Steam network

The flue gas from post-combustion is cooled from 1200 °C to 230 °C to 300 C. Here, energy is recovered. Steam is produced that is added to the steam network of the BSL Schkopau site. In the flue gas purification, the HCl is absorbed from the flue gas by water. Also, other impurities are removed from the gas. The raw HCl is then purified to a useful feedstock. 

Pure steam network piping production and distribution... 

Another solution is given in Fig. 7.3 (Dimian, 1996). This time the heat integration considers a more global viewpoint based on site integration . Excess heat available at high temperature is exported to the utility system. The heat needed to drive the distillation columns is imported from the steam network, at a temperature level compatible with the site policy. Exported energy as high-pressure steam is more valuable, and can be used to produce electricity in a combined heat and power cycle. Therefore, heat recovery is more efficient if treated as a plantwide problem. 

The total steam network (Figure 2.5-1) consists of individual steam lines (corresponding to steam pressures). Large chemical installations usually have three steam pressures (e.g., 40,25, and 4 bar) and hence three temperatures. Each hne can take up... 

Auxiliary processes may fail e.g. steam or electric power supply breaks down which causes plant breakdowns or a site-wide breakdown. For simplicity only two events are modelled here First, a breakdown of the steam network which forces all plants with energyconsuming reactions to shut-down. This set includes the cracker. Butadiene extraction. Benzene production (hydrogenation plant) as well as Cumene and Styrene production. To model such an event, a Markov approach is used with the following transition matrix where state oj = 1 indicates normal operations and w = 0 indicates a breakdovm ... 

Plant-wide steam network optimization repair passing steam traps improved steam condensate recovery, use better insulation... 

Reddy, C.C.S., Naidu, S.V., and Rangaiah, G.P (2013a) Optimization of a steam network. Chemical Engineering, 54-59. 

The solar support of process steam generation is usually only economical when a significant part of the steam is used in the processes directly (the steam network is an open or partly open system). Solar heating of the additional, demineralised make-up water can be attractive heating of the condensate return flow or the feed water directly is more expensive because of the high temperatures. Additionally, at state-of-the-art installations, the feed water is usually pre-heated by an economizer. 

In (partially) open steam networks, the demineralised make-up water is usually mixed with the returning condensate and has to be degassed before it can enter the steam boiler. This degasification is usually done thermally using process steam from the steam boiler. 

It will be very understandable if you are exuberant and happy after you build the steam balance. It gives you a sense of pride when you visualize the complex steam network of energy generation, distribution, and demand at a glance. 

This is an importent step in developing site steam balance because it allows visualizing a complex steam network at a glance, provides insights for individual generation and usage, and helps to identify synergetic opportunities in the boiler house and processes. 

The block diagram (Figure 4.13) shows the separation of the system under investigation from the complete system. By way of inlets the subsystem separation butene/washing liquid has the line from the crude-butene tank and the line from the low-pressure steam network for heating the settling tank, and by way of outlets, the line to the purified butene heating system, the lines to the removal system, namely the line for... 

Table 4.9. The components include four measuring instruments with indicators or alarms by means of which action by service personnel may be requested if necessary. For this reason human service must be introduced four times as system components Ml to M4. In addition, the tank material is formally introduced as components W1 and W2. W1 designates the tank material at temperature T below permissible tank temperature W2 designates the tank material at temperatures above permissible operating temperature. The tank temperature is determined by heating temperature which in turn depends on pressure Pq in the steam network. For this reason, pressure P is formally treated as a component.

