An efficient and environmentally friendly crushing equipment can increase the efficiency of the entire production line and increase the economic income of the company. But do you know what issues to consider when choosing a device? This is really not as simple as everyone thinks, don't believe it? Look down.

 

Basic principle of equipment selection

 

1. For construction projects with long construction period and relatively concentrated amount of crushed stone, fixed joint crushing and screening equipment should be used; for projects with short construction period and relatively scattered amount of crushed stone, especially for roads. For linear projects, it is suitable to use mobile combined crushing and screening equipment.

 

2. Stone specifications such as stone size are large, and the jaw crusher can be used as the first-stage crushing. When the stone size is strict and needs to be composed of certain grades of stone, it is necessary to use joint crushing and screening equipment. The jaw crusher is a combined crushing device consisting of a cone or a counter-attack type and a hammer crusher, and is matched with a screening device of a certain size and specification.

 

3, the nature of stone broken hard or medium hard stone, should use the jaw crushing equipment as a primary crushing equipment, when crushing medium hard or soft stone, you can directly use cone, counterattack or hammer crusher.

 

Equipment selection considerations

 

1. Economic indicators 1 Pre-expenditure expenses The pre-expenditure expenses refer to the necessary early inputs for the normal operation of the equipment, such as the recruitment and training of relevant personnel, equipment packaging, calibration, certification and so on.

 

2 Total price of equipment and payment method The selling price and payment method of equipment are often the key factors for enterprises with tight capital, which is directly related to the continuity of the project.

 

3 Installation Relocation Cost The cost of equipment installation and relocation, plus the sum of the relocation and clearance costs. The installation cost includes the cost of steel and concrete materials used in the foundation, labor costs and equipment cost for lifting and hoisting.

 

4 Operating expenses In addition to the work shift costs including the crushing and screening system, the cost of parking and maintenance, and the maintenance and repair of equipment, the blasting production and operation costs should be included.

 

2, technical indicators

 

1 Reliability of use Equipment reliability is one of the important factors in evaluating the technical performance of equipment.

 

Generally, foreign countries are required to continuously use 1500-2000h after leaving the factory without mechanical failure. The continuous use period of such machinery in China should be guaranteed to be no fault at 1000-1500h. Reliability is even more important if the operating environment is harsh.

 

2 Manufacturing Process Manufacturing process is an important prerequisite for ensuring the reliability of equipment. It reflects and measures the technical and management level of the manufacturer.

 

3 Productivity Equipment productivity is an important control parameter in the selection of equipment. Generally, an optimistic and pessimistic production capacity can be determined, that is, the upper and lower limits of equipment capacity that are suitable for the project are determined.

 

There is a certain gap between the actual production capacity of the equipment and the theoretical production capacity, which varies with the changes in the types, strength, hardness, and specifications of the fractured materials. The actual production capacity selected should be higher than the average production capacity of the project to ensure a certain margin of production capacity.

 

4 Self-control degree The degree of self-control is the basic indicator reflecting the technical level of the equipment itself. The self-control level of mechanical equipment is a concentrated expression of the technological development level of the entire manufacturing enterprise.

 

