How to completely replace an ammonia pump, including the pump body and outlet piping?
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This post was last edited by 1025199692 on 2009-10-20 at 19:42. Close the first inlet valve and the second outlet valve; open the auxiliary line to release ammonia from within the pump. Open both outlet valves and use the auxiliary line discharge pipeline to release ammonia. Close the first outlet valve. Connect a drainage hose between the valves, and fill them with water using the coagulant solution from the supply station for displacement. Lead the drainage hose outside the building; once the water has no odor, it is ready.
Our ammonia equipment and pipelines are not cleaned using water at all; we simply direct the fluid to the flare, or connect hoses to it to send it to the flare as well, and then use N2 for purging before sending it to the flare.
We first depressurize the pump body, and then replace it with instrument air in the tail suction tower.
It should be noted that if an ammonia pump needs to be drained and replaced for maintenance, first ensure that the operating pump is functioning properly. Then close the outlet valve and inlet valve of that pump, and control the amount of fluid discharged using the drain valve located between the outlet valves. Once it has been confirmed that no ammonia is escaping from the ammonia tank and all the liquid ammonia in the pump has been drained, connect a quick-connect fitting to the inlet to fill it with water for replacement. After ensuring that no odor is emitted from the outlet, stop the water flow, turn the pump shaft to drain any remaining water, and verify that there is no internal leakage in the inlet and outlet valves. Finally, stop the oil pump, cut off the power supply, and proceed with the maintenance work.
For the replacement of an ammonia pump, it is generally sufficient to replace just the pump itself; the outlet pipe is not necessary, unless maintenance is required. Water or air can be used for replacing the ammonia pump, as long as the requirements are met. It is best to avoid wasting ammonia by recycling it, in order to save energy and reduce emissions.
Although water is the best solvent for absorbing ammonia, it is not recommended to use water for displacement, as the equipment involved in this process is made of carbon steel. The traditional method involves first releasing the liquid ammonia in the equipment/pipelines into an ammonia solution tank (with a pipe inserted at the bottom of the tank); once the pressure reaches normal levels, nitrogen is introduced for displacement (air can be used in cases where nitrogen is not available). While introducing the gas, the pump should be rotated slightly, and it is necessary to check that there is no odor coming from the outlet of the rubber hose.