Titanium plates

Titanium is the only one of the more common structural metals which is not attacked by wet chlorine gas and it is thus widely used as a heat exchange material for cooling the gas after the electrolysis stage. Preheating of sodium chloride brine is carried out in titanium plate heat exchangers, while titanium butterfly valves, demisters, and precipitators handle the chlorine gas produced in the cell. The most important use of titanium in chlorine production is as anodes in place of graphite in the electrolytic process. This is covered in more detail later. 

Investigate the use of a gasketed plate heat exchanger for the duty set out in Example 12.1 cooling methanol using brackish water as the coolant. Titanium plates are to be specified, to resist corrosion by the saline water. 

The anodes are platinized titanium (titanium plated with 5 microns of platinum) the cathodes are also titanium plated with 2.5 microns of platinum. All gaskets are Viton GF (peroxide grade), and the cell membranes are DuPont Nation 324. Flow through the cells is in parallel using manifolds with /4-inch fluid-flow inlet port orifices to provide equal flow to all cells. 

In cases where low intensity irradiation is needed batch treatment could be as simple as using a large-scale ultrasonic cleaning bath as the reaction vessel. However the tank would need to be constructed of a material which was inert towards the chemicals involved. An appropriate grade of stainless steel might prove adequate or plastic tanks could be used. In the latter case however the transducer would need to be bonded onto a stainless or titanium plate and this assembly then bolted to the tank. A useful variant to this and indeed one which offers greater flexibility in use is the sealed, submersible transducer assembly (Fig. 7.17). With either system some form of additional (mechanical) stirring would almost certainly be needed. 

Carbon-epoxy plates are now used in bone surgery replacing the titanium plates that had been employed. Usually a layer of connective tissue forms around the composite plate. 

For high-pressure applications in the hydrocarbon and chemical processing industries, a titanium compact heat exchanger has been developed by Rolls-Laval. This heat exchanger consists of diffusion-bonded channels that are created by superplastic forming of titanium plates (18). This heat exchanger can handle high pressure and corrosive fluids and is suitable for marine applications. 

Membrel cell — (membrane electrolysis) Electrochemical cell developed by BBC Brown Boveri Ltd, now joined with ASEA AB, to ABB Asea Brown Boveri Ltd) for water electrolysis. A polymeric cation exchange membrane acting as -> solid electrolyte is placed between a catalyst-coated porous graphite plate acting as cathode and a catalyst-coated porous titanium plate acting as anode. 

The experimental setup is schematically depicted in Figure 15.23. Each anode was a 7 X 7 in. titanium plate. Eight permanent magnetic bars were placed on the... 

FIGURE 1.11 Schematic of the electrochemical cell and circuit arrangements for anodic oxidation of a titanium metal plate under hydrothermal conditions. (A) Counter electrode (platinum plate), cathode (B) thermocouple (C) stirrer (D) reference electrode (platinum plate) (E) working electrode (titanium plate), anode. 

FIGURE 1.12 TliM of BaTi03 powders prepared by the hydrothermal electrochemical method (250°C, 0.5 N Ba(N03)2, titanium plate). 

In the next step, we carried out the polymerization experiments using three vinylic monomers, i.e. styrene, methyl methacrylate, and 4-chloromethyl-styrene, by dipping the appropriate titanium plates into deoxygenated monomer/toluene solutions (1 2, v/v) at 90 °C for 24 h. Interestingly, grafted initiators ACTP and ACTU gave very comparable polymer films from the two styrene monomers, whereas polymerization of methyl methacrylate was found to be significantly better on Ti-ACTP than on Ti-ACTU. 

Fig. 2. A XPS spectra of (a) ACTU-grafted titanium plate and (b) the same after polymerization (90 °C, 24 h) of 4-chloromethyl-styFene B Cls spectrum ofpo/y-(4-chloromethyl-styrene) film obtained in (b).

At this Stage we examined the efficiency of further frmctionalizations at the surface of / o/y-(4-chloromethyl-styrene) films bound to the titanium plates. For this purpose the plates were immersed in pure butylamine (24 h, reflux) and in a DMSO solution of sodium azide (10 M, 24 h, 65 °Q, respectively. 

Fujishiro, Y. et al.. Coating of hydroxyapatite on titanium plates using thermal dissociation of calcium-EDTA complex in phosphate solutions under hydrothermal conditions, 7. Colloid Interf. Sci., 173, 119, 1995. 

Tokuyama Soda Co., Ltd. has developed a large bipolar electrolyzer that has an electrolysis area of 2.7 m per unit. The cell bodies are metallic. The anode chamber is lined with titanium plating and the cathode chamber and structural frame are carbon steel. The anode surface is titanium mesh with an... 

The electrolysis of sucrose was performed in a filter press cell (micro-flow cell, electro-cell AB) (Figure 21.19). The working electrode was platinum deposited electrochemically on a titanium plate. The counter electrode was a plate of stainless steel. The two compartments of the cell were separated by an ion-exchange membrane (Nation 423). A part of this membrane immersed in a saturated potassium sulfate permitted to connect by capillarity the MSE. The electrolyte in the cell was circulated by an external peristaltic pump (1 cm3 min-1) and passed through a reservoir (100 cm3). 

Fig. 13.27 The Edison Welding Institute used a combination of friction stir welding, gas metal arc welding, (GMAW), and hybrid ° laser welding to fabricate this demonstration article from thick-section titanium plates. Friction stir welding was used...

The low density of carbon fibre composites compared with metals has resulted in their application as biomaterials. Carbon fibre/epoxy composites are used as plates in bone surgery, replacing the titanium plates previously employed. The combination of high strength and flexibility exhibited by carbon fibre composites has had a huge impact in the performance of sports equipment Fishing rods, golf clubs, bicycle frames, rackets and skis are examples of applications for carbon fibre composites. 

Folded tube HXs of JHU/APL design with nested 0.072-m (3-in.) tubes, or plate HXs of Lockheed design using titanium plates Internal ammonia flow 4 10-MWe (net) modules Nominal operating characteristics Nominal Ar(°C)... 

Manara S, Paolucci F, Palazzo B, Marcaccio M, Foresti E, Tosi G, et al. ElectrochemicaUy-assisted deposition of biomimetic hydroxyapatite-coUagen coatings on titanium plate. Inorganica Chimica Acta 2008 361 1634-45. 

Maia, L. Wanga, D. Zhangb, S. Xiea, Y Huangc, C. Zhang, Z. Synthesis and bactericidal ability of Ag/Ti02 composite films deposited on titanium plate, Appl. Sutf. Sci 2010,257, 974-978. 

Plate-and-frame coolers have made some inroads into this application. These will be much smaller than the typical shell-and-tube coolers, at the expense of a greater pressure drop. Titanium plates are necessary, and welded construction of the plates is highly recommended [16]. Plate-and-frame units will probably become more common as the increasing use of the newest membrane cells allows operating pressures to increase. Few units are found today in sizes above 100 tpd chlorine. Section 9.3.2.4 on caustic cooling briefly discusses the general characteristics of plate exchangers. 

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