Instrument vessel sketch

Level, pressure, and temperature instruments are used to control the operation of the drum and should, be placed in a position for optimum operation and maintenance. Instrument requirements are usually highlighted on an instrument vessel sketch furnished by the instrument engineer assigned to the project. Exhibit 5-29 is a typical instrument vessel sketch. 

Level instruments are located in the liquid section of the tower, usually at the bottom. The elevation of the nozzles is dictated by the amount of liquid being controlled or measured and by standard controller and gauge glass lengths. This information is furnished on the instrument vessel sketch. Exhibit 10-35 illustrates level instrument requirements. 

For example, the platform elevations shown on the process vessel sketch in Exhibit 10-3S> are the minimum requirements for instrument, valve, and maintenance access. Exhibit 10-50 displays a platform arrangement for the tower using the information in Exhibit 10-39 and the guidelines in this chapter. 

In this section we would like to address in brief the problem of wall adsorption. By this we understand the phenomenon that any gas or Uquid contacting the inner surfaces of vessels, tubes, valves etc. of any device will be adsorbed to a certain, though normally only tiny, amount on them. This phenomenon first has observed in gas thermometers at very low temperatures i. e. low gas pressures [4.20]. Here it added considerably to the uncertainties of measurements. The same can be tme for volumetric or volumetric-gravimetric adsorption measurements at low pressures or if only very small amounts of sorbent material - say 100 mg or less - are available, cp. Chap. 2. Therefore it sometimes may be necessary in setting up mass balances for adsorption measurements to take this phenomenon into account. A possibihty to do this is to measure it. This on principle can be done by using the instrument sketched in Fig. 4.20 below. It mainly consists on three parts a gas storage vessel (SV) equipped with a piston to change its volume (Vsv) and... 

We also would like to draw reader s attention to the possibility to combine oscillometric, gravimetric, and manometric measurements in a single experiment. The schematic diagram of such an instrument is given in Figure 5.16. It basically consists of a rotational pendulum, a microbalance (two beams as indicated in Fig. 5.16 or single beam as sketched in Fig. 5.15) and a storage vessel for the sorptive gas. This instrument would allow cosorption... 

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