Concrete Tanks

The zinc electrolyte contains ca 60 kg/m zinc as sulfate and ca 100 kg/m free sulfuric acid. It is electrolyzed between electrodes suspended vertically in lead or plastic-lined, eg, poly(vinyl chloride), concrete tanks. The insoluble anodes are made of lead with small amounts of silver. The anodic... 

For high, heavy tanks, a foundation ring may be needed. Prestressed concrete tanks are sufficiently heavy to require foundation rings. Foundations must extend below the frost line. Some tanks that are not flat-bottomed may also be supported by soil if it is suitably... 

Spheres, spheroids, and toroids use steel or concrete saddles or are suppoi ted by columns. Some may rest directly on soil. Horizontal cyhndrical tanks should have two rather than multiple saddles to avoid indeterminate load distribution. Small horizontal tanks are sometimes supported by legs. Most tanks must be designed to resist the reactions of the saddles or legs, and they may require reinforcing. Neglect of this can cause collapse. Tanks without stiffeners usually need to make contact with the saddles on at least 2.1 rad (120°) of their circumference. An elevated steel tank may have either a circle of steel columns or a large central steel standpipe. Concrete tanks usually have concrete columns. Tanks are often supported by buildings. 

Prestressed (posttensioned) concrete tanks cost about 20 percent more than steel tanks of the same capacity. Once installed, however, concrete tanks require veiy little maintenance. A true comparison with steel would, therefore, require evaluating the maintenance cost of both types. 

LNG is stored in metal double-wall or prestressed concrete tanks, frozen earth, or mined quarries or caverns. 

Method Cyanide is destroyed by reaction with sodium hypochlorite under alkaline conditions. System component Reaction tanks, a reagent storage and feed system, mixers, sensors, and controls two identical reaction tanks sized as the above-ground cylindrical tank with a retention time of 4 h. Chemical storage consists of covered concrete tanks to store 60 d supply of sodium hypochlorite and 90 d supply of sodium hydroxide. 

An electroflotation plant usually consists of a steel or concrete tank with a sloping bottom as shown in Figure 1.49 liquid depth may typically be about 1 m. Since the flotation process is much faster than sedimentation with fine particles, flotation can be achieved with much shorter retention times — usually about 1 hour (3.6 ks) — and the land area required may be only about one-eighth of that for a sedimentation tank. 

Thickeners may vary from a few metres to several hundred metres in diameter. Small ones are made of wood or metal and the rakes rotate at about 0.02 Hz (1 rpm). Very large thickeners generally consist of large concrete tanks, and the stirrers and rakes are driven by means of traction motors which drive on a rail running round the whole circumference the speed of rotation may be as low as 0.002 Hz (0.1 rpm). 

On wooden or on concrete tanks the tarpaulin has to be fit out with loops at the border. The tank border is pasted with felt, so that the tarpaulin can be stretched over the tank border and is fixed on hooks in the tank wall. 

Partially roofed concrete tank containing chemical feed for unattended winter operation of pilot plant. 

In German plants cylindrical concrete tanks equipped with stirrers are the most widely used. The capacity of these tanks is 100 m3, and they are charged with 10,000 kg of nitrocellulose. After mixing the product for several hours with water,... 

In addition to deposits of crystalline potassium bitartrate, infrequent calcium tartrate deposits occur in wines. The calcium level of carefully produced wines is seldom high enough to cause stability problems. Occasionally, however, wines may extract calcium from improperly prepared filter materials. Prolonged storage in uncoated concrete tanks also will release calcium into wine. 

Fluorine (or fluorides) has a suggested international limit of 5 mg/liter. Fluoride pickup occurs only in the rare case where concrete tanks may have been treated with fluosilicate. With the disappearance of concrete tanks and prohibition of fluosilicate which may contaminate food, this determination should be superfluous. It is done on an ashed sample distillation of fluosilicic acid with super-heated steam and titration with thorium nitrate in the presence of sodium alizarinsulfonate. 

Calcium. Excess calcium can occur in wines stored in concrete tanks or otherwise exposed to calcium (filter aids, calcium bentonite, etc.). After fortified wines are bottled, calcium tartrate may slowly precipitate. 

The liquid waste is stored for at least 6 y prior to solidification to reduce the decay heat (Fig. 16.8) by a factor of 10 or more. The first U.S. military fuel reprocessing wastes were stored as neutralized waste in mild steel tanks at the Hanford reservation in eastern Washington. These steel-lined, reinforced-concrete tanks were 500,000-1,000,000 gal in capacity with provisions for removal of waste heat and radiolysis products. Corrosion of several tanks occurred with the release of waste. Fortunately, the soil around these tanks retarded nuclide transport. A better (and more expensive) design for storage tanks was implemented at the Savannah River site in South Carolina consisting of a second steel tank inside of a Hanford-style tank. The storage of acid waste in these tanks has not encountered the corrosion problems seen with the Hanford tanks. 

High-level radioactive defense waste solutions, originating from plutonium recovery and waste processing operations at the U.S. Department of Energy s Hanford Site, currently are stored in mild steel-lined concrete tanks located in thick sedimentary beds of sand and gravel. Statistically designed experiments were used to identify the effects of 12 major chemical components of Hanford waste solution on radionuclide solubility and sorption. 

The question arises as to how much aging can take place in an air-impervious container such as metal or concrete. In a wooden tank, the air transfer through the wood pores to the wine takes place slowly, but in a metal or concrete tank there is essentially none. How does aging take place Is aging necessary or desirable for Interior Valley table wines First, we note... 

A — Concrete tank, B — Bell-jar, f — Graphite anode D — Chlorine outlet, D — Opening for connection o gas spaces of two adjacent bell-jars, E — Iron oathode. 

A — Brine inlet, B — Bell-jars, C — Pipes interconnecting individual bells, D — Chlorine outlet, E — Main brlno feed pipe, F — Caustic solution drain, G — Concrete tank. 

It is on account of its softness and aeration that rain water is particularly corrosive in its action on metals, and, if it is to be used for domestic purposes, great eare must be exercised in its collection and storage. Iron tanks are readily corroded, and lead is dissolved. Stone or concrete tanks may be used. 

In the Jacobs system, the annulus of a large concrete tank is fitted with a series of agitators. There is baffling, but there are no walls between the agitators. High slurry... 

There have been a few steel wire-wrapped concrete tanks used for LNG however, the majority are of double wall construction. As shown in Figure 5.29, the inner tank is separated from the outer tank by insulation. The inner tank is made of either 9% nickel steel (usually economical for large tanks), type 304 (UNS S30400) SS, or aluminum (usually economical for small tanks). 

Spent nuclear fuel (SNF) was initially stored in two large pools within Building 5, however in the early 1980 s, after serious leaks from the pools, the fuel was transferred to an external drystore constructed by adapting three existing concrete tanks, previously allocated for the storage of liquid radwaste. There are currently approximately 20,000 spent fuel assemblies (SFA) stored within the three tanks. 

Oxidation of the dinitro acid is Ciurried out in concrete tanks. It should be pointed out that a small amount of iron or copper decomposes the hypochlorite solution immediately, and for this reason, wooden tanks cannot be used. 

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