References tank design

A distributor is frequently installed at the top of the column for use during backwash. It collects water evenly and prevents resin from escaping the column should unexpected surges develop in the water flow during backwash. Columns lacking an upper distributor or screen to prevent loss of resin should have an external system to prevent resin from being lost to the drain. It is referred to as a resin trap and may consist of a porous bag that fits over the outlet pipe or a tank designed to lower the linear velocity. Resin drops to the bottom of the tank and is returned to the column when convenient. 

Further information related to the core make-up tank design can be found in Section 5.4.13 of Reference 6.1. 

The reactor vessel is constructed of 2 % Cr-1% Mo steel, 2 inches thick, designed for a temperature of 1150°F and maximum pressure of 120 psi. Three 28-in.-diameter pipes carry the fluid into the reactor at the bottom and leave at the top. The entire reactor vessel is doubly contained by a relatively thin-walled containment vessel. A drain line to the fuel dump tanks is also provided. The free space above the reactor core is used as the degasser to remove volatile fission products. The reference core design has the following specifications ... 

Industrial appHcations often require that bulk materials or Hquids be weighed in hoppers, silos, tanks, or reactor vessels, referred to collectively as vessels. Because they come in such a wide variety of si2es, shapes, and capacities, scales using these vessels as load receivers are not typically available as standard products. Vessels are usually custom-fabricated to suit a particular appHcation, then mounted on a scale. Some can be mounted on a standard scale such as a bench, portable, or floor scale. More typically, a number of weigh modules are used to support the vessel. This offers the scale designer great flexibiHty but certain precautions are necessary in order to constmct an accurate scale. Some of the more important factors associated with the design of vessel scales are discussed herein. 

Liquefied petroleum gas (LPG) is the subject of API Standard 2510, The Design and Construction of Liquefied Petroleum Gas Installations at Marine and Pipehne Terminals, Natural Gas Processing Plants, Refineries, and Tank Farms. This standard in turn refers to ... 

NFPA 30 and API Standard 2000 provide gmdance for design of overpressure protec tion involving storage tanks that operate at or near atmospheric pressure. In particular, NFPA 30 focuses on flammability issues, while API 2000 addresses both pressure and vacuum requirements. The ASME code (Sections I and TII) and API RP 520 are the primaiy references for pressure rehef device sizing requirements. 

For additional details on the design of blowdown drums, cyclone separators, and quench tanks, such as mechanical design, thrust forces, ancillary equipment, and safety considerations, refer to the books and articles listed in the General References. 

The European philosophy on area classification varies from that of the United. States and Canada. Specifically, in Europe and most other inter national areas, the Zone concept is utilized. An area in which an expio sive gas-air mixture is continuously present, or present for long perioiK of time, is referred to as Zone 0. The vapor space of a closed, but vented, process vessel or storage tank is an example. An area in which an explosive gas-air mixture is likely to occur in normal operations is designated Zone 1. An area in which an explosive gas-air mixture is less likely to occur, and if it does occur will exist only for a short time, is designated Zone 2. Zone 0 and Zone 1 correspond to Division 1 in the U.S. and Canada System. Zone 2 is equivalent to Division 2. 

As vent collection systems normally contain vapor/air mixtures, they are inherently unsafe. They normally operate outside the flammable range, and precautions are taken to prevent them from entering it, but it is difficult to think of everything that might go wrong. For example, an explosion occurred in a system that collected flarmnable vapor and air from the vents on a number of tanks and fed the mixture into a furnace. The system was designed to run at 10% of the lower explosion limit, but when the system was isolated in error, the vapor concentration rose. When the flow was restored, a plug of rich gas was fed into the furnace, where it mixed with air and exploded [17]. Reference 34 describes ten other incidents. 

Flame arrester pressure drops mnst he taken into consideration when selecting and specifying them, especially when they are installed on vent systems of low pressure storage tanks, snch as API-type tanks. If the total system pressure drop exceeds the design pressure of the tank, the tank will he overpressnred and may he strnctnrally damaged. Refer to Section 6.1 for additional discnssion of this topic. 

Follow the example of Reference [32], using scale-up rules. A pilot plant test run has been conducted using a laboratory equipped test vessel. Design equivalent process results for a 10,000 gallon tank are ... 

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