Centrifugal pumps are widely used in petrochemical, coal chemical and other chemical industries, the transmission of different nature of the liquid to provide the chemical reaction pressure, flow. Centrifugal pump of a wide range, according to the nature of the transmission medium can be divided into acid pump, alkali pump, water pump, mud pump. Transmission medium temperature and working pressure of different, therefore, effectively extend the life cycle of centrifugal pumps and reduce the amount of maintenance, to improve the economic efficiency of the plant has a significant role.
1, centrifugal pump selection and installation
Centrifugal pumps should be selected according to the liquid being conveyed and to check the required performance, analyze the suction, discharge conditions, intermittent operation or continuous operation. Centrifugal pumps should normally be operated at or near the pressure and flow rates specified by the manufacturer's design. The pump should be installed for the following review:
â‘ The basic size, location and elevation should meet the design requirements. The anchor bolts must be properly and correctly fixed on the concrete foundation. The machine should not be missing, damaged or corroded.
â‘¡ According to the characteristics of the pump transmission medium, if necessary, check the main parts, shaft seals and gasket material;
â‘¢ Pump leveling, find work should be consistent with the provisions of technical documents, if there is no provision, should be consistent with the existing national standards, "Machinery and Equipment Installation Engineering Construction and Acceptance of Common Specifications" requirement;
â‘£ All connected with the pump pipe, pipe fittings and oil pipe cleaning requirements should be consistent with the relevant national standards.
2, the use of centrifugal pumps
Pump running test should meet the following requirements:
â‘ drive the steering should be the same with the pump steering;
â‘¡ identify the pipeline pump and coaxial pump steering;
Ã‚ 'Â¢ the fixed connection should be no loose parts, the lubricating parts filling lubricant specifications and quantity should be consistent with the provisions of technical documents;
â‘£ pre-lubrication requirements of the site should be pre-lubricated;
â‘¤ all indicating instruments, safety devices should be sensitive, accurate and reliable;
â‘¥ crank should be flexible, no abnormalities;
â‘¦ high temperature pump should be carried out before commissioning pump body preheating, the temperature should rise evenly, the temperature rise per hour should not exceed 500 â„ƒ; pump the surface of the working medium with a working medium inlet temperature difference should not exceed 4090;
â‘§ set to eliminate the impact of temperature rise of the connection device, set the bypass connection device to provide cooling water.
Centrifugal pump operation should note the following:
â‘ prohibit anhydrous operation, do not adjust the suction port to reduce emissions, prohibit the operation of low flow;
â‘¡ monitor the operation of the process, completely prevent the stuffing box leak, replace the stuffing box with a new filler;
â‘¢ to ensure that mechanical seals have a full flush of water, water-cooled bearings prohibit the use of excessive water flow;
â‘£ lubricant do not use too much;
â‘¤ according to the recommended cycle of inspection. Establish operating records including operating hours, packing adjustments and replacements, adding lubricants and other maintenance measures and times. Centrifugal pump suction and discharge pressure, flow, power input, lotion and bearing temperature and vibration conditions should be measured regularly recorded.