factors should be considered in the selection. The movable steel structure support has simple construction, easy assembly and disassembly, rapid transfer, and small foundation reinforced concrete engineering volume and some other advantages. It is suitable for long linear highway projects with scattered demand for raw materials.
1. Source of equipment
Equipment selection should be based on the regional differences in the use environment (such as Asia or Africa), the degree of market development, the versatility of maintenance parts in construction and supply channels, and different sources of equipment should be fully demonstrated and carefully selected.
2. Supply or delivery cycle
In principle, the shorter the supply or arrival period is, the better. However, for the equipment selected or ordered, the manufacturer should have enough time to produce without affecting the progress of the entire project, so as to avoid rushing and affecting the quality of equipment manufacturing.
3. Transportation methods and requirements
Different methods of transportation bear different costs and different risks. Whether there are special requirements for transportation, this indicator also reflects the design level of the manufacturer.
4. After-sales service
After-sales service includes professional technical training, supply, location& price of spare parts, technical testing and equipment maintenance, etc.
1. Maintainability
This refers to the accessibility of maintenance, the interchangeability of spare parts, and the error-proof design for maintenance, etc. It is realized by scientific and reasonable design and good processing technology. In the production process of project, in order to improve the utilization rate of machinery, it is often required that machinery failures can be handled on-site. This requires that the machinery must be convenient to disassemble and assemble, the supply of spare parts must be reliable and interchangeable, and there should be specialized tools for special parts.
2. Spare parts supply
Spare parts supply not only refers to the supply of spare parts in the after-sales service, it also includes the difficulty of obtaining repair parts in addition to the after-sales service organization.
main spare parts of jaw crusher
Project compatibility: refers to the applicability of the introduced equipment and project engineering features.
Fleet compatibility: refers to the degree of matching of the introduced equipment with the existing equipment of the project, such as loaders, dump trucks, etc., and the impact on the matching of existing equipment.
Operational safety: refers to the completeness of equipment safety protection devices.
Operating comfort: refers to the operating conditions of the operator.
Related supporting number: This indicator reflects the degree of equipment operation and automation.
Environmental requirements mean the degree of environmental pollution. The degree of environmental pollution also refers to the influence of equipment installation and operation on the surrounding environment, which mainly reflected in two aspects, dust and noise.