3. Product index 1 Stone condition a) Type: Select representative stone materials for analysis of lithofacies and chemical composition, identify types such as limestone, granite, basalt, etc., and the types of major minerals, secondary minerals, secondary minerals in rocks and content. b) Strength: Generally refers to uniaxial compressive strength, which can be divided into special hard rock (250 ~ 160MPa), hard rock (160 ~ 100MPa), sub-hard rock (100 ~ 140MPa) and soft rock (<40MPa). c) Hardness: Generally refers to Mohs hardness, which indicates the ability of minerals to resist external mechanical action. d) Water content: general requirements ≤ 2%, not more than 5%. e) Mud content: general requirements ≤ 1%, not more than 2%. f) Side length size: The feed size should meet the requirements of the crushing equipment, otherwise the wear parts are easy to wear. g) Feeding method: Select which method to use for feeding, such as loading the loader or feeding directly from the dump truck. 2 Expected finished product a) The total output is generally based on how many tons of stone is broken per hour. If the annual or monthly output is used as the standard, it is required to determine the annual working day and daily working time to determine the hourly workload, that is, the expectation. Production efficiency. b) Gradation requirements Generally, there are several specifications such as 0 to 5 mm, 5 to 15 mm, 15 to 25 mm, and 25 to 40 mm. According to the construction needs of the project, determine the engineering quantity of various graded aggregates, and select the appropriate type of screen, pore size and mesh form, such as steel screen or resin screen, square hole or round hole. c) Granular requirements Determine the percentage of needles and flakes allowed for products of various sizes. d) Other requirements If it is necessary to rinse the broken material with water on the vibrating screen.

 

4. Installation site

 

1 Site topography selection The crushing and screening equipment is installed on the site with a certain slope, which is beneficial to reduce the amount of earthwork. When selecting equipment, the focus is on the natural drop height of the feed floor and equipment installation floor, as well as the shape and floor space of the equipment installation floor.

 

2 Site area The site area is generally covered by equipment installation, feeding and discharge location, access to the site and on-site transportation and transportation, product storage methods, product specifications and storage, generator room, warehouse, living facilities, guard room And other factors are determined.

 

5. Foundation and pillars The form of the crushing and screening equipment, the difficulty of installation and the amount of foundation steel and concrete are also a factor to be considered during the selection. The movable steel structure support has the advantages of simple construction, easy assembly and disassembly, rapid transition, and small amount of foundation reinforced concrete. It is suitable for long linear road projects with scattered stone materials.

 

6. Supply 1 Source of supply and supply channel If the equipment is leased, it means that the equipment is rented; if it is purchased, it refers to the equipment agent or manufacturer. When selecting equipment, it should be fully demonstrated according to the regional differences in the use environment (such as Asia or Africa), the degree of market development, the versatility of the repair parts in the construction and the supply channels, and choose carefully.

 

2 The delivery or arrival period is in principle as short as possible, or the delivery period is as short as possible. However, for equipment that is selected or ordered, the manufacturer should have sufficient time to produce it without affecting the progress of the entire project. The phenomenon of catching up with workers affects the quality of equipment manufacturing.

 

3 Transportation methods and requirements Different transportation methods bear different costs, and the risks caused by transportation are also different. Whether the transportation has special requirements or not, this indicator also reflects the design level of the manufacturing company.

 

4 After-sales service The after-sales service here refers to the general technical training, spare parts supply capacity, supply location and price, technical testing and equipment maintenance.

 

7. Equipment maintainability 1 Maintainability This refers to the accessibility of maintenance, the interchangeability of spare parts, and the error-proof design for maintenance. In the implementation process, in order to improve the utilization rate of the machine, it is often required that the mechanical failure can be handled on site. This requires that the machine must be disassembled and assembled easily, the supply of spare parts must be reliable and interchangeable, and special tools for special parts should be provided. Wait. 2 Parts supply This item is originally in the scope of after-sales service, but it is listed separately because of its importance. The supply of repair parts here is not only 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. 8. Equipment Supportability Project Supportability: Applicability of imported equipment and project engineering features. Matching of the fleet: the impact of the imported equipment and the existing equipment of the project, such as loaders and dump trucks, on the existing equipment. 9, man-machine relationship Operational safety: the degree of perfection of equipment safety protection devices. Operational comfort: The machine must have comfortable operating conditions, wide visibility and good air conditioning and ventilation. Related supporting personnel: This indicator reflects the operability and automation of the equipment. 10, environmental requirements The degree of environmental pollution, here is also a general term, refers to the degree of impact of equipment installation and operation on the surrounding environment, mainly reflected in two aspects, namely dust and noise.