Cooling towers construction

The OSBL costs comprise land, site development, process buildings, auxiliary buildings, Storage buildings, equipment and construction for utilities including cooling towers, construction expenses, waste-disposal facilities, etc. The OSBL costs may be assumed to be about 20-40% of the ISBL costs, with the upper limit applying better to small batch plants. 

GEA 2H Water Technologies - Practical solutions for Mass Transfer, Cooling Tower Construction and Sewage/ Water Treatment made of PP, PVDF and PVC. 

Natural and forced-draft cooling towers are generally used to provide the cooling water required on a site, unless water can be drawn from a convenient river or lake in sufficient quantity. Seawater or brackish water can be used at coastal sites, but if used directly will necessitate more expensive materials of construction for heat exchangers. 

Most cooling towers are built of redwood or cypress. However, special conditions and atmospheres dictate other types of construction. 

Materials of construction must he corrosion resistant. Steel should he hot galvanized, although some resin coatings may suffice. GRP casings are used hy some manufacturers. The water-dispersal packing of a cooling tower is made of treated timber or corrugated plastic sheet. 

Figure 13.16. Construction for determining the height of water-cooling tower...

Natural draft. Natural draft cooling towers consist of an empty shell, usually constructed in concrete. The upper, empty portion of the shell merely serves to increase the draft. The lower portion is fitted with the packing. The draft is created by the difference in density between the warm humid air within the tower and the denser ambient air. 

The next stage is to find the target supply conditions for the cooling tower. This can be achieved by constructing a simulation model of the cooling tower to simulate the conditions of the exit water and air for given inlet air and water conditions2. The model must also consider the... 

In the United States, about 80% of the 23 million kg of technical PCP produced annually — or about 46% of worldwide production — is used mainly for wood preservation, especially utility poles (Pignatello etal. 1983 Kinzell etal. 1985 Zischke etal. 1985 Choudhury etal. 1986 Mikesell and Boyd 1986 USPHS 1994). It is the third most heavily used pesticide, preceded only by the herbicides atrazine and alachlor (Kinzell et al. 1981). Pentachlorophenol is a restricted-use pesticide and is no longer available for home use (USPHS 1994). Before it became a restricted-use pesticide, annual environmental releases of PCP from production and use were 0.6 million kg to the atmosphere from wood preservation plants and cooling towers, 0.9 million kg to land from wood preservation use, and 17,000 kg to aquatic ecosystems in runoff waters of wood treatment plants (USPHS 1994). There are about 470 wood preservative facilities in the United States, scattered among 45 states. They are concentrated in the South, Southeast, and Northwest — presumably due to the availability of preferred timber species in those regions (Cirelli 1978). Livestock facilities are often constructed of wood treated with technical PCP about 50% of all dairy farms in Michigan used PCP-treated wood in the construction of various components of livestock facilities (Kinzell et al. 1985). The chemical is usually applied to wood products after dilution to 5% with solvents such as mineral spirits, No. 2 fuel oil, or kerosene. More than 98% of all wood processed is treated with preservative under pressure about 0.23 kg of PCP is needed to preserve 1 cubic foot of wood (Cirelli 1978). Lumber treated with PCP retains its natural appearance, has little or no odor, and can be painted as readily as natural wood (Wood et al. 1983). 

Cooling towers can be either the victim of an outside ignition source or they can be the culprit causing propagation of a fire to other nearby processing, storage, or utility operations or facilities. In fire protection terms, they may present an "exposure to" or they may suffer "exposure from" other facilities or hazards. Some of the situations and events that have led to fires in cooling towers of combustible construction are ... 

Passive fire protection for cooling towers involves increasing spacing distances and using noncombustible materials of construction. For cooling towers of totally noncombustible materials of construction, there are no fire protection requirements. Noncombustible means that the cooling tower s structure, fan and distribution decks, louvers, and fill materials must all be noncombustible materials. 

In July of 1997, a cooling tower at an ammonia and urea plant, originally constructed in 1968, caught fire and was destroyed. The plant produced 1,450 tons/day (1,315 tonnes/day) of ammonia and 240 tons/day (218 tonnes/day) of urea. The coolingtowerwasa 5-cell, induced draft, cross flow unit. It was constructed of redwood with steel supports and fiberglass fill. The capacity of the cooling tower was 50,000 gallons (190,000 liters). 

Induction motors are the most frequent in use because of their simple and rugged construction, and simple installation and control. They are constant speed devices available as 3600 (two-pole), 1800, 1200, and 900 rpm (eight-pole). Two speed models with special windings with 2 1 speed ratios are sometimes used with agitators, centrifugal pumps and compressors and fans for air coolers and cooling towers. Capacities up to 20,000 HP are made. With speed... 

Natural-draft cooling towers with a hyperbolic configuration are usually constructed of concrete, have a large dimension and, consequently, large capacities. They are generally used in power plants. Figure 4.3 also illustrates this design. 

Figure 4.10 Various geometries employed in constructing redwood fill for cooling towers.

Mechanical-draft cooling towers can be either field-constructed or factory-assembled systems. Installations that are constructed onsite are generally those employed at utility stations. Factory-assembled towers have applications in smaller industrial operations. 

The use of these relationships in constructing and applying humidity charts is best illustrated by examining a simplified case, that of adiabatic cooling or humidification. Figure 5.4 illustrates this process between air and water that is recycled through the cooling tower. In this operation air is both cooled and... 

Plant operations personnel generally purchase cooling towers rather than construct them themselves. The philosophy behind this policy is that it makes available to operators a wealth of practical knowledge directly applicable in the field. The operator must specify the amount of water and the temperature range required to handle a specific set of process conditions. It is the fabricator s responsibility to propose a system that will meet the operator-furnished conditions for the 5% wet-bulb in the plant locality. This also means that the fan power with which the operation will be accomplished will be guaranteed. 

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