Knock-out

A knock out vessel may on the other hand be followed by a variety of dehydrating systems depending upon the space available and the characteristics of the mixture. On land a continuous dehydration tank such as a wash tank may be employed. In this type of vessel crude oil enters the tank via an inlet spreader and water droplets fall out of the oil as it rises to the top of the tank. Such devices can reduce the water content to less than 2%. 

Electrons interact with solid surfaces by elastic and inelastic scattering, and these interactions are employed in electron spectroscopy. For example, electrons that elastically scatter will diffract from a single-crystal lattice. The diffraction pattern can be used as a means of stnictural detenuination, as in FEED. Electrons scatter inelastically by inducing electronic and vibrational excitations in the surface region. These losses fonu the basis of electron energy loss spectroscopy (EELS). An incident electron can also knock out an iimer-shell, or core, electron from an atom in the solid that will, in turn, initiate an Auger process. Electrons can also be used to induce stimulated desorption, as described in section Al.7.5.6. 

A popular electron-based teclmique is Auger electron spectroscopy (AES), which is described in section Bl.25.2.2. In AES, a 3-5 keV electron beam is used to knock out iimer-shell, or core, electrons from atoms in the near-surface region of the material. Core holes are unstable, and are soon filled by either fluorescence or Auger decay. In the Auger... 

In any case, I eventually recovered (and so did Jerry), but my immune system must have suffered serious damage, which manifested itself three years later, when I collapsed in my office one day and was found to be bleeding internally from a form of rare stomach cancer, which necessitated major surgery but was fortunately localized. I again recovered and have had no further difficulties since. Whether weakening and knocking out my immune system to overcome the previous problems had any effect is not clear, but it could have been a factor. Despite my health problems I was able to continue my work without much interruption, and the scientific productivity of my group has not... 

Arrhythmias. The first solution to cardiovascular problems arising from arrhythmias came about as a result of a complication caused by open-heart surgery. During procedures to correct congenital defects in children s hearts, the electrical conduction system often became impaired, and until it healed, the heart could not contract sufficiently without outside electrical stimulation. A system that plugged into a wall outlet was considered adequate until an electrical storm knocked out power, lea ding to the development of the first battery-powered external pacemaker. 

Make sure vent system is sloped to drain to knock-out pot (separator)... 

The main outer door on the frame may have either an opening to seat the auxiliary door of the trolley on it or telescopic knock-outs for all such door mounts to provide a peep-through type of aperture. On it are mounted the light and pushbutton tops. Figures... 

Trays knocked out and in bottom of tower. Poor stripping. Low pressure drop that was 2/3 of expected. Six of 18 trays were knocked out. Scan proved problem. Operational problem. 

Venting to a knock-out vessel, to remove non-gaseous substances. (This may be followed by a scrubbing unit for gases or a flare-stack.)... 

Install a knock-out drum immediately upstream of the flare seal drum, to remove material condensed in the flare header. 

This specification covers the minimum requirements for the process, mechanical and structural design, materials, fabrication, shop inspection testing and supply for a flare system. The knock-out drum will be by N P Refinery. 

Relieving vapors from various pressure-relief and depressuring valves in the system must be collected in individual flare headers that should be appropriately located near each process area. Subheaders must be interconnected to a main flare header which feeds to a knock- out drum and disposal system. Condensates that are carried over by vapors are separated in the knock-out drum. The vapors that exit the vessel go to the flare stack where they are burned. 

A second trial is required for two main flare headers, one collecting the low-pressure flares (usually 5 to 10 psig) and the other collecting relatively high-pressure flares (usually 15 to 20 psig). The two headers are connected to their individual knock-out drums. The vapor lines from the knock-out drums are combined into a single header connected to the flare stack. 

The maximum simultaneous load in each header must be calculated separately and the pressure drop must also be computed for the entire length of the pipe including the combined length from the knock-out drum to the stack. 

The main flare header connecting the subheaders leading to the knock-out drum. 

The final header connecting the vapor line (or lines) from the knock-out drum leading to the flare stack. 

In the absence of actual line distances, a conservative estimate of the distance between the knock-out drum and the flare may be taken as 500 ft. 

Once the diameter is known, the Reynolds number. Re can be computed and the friction factor f obtained from Figure 21. Assuming a straight length of pipe for L = 5(X) ft, N (line resistance factor) can be calculated. Next Gj, is calculated based on the downstream pressure and G/G j evaluated. From Figure 20 the ratio Pj/Pfl can be obtained. Since Pj is known, Pq can then be calculated. The pressure at the inlet of the knock-out drum is given by Pq -I- 0.5 psi. Table 6 provides typical values of resistance coefficients for various pipe fittings. 

Example The maximum flare load of a system is 1,000,000 Ibs/hr of vapor. The pressure at the base of the flare stack is 2 psig, the average molecular weight of the vapor is 50, at a temperature of 200°F at the combined header to the flare stack. The distance from the drum to the stack is 500 ft. The line consists of two 90° welding elbows and an orifice for a flow controller. The total pressure drop at the knock-out drum is 0.5 psi. Determine the pressure at the inlet of the knock-out drum. 

Example Calculate the dry flare header size, which is connected to the above knock-out drum. Previously noted conditions remain the same. Additional data are ... 

A process foreman had a last look in a vessel before it was boxed up. He saw an old gasket lying on the floor. He decided to go in and remove it. Everyone else was at lunch, so he decided to go in alone. On the way out, while climbing a ladder, he slipped and fell and was knocked out. His tongue blocked his throat, and he suffocated. 

It is wortli noting tluit design calculations for tlie sizing of relief systems (relief valves, headers, scmbbers and knock-out drums, etc.) are conservative in order to protect tlie integrity of vessels and relief systems. Tlie calculations used for risk assessments are tliose which most accurately describe the discliarge rate from tlie luizardous incident being modeled. 

Employee Letik in knock-out Clironic healtli Install warning... 

A superheat exchanger is not needed for a centrifugal compressor system as far as gas condition is concerned. It may be a good unit as fer as other aspects of the process are involved. The centrifugal compressor requires only a suction knock-out drum to remove entrained liquid and foreign particles. 

Sherman et al. have analyzed the function of the MitM methyltransferase in more detail [113]. They knocked out the MitM gene and found that mitomytin C production was abolished, and were able to isolate a small quantity of 9a-demethyl mitomycin A (62) from this mutant (Figure 11.9). MitM was expected to act as an O-methyltransferase, but surprisingly recombinant MitM converted 62 into 9-epi-mitomydn B (63), hence acting as an aziridine N-methyltransferase. Mitomy-... 

The knock-out drums or separator tanks/pots can be designed using the techniques offered in the chapter on Mechanical Separation, and will not be repeated here. API-RP 521 [13] specifies 20-30 minutes holdup liquid capacity from relief devices plus a vapor space for dropout and a drain volume. 

---