Tower Piping

Overall loss of nitrogen oxide catalyst was equivalent to abont 0.15 tons of nitric acid per ton of sulfuric acid produced, which was lower than in the conventional, less sophisticated lead chamber process plants. Sulfuric acid could be obtained as either 77-82% or 60-80% solutions. An advantage of the more modem process was that the low-temperature operation allowed the use of PVC as piping, tower cladding, and storage tank finings. 

The pipe stiU furnace heats the feed to a predeterrnined temperature, usuaUy a temperature at which a predeterrnined portion of the feed changes into vapor. The vapor is held under pressure in the pipe in the furnace until it discharges as a foaming stream into the fractional distUlation tower. Here the nonvolatile or Hquid portion of the feed descends to the bottom of the tower to be pumped away as a bottom nonvolatile product, while the vapors pass up the tower to be fractionated into gas oU, kerosene, and naphtha. 

Skirts are used in vessels and towers. They transmit high axial and bending loads and offer favorable geometry for thermal gradients. In piping, when loads are beyond the capacity of lugs and tmnnions, skirts are often favored. 

Fig. 3. Rough layout sketch (/) the two fined heaters F-1 and F-2 are located together but are separated from the other equipment with a subpipeway connecting the process area to the heater area (2) the reboiler E-2 is located adjacent to its column, T-1. The preheat exchanger E-4 is located adjacent to tower T-3 (J) the elevated overhead condenser E-3 is located next to the overhead accumulator V-1. Also, the ain condenser EE-3 is located adjacent to its overhead accumulator V-2 (4) the rest of the ain coolers (EE-1—3, -5) are grouped together ia a common fan stmcture (5) all equipment and related piping is routed to and from the existing piperack saving the addition of a new piperack (6) all pumps (P-1—P-6) are located ia a row under the piperack, and each...

Because carbon is difficult to machine, very tittle impervious carbon equipment is made. However, impervious graphite has been accepted as a standard material of constmction by the chemical process industry for the fabrication of process equipment, such as heat exchangers, pumps, valves, towers, pipe, and fittings (9,10). 

Commercial chlorohydrin reactors are usually towers provided with a chlorine distributor plate at the bottom, an olefin distributor plate about half way up, a recirculation pipe to allow the chlorohydrin solution to be recycled from the top to the bottom of the tower, a water feed iato the recirculation pipe, an overflow pipe for the product solution, and an effluent gas takeoff (46). The propylene and chlorine feeds are controlled so that no free gaseous chlorine remains at the poiat where the propylene enters the tower. The gas lift effect of the feeds provides the energy for the recirculation of the reaction solution from the top of the tower. 

A popular overall factor refinement, known as the Hand factor approach, uses a different factor to estimate overall costs for each class of equipment to cover all labor field materials, eg, piping, insulation, electrical, foundations, stmctures, and finishes and indirect costs, but not contingencies. Hand factors range from 4 for fractionating towers down to 2.5 for miscellaneous equipment. 

Galvanized steel Cooling tower components, fan blades and shrouds, transfer pipes, plumbing fixtures... 

Cooling tower Threaded pipe joints Bolts, nuts, washers Partially exfoliated coatings Lap joints in sheet metal Between bushings and shafts on pumps Pump gaskets... 

Figure 5.12 Severely corroded galvanized steel pipe supplying water to a cooling tower fan-bearing system. Where the galvanized metal has been consumed, only a brown rust patch is visible.

Horizontal natl. circ. Ease of maintenance Lower skirt height than vertical Less pressure drop than vertical Longer tubes possible Less cost than kettle No theoretical tray Extra space and piping as compared to vertical Fouls easier as compared to vertical Accumulation of higher boiling point components in feed line, i.e., temperature may be slightly higher than tower bottom... 

Balancing Valve Hand or mechanically operated valve installed in each riser pipe of a multicell tower to control water flow. 

Distribution System Mechanical method of passing hot water over the fill uniformly. Low-pressure spray-through piping and nozzles are usually used in counterflow towers gravity drop is normally utilized in crossflow towers. 

An innovation is a direct-contact condenser mounted on the vapor body. A short piece of vertical pipe connects the vapor body with the condenser to minimize piping and pressure drop. This design also eliminates structural steel for support of a separate condenser. For cooling tower applications, the hotwell is elevated to permit gravity flow of water from the hotwell to the top of the cooling tower, thus eliminating the need for a pump. 

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