Gas manifolds

The cell head is fabricated from a 2.54-cm steel plate and has separate compartments for fluorine and hydrogen. The oudet-gas manifolds, hydrogen fluoride feed and purge lines, and electrical connections are on top of the head. The gas separation skirt is made of Monel. An insulating gasket maintains the seal between the tank and the head. The anode assembly consists of 32 carbon blades bolted onto a copper bar, each of which contains three copper conductor posts. The cathode assembly consists of three vertical, 0.6-cm parallel steep plates. The plates surround the anode assembly and are supported by three steel posts which also serve as conductors. 

Fig. 3. Schematics of gas manifolds for MCFC stacks (a) internally manifolded fuel cell stack (b) externally manifolded fuel cell stack.

The vertical tube (water-cooled) generator consists of two concentric tubes the outer of which is cooled with water and acts as the ground electrode. Feed gas is introduced into the top of the inner stainless steel tube (which serves as the high voltage electrode), exits at the bottom of the outer tube, flows upward through the aimular space (which contains the electric discharge), and emerges at the top of the outer tube into a product gas manifold. 

Thin-film epitaxy by OMCVD is generally more flexible, faster, lower in cost, and more suited for industrial production than MBE. An OMCVD system usually consists of two principal components, a gas manifold for blending the gas composition, and a graphite substrate holder which is usually inductively heated. A schematic diagram of an OMCVD system is shown in Figure 5. 

Fig. 5. A gas manifold for the production of epitaxial layers of Group 111—V semiconductors by OMCVD where [...

Because this design has relatively low power density, recent work has focused on a monolithic SOFC, since this could have faster cell chemistry kinetics. The very high temperatures do, however, present sealing and cracking problems between the electrochemically active area and the gas manifolds. 

AUS105 AUS205 Type 3 Type D-3 Good thermal shock resistance high resistance to erosion particularly in alkaline media Pumps, valves, pressure vessels, filter parts, exhaust gas manifolds... 

During the last year we have built an FTMS instrument specifically designed for laser-induced thermal desorption from single-crystal surfaces. Figure 5 is a perspective drawing of the Instrument. The chamber is pumped by a 150 1/s ion pump and has a base pressure of 2.0 X 10- torr. Gases are Introduced through sapphire-sealed leak valves from a diffusion pumped gas manifold. 

Gases were supplied to the infrared cell from a gas manifold. 4.99% NO in He and 2.14% CH4 in He were obtained from Matheson. Oxygen and helium were obtained on-site. The He, NO, and CH4 cylinders were passed through an oxysorb trap, an ascarite trap, and a molecular sieve trap, in that order, for additional purification. The O2 was passed through an ascarite and a molecular sieve trap. 

FIGURE 3.8 Outline of the vacuum/gas manifold for anaerobic sample preparation. 

FIGURE 5.1 Schematics of edge sealing of planar cells (above) and external gas manifold seals (below) used for a simple cross-flow SOFC stack design. 

FIGURE 5.2 Schematic of seals typically found in aplanar design SOFC stack with metallic interconnect and metallic internal gas manifold channels (possibly for counter flow pattern of fuel and air gases). 

The tar is dissolved in acetone (300 mL, 02-free) and added to a solution of excess [Et4N]Br (12.0 g) in ethanol (200 mL, 02-free). After evaporation of about 400 mL of solvent in vacuo, 600 mL of water (02-free) is added to precipitate the product. [Note A dry-ice/acetone trap (—78°C) is needed to prevent moisture from diffusing back into the inert-gas manifold of the vacuum line during this and subsequent operations involving water ] The yeUow-brown solid is collected on a large (70-mm-diameter) coarse-porosity frit, thoroughly washed with 2 X 20 mL of water, and dried in vacuo for 12 h. Note If appreciable... 

Figure 13.9 Schematic diagram of a polymer electrolyte fuel cell (A) gas manifolding, (B) porous graphite block, (C) active catalyst layer (dispersed Pt and Teflon binder), and (D) polymer electrolyte.

D. Purging Syringes. Syringes are conveniently purged from an inert-gas source such as a tube with a rapidly flowing inert-gas stream or a special septum attached to the inert-gas manifold. Two or three cycles of filling, removing the... 

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