Outflow vessel

DUP, is due to closure of the semilunar valves in the outflow vessels from the ventricles, the aorta and pulmonary artery. 

Type I endoleak is caused by failure to achieve a circumferential seal at either the proximal (type lA) or distal end (type IB) of the stentgraft. Type IC endoleak is due to non-occluded iliac artery in patients with aorto-mono-iliac stent and femoral-femoral bypass. With type I endoleak, the aneurysm is perfused directly from the aorta or the iliac arteries (inflows). The leak usually communicates through a channel (sometimes multiple channels) with the aneurysmal sac. There are several outflow vessels, mainly lumbar arteries and inferior mesenteric artery (IMA) that communicate with the channel and or the sac (Figs. 14.1,14.2). The pressure within a type I leak is systemic. The tension on the aortic wall remains high. 

Fig. 14.5a,b. Type III endoleak due to a hole in the fabric, a Aortogram demonstrates the endoleak (large black arrow) with IMA (small black arrow) and a lumbar artery (white arrow) acting as an outflow vessel, b The wire is passed through the hole in the aortic aneurysm (arrow)... 

In case of type I endoleak, the origin of the sac is catheterized by placing the catheter between the stentgraft and aortic wall and intra-aneurysmal injection is performed for optimal evaluation of the outflow vessels. 

The occlusion of the iliac artery is usually sufficient to treat the leak. However, in cases of long-term type IC endoleak, many outflow vessels may have developed and the leak may communicate with multiple lumbar arteries and the IMA. These enlarged vessels might be source of late type II endoleak. Thus, we usually embolize both the outflow vessels and the sac before occluding the iliac artery. Another attractive technique to achieve the occlusion of the common iliac artery is to perform an endovascular internal to external iliac artery bypass using stentgraft. This technique can allow the exclusion of the common iliac preserving the internal iliac artery. 

Figure 7.4 Microcomputer programming of a hatch cooling crystallizer. A, crystallization vessel, B, control heater, C, control cooler. surrounding the draft-tube), D, contact thermometer, E, discharge plug and conical baffle), F, recorder, G, relay, H, temperature programmer, I, cooling water pump, J, cooling water reservoir, K, water inflow L, water outflow after Jones and Mullin, 1974)...

One source of an oil spill could be the filling of a vessel that has an outlet to atmosphere until it overflows. Whenever inflow exceeds outflow, the tank can eventually overflow. Another source is a rupture or sudden inability of a piece of equipment to contain pressure. Events leading to rupture are listed in Figure 14-2. Note that some of these events can be anticipated by sensing changes in process conditions that lead to the rupture. Other events cannot be anticipated from process conditions. 

Inflow exceeding outflow is sensed by a high-level sensor (LSH). Back-up protection is furnished by the PSH (to keep the relief valve from operating) or an LSH in a downstream vent scrubber if the vessel gas outlet goes to atmosphere. That is, a vent scrubber must be installed downstream of any vessel that discharges directly to atmosphere. 

Despite the advantages of continuous cultures, the technique has found little application in the fermentation industry. A multi-stage system is the most common continuous fermentation and has been used in the fermentation of glutamic add. The start-up of a multi-stage continuous system proceeds as follows. Initially, batch fermentation is commenced in each vessel. Fresh medium is introduced in the first vessel, and the outflow from this proceeds into the next vessel. The overall flow rate is then adjusted so that the substrate is completely consumed in the last vessel, and the intended product accumulated. The concentration of cells, products and substrate will then reach a steady state. The optimum number of vessels and rate of medium input can be calculated from simple batch experiments. 

A population balance is a balance on a defined set of countable or identifiable entities in a given system as a result of all phenomena which add or remove entities from the set. If the set in question is the number of droplets between diameter D and (D + dD) in a vessel, the set may receive droplets by flow into the vessel, by coalescence or by growth from smaller droplets. The set may also lose droplets by outflow from the vessel, by coalescence or by growth out of the set s size range. 

Equation (II-9) simply says that the rate of change of total property P(t) equals the total property inflow minus the total property outflow plus the nucleation term (p(t,t) denotes property at birth, i.e. t=x) plus the growth terms. Remember that nxoT(t,t) denotes, in the general case, particles nucleated in the vessel which grew to the property p(t,x) and particles nucleated somewhere else, which entered the reactor with the inlet streams and subsequently grew to p(t,x). 

With these observations in mind, the simplest practical measure to reduce electrostatic discharge risks associated with vessel loading is to reduce the rate at which the dry solids are added to the vessel. This approach works because the slower rate of flow provides an opportunity for accumulating charge to relax away by various mechanisms before hazardous conditions become established. Often, the same type of flow limitation is effective in reducing the likelihood of ESD during vessel unloading. In many cases, the maximum safe rate of inflow (or outflow) has to be determined by empirical means. 

In the early days, see, e.g., Bakker and Van den Akker (1994a), a black box representing the impeller swept volume was often used in RANS simulations, with boundary conditions in the outflow of the impeller which were derived from experimental data. The idea behind this approach was that such nearimpeller data are hardly affected by the rest of the vessel and therefore could be used throughout. Generally, this is not the case of course. Furthermore, this approach necessitates the availability of accurate experimental data, not only... 

The kinetics of a liquid-phase chemical reaction are investigated in a laboratory-scale continuous stirred-tank reactor. The stoichiometric equation for the reaction is A 2P and it is irreversible. The reactor is a single vessel which contains 3.25 x 10 3 m3 of liquid when it is filled just to the level of the outflow. In operation, the contents of the reactor are well stirred and uniform in composition. The concentration of the reactant A in the feed stream is 0.5 kmol/m3. Results of three steady-state runs are ... 

For flows of ao kmol/s and bo kmol/s of A and B respectively into a vessel of volume V with an outflow of v kmol/s, then a mass balance at steady-state gives ... 

Outflow Rate Exceeds Inflow Rate If material is being withdrawn from a tank or vessel faster than the incoming rate to compensate for the removal suction a vacuum will occur. If the vessel or tank is not strong enough to withstand the negative pressure levels it will collapse in on itself... 

The CSTR model, on the other hand, is based on a stirred vessel with continuous inflow and outflow (see Fig. 1.2). The principal assumption made when deriving the model is that the vessel is stirred vigorously enough to eliminate all concentration gradients inside the reactor (i.e., the assumption of well stirred). The outlet concentrations will then be identical to the reactor concentrations, and a simple mole balance yields the CSTR model equation ... 

The flow out of the reactor passes through a restriction (control valve) inW another vessel which is held at a constant pressure Pp (absolute). The outflow will vary with the pressure and the composition of the reactor. Flows through control valves are discussed in more detail in Part III here let us use the formula... 

Fig. 4. 33 The AKUFVE solvent extraction apparatus Efficient mixing is achieved in the separate mixing vessel, from which the mixture flows down into the continuous liquid flow centrifugal separator (the H-centrifuge, hold-up time <1 s). (From Refs. 83a,b.) The outflow from the centrifuge consists of two pure phases, which pass on-line detectors, AMXs, for on-line detectors or continuous sampling. (From Refs. 80a-80d, 81.)...

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