Assembly and operation of IH-type chemical centrifugal pumps

Thread Content

Assembly and operation of IH-type chemical centrifugal pumps. The IH chemical centrifugal pump is a single-stage, single-suction cantilever centrifugal pump; its designation, rated performance parameters, and dimensions are in accordance with the international standard ISO 2858-1975 (E). It has been designated by the Ministry of Machinery Industry as a replacement for F-type corrosion-resistant centrifugal pumps, offering energy savings and being suitable for transporting corrosive liquids with viscosity similar to that of water in chemical processing systems. The temperature of the medium transported by IH chemical centrifugal pumps is generally between -20°C and 105°C; appropriate cooling measures can be employed if necessary, allowing the temperature of the transported medium to be even higher. Installation of IH chemical centrifugal pumps: 1. After unboxing, inspect the pump and motor. If it is confirmed that there is no damage resulting from installation, disassembly, or transportation, and that the fastening connections are secure, as well as that the inlet and outlet covers of the pump are intact with no dust or dirt inside the pump, then there is no need to disassemble and reassemble it; it can be taken directly to the installation site. 2. The base surface on which the pump is installed should be leveled using a level. Once the cement in the foundation has set, the pump should be placed on this base, and a level should be used to check whether the pump and the motor shaft are level. If they are not level, shims should be used to adjust them until they are level. Then, the base and the holes for the anchor bolts are filled with cement through the grouting holes. 3. After the cement has hardened, check whether the base and the anchor bolt holes are loose. Once satisfied, tighten the anchor bolts and recheck the levelness. 4. When the motor pump and base are reinstalled, the concentricity of the pump shaft and the motor shaft must be carefully checked. The difference in the outer diameter of the couplings between the top, bottom, left, and right sides must not exceed 0.1 millimeters, and the maximum and minimum gaps around the joint surface between the two couplings must not exceed 0.3 millimeters. 5. The suction and discharge pipes of the pump should each have their own supports; it is not allowed for the weight of the pipes to be borne directly by the pump, in order to prevent the pump from being damaged. 6. When the pump is installed at a height above the liquid level (within the range permitted by the pump’s suction head), a foot valve should be installed at the end of the suction pipeline, and a filling screw hole or valve should be provided on the discharge pipeline. For filling the pump before starting. When the pump is installed below the liquid level (in a flooded condition), a control valve and a filtering device should be installed on the pump’s suction line to prevent foreign objects from entering the pump. Use of IH chemical centrifugal pumps: 1. Starting 1) Prepare the necessary tools. 2) Check the oil level in the oil reservoir of the suspension assembly; it should not be too high or too low. 3) Check whether the motor’s rotation direction is correct. Reversing is strictly prohibited. 4) When turning the coupling by hand, it should feel easy to operate with even force; pay attention to checking for any friction sounds or noises caused by foreign objects moving inside the pump. If such noises are present, they must be eliminated, and the protective cover of the coupling should be installed properly. 5) When the pump is installed below the liquid level (in a filled condition), the gate valve on the suction line should be opened before starting the pump, so that the pump is filled with liquid. If the pump is installed above the liquid level (in a vacuum condition), it is necessary to fill the pump or create a vacuum before starting it, in order to fill both the pump and the suction line with liquid and remove any air from within the pump. 6) Turn off the inlet and outlet pressure (or vacuum) gauges as well as the gate valves on the discharge pipeline. Start the motor (it is best to do a test run first to confirm that the pump rotates in the correct direction before starting it fully), turn on the inlet and outlet pressure gauges, and then slowly open the gate valve on the outlet pipeline to the desired position. 2. Inspection 1): It is necessary to regularly check the temperature rise of the pump and motor; the temperature rise of the bearings should not exceed 35°C, while the maximum allowable temperature should not be higher than 75°C. 2) Pay attention to changes in the oil level in the oil reservoir of the suspension body; it should be kept within the specified range at all times. To maintain oil cleanliness and proper lubrication, new oil should be replaced regularly based on the actual operating conditions on site. Generally, the oil should be completely replaced once every 1,500 hours of operation. 3) During operation, if abnormal noises or other faults are detected, the machine should be stopped immediately for inspection; it can resume operation only after the fault has been resolved. 4) It is strictly prohibited to use the gate valve on the suction line to regulate flow, in order to avoid cavitation. 5) Pumps should generally not be operated for extended periods at a flow rate lower than 30% of their design flow rate. If operation under such conditions is necessary, a bypass pipe should be installed on the outlet pipeline to ensure that the pump’s flow rate remains within the specified range. 3. Parking 1) Slowly close the pressure outlet pipeline gate valve and stop the motor. 2) Turn off the inlet and outlet pressure (vacuum) gauges; also close the suction line valve when filling. If external liquid introduction is used for sealing, the external liquid introduction gate valve must also be closed. 3) When the ambient temperature is below the freezing point of the liquid. The liquid inside the pump must be completely drained to prevent freezing and cracking. 4) For pumps that have not been in use for an extended period of time, in addition to draining out any corrosive liquids inside the pump, it is also necessary to rinse them thoroughly with clean water; in particular, the sealing chamber must be cleaned carefully. It is best to remove the pump, clean it, reinstall it, seal its inlet and outlet, and store it properly.