Precautions for avoiding major errors of bulk mate

Precautions to avoid major mistakes of bulk machinery

the occurrence of major accidents of bulk machinery mainly refers to the collapse of equipment during installation and use, large cracking of local steel structure of equipment, fracture of reducer shaft of important mechanism, causing casualties, etc. To avoid this kind of incident, we should strengthen management in many aspects. From the initial selection, design, installation, use and maintenance and other aspects

1. Correct design is an important guarantee for equipment quality.

the design of bulk material machinery is a relatively complex design process, because the function, capability, parameters, etc. of the equipment often change with different users. Therefore, its mechanism and structure will change accordingly. This change increases the difficulty of design work. In general design, iso5049 and FEM standards are used for bulk material machinery design. But for some specific institutions, therefore: a ≈, at this time, the unit of a is m/s2, which is not necessarily specified in the standard, and design errors will occur. For example, in the design process of the driving part of the crane running gear, the problem of fracture of the reducer output shaft or short bearing life often occurs. The reason is that there are redundant constraints in the design. There are four bearing points on the reducer and the wheel, which are connected by a set of keys, and the reducer shell is fixed on the bench frame with flange multi bolts. There are four bearing points on the same axis. It is impossible for these four bearing points to be installed on the same axis, so shaft breakage and other phenomena will occur. In the design of steel structure of equipment, there is usually no problem with the main body of the beam, because the main body of the beam is continuous. Problems will occur when rounded corners, sharp corners or pin shaft connections occur at a certain point of the beam and its stiffened grid plate needs to transmit force. If it is serious, the whole equipment will collapse. This kind of equipment must have been strictly calculated, but there are problems with the treatment method of local mechanical model calculation and welding treatment method. Therefore, the design of steel structure is an important link in the design of bulk machinery. Compared with the steel structure of other machines, the details of the steel structure of bulk machinery vary widely, and the design of the steel structure of bulk machinery is a complex and meticulous work. It is often in small details that design errors lead to major accidents. The influence of fatigue stress on the structure should be fully considered in some parts of alternating load, and the actual stress should be appropriately reduced in the parts with stress concentration

2. Reliability of the control system

now the control system is generally controlled by PLC, and the reliability has been greatly improved. For the electrical system, the key is the reliability of the execution system and the detection system. The detection system includes various position detection, speed detection and other primary instruments, limit switches. The executive system mainly refers to the frequency converter, contactor and other electrical components

3. Correct operation and use

unnecessary accidents will also occur when the equipment is installed and used improperly. During the installation stage, special attention should be paid to the installation process and lifting process. Pay special attention to the center of gravity position of each part. The installation process is because many structural parts are not fully in place. Special attention should be paid to the use of tooling parts, and attention should be paid not to overload or instability of structural parts. There have been major accidents of equipment collapse and local instability of steel structures during installation on some sites. In the stage of putting into use, the operation shall be strictly in accordance with the operating procedures, and the equipment shall not be overloaded. The equipment should not be used as lifting equipment. In windy weather, the operation shall be stopped according to the provisions of the equipment manual, and the rail clamp and anchor device shall be put into use to prevent the equipment from being blown away by the wind. In daily work, the intactness rate of the equipment should be checked frequently, and problems should be repaired in time. It is important to check whether the main steel structure of the equipment is cracked and whether the connecting bolts are loose and fall off. Whether there is abnormal vibration and noise in each transmission mechanism. Whether all electrical parts are safe and reliable

4. Quality in the manufacturing stage

the quality of equipment in the manufacturing stage is crucial to the reliable use of equipment. From the purchase of raw materials of equipment to the purchase of equipment accessories, the competitiveness of the market will also be further improved. Quality control is required. Radiographic inspection or ultrasonic inspection shall be carried out for important parts of weldments. The welded structural members shall be polished as necessary. The gears and shafts of transmission components shall be properly heat treated to ensure good mechanical performance. The products of welded parts shall be protected by 3-position disengagement. The oil inlet valve cannot be completely closed, and the assembly and forming shall be regular. Transmission parts shall be installed before shipment, and large structural parts shall also be assembled before shipment to inspect the connection size between various parts. The cabinets of the electrical part shall be manufactured by professional manufacturers and comply with the current specifications and requirements