On the basis of the flow chart and component list, it can be assumed that seven components are possibly involved in the origin of the undesired incident. They are entered in the upper left field in Table 4.10(a). The complete decision table would have to include 2 = 128 columns. If it is noted, however, that occurrence of the undesired incident UE2 is based on the premise, in every case, that there is excess pressure in the steam network and that the material then fails, this means that only those columns are to be considered which include a 1 (one) in the first two lines. Thus, for the description of the conditions to be observed, the columns entered in the decision table [Table 4.10(a)] remain, with 1 designating the failure of a component, or the undesired behavior of a relevant magnitude and 0 the desired behavior, The system states represented in one column and leading to the undesired event UE2 are marked by an X. This shows that the columns marked X differ in pairs such that in the case of component 9, a 0 or 1 (one) is entered. This means that the component, a safety valve on the tank, has no effect. Then the first 13 columns must be considered, while neglecting component 9. From column 8 it is obvious that the failure" of components W2, Piy. and 31 T already lead to the undesired event, irrespective of whether another component does or does not fail. Therefore columns 1-8 in Table 4.10(a) can be compressed into column 1 (one) in Table 4.10(b). Columns 9 and 10 differ merely in the... 

The S02/air gas of 600-650 0 has to be cooled to about 450 C. Waste heat boilers can be used to raise saturated steam of 15 bar (195 C). A waste heat boiler has the advantage of quickly reducing the gas temperature and supplying steam to the factory steam network. 3 kg steam can be raised per kg sulphur burnt. Indirect systems are intrinsically safer. 

Different utility options such as furnaces, gas turbines, and different steam levels can be assessed more easily and with greater confidence knowing the capital cost implications for the heat exchanger network. 

Figure 16.17 Network design for the process from Fig. 6.2 using two steam levels.

Given a network structure, it is possible to identify loops and paths for it, as discussed in Chap. 7. Within the context of optimization, it is only necessary to consider those paths which connect two different utilities. This could be a path from steam to cooling water or a path from high-pressure steam used as a hot utility to low-pressure steam also used as a hot utility. These paths between two different utilities will be designated utility paths. Loops and utility paths both provide degrees of freedom in the optimization. ... 

Although it is hard to draw a sharp distinction, emulsions and foams are somewhat different from systems normally referred to as colloidal. Thus, whereas ordinary cream is an oil-in-water emulsion, the very fine aqueous suspension of oil droplets that results from the condensation of oily steam is essentially colloidal and is called an oil hydrosol. In this case the oil occupies only a small fraction of the volume of the system, and the particles of oil are small enough that their natural sedimentation rate is so slow that even small thermal convection currents suffice to keep them suspended for a cream, on the other hand, as also is the case for foams, the inner phase constitutes a sizable fraction of the total volume, and the system consists of a network of interfaces that are prevented from collapsing or coalescing by virtue of adsorbed films or electrical repulsions. 

In 1840 a hydrauHc power network, which involved large reciprocating pumps that were driven by steam engines, suppHed fluid power to London. However, concurrent technology in steam (qv) turbines and the electric generators outmoded such networks until hydrauHc systems were improved with the use of rotary pumps and oil. The rotary piston pump marked the transition from use of water to oil as the hydrauHc fluid (4). The use of vacuum-distilled, refined mineral oils were instmmental in the success of rotary axial piston pumps and motors such as the Waterbury variable speed gear... 

There are many reasons for significant investment in FCC power trains and, thus, power train maintenance. These power recovery machines handle catalyst-laden gas at high temperature. Because the recovery system is connected to the processing plant, the steam pipe network and the electrical power grid, a power train upset is likely to rapidly extend from the FCC unit to the entire plant. 

It is important for crosstied systems that a sufficient condensate network is provided for balancing the mix of condensate return and makeup treated water as required. The author has seen a system designed with process area and utility area fired boilers of the same pressure. Periodically, the utility area was required to supply makeup steam to balance a shortage in the process area, but no provisions were made to return equivalent condensate from the process to the utility area. The earlier such a mistake is caught, the better. 

On an industrial scale PCI3 is sprayed into steam at 190 and the product sparged of residual water and HCl using nitrogen at 165. Phosphorous acid forms colourless, deliquescent crystals, mp 70. T, in which the structural units shown form four essentially linear H bonds (O - H 155-I60pm) which. stabilize a complex 3D network. The molecular dimensions were determined by low-temperature single-crystal neutron diffraction at 15K.f - ... 

In March 1877, New York inventor Birdshill I lolly introduced the Holly Steam Combination System to provide heat and power using steam distributed through an underground piping network. The first... 

---