About high-speed pumps

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I. Overview: This pump is a special high-speed pump designed specifically for transporting media with high head and low flow rates, those that are prone to vaporization, as well as other petrochemical products that do not contain particles. Performance range of the SHP series high-speed pumps: Flow rate: Q=2~30 m3/h; Head: H=100~850 m. SHP 50-32-7/560. I. Working principle of centrifugal pumps: As the liquid rotates with the impeller, it is thrown outward from the center of the impeller under the effect of inertial centrifugal force, thereby gaining energy. This increases the static pressure of the liquid flowing toward the periphery of the impeller and raises its flow velocity. The liquid leaves the impeller and enters the volute, where the flow path gradually widens, causing the fluid velocity to decrease; part of the liquid’s kinetic energy is converted into static pressure energy. Thus, the liquid with higher pressure enters the discharge pipeline from the pump’s discharge port and is delivered to the desired piping system. II. Performance parameters of centrifugal pumps 1. Flow rate (Q): The volume of liquid delivered by the centrifugal pump to the pipeline system per unit time, with common units being L/s or m3/h ； 2. Head (H): The effective energy that a centrifugal pump can provide per unit weight of liquid, measured in meters ； 3. Efficiency (h): Not all of the energy supplied to the pump shaft by the prime mover is transferred to the liquid; efficiency is used to indicate the energy losses ； 4. Shaft power (N): Refers to the power required by the pump shaft of a centrifugal pump, with units of W or kW. III. Structural composition: The lubrication system of a vertical high-speed pump’s speed increase gearbox is primarily composed of the following components: the oil sump of the speed increase gearbox, the main oil pump, the oil cooler, the oil filter, the pre-lubrication auxiliary system, and the associated piping. It is used for transporting liquid media that may contain a small amount of solid particles, such as acids, alkalis, salts, benzene derivatives, pharmaceutical solutions, and water. The temperature range for the transported media is from -200 to +300°C. It can be widely applied in industrial fields such as petroleum, petrochemicals, pharmaceuticals, metallurgy, papermaking, electricity, food, and light industry. IV. Preparations before startup (1) Inspection (2) Check that the pump’s foot bolts and the motor’s flange connection bolts are firmly tightened. (3) Check that the motor’s power cable and ground wire are connected correctly. (4) Check the cooling water pipeline of the oil cooler; it should be properly connected with no leaks. (5) The instruments related to pump operation should be in good working condition. (6) Check the correctness of the connection of the mechanical seal auxiliary control system. (7) Fill the reduction gearbox with oil. If there is rust preventive oil inside the gearbox, it should be removed first. (8) The physical and chemical properties of the lubricating oil shall meet the requirements specified in Table 1, and it shall be filtered through three stages of filters with mesh sizes of 60, 80, and 100. (Lubricant properties) Specific gravity: 0.875. Kinematic viscosity: 40.59 cSt at 40°C, and 7.4 cSt at 100°C. Viscosity index: 150. Flash point: 202°C. Freezing point: below -40°C. Acid number: 0.97 mgKOH/g. Residual carbon: 0.20 wt%. Recommended products include (1) N46 hydraulic fluid from group H of GB7631.2−87, and (2) Shell‖D fluid specifically designed for automatic transmissions. The allowable operating temperature is 0°C to 80°C, with the optimal temperature range being 40°C to 70°C. (9) Remove the cover and nozzle of the exhaust fuel filler, fill the tank using a flexible tube, and at the same time open the valve located below the flexible tube to allow exhaust. Fill with approximately 8 liters of oil (excluding the amount stored in the auxiliary pipelines and oil cooler), until the oil level reaches 1/4 of the way up from the top of the sight glass, and then install the cover nozzle and plug. (10) Pre-lubrication system test. (11) Move the handle of the manual oil pump up and down or start the electric oil pump; observe the oil pressure on the lubricating oil pressure gauge – a pressure of not less than 0.1 MPa⋅G is considered acceptable. (12) Check the seal integrity of the lubrication oil circuit under pressure; any oil leaks should be rectified. (13) Recheck the oil level in the gearbox; if it is low, top it up with oil. (15) Open the inlet valve of the pump to fill it, ensuring that the pump chamber is completely filled with liquid. (16) Open the port 6 on the seal to discharge the air or medium vapor from the pump chamber. For low-temperature or high-temperature media, the pump needs to be pre-cooled or pre-heated. Note: When the mechanical seal type is a dual-seal or tandem seal, the seal buffer fluid should be introduced first, followed by the pump. (17) Adjust the motor direction. (18) Remove the protective cover of the motor cooling fan. (19) For motors tested with oil pressure points, the rotation direction of their fans should be consistent with the direction indicated on the product’s orientation label; that is, viewed from the top of the motor, it should be in a counterclockwise direction, and the rotation direction of the pump impeller should be the same as that of the motor. (20) Supply cooling water to the oil cooler. (21) Start the mechanical seal auxiliary control system to keep it in good condition. V. How to enable it: (1) Slightly open the pump outlet valve. The pump cannot be started with that valve closed. (2) Operate the manual oil pump handle up and down 4 to 5 times, or start the electric oil pump for about 30 seconds; if the oil pressure is not lower than 0.1 MPa, the main pump can be started with this oil pressure. Once the main pump starts, the manual oil pump should be stopped, or the electric oil pump should be turned off within 5 to 7 seconds. (3) Adjust the opening degree of the pump outlet valve to the pump’s operating flow rate point. (4) Check the pump’s head and the motor’s current and voltage, and compare them with the values indicated on the product label. (5) Adjust the cooling water flow to keep the gearbox oil temperature between 40 and 70°C. It takes about an hour for the oil temperature to stabilize. (6) Check the lubricating oil pressure gauge of the gearbox; its reading should be within the range of 0.2 ~ 0.6 MPa⋅G. (7) Observe the leakage of the seal. VI. Operations during shutdown (1) If, after the pump starts up, the head, oil pressure, oil temperature, seal condition, or motor current and voltage are abnormal, the pump should be shut down immediately. Its faults are eliminated using the methods described in the sections on \"Pump and gearbox fault handling\" and \"Mechanical seal fault handling\". (2) When shutting down the pump, the pump outlet valve should be closed gradually first, then the power supply should be cut off, and finally the pump inlet valve should be closed. VII. Maintenance (1) While the pump is in operation, if abnormal parameters or unusual noises are detected, the pump should be stopped immediately for inspection. (2) After the pump is reassembled, the oil level should be checked after it has been running for 24 hours; if the oil level is below the specified range, oil should be added, and this can also be done while the pump is running. The oil level must not be above the specified level, otherwise excessive foam will be generated, leading to overheating or failure of the bearings at the lower part of the intermediate shaft. (3) After the pump has run for 4,000 hours, it should be shut down to replace the gearbox lubricant and oil filter. Pay constant attention to changes in the oil color.