Gaskets graphite

Cell DC-2. Earlier demineralization studies by Lyon (9) employed cell DC-2. This was a sandwich-type cell with Lucite side plates bolted together with two epoxy resin-gasketed graphite electrodes separated by an anion-permeable membrane. The membrane was necessary because a suitable anion-responsive electrode was not then known. The principle of operation is that in the cathode compartment, after several current reversal conditioning cycles, sodium ions are removed by the cathode while chloride ions migrate from the cathode through the membrane to the anion chamber. In the anode chamber, sodium ions, from the previous half cycles, are rejected from the anode. The net result was salt depletion in the cathode chamber and a similar concentration increase in the anode chamber. 

Eig. 4. Constmction of a sodium—sulfur battery. A, Negative terminal B, springs plus graphite felt C, sulfur D, carbon E, sodium reservoir E, positive terminal G, iasulator H, aluminum sealing gaskets 1, steel case J, film of sodium K, P-alumiaa tube L, carbon felt M, wick N, aluminum can (67). 

Gaskets uti1i2ed in ethyleneamine service generally are made of Grafod flexible graphite or polytetrafluoroethylene (TEE). There is no single elastomer that is acceptable for the entire product line, although TEE may be considered as an alternative to elastomers across the product line. However, because TEE is not a tme elastomer, it may not always prove suitable as a replacement. 

The construction materials for the plates include most corrosion-resistant metals, usually 304SS, 316SS, titanium, Incoloy 825 , Hastelloy , and others, plus nonmetallic fused graphite, and fluoroplastic Diabon F . Typical gaskets between the plates include nitrile rubber, butyl, and EPDM elastromers, Hypalon and Viton , based on the various manufacturers literature. 

Reactor material Silicon Pyrex Gasket material Kalrez hybrid Kalrez /graphite... 

Chemically universally stabile is poly-tetrafluoroethylene (PTFE, Teflon ), but it is relatively expensive. A problem is the cold flow , that is, the polymer is slowly deformed under the mechanical stress of the pressure on the gaskets and a leakage of the cell can occur (PTFE compounds, e.g. with glass powder or graphite, show a better behavior.)... 

Unless otherwise specified, the gland plate to seal chamber seal shall be a fluoroelastomer O-ring for services below 150°C (300°F). For temperatures 150°C (300°F) and above or when specified, graphite-filled austenitic stainless steel spiral wound gaskets shall be used. The gasket shall be capable of withstanding the full (uncooled) temperature of the pumped fluid. 

Baked phenolic-lined earhon steel is acceptable for storage of many pure ethyleneamincs. except EDA. Gaskets utilized in ethyleneamine service generally are made of Grafoil flexible graphite or polylclrafluoroelhy-lene (TFE). 

The distributor plate is sandwiched against the catalyst wafer using a gasket of polymer or graphite and the volume above each catalyst patch defines a reaction volume. A cross-section view of one of the 256 reaction/detection channels is shown below (Fig. 3.8). Feed gas enters the reaction volume from the side. For residence times greater than 100 ms the reactor behaves as a difFusionally mixed... 

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