Precautions for the Use of Multi-stage Pumps in Snow Makers

The snowmaking season of ski resorts is mostly in a low-temperature environment, and multistage centrifugal pumps need to operate continuously for a long time. The core of daily operation and maintenance is to "prevent low temperature, blockage and failure" to ensure stable equipment operation and extend service life. Combined with the characteristics of multistage centrifugal pumps and the working conditions of ski resorts, the specific operation and maintenance points are as follows :

(I) Pre-startup Inspection: Complete Preheating and Inspection to Avoid Cold Start Damage

1. In a low-temperature environment, ice is likely to form in the pump body and pipelines. Before starting the machine, it is necessary to thoroughly remove the ice in the pump body and pipelines. Methods such as hot water flushing and heat preservation heating can be used to ensure that the pump body and pipelines are free of ice and blockage; at the same time, check the sealing of the pipeline connection parts to prevent high-pressure water leakage .

2. Check the lubricating oil level and oil quality in the pump to ensure that the lubricating oil is sufficient, free of deterioration and ice. If the viscosity of the lubricating oil increases due to low temperature, replace it with lubricating oil suitable for low-temperature environments to avoid bearing wear; manually rotate the rotor to ensure flexible rotation without jamming .

3. Check whether the motor rotation direction is consistent with the requirements of the centrifugal pump, open the air release valve at the outlet flange, fill the pump with water, discharge the air in the pump to prevent cavitation; close the gate valve and pressure gauge cock on the discharge pipe to prepare for startup.

4. Check whether the pressure and flow monitoring instruments are normal and whether the parameters of the frequency conversion control system are set reasonably to ensure that the operating parameters can be monitored and adjusted normally after the equipment is started .

(II) In-operation Monitoring: Real-time Status Control and Timely Handling of Abnormalities

1. After the equipment is started, slowly open the outlet gate valve, adjust to the required pressure, and closely monitor the operation status of the pump: focus on observing whether the pressure and flow are stable. If the pressure fluctuates greatly or the flow is insufficient, timely check whether the pipeline is blocked, the impeller is worn, or the snowmaker nozzle is blocked .

2. Monitor the temperature of the pump body and motor. The temperature of the pump body should be controlled within the normal range (≤80℃), the bearing temperature should not exceed 35℃ of the ambient temperature, and its limit temperature should not be greater than 75℃; if the temperature is too high, stop the machine for inspection, check for insufficient lubricating oil, bearing wear, pipeline blockage and other problems to avoid equipment burnout .

3. Listen to the operation sound of the pump body. During normal operation, there should be no abnormal noise or severe vibration. If there is abnormal noise or excessive vibration, it may be due to unbalanced impeller, damaged bearing or offset pump shaft, and the machine should be stopped for maintenance in a timely manner .

4. Pay attention to the leakage at the sealing part. The normal water leakage in the packing chamber or mechanical seal chamber should be 30-60 drops per minute. The compression degree of the packing gland or mechanical seal gland should be adjusted at any time to avoid excessive leakage affecting the pressure or insufficient leakage leading to overheating and damage of the seal .