Break tank

Another incident is illustrated in Figure 18-3. Town water should never be directly connected to process lines by a hose [19] or permanent connections. A break tank should be provided. 

The reactant(s) should be added via a small break tank so that if reverse flow occurs only a small quantity will react and not the main stock, or... 

Correction of pH level via caustic soda (after the degasser and before the BX) is standard practice. Because both acid regeneration and caustic pH correction are practiced, it is usual to isolate the plant from the mains by providing a break tank. The full plant therefore tends to be break tank, RW booster pump, acid measuring tank, WAC, degasser, degassed water booster pump, pH correction, and BX. A schematic layout of this type of plant is shown in Figure 9.3a. 

The pickling wastewater has a low pH and contains dissolved iron and other metals. The blowdown and dumps from the cold rolling mill solutions, which may contain up to 8% oil, are collected in emulsion-breaking tanks in which the emulsions are broken by heat and acid. The oil is then... 

Hot oil tanks heated above 65.6 °C (150 °F), excluding flash asphalt, slop oil and emulsion breaking tanks should be spaced apart by the diameter of the largest tank in the group. 

Usually, immediately upon entering the plant, supply water is split into potable water and process water. This is done by using an air break or back flow preventers. This is a precaution against process contaminants backing up into potable or city water and vice versa. Often a break tank is used as the air break since it also provides storage capacity for demand surges at the use points. 

After the break tank, process water is treated using various equipment and technologies depending on its intended use and the water analysis. Some of the technologies are multimedia filtration, water softening, activated carbon adsorption, UV treatment, deionization, ultrafiltration, reverse osmosis, final filtration and distillation. 

Account for the "missing 7%" in the record-breaking tanks burst in July 2000, then extend models to forecast performance across wide classes of hydrogen contaimnent structures... 

A preferred system, which the process industries increasingly tend to use, provides a free fall or an air gap to achieve isolation. Figure 12.13 is the familiar break tank. As drawn, the water supply line does not enter the break tank. It should end at least two line diameters above the flood level of the receiver. The supply line can extend into the tank if a positive overflow is provided and the proper gap is maintained between supply and overflow. Good practice then also includes a break in the overflow pipe. The disadvantage of a break tank, especially the open type, is the loss of line head when the water is held under atmospheric pressure. This can be restored by elevating the break tank or by pumping the water from the break tank for distribution. 

A carrier water system (with break tanks) where necessary... 

In many countries it is compulsory to have a so-called break tank, or storage tank, between the actual water supply and the manufacturing plant. Such storage tanks are common foci of contamination, often in the form of adhered biofilm on the tank walls and in associated pipework (Figure 4). 

Sterile Filtration of Gases. Primary appHcations for sterile gas filtration are the sterilization of fermentor inlet air, fermentor vent gas, vents on water for injection tanks, and vacuum break filters during lyophilization. Operational and process considerations apply. Typically, the membrane in gas... 

One of the problems with early hydride systems was decrepitation of the alloy. Each time the metal hydride storage tank was recharged the particles would break down and eventually the particles became so small that they began to pass through the 5-p.m sintered metal filter which kept the hydride inside the tank. Addition of 0.5% manganese, which caused the decrepitation process to cease once the particles reached a size of about 10 p.m, solved this problem. 

Less stable parts of the sludge can be treated by holding in tanks for extended periods of time to allow the weaker emulsion to break and separate a clean product. The mote stable sludges can be broken by mechanical action in filters or centrifuges, by recycle to the furnace for redistillation, or by redistillation in auxiliary units. Chemical attack via oxidation or complexing agents that break the emulsion has also been employed. 

Water. Water mains should be connected to plant fire mains at two or more poiats, so that a sufficient water supply can be deHvered ia case of emergency. The plant loop and its branches should be adequately valved so that a break can be isolated without affecting a principal part of the system. If there is any question of maintaining adequate pressure, suitable booster pumps should be iastaHed. Any connection made to potable water for process water or cooling water must be made ia such a manner that there can be no backflow of possibly contaminated water check valves alone are not sufficient. The municipal supply should faH freely iato a tank from which the water is pumped for process purposes, or commercially available and approved backflow preventers should be used. 

Tanks that could be subjected to vacuum should be provided with vacuum-breaking valves or be designed for vacuum (external pressure). The ASME Pressure Vessel Code contains design procedures. 

Wet feed enters the feed tank which has a slow-rotating impeller to break up large particles. The level in the feed tank is maintained by a... 

Storage Segregated storage Uncongested storage of combustibles gangways/adequate breaks Material stacked in the open should be away from windows Flammable liquids in properly designed storerooms bulk quantities in fixed, bunded, adequately spaced tanks... 

---