Acid tank

Tanglefoot Tame acid Tank cars Tank cells Tanks... 

Water rinsing To rinse, wash the surface in clear, continuously running water to remove all traces of acid from the surface. Two or three dips at room temperature will be sufficient. The details of tank will be similar to those for the acid tank but without any heating arrangement. 

Materials that are corrosion resistant to the expected cathodic polarization qualify as impressed current cathodes. Austenitic CrNi steels are used with strong acids. The oleum (i.e., fuming sulfuric acid) and concentrated sulfuric acid tanks used in sulfonating alkanes and in the neutralization of sulfonic acids are anodi-cally protected using platinized brass as cathodes [15]. Lead cathodes are used to protect titanium heat exchangers in rayon spinning baths [16]. 

The first vessel in the blowdown system is therefore an acid-hydrocarbon separator. This drum is provided with a pump to transfer disengaged acid to the spent acid tank. Disengaged liquid hydrocarbon is preferably pumped back to the process, or to slop storage or a regular non-condensible lowdown drum. The vented vapor stream from the acid-hydrocarbon separator is bubbled through a layer of caustic soda solution in a neutralizing drum and is then routed to the flare header. To avoid corrosion in the special acid blowdown system, no releases which may contain water or alkaline solutions are routed into it. 

An 80 m3 tank fiberglass-reinforced plastic acid tank was blown apart at the base as the result of overpressure. The vent had been slip-plated so the tank could be entered for inspection. The steel slip-plate was covered with a corrosion-resistant sheet of polytetrafluoroethylene. Afterward, when the slip-plate was removed, the sheet was left behind. This did not matter at the time, as the tank was also vented through an oveiflow line,... 

Fortunately in this case the two materials did not react. People who have emptied acid into alkali tanks have been less fortunate. A plant received caustic soda in tank cars and acid in tank trucks. One day a load of caustic soda andved in a tank truck. It was labeled Caustic Soda, the delivery papers said it was caustic soda, and the hose connections were unusual. But the operators had a mind-set (see Section 3.3.5) that anything in a tank truck was acid, and they spent two hours making an adaptor to enable them to pump the contents of the tank truck into the acid tank. 

Figure 16-1. Acid tanks should be fitted with a high-point vent, as well as an overflow, so that hydrogen can escape.

The circulation pump should be a centrifugal type with a plastic or PVC impellor, or cast iron with adequate corrosion inhibitor. The acid tank, hoses, and other equipment should be connected to and from the boiler using suitable connection points. This usually is the bottom BD connection (with the valve removed) and the open manhole as the top point. 

Use the rinse bath water again in a different area. For example, if there is a line with a chromic acid etch bath followed by counter-flow rinse baths and a neutralizer bath followed by counter-flow rinse baths, use the dirtiest rinse after the neutralizer bath and pipe it to the rinse baths after the chromic acid tank. This saves water and reduces sludge. 

For instance, if the material arrives via tank car he must visualize how the material is going to get to the storage tank. First he must realize that most fluids are removed through openings in the top of a tank car. The bottom openings are used mainly for washing out the cars prior to their being refilled. Acid tank cars by law do... 

Steel is normally considered a safe material for contact with (reasonably pure) sulphuric acid. However this report is of a fatal explosion when working on a sulphuric acid tank with cutting torches, attributed to hydrogen in the headspace arising from corrosion of the metal ascribed to poor maintenance. 

A truck driver arrived at the facility to deliver a load of sodium hydrosulfide solution. The delivery took place on the night shift. During prior deliveries on this shift, the shift supervisor had received only pickle acid. (The material commonly known onsite as pickle acid was actually ferrous sulfate.) He assumed that the sodium hydrosulfide was pickle acid and directed the truck driver to unload at the facility s pickle acid tank. Hydrogen sulfide gas was produced when the sodium hydrosulfide solution was unloaded into the ferrous sulfate tank. The truck driver was exposed to the gas and died one Whitehall Leather employee was injured (NTSB, 2000). 

The activated sludge tanks (2) are fed by the acidic tank (4) and the alkaline tank (5). In order to replace evaporation losses and also to prevent salt formation in the sembbing fluid, a small quantity of fresh water runs continuously into the tank (7). Small quantities of fluid are continuously removed from the two sembbing stages and then clarified in sedimentation tanks (8). The resultant activated sludge is recirculated to the sembber. 

Three pulp mill workers died after inhalation of fumes for approximately 10-15 minutes from a nitric acid tank explosion (concentrations not available). No significant respiratory complaints were apparent during initial examination. However, 4—6 hours later they became cyanotic with frothy fluid escaping from the nose and mouth. All died in less than 24 hours. Necropsy showed bronchiolar epithelial necrosis, marked capillary engorgement, and slight interstitial edema of alveoli the lungs were five times heavier than normal and released abundant frothy fluid from all lobes. The delayed manifestations of lung injury were consistent... 

Remove as much water as possible from the fuel storage and transportation system Check pH of tank bottom water for presence of acidic compounds remove acidic tank bottom water as soon as possible... 

The batch nitrator (1) is connected with a separator (2) and the drowning tank (3). The displacing acid tank (4) can produce a flow of nitroglycerine from the separator through the pipe (6) to the wash columns (7), (P) and (11). These columns... 

Crystallizer ducts Return acid tanks Conveyor drums and pullies... 

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%... 

Law, J.D., Herbst, R.S., Todd, T.A., Wood, D.J., Romanovskiy, V.N., Esimantovskiy, V.N., Smirnov, I.V., Babain, V.A., Zaitsev, B.N. 1999. Demonstration of a universal solvent extraction process for the separation of actinides, cesium and strontium from actual acidic tank waste at the Idaho National Engineering and Development Laboratory. Global 1999 Nuclear Technology - Bridging the Millennia, August-September, Jackson Hole, WY. 

Todd, T.A., Mann, N.R., Tranter, T.J., Sebesta, F., John, J., Motl, A. Cesium sorption from concentrated acidic tank wastes using ammonium molybdophosphate-polyacrylo-nitrile composite sorbents. J. Radioanal. Nucl. Chem. (2002), 254 (1), 47-52. 

Herbst, R. S., J. D. Law, T. A. Todd, et al. 2002. Development and Testing of a Cobalt Dicarbollide Based Solvent Extraction Process for the Separation of Cesium and Strontium from Acidic Tank Waste. Sep. Sci. Technol., 37(8), 1807-1831. 

Internet, US Chem. Safety Haz. Investigation Board, CSB 1999-4319 A delivery of the above was charged to a hydrochloric acid tank, poisonous yellow-green fumes were evolved. 

Nitric Acid Tank- Design Data Design tank capacity Design temperature Design pressure Working pressure Nitric acid density Material of construction Design tensile strength Joint efficiency... 

Warning Materials DIN/EN 1.4301 or 1.44001 [UNS S 30400orS 31600(AISI 304 or316)] ate not suitable for nitric acid tanks and should be avoided. 

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.)... 

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