30 Calculated formula As a cause of the proper tension sieve net to break, a secondary vibration that is different from the original vibration of the sieve machine is generated due to looseness of the net, resulting in fatigue destruction of the baseline. Therefore, it is necessary to apply appropriate tension to the sieve net. The figure below is the result of a tensile test of wire mesh and is generally called an S-S curve. The strain is applied to the horizontal axis, and the vertical axis is applied to the tensile load, such as unit width, and this is used as tension. The strain at the surrender point is usually around 1%. Kansai Wire Netting uses the appropriate tension at 0.25 to 0.5 times the surrender point. Therefore, proper tension is the point where 0.25 to 0.5% strain is shown. The higher the opening rate, the less the clogging. ○The processing capacity is improved. ○Sieve separation efficiency increases (beware of misalignment). ○The net is weak and the life span is shorter. ○There is a misalignment, and the opening of the eyes is more likely to be mad. Clogging problem The biggest challenge in sifting is clogging, which has various symptoms as shown below. You need to take measures according to each symptom. Cause of symptoms Increase the amplitude and frequency of vibration of the machine. Increase the opening rate by narrowing the wire diameter. Manage the tension of the net and make it the optimal tension. Take measures to prevent clogging, such as tapping balls and chain installations. Tonncap wire mesh and tierod wire mesh will be examined. The vibration of the machine is weak. The opening rate is low. The tension of the net is weak. We are not taking measures to prevent clogging. The shape of the mesh. A particle of a size close to the size of a mesh in one mesh is clogged so that each mesh is pierced one by one. It has a net wire and three to four contact points, making it the most difficult to remove. A two-stage system is used to remove long items separately. It's caught in the net. It occurs when long things such as lint, piece of cloth, wire are contained. Reduce the supply. Change the vibration condition of the machine. Take measures to prevent clogging, such as tapping balls and chain installations. Take measures to remove electricity such as earth, corona discharge, and humidification. There is a lot of supply. We are not taking measures to prevent clogging. It depends on static electricity. Particles smaller than the mesh in one mesh are gathered together and pressed together. Generally, it is easy to supply. Single clogging collective clogging adhesion clogging clogging 5 0.5% 1.0 10 15 strain (%) 20 25 tension (N/mm) opening rate 25% opening rate 40% opening rate 60% “Sift reading book” Shigeo Miwa 0 Reduce or remove water. Take measures to remove electricity such as earth, corona discharge, and humidification. Increase the amplitude and frequency of the machine. Consider a tonncap wire mesh with a rectangular mesh and a tie rod wire mesh. Consider fluoropolymer coating. It depends on water. It depends on static electricity. Others Particles are stuck and packed. d A Ｇ： Estimated weight (kg/m) A: Eye opening (mm) ε: Opening rate (%) G = 12.7 × d A+d G = M × d 2 2 2 A+d A = 2 × 100 εd M 25.4 = A M: Mesh d: Line diameter (mm)
RkJQdWJsaXNoZXIy NDY3NTA=