Condensers shell

Recovery system SheU-and-tiibe condenser Shell-and-tiibe condenser Direct-contact condenser Shell-and-tiibe condenser... 

Deterioration of tubes near the inlet nozzle of condenser shells due to impingement of water and steam mixtures can be alleviated through the use of appropriately placed and sized baffles or impact plates or by applying clip-on impingement shields to the tubes (see Case History 11.3). 

Condenser shell and tube heat exchanger, fixed tube sheets, heat transfer area 25 m2, design pressure 2 bar, materials stainless steel. 

Process designers sometimes like to use dephlegmators or partial condensers mounted directly in the top of the distillation column when the overhead product is taken off as a vapor. They arc particularly popular for corrosive, toxic, or hard-to-handle chemicals since they eliminate a. separate condenser shell, a reflux drum, and a reflux pump. Comment on the relative controllability of the two process systems sketched below. 

The tower overhead vapor, shown in Fig. 13.6, condenses to a liquid on the outside of the cold condenser tubes. The liquid drips off the tubes. These droplets of liquid are in close contact with the saturated vapor in the condenser shell. This means that the liquid is in equilibrium with the vapor. The condensed liquid is therefore, initially, at its bubble-point temperature. This liquid accumulates in the bottom of the condenser s shell. The submerged tubes then must subcool this liquid. Part of the surface area of the condenser is hence devoted to subcooling liquid, and part is devoted to condensing vapor. 

The mechanical pressure rating of the compressor case or the refrigerant condenser shell. 

HUM Required hot water mass flow rate WA Net turbine shaft work output CR Condenser shell-side pressure loss coefficient X2 Turbine exit quality... 

Product column condenser shell and tube, floating head, heat transfer area 15 m, design pressure 2 bar, material stainless steel ... 

An inert blanketing problem in a condenser shell can often be diagnosed by measuring surface temperature. Areas blanketed by inerts tend to be considerably cooler. If safety regulations permit, feeling the shell by hand at different spots can sometimes be an effective surface thermometer. 

Refineiy Debutanizer The ability to condense the overiiead product was lost because of vapor blanketing in the condenser shell. Venting solved the problem. A newly installed, nitrogen-purged instrument caused the problem. Ensure adequate venting when inerts are likely to be present... 

Low-pressure steam exiting the turbine enters the condenser shell and is condensed on the condenser tubes. The condenser tubes are maintained at a low temperature by the flow of cooling water. The condenser is necessary for efficient operation by providing a low-pressure sink for the exhausted steam. As the steam is cooled to condensate, the condensate is transported by the boiler... 

Chemical and mineral Heat exchangers A major industrial application for titanium remains in heat-transfer applications in which the cooling medium is seawater, brackish water, or polluted water. Titanium condensers, shell and tube heat exchangers, and plate and... 

In one debutanizer, the ability to condense the overhead product was lost. Investigation showed that a nitrogen-purged instrument had been recently installed. The nitrogen had accumulated in the top of the condenser shell, and gas blanketed the water-cooled tubes. A vent on the top of the condenser shell was opened, and condenser capacity was restored. Note that a small amount of really noncondensable gas can effectively vapor bind a shell-and-tube condenser. 

As shown in Figure 13-6, ihe seal legs function to drain oil and water from the shell side of the condenser. The inability to maintain condenser drainage will severely reduce ejector efficiency by backing liquid up in the condenser shell. With experience, one can find the liquid level inside the condenser shell by feeling for the temperature gradient by hand. Condenser tubes submerged in liquid are effectively out of service. 

Exhibit 4-27 illustrates how primary process considerations govern the elevation of the surface condenser and some of its auxiliary equipment. Because a pump is needed to remove the condensate from the hot well, the pump net positive suction head (NPSH) must be satisfied to operate satisfactorily. Vertical pumps are generally used in this application because the NPSH requirement is calculated from the bottom of the lower impeller for vertical pumps, compared with the centerline of the inlet nozzle for horizontal pumps. Setting the elevation of the inter-after condenser, usually located to the side of the suifice condenser, can be done with fewer restriaions. Ilie bottom of the inter-after condenser shell must not be more than 3 ft (900 mm) below the condensate return nozzle on the side of the hot well. The plant layout designer is then free to set the elevation as high as necessary. 

Failure of the condenser air removal system for one of the main condenser shells would result in a gradually increasing back pressure in that particular condenser shell. Eventually, if not resolved by the operators, this would result in a turbine trip (Section 10.4.2.2.1 of Reference 6.1). 

The main condenser is designed to receive and condense the full-load main steamflow exhausted from the main turbine. It also receives discharges from auxiliary systems such as the feed water heater vents and drains and the gland sealing steam spillover and drains. To protect the condenser shells and turbine exhaust hoods from overpressurisation, steam relief blowout diaphragms are provided in the low-pressure turbine exhaust hoods. Two low-pressure feedwater heaters are located in the neck area of each condenser shell, adjacent to where their steam is bled from the low-pressure turbine. 

The underground portions of the circulating water system piping are constructed of concrete pressure piping. The remainder is carbon steel, with an internal coating of a corrosion-resistant compound. Motor-operated butterfly valves are provided in each of die circulating water lines at their inlet to and exit from die condenser shell, to allow isolation of portions of the condenser. 

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