Acid storage tank system

Figure 8.17 Acid storage tank system prior to the partial suck in of the horizontal acid tank. Sketched by Jack M. Jamagin.

Improved next-generation ODC with a catalyst based on rhodium [6] promises an even more simplified plant concept. This is due to the fact that this type of ODC does not require polarisation during shut-down as an inert cathode is no longer necessary. The plant can simply be put at stand-by where the anode side, as well as the HC1 circuit, remains pressurised under chlorine saturation. Therefore, re-starting the operation is very simple and the chlorine supply is derived directly from the electrolysis and liquid chlorine evaporation is no longer necessary. Instead, with a liquid chlorine buffer, the system can be re-started from the hydrochloric acid storage tank. 

Thomson s nitrator (See Fig, which is a copy of Fig given in Ref 2) is a shallow earthenware pan, 3.5 ft diam, 10" deep at the sides and 12 deep at the center, where a run-off cock is located. The pan has a false bottom of perforated earthenware segments. Four nitrators are usually connected together by lead pipes so as to be worked as one unit. These pipes are also connected, (thru a gage-box) to the mixed acid storage tanks, to the waste acid tanks, and to the drain system. The mixed acid used at Waltham Abbey consists usually of HN03 21.0, HzSO 70.5, HNOz 0.6 HaO 7.9%... 

The intentions to improve the environment were noble, but the simple vent system design possessed an unrecognized flaw that allowed a minor overfill situation to suddenly and completely destroy the vessel. The acid tank project was rather simple, so the proposal was accepted and no one asked pointed questions like, What happens if the acid storage tank is overfilled by a tank truck (As we shall see, many unforeseen problems have occurred on equipment so simple that a detailed examination of the proposal may have been considered unnecessary in years past.)... 

Rubber lining by the Cold Bond System three of the four phosphoric acid storage tanks, rubber lined for Madras Fertilizers Limited. These three tanks are each 24 metres diameter and 14.4 metres high perhaps the largest in the world ever to be rubber-lined. 

Fig. 4.19 Schematic for anodic protection system for sulfuric acid storage tank.

To borate the reactor coolant system, the operator sets the makeup control system to automatically add a preset amount of boric acid by fully diverting the three-way valve in the pump suction line to the boric acid storage tank, with delivered flow measured at the discharge of the makeup pumps. Dilution operates in a similar feshion. In either case, if the pressuriser level exceeds its control point, the letdown path to the liquid radioactive waste system holdup tanks is automatically opened by the protection and safety monitoring system. 

Acid cleaners based on sulfamic acid are used in a large variety of appHcations, eg, air-conditioning systems marine equipment, including salt water stills wells (water, oil, and gas) household equipment, eg, copper-ware, steam irons, humidifiers, dishwashers, toilet bowls, and brick and other masonry tartar removal of false teeth (50) dairy equipment, eg, pasteurizers, evaporators, preheaters, and storage tanks industrial boilers, condensers, heat exchangers, and preheaters food-processing equipment brewery equipment (see Beer) sugar evaporators and paper-mill equipment (see also Evaporation Metal surface treati nts Pulp). 

Anodic Protection This electrochemical method relies on an external potential control system (potentiostat) to maintain the metal or alloy in a noncorroding (passive) condition. Practical applications include acid coolers in sulfuric acid plants and storage tanks for sulfuric acid. 

It was likely that water entered the storage tank due to condensation of moisture-laden air that was sucked into the tank. As night fell and temperature decreased, moisture would condense and dilute the acid. Airdrying systems were not in good operating order. Suggestions were made to test acid water content, and if the acid was found to contain 10% water or more, acid was to be added to reduce water concentrations to below 5%. 

FIG. 21 Schematic diagram for the production of L-malic acid from fumaric acid using a six-compartment (Zi-Z6) ED stack composed of anionic (a) and cationic (c) membranes, as extracted from Sridhar (1987). As ammonium fumarate is formed, it is enzymatically converted into ammonium malate in an external bioreactor (R). The combined system is also provided with a series of storage tanks for the acidic cathode-(Dl) and anode-(D6) rinsing solutions, raw materials (D2), ammonium fumarate (D3), ammonium malate (D4), and final product (D5). 

In this section we will demonstrate the use of water sprays as a postrelease mitigation measure. The theory and design of water spray systems has been detailed in Chapter 4. The scenario will involve the accidental release of hydrofluoric acid (HF) from a storage tank. Again we will be considering the distance to reach the ERPG-2 concentration for HF of 20 ppm (AIHA, 1992). 

About a year after the system was put in service, the tank was filled via a tank truck, instead of being supplied by the usual pipeline. As the delivery tank truck was unloaded, the acid level rose in the small storage tank. The company representative wanted to top off the tank. 

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