Time : 2024-01-18 Browse : 11
Climate has a significant impact on the normal operation of fluid couplings, especially for speed-regulating hydrodynamic couplings used in open or semi-open environments. There have been multiple accidents of input end bearing seizure in fluid couplings under harsh climatic conditions. Through analysis, the main issues of fluid couplings affected by climate and corresponding correct operating procedures are as follows:
Main Issues and Causes of Fluid Couplings Caused by Climate:
I. Lubrication Failure in Turbo Couplings Due to Low Temperatures
In extremely low temperatures, the working oil of turbo couplings is prone to condensation, and the lubricating oil pipes may freeze. This deprives the bearings and gears of turbo couplings of lubrication, leading to dry friction that generates heat, causing bearing seizure. In severe cases, it may even ignite the working fluid of turbo couplings.
II. Aggravated Failures Due to Improper Operation of Fluid Drive Couplings
When restarting a shutdown fluid drive coupling without heating the working oil and cooler, the extremely low temperature of the working oil, tank, and cooler during shutdown can cause the working oil to condense and stop circulating. This freezes the lubricating oil pipes, resulting in oil starvation and damage to the bearings and gears of fluid drive couplings.
III. Failure to Detect Abnormalities in Hydraulic Couplings in Time
If operators neglect changes in the oil pressure gauge and oil temperature gauge of hydraulic couplings, abnormalities (such as no pressure due to oil pump suction failure or pressure rise due to condensed working oil in the cooler causing circulation interruption) may go undetected, leading to serious accidents in hydraulic couplings.
IV. Water Contamination in Fluid Couplings Blocking Pipes
When water is mixed in the working oil of fluid couplings, freezing water can block the pipes, interrupting the circulation of the lubrication system in fluid couplings.
Correct Operating Procedures for Hydrodynamic Couplings:
I. Selecting Appropriate Working Oil for Turbo Couplings
Turbo couplings should use No. 6 or No. 8 hydraulic transmission oil instead of L-TSA32 turbine oil. L-TSA32 turbine oil has a pour point of -7℃, which easily causes working oil condensation in freezing conditions; in contrast, No. 6 hydraulic transmission oil (pour point -30℃) and No. 8 hydraulic transmission oil (pour point -35℃) are more suitable for turbo couplings in low-temperature environments.
II. Preheating Hydrodynamic Couplings Before Startup
Before starting hydrodynamic couplings, electric heaters must be used to heat the working fluid until the temperature reaches above 10℃. Meanwhile, exposed lubricating oil pipes of hydrodynamic couplings should be warmed with hot water to ensure all oil pipes are unobstructed.
III. Special Handling for Fluid Drive Couplings in Severe Cold
In severe cold weather, to prevent working oil condensation in the cooler of fluid drive couplings, the cooling water flow can be appropriately reduced. When restarting after shutdown, the cooler shell of fluid drive couplings must be heated with hot water to ensure oil in the cooler does not condense and the oil circuit remains unobstructed.
IV. Dedicated Monitoring During Test Operation of Hydraulic Couplings
Test operation of hydraulic couplings must be monitored by a dedicated person at the machine, who should stop the machine immediately upon detecting abnormalities.
V. Paying Attention to Instrument Data of Fluid Couplings
Always monitor the oil temperature gauge and oil pressure gauge of fluid couplings. If the inlet oil temperature is below 35℃, or the outlet oil pressure is below 0.05MPa or above 0.35MPa, shut down the fluid coupling for inspection and restart only after confirming no faults.
