Life testing of corrosion-resistant concrete conveying pipes
1、 Analysis of Core Technology of Wear resistant Rubber Tube
The wear-resistant rubber tube adopts a multi-layer composite structure, consisting of an inner rubber layer, a reinforcement layer, and an outer rubber layer. The inner rubber layer is usually made of high wear-resistant natural rubber (NR) or nitrile rubber (NBR) formula, with a Shore A hardness of 65-75 and a friction coefficient of less than 0.35. It can withstand slurry media with a sand content of 40%. The reinforcement layer is supported under pressure through high-strength polyester curtain or steel wire weaving technology. The single-layer curtain reinforcement structure can withstand a pressure of 0.8-1.5MPa, while the double-layer steel wire weaving structure can extend the pressure range to 2.5-4.0MPa. The outer rubber layer adopts tear resistant neoprene (CR) or ethylene propylene diene monomer (EPDM), and the anti-aging performance is improved by 30% through special vulcanization process. Typical specifications range from an inner diameter of 50mm to 300mm, and the wall thickness can reach 8-20mm according to working conditions.
In terms of structural design, the spiral winding reinforcement process enables the pipe body to have both flexibility and blast resistance, and the bending radius can be reduced to four times the diameter of the pipe. For high wear conditions, some products adopt the "rubber metal composite layer" technology, embedding wear-resistant ceramic plates with a thickness of 1-2mm on the inner wall of the pipe body, which improves the local wear resistance by 200%. Experimental data shows that when transporting crushed stone slurry with a particle size of 5mm, the service life of the composite layer structure is extended by 3-5 times compared to pure rubber pipes.
2、 Special technical characteristics of concrete conveying pipes
Concrete conveying pipes are designed specifically for high-density media, with a special corrugated structure on the inner wall that reduces friction resistance to 60% of that of ordinary smooth pipes. The reinforcement layer uses a four layer high-strength steel wire winding process to increase the blasting pressure to more than 5 times the working pressure. Add UV resistant coating to the outer layer, extending the outdoor service life to more than 5 years. Typical specifications include DN50-DN300, with a single length of up to 6-12 meters, supporting various connection methods such as flanges and clamps.
2、 Application scenarios of concrete conveying pipes
1. In the field of construction engineering
In high-rise pumping construction, the conveying pipe needs to cope with pulse pressure and concrete aggregate impact. A certain super high-rise project adopts double spiral steel wire reinforced pipes. In C50 concrete pumping, the daily average throughput of a single pipe reaches 1200m ³, and the wear rate of the pipe body is reduced by 70% compared to traditional steel pipes. For long-distance transportation, a combination design of "straight pipe+bent pipe" is adopted, with the curvature radius of the bent pipe optimized to 5 times the diameter of the pipe, reducing fluid resistance by 25%. A construction case of a certain bridge shows that the DN150 conveying pipe operated continuously for 1500 hours under a sand content of 35%, with only slight surface wear.
2. Mining and infrastructure engineering
In the transportation of slurry in quarries, wear-resistant rubber pipes need to withstand the impact of coarse aggregates with a particle size of 5-20mm. A certain mining project adopts a rubber lining containing silicon carbide particles, which doubles the wear resistance of the pipe body. When transporting concrete containing 30% coarse aggregate, the continuous use time can reach more than 800 hours.
Typical application scenarios
Construction engineering: In the concrete pouring of high-rise buildings, wear-resistant rubber pipes, as flexible connectors, need to withstand high voltage pulses and particle wear. A certain engineering case shows that when using optimized formula rubber pipes to transport C40 concrete, the daily throughput reaches 1000 cubic meters, the pipe wear rate is controlled at 0.5mm/thousand hours, and the service life is extended by three times compared to traditional products.
In the mud discharge operation, perforated concrete conveying pipes achieve uniform discharge of mud through evenly spaced holes (with a diameter of 30-50mm). Data from a dredging project at a certain port shows that optimizing the hole layout improves the efficiency of mud discharge by 35% and reduces energy consumption by 20%.
3、 Key indicators for selection and maintenance
1. Parameter matching principle
Media compatibility: NBR based rubber hoses are required for transporting cement slurry, while EPDM formula can be used for pure water media.
Pressure adaptation: The peak pressure of the system should be lower than 75% of the nominal pressure of the hose. For example, for a hose with a nominal pressure of 1.6 MPa, the actual operating pressure should not exceed 1.2 MPa.
Wear resistance verification: According to the DIN 53516 standard wear test, the wear of high-quality rubber hoses should be ≤ 0.1cm ³/1.61km (DIN 53516 standard test, volume loss after 500 hours should be ≤ 1cm ³). ）
2. Installation and maintenance specifications
Bending radius: The minimum bending radius of DN100 rubber hose shall not be less than 500mm, otherwise it may cause the reinforcement layer to break.
Temperature protection: In low-temperature environments (below -10 ℃), the hose should be preheated to above 10 ℃ before operation; Insulation sleeves should be installed in high-temperature environments (above 80 ℃) to prevent accelerated rubber aging.
Regular inspection: It is recommended to conduct a visual inspection every 500 working hours, with a focus on potential hazards such as rusting of the steel wire layer and cracking of the adhesive layer, to ensure safe operation.