Water circulation pump

For circulating water through a refractometer any commercial water circulating pump may be used.J... 

Example 6.5 A water tower serves a condenser rated at 880 kW and the water-circulating pump takes another 15 kW. What will be the evaporation rate, the approximate circulation rate, and the air mass flow ... 

Let s imagine we are operating the air-water scrubber in the Unit-Ops Lab at Cooper Union (Fig. 7.5). The water is circulating from the bottom to the top of the tower. The water level in the bottom is 2 ft. The height of the packed bed is 20 ft. At 3 30 p.m., Professor Liebskind shuts off our air compressor and the water circulation pump. As the water, which had been held up on the packing by the flowing air, drains down, the water level in the bottom of the tower rises from 2 to 5 ft. We say, then, that the holdup of the packing was 15 percent (5 ft - 2 ft -r 20 ft = 15 percent). 

The power consumption of an electrodialysis plant is directly proportional to the salt concentration of the feed water, varying from 4 kWh/1000 gal for 1000 ppm feed water to 10-15 kWh/1000 gal for 5000 ppm feed water. About one-quarter to one-third of this power is used to drive the feed water circulation pumps. 

Table 8.31 provides the added cost for a gas engine driver. These supplemental equipment items are the starter (electric motor or air piston), air tanks, air filters, cooling water pumps, and local piping. An air-cooled radiator is included in Fig. 8.10, the engine cost curve. The radiator of course requires water circulation pumps. For 500 BHP or less, the assumption is made that cooling water of the recirculated inhibited type is available from outside circulated cooling water plant... 

TDIC-2 is the range controller, which is set by the optimized set point of SP-2. This is the range value corresponding to the optimum approach. TDIC-2 throttles the water circulation rate and sets the speed of the CT water circulating pumps in such a way that none of the process user valves (CV-4) will be fully open. This is guaranteed by the cascade loop of PDIC-3 and valve position controller (VPC-4). 

The water circulation pump must be of sanitary design and may be equipped either with a single or a double mechanical seal. In the latter case, the purified water from the pump s discharge is used as a seal flush fluid (Fig. 5). If a spare circulation pump is installed for reliability, it is important to ensure that it does not constitute a long dead leg. This can be avoided either by valving it off and draining it free of water... 

A similar technology trend took place for the water circulating pump. Also in this case the possibility to regulate the circuit water flow by motor speed instead of a classical 3-way valve, introduces a big opportunity in energy saving. 

FIGURE 6.5 Horizontal agitated dryer (1, horizontal agitated dryer, 2, dust collector 3, surface condenser 4, liquid ring vacuum pump 5, water circulation pump). 

In case of a condensing turbine, a complete package (steam condenser, condensate extraction pump, vacuum pump/steam ejector (if possible, cooling tower and water circulation pumps, valves, and piping also)) shall be included in scope of supply. 

For the MP header, steam input comes from the process-fired heater F-5001 where the radiation section is used for process feed heating, while the convection section for MP steam generation. MP steam is also made from the extraction of CT-1401 turbine, the HP letdown, and two WHBs. On the other hand, MP steam is used as column reboiling and stripping as well as in the steam turbines and MP letdown. CT-1601 turbines run a compressor and boiler PTs include four small turbines used for running a boiler water circulation pump and three AD fans. Since MP letdown is not measured, it is unknown and to be determined together with the MP imbalance. The MP imbalance includes metering error, steam losses due to steam traps, leaks, and so on. Table 16.10 shows the balance for the MP header. 

Some explanation is required for specific fuel consumption of 1.56MMBtu/klb steam. About 5-10% of the boiler gross steam is used internally for spinning steam turbines to run water circulation pumps and air fans. As an average, 7% internal... 

Two medium-voltage buses supplied from the secondary windings of two transformers on the primary medium voltage buses. These buses supply the main heat transport pumps, feed pumps, water circulation pumps, extractor pumps, and chillers. 

The existing water circulation pump was kept stopped and a much smaller feedwater pump was provided to maintain the level in the flash drum.)... 

Circulation pumps (one working + one stand by) for chilled water Circulation pumps (one working + one stand by) for cooling water Cooling tower... 

Cooled water outlet nozzles To be coimected to water circulation pump for supply to process plant. 

If the water effluent from a cooler is unusually warm but the inlet temperature is about normal, check the pressure on the discharge of the cooling water circulation pump. Low cooling water pressure is sometimes due to deterioration of the cooling water pump s impeller or wear rings (see Chapter 11). A badly fouled screen on the inlet to the pumping sump (see Fig. 16-1) will also reduce the efficiency of the pump. If the level in the pump is more than a few feet below the water level in the basin, the screen should be cleaned. 

Failure of the cooling water pump is an important consideration, and the number of cooling water circulation pumps needs to be established carefully. The number of cooling water circulation pumps can be equal to the number of steam turbine-driven pumps that normally operate. 

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