Tank filling operations generally

Process operations. The third source of process waste we can classify under the general category of process operations. Operations such as start-up and shutdown of continuous processes, product changeover, equipment cleaning for maintenance, tank filling, etc. all produce waste. 

These are actions of the computer which are initiated by events, e.g. switching off a pump when a tank has been filled to a certain level. They form the basis of the response of computer-controlled plant to alarm conditions, e.g. if the temperature in the reactor described in Fig. 7.102 exceeds a specified value then action must be taken by the computer, such as rapidly increasing the flow of coolant or reducing the feed to the reactor. Generally, sensor-initiated operations must be performed within a specified maximum time interval and are often in the form of alarm interrupts (Section 7.18.3). Smaller systems will regularly scan a set of specific process variables via a multiplexer to see if any action is necessary. The latter arrangement is called polling. 

For almost every case, operation without a vortex is desirable, both because performance is generally better and because the absence of the vortex often eliminates a variable-group otherwise necessary to account for gravitational forces. As discussed in Sections II and III, operation with baffles, with particular propeller locations, or with completely-filled closed tanks will eliminate vortexing. 

In road tankers transporting different chemicals in the same rubber lined tankers is a common practice since it is uneconomical to have the tank lined for each type of acid/chemical. In this case, it is advisable to rinse the tank with water before filling up different chemicals each time. In general, the transportation tankers such as railway tankers, road tankers and ship tankers have dimensions, which can still be vulcanised in autoclaves [4]. The size of the tank is limited by the maximum size of the autoclave and also depends on the feasibility to transport them before and after rubber lining. The author s opinion is that the maximum size of the autoclave can be 5 m diameter x 10 m long which is considered to be a techno-economically viable size for factory operations, which in most cases can accommodate road tankers, railway tankers and ship tankers. 

The electronic circuit is mounted on a portable relay rack. In this manner, one power supply can service a number of liquid metals operations. In general, this device is most useful in filling a closed system to a known level. An important accessory for the electronic probe is a small, completely welded cylinder of pipe half filled with sodium and having a 1-inch well or thimble for the probe. Using this portable cylinder as a test tank of known level, one can quickly balance the electronic circuit for proper operation. 

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