Capacity trapping

It is clear that in most cases other than very large distribution mains, in TD traps are sufficiently large. With shorter distances between drain points, or smaller diameters, then i in low-capacity traps more than meet even start-up loads. On very large pipes it may be worth fitting I in traps, or two in traps in parallel. Low-pressure mains often are drained through float/thermostatic steam traps, and these traps are now available for use at much higher pressures than formerly, where it is known that waterhammer will not be present. 

Aspirator with large ( 1 liter capacity) trap... 

See Volume 4, Chapter 13 An Examination of the Physics of the High-Capacity Trap (HCT) by Andreas Brekenfeld, Ralf Hartmer, Desmond Kaplan, Carsten Baessmann, Jochen Franzen, and Michael Schubert. 

Chapter 13 An Examination of the Physics of the High-Capacity Trap (HCT)... 

Storage. For receiving glycerol from standard 30.3-m (8000-gal) tank cars (36.3-t), a storage tank of 38—45-m ((10-12) x 10 — gal) capacity should be employed. Preferably it should be of stainless steel (304 or 316), of stainless- or nickel-clad steel, or of aluminum. Certain resin linings such as Lithcote have also been used. Glycerol does not seriously corrode steel tanks at room temperature but gradually absorbed moisture may have an effect. Therefore, tanks should be sealed with an air-breather trap. 

The sulfur is thus removed from the gas stream and trapped in the sorbent as iron sulfide [1317-37-9]. Over time all of the iron oxide becomes sulfided and the adsorptive capacity of the sorbent becomes exhausted. The bed can be partially regenerated by oxidation, as follows ... 

Ion-exchange resins swell in water to an extent which depends on the amount of crosslinking in the polymer, so that columns should be prepared from the wet material by adding it as a suspension in water to a tube already partially filled with water. (This also avoids trapping air bubbles.) The exchange capacity of a resin is commonly expressed as mg equiv./mL of wet resin. This quantity is pH-dependent for weak-acid or weak-base resins but is constant at about 0.6-2 for most strong-acid or strong-base types. 

The required orifice continuous flow capacity is determined at steam chest pressure to condensate system pressure at a flow 6 to 8 times design. If designed for normal flow the trap would have to be open 100% of the time. Then, as stated above, a body size is selected that can contain the required orifice (not be above the stated... 

Earlier in the chapter, when the compression cycle was described, a portion of the indicator. Path 3-4, was referred to as the expansion portion of the cycle. The gas trapped in the clearance area expands and partly refills the cylinder taking away some of the capacity. The following equation reflects the expansion effect on capacity and is referred to as the theoretical volumetric efficiency Ev,. 

Pilot-operated valves have the advantage of allowing operations n the set point v/ith no leakage, and the set position is not affected by ba pressure. However, they will not function if the pilot fails. If the sens line fills with hydrates or solids, the valve will open at 25% over pressure trapped above the disc (usually the normal operating pre the vessel). For this reason they should be used with care in dirty vice and liquid service. They are used extensively offshore where all platform relief valves are tied into a single header because up to 5 back-pressure will not affect the valve capacity. 

The steam traps (used to drain water from a separator where this is fitted, perhaps to deal with carry-over from a boiler, or to drain condensate from collecting legs at intervals of not more than, say, 50 meters along the steam line) clearly must have adequate capacity. For the separator at the boiler off-take or at a header supplied from the boiler(s) and itself supplying the steam mains, it may be necessary to have capacity in the trap(s) of 10 per cent or even more of the boiler rating. On the steam lines themselves it is rare for a trap larger than inch or 15 mm size to be needed. Very often, the low-capacity versions of the i-inch steam trap are more than adequate. 

The capacity of any steam trap will depend on the difference in pressure between its inlet and outlet connections. Under system start-up conditions the steam pressure in the line will at first be only marginally above atmospheric. If the trap discharge line rises to a higher level, or delivers to a pressurized return pipe, no condensate will flow through the trap until the line pressure exceeds the back pressure. It is important that steam traps which can drain by gravity, with zero back pressure, are fitted... 

Whatever automatic start-up method is adopted, steam will only flow into the mains and discharge air from the air vents at a pressure at least a little above atmospheric. It then reaches the pipe and condenses on the cold metal, and at first the condensate temperature will be well below 100°C (212°F). This means that the steam traps will have a greater capacity than their normal rating when handling saturated condensate. If the traps are fitted to a collecting leg, at about 700 mm below the main, then filling of the collecting leg will provide a hydraulic head of about 0.07 bar or 1 Ib/in in addition to the line pressure. 

Gt capacity associated with trapping of Li inside the structure of the carbon III. 6... 

Activated carbon filters remove a wide range of organic matter by adsorption onto the carbon bed. The bed may be derived from a number of different carbon sources, and the correct selection of bed type, capacity, and porosity is a specialized function. Activated carbon may be usefully employed in organic traps, complementing the resin bed, but its capacity and organic removal rate characteristics are flow-dependent. Excessive flows may compromise the rate of adsorption of organic matter. 

Where an organic trap is part of a demineralization plant system, it is placed in the train upstream of the strong base anion (SBA) resin unit. When the organic trap resin is placed within the same pressure vessel, physically on top of the anion resin (stratified bed), in which case, as it forms part of the overall anion capacity, a weak base anion resin operating in the free base form is employed. 

Toluene (99.8% anhydrous, water <0.001%, evaporation residue <0.005%) was purchased from Aldrich Chemical Company and used as received. The capacity of the receiver in the Dean-Stark trap was 28 mL. The initial amount of toluene placed in the flask was 88 mL. Upon heating to reflux, 28 mL of toluene was distilled from the flask and collected in the receiver. The remaining volume of toluene in the reaction flask was ca. 60 mL, corresponding to an approximately 0.50M concentration of the reactants. 

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