Down pipes

Figure 8.8 Severe grooving on the internal surface of a copper pipe carrying condensate. Grooves were cut by condensing vapors running down pipe walls. Note the vivid blue corrosion products and deposits near the bottom.

When how values exceed 1% to 2 in., consider special downcomers or down pipes to conserve cap area for high vapor loads. 

Cross-section flow area, minimum, of down-pipe clearance area between tray floor and down-pipe bottom edge, or up-flow area between outer circumference dotvn-pipe and any inlet tray w eir, in. Individual hole area per hole on sieve tray, in. Riser inside cross-section area per riser, in. Reversal area per cap assembly, in. ... 

Although these units find initial application in areas of limited water, they have not been limited to this situation. In many instances they are more economical than cooling tower systems and have been successfully applied in combination with cooling towers (see Figure 10-184). Economic comparisons should include such items as tower costs, basin, make-up facilities, water treatment, pumps for circulation, power supply, blow down, piping, etc. For small installations of air-cooled units, they should be compared... 

To clean, wash down pipe in derrick with freshwater. 

Flat roofs. Flat roofs are popular with architects due to their reduced visual impact. However, they generally require a much higher standard of waterproofing, and may be susceptible to ponding, moss growth and dirt/debris entrapment. Inevitably, they also require internal down-pipes for rainwater disposal. 

NOTE BEFORE ASSEMBLING PIPE. CLEAN AND SAND LIGHTLY THE SHOULDER OF BELL AND END OF SPIGOT. APPLY MORTAR TO SPIGOT END AND TO SHOULDER OF BELL. THEN SEAT AND CENTER SPIGOT INTO BELL. TIE DOWN PIPE TIGHTLY BEFORE CAULKING JOINT. 

Disadvantages Natural solid sump in bottom, Boilout cycles are usually frequent. Internal down-pipe may plug. Difficult to model and scale-up. Flow patterns in suspension chamber not uniform. 

The column shown in Fig. 17.1 often contains a number of perforated plates, or trays, stacked one above the other. A cascade of such trays is called a sieve-plate column. A single sieve plate is shown in Fig. 17.2. It consists of a horizontal tray A carrying a down pipe, or downcomer, C, the top of which acts as a weir, and a number of holes B. The holes are all of the same size, usually 5 to in. in... 

One of the best things anyone with outdoor space can do is to store rainwater and use it to water plants and top up water features or bird baths, especially in periods of no rain. Rainwater barrels are widely available in various sizes, shapes, and materials (usually recycled plastic or wood), and many municipalities offer them at discounted prices to encourage gardeners to use them. A barrel can be connected to a down pipe with a simple diverter kit, which also prevents the barrel from overflowing. If you have space, you can even connect a second barrel to the first one, and install others to catch rain from sheds or flat roofs. 

Fig. 20. Cryostat with electrical control h) bath liquid d) copper vaporizer f) down pipe h) siphon h) condenser 1) liquid nitrogen r) relay Sj) power supply of about 2 volts Sa) power supply of about 18 volts t) vapor pressure thermometer u) pressure head regulator (manostat) v) electromagnetic gas valve the valve plunger must be sufficiently heavy not to stick in its seat.

These have a constant cross section. Examples are domestic gutters or down-pipe, or (replacement) window frames, made from PVC. Look through a length of an extrusion, towards a window, for markings parallel to the extrusion direction, which have come from the die. The outer surface is in contact with a sizing die, whereas the inner surface cools in air and can... 

Have the participants been provided with a package containing the charge letter, shot-down Piping and Instrument Diagrams (P IDs), copies of key Material Safety Data Sheet (MSDS) and other pertinent materials ... 

Stainless pipes replaced SG blow-down pipes. 

The pressure-suppression type primary containment is a cylindrical concrete structure with an embedded steel liner type with two major compartments a drywell and wetwell. The lower part of wetwell volume is filled with water that works as the condensation pool, and the upper part is a gas compression chamber. The blow-down pipes from the safety relief valves are routed to the pressure suppression pool. 

A sedimentation shaft (downpipe) Gradis was used instead of the air-jet injection for feeding the silica particles. They fell onto two sloping planes (45°) and then through the laser beam. A low-vibration 1 mm sieve was used for dosing the down-pipe with the agglomerates. 

The offshore oil and gas sector, be the plants used by the industry necessary to extract and process the fluids located on ships, platforms, down pipes or under the sea bed, was one of the first to embrace process intensification with compact heat exchangers such as the PCHE. The sector has pioneered other PI uses in separations and more recently in reactions, and the potential for growth and further innovation is considerable. More extensive replication onshore, as the demand for these resources continues to grow, is likely. 

Liquid Flow. Weirs and Down Pipes. The liquid depth on a plate is controlled by exit overflow weirs. The action of the liquid flowing over the weir is complicated by the action of the caps and by the restrictions due to the wall. The last row of caps may blow a con-... 

A variety of different weir and down-pipe arrangements are employed (see Fig. 16-4). 

Locke (Ref. 22) from a study of circular down pipes with the tops acting as weirs concluded that at least three types of liquid flow were possible in circular down pipes with liquid seals at the bottom. At low rates of liquid flow, the top of the pipe acted as a weir, and the liquid flowed down in a film. As the liquid head was increased, the pipe became full and sucked vapor bubbles down with it at still higher liquid rates, the pipe ran full but did not entrap vapor. The first type flow occurred for liquid head less than one-sixth to one-fifth of the pipe diameter, and this type of flow could be represented by the familiar Francis weir formula ... 

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