Liquid pump, unloading with

Huge oil tankers easily load and unload liquid petroleum, as shown in Figure 19.9. On land, petroleum can be pumped vast distances via a network of pipelines. Coal, on the other hand, must be dug out of the ground with heavy machinery and shipped as solid cargo, usually aboard trucks or freight trains. 

The plant operator opened the nitrogen valves that were both upstream and downstream of the plants nitrogen pressure regulator to pad the truck. The truck manifold that was in front the right rear wheels contained a pressure gauge that read the expected 20 psig (1.36 bar). The operator opened the proper liquid delivery valves, started the unloading pump, and left to handle other chores. The driver stayed with the truck, as was the normal procedure. 

More recently, Ablcht [34] proposed a controlled dynamic titrator which operates Inversely to the above-described system, so that the titrant flow-rate is maintained constant while that of sample changes with time. Figure 7.19a shows the titrator. The liquid samples to be measured are placed on the sampler. Every 2 min the sampling burette takes a new sample and unloads it Into the mixing cell as It sends a suitable order for the titration to be started. The flow of titrant Is activated simultaneously with that of the sampling burette. A second pump supplies the cell with a constant flow of solvent, which mixes homogeneously with the sample and titrant. After a short reaction tube, the mixture enters the detector flow-cell, from which It is... 

The venting arrangement is an integral part of a loading or unloading system. Figure 9.37 shows a connection at the pump and two at the loading spot, near the flexible connections. Each vent line contains a trap with liquid detection to keep liquid out of the vent scrubber and chlorine recovety systems. 

The tank is usually filled with the liquefied oxygen from the liquefaction unit, although sometimes it can be stocked up with liquid from tanker track. The unloading operation is performed by means of cryogenic pumps, which fill the tanker tracks for final distribution. A drain system is also installed on the inner vessel to allow the complete removal of the stored liquid in emergency conditions. 

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