Tanks filling

In preliminary process design, the primary consideration is contact by inhalation. This happens either through accidental release of toxic material to the atmosphere or the fugitive emissions caused by slow leakage from pipe flanges, valve glands, and pump and compressor seals. Tank filling causes emissions when the rise in liquid level causes vapor in the tank to be released to the atmosphere. 

Process operations. The third source of process waste we can classify under the general category of process operations. Operations such as start-up and shutdown of continuous processes, product changeover, equipment cleaning for maintenance, tank filling, etc. all produce waste. 

Reservoir engineers describe the relationship between the volume of fluids produced, the compressibility of the fluids and the reservoir pressure using material balance techniques. This approach treats the reservoir system like a tank, filled with oil, water, gas, and reservoir rock in the appropriate volumes, but without regard to the distribution of the fluids (i.e. the detailed movement of fluids inside the system). Material balance uses the PVT properties of the fluids described in Section 5.2.6, and accounts for the variations of fluid properties with pressure. The technique is firstly useful in predicting how reservoir pressure will respond to production. Secondly, material balance can be used to reduce uncertainty in volumetries by measuring reservoir pressure and cumulative production during the producing phase of the field life. An example of the simplest material balance equation for an oil reservoir above the bubble point will be shown In the next section. 

A few percent TCNE added during formation of urethane foams imparts enough conductivity to dissipate electrostatic charges. Airplane fuel tanks filled with this foam stiU have about the same volume for fuel but do not build up static charges (29). 

Types of Jigs A jig is essentially an open tank filled with water and provided with a horizontal screen on the top and a hutch compartment fitted with a spigot (Fig. 19-27 ). A layer of coarse, heavy particles, known as ragging, is placed on the top of the screen onto which the feed slurry is introduced. The feed moves over the ragging and the separation takes place as the bed is pulsated by a different mechanical device. The heavy particles are collected into the hutch compartment and removed through the spigot while the hghter particles are made to overflow from the top or the tank. 

The relationship for liquid surface potential <5 during tank filling is of the form [22]... 

Table 5-4 gives solutions for various tank filling criteria discussed in this chapter in which either a maximum velocity or a maximum velocity-diame-... 

TTiBLE 5-4. Solutions (Qallons per Minute) for Various Tank Filling Criteria... 

Liquid relaxation times are normally less than 30-100 s while tank filling times generally exceed 1000 s. The exponential term in Eq. (5-2.4.4) is therefore negligible by the time most tanks are 30-50% filled. Hence... 

As the tank fills the capacitance increases while the leakage resistance decreases in proportion to the wetted area. The conservative case is to consider only the floor area. Assume that the charging current Iq < 10 pA and that the gas involved is hydrogen, whose LMIE W = 0.016 mJ. Eor lining thickness d = 2 mm, dielectric constant = 4, and floor area A = 10 m, the... 

Note 1. When loading volatile products such as gasoline, whose vapor concentration can be shown to rapidly exceed the upper flammable limit during tank filling, the velocity-diameter product may be increased to 0.50 mVs- This is consistent with API RP2003 [3]. Similarly, shorter wait periods of 1-2 min can be used. 

Just after 10 00 a.m., a tank filled with approximately 1500 1 (750 kg 1650 lb) of liquid propane was moved by a power shovel. During relocation maneuvering, the tank fell from the shovel and its valve struck against a pile of concrete slabs. The valve was sheared from its flange by the crash, thus allowing the release of propane. 

The German Federal Institute for Material Testing (BAM) carried out full-scale fire tests on commercial liquefied-propane storage tanks. Tank volume was 4.85 m in each test (Schoen et al. 1989 Droste and Schoen 1988 Schulz-Forberg et al. 1984). Unprotected and protected tanks filled with propane (50% filled) were exposed to a fire. In some tests, the propane was preheated. 

Maurer, B., K. Hess, H. Giesbrecht, and W. Leuckel. 1977. Modeling vapor cloud dispersion and deflagration after bursting of tanks filled with liquefied gas. Second Int. Symp. on Loss Prevention and Safety Promotion in the Process Irui., pp. 305-321. Heidelberg. 

Table 2 compares the heating value of 20-gal tanks of natural gas at different pressures. Pipelines deliver natural gas at a relatively low pressure of 60 pounds per square inch (psi). A 20-galloii vehicular tank filled at this pressure would provide only about... 

Tank formation means that the cured positive and negative raw plates are inserted alternately in special tanks filled with fairly dilute sulfuric acid (generally in the range 1.1 to 1.15gcm 3) and positive and negative plates are connected, a number of each, in parallel with a rectifier. The formation process means that the active material of the plates is electrochemically transformed into the final stage, namely ... 

Howitzer (Trademark of Reactor Experiments, Inc). The assembly is a 6-cu ft cylindrical Lucite tank filled with distilled water and containing three access ports (Fig 3). The large spherical container on the right is the shielded storage cask for the 2S2Cf neutron source when not in use... 

This result applies until the tank is full at time tf u = VfuulQm- If the tank fills rapidly, f/ // 0 and Ufuu —> If the tank fills slowly, t/uu —> oo and afuii 0. By regulating g, , we regulate tf u and can achieve any desired concentration in the range from 0 to a, . 

Proton transfer occurs as well as solid formation.) (c) How many kilograms of lime are required to remove all the phosphoms from a 1.00 X 10 L holding tank filled with contaminated water that is... 

Liquid flows continuously into an initially empty tank, containing a full-depth heating coil. As the tank fills, an increasing proportion of the coil is covered by liquid. Once the tank is full, the liquid starts to overflow, but heating is maintained. A total mass balance is required to model the changing liquid volume and this is combined with a dynamic heat balance equation. 

Another way storage tanks can breathe to atmosphere results from the expansion and contraction of the tank contents as the temperature changes between day and night. However, such effects tend to be smaller than those associated with tank filling and emptying. 

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