Condenser cooling water outlet temperature

I now observed that the surface condenser cooling-water outlet temperature had increased from 100 to 135°F. This is a sign of loss of cooling-water flow. As none of the other water coolers in the plant had been affected, I concluded that the cooling-water inlet to my surface condenser was partly plugged. 

Let s say that the cooling-water outlet temperature from the condenser was 140°F. This is bad. The calcium carbonates in the cooling water will begin to deposit, as water-hardness deposits, inside the tubes. It is best to keep the cooling-water outlet temperature below 125°F, to retard such deposits. Increasing the pumparound heat removal will lower the cooling-water outlet temperature. 

Ejector (steam-jet) refrigeration systems are used for similar apph-cations, when chilled water-outlet temperature is relatively high, when relatively cool condensing water and cheap steam at 7 bar are available, and for similar high duties (0.3-5 MW). Even though these systems usually have low first and maintenance costs, there are not many steam-jet systems running. 

The condensing water temperature has an important effect on steam rate per refrigeration effecd, rapidly decreasing with colder condenser cooling water. Figure 11-108 presents data on steam rate versus condenser water inlet for given chiUed-water outlet temperatures and steam pressure. 

When using cooling water to cool or condense a process stream, assume a water inlet temperature of 90°F (from a cooling tower) and a maximum water outlet temperature of 120 F. 

Figure 2. Reactor set-up used for oxidative degradation experiments in which, PI pressure indicator, TI temperature indicator, TIC temperature indicator controller, SI speed indicator, SIC speed indicator controller, R reaction vessel/autoclave, T thermocouple, H electric heater, RD mpture disc, I impeller, GS gas sparger, SC sample condenser, C cooling coil, CW cooling water inlet, CWout cooling water outlet, S solenoid valve, LSP liquid sampling port.

Absolutely the first things to look for on water-cooled condensers are back-flush connections. Such condensers must be back-flushed periodically to obtain peak performance. This is especially true if the water outlet temperature is higher than design. Plastic bags are typical of the type of material that blocks the tube inlets. Mud, grass, crabs, and paper cups are also common. 

These include undersized surface condenser area, water-side fouling, lack of water flow, condensate backup, leaking seal strips around the air baffle, and excessive cooling-water inlet temperature. To determine whether a poor vacuum in a surface condenser is due to such heat-transfer problems, plot the surface condenser vapor outlet temperature versus pressure on the chart shown in Fig. 25.4. If this point is on or slightly below the curve, it is poor heat transfer in the surface condenser itself that is hurting the vacuum. 

In this case the temperature at the air outlet of this type condenser is generally assumed to be 5°F above the inlet temperature of the cooling water. In addition to the normally expected air leakage, an allowance must be made for air liberated from the injection water [10],... 

A typical ethane cracker has several identical pyrolysis furnaces in which fresh ethane feed and recycled ethane are cracked with steam as a diluent. Figure 3-12 is a block diagram for ethylene from ethane. The outlet temperature is usually in the 800°C range. The furnace effluent is quenched in a heat exchanger and further cooled by direct contact in a water quench tower where steam is condensed and recycled to the pyrolysis furnace. After the cracked gas is treated to remove acid gases, hydrogen and methane are separated from the pyrolysis products in the demethanizer. The effluent is then treated to remove acetylene, and ethylene is separated from ethane and heavier in the ethylene fractionator. The bottom fraction is separated in the deethanizer into ethane and fraction. Ethane is then recycled to the pyrolysis furnace. 

Let the cooler-condenser outlet temperature be 40°C. The maximum temperature of the cooling water will be about 30°C, so this gives a 10°C approach temperature. 

Tcond — Tcwi condenser temperature (°C) inlet cooling water temperature (°C) outlet cooling water temperature (°C)... 

The gas leaving an ammonia oxidation unit in a continuous process is cooled rapidly to 20°C and contains 9 mol % NO, 1% N02, 8% O2, and 82% N2 (all the water formed by reaction is assumed to be condensed). It is desirable to allow oxidation of NO to N02 in a continuous reactor to achieve a molar ratio of N02 to NO of 5 before absorption of the N02 to make HNO3. Determine the outlet temperature of the reactor, if it operates adiabatically (at essentially 6.9... 

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