Boiler water feed pump

The title of the August 2013 Beacon was Can a Water Pump Explode [19] The rest of this one page valirable prtblication describes the how explosions have occinred on boiler water feed pumps, condensate pumps, and deionized water pttmps. In each... 

At 315 °C the corrosion rate in the pH range 7.0-10.6 under operating conditions after 100 days goes from 42 down to 6 g/m a (< 0.01 mm/a), and then remains constant. For boiler water feed pumps a pH value between 8.3 and 9.0 has proven... 

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. 

Simplified Cycle. A simplified fossil steam cycle appears in Figure 19. The water accumulates in the bottom of the condenser, called the hotweU. It goes through a feed pump to pressurize it. The pressurized water passes through one or more feedwater heaters, which raise the temperature. The water then enters the boiler where heat from the fuel converts it to steam. The steam expands through the engine, usually a turbine, which extracts work. In the middle of the turbine some of the steam is extracted to supply heat to the feedwater heater. The remainder expands through the turbine and is condensed. The rejected heat is carried away by the condenser coolant, which is usually water, but sometimes air. The condensed steam then returns to the... 

Thermal power plant auxiliaries such as flow control of primary air fan, ID fan and forced-draught fans, boiler feed pumps circulating water pumps and condensate pumps, coal handling plant (e.g. ball mill, wagon tippler, and stacker reclaimer)... 

These applications have considerably more stringent performance requirements than any other application. Circulating water pumps, boiler feed pumps, forced-draught (FD) and induced-draught (ID) fans, pulverizers (ball mills) and condensate pumps are components in a thermal power station that may require extra safety in a standard motor to make it able to fulfil these requirements and withstand abnormal service conditions and system disturbances. Abnormal operating conditions may be one or more of the following ... 

Feedwater pipework will normally be gravity head suction from the hotwell or feed tanks to the pumps and at a pressure in excess of the boiler working pressure from the pumps to the boiler. Few problems occur on the pipework between pumps and boilers. However, inadequately sized suction lines can give rise to cavitation at the feed pump with subsequent boiler shutdown. The feed tank should always be positioned to suit the temperature of the feed-water and the pipework sized to give free flow at that head, taking account of bends, valves and filters. 

The de-alkalized and degassed water has a pH of 4-5 and (having just passed through an air-blown tower) is laden with oxygen and extremely corrosive. Normal practice is to dose NaOH into the degasser tower sump, at a level sufficient to approach to desired boiler water pH. If this dosing fails, severe corrosion in the degassed water pump, the softener and the feed system will result. 

The chemical feed pump should be wired into the boiler FW pump, so that when the boiler calls for water, both phosphate and alkali are added in proportion to the FW volume and the hardness it contains. 

Boeing Rocketdyne, corporate decision making by, 24 386 Boggsite (BOG), 16 813 Boghead coal, 6 705 Bohr, Niels, 21 289 Bohr frequency, 23 128 Bohrium (Bh), l 492t Boiler deposits, in industrial water treatment, 26 131 Boiler economizers, 10 146 Boiler feed pumps, 21 56 Boilers, 10 152 23 215-216... 

Few high pressure drum boilers are equipped with the condensate polishing plant illustrated in Fig. 1 but once-through boilers (having no drum to allow the accumulation of impurities in the water phase) normally are. The water is pumped from the condenser back through feed-heaters and into the boiler again. 

Steam systems. An investment cost of 35 per lb/h of total steam generation capacity is recommended for preliminary estimates (costs as of 2001). This represents the total installed costs for gas- or oil-fired, forced-draft boilers operating at 250 to 300 psig, and all appurtenant items such as water treating, deaerating, feed pumps, yard piping for steam, and condensate. 

Cost of package boiler plants. Price includes complete boiler, feed-water deaerator, boiler feed pumps, chemical injection system, stack, and shop assembly labor. 

Related Calculations. Use this procedure for any condensate or boiler-feed pump handling water at an elevated temperature. Consult the Standards of the Hydraulic Institute for capacity curves of... 

Centrifugal boiler-feed pumps usually have a maximum allowable temperature rise of 15°F. The minimum allowable flow through the pump to prevent the water temperature from rising more than 15°F is 30 gal/min for each 100 bhp input at shutoff. 

In this ideal regenerative Rankine cycle, the steam extracted from the turbine heats the water from the condenser, and the water is pumped to the boiler. Sometimes, this occurs in several stages. The condensate from the feed water heaters is throttled to the next heater at lower pressure. The condensate of the final heater is flashed into the condenser... 

Figure 8.17 A simplified representation of a power plant steam-water circuit. Legend 1 boiler 2 steam-water drum 3 superheater 4 turbine, high (H), intermediate (I), low (L) pressure 5 reheater 6 generator 7 condenser 8 make-up water treatment plant (MUP) 9 condenser extraction pump(s) 10 condensate polishing water treatment plant (CPP) 11 LP heater(s) 12 deaerator 13 boiler feed pump (s) 14 HP heater(s) 15 economizer...

Pumps.—Boiler-feed pumps are of the plunger (direct-steam or power-driven) or rotary (centrifugal) type the latter being driven by a steam turbine or electric motor. Steam-driven pumps are used when there is need of their exhaust for feed-water heating. Centrifugal pumps are generally more compact, and easier to maintain than plunger pumps. 

A boiler feed pump takes water from a tank at 95°C and 100 kPa absolute and delivers it at 190 C and 2000 kPa absolute. The flow is steady, and the heat loss from the pump is 2 kJ/kg of water passing through it. What is the work input to the pump in kilojoules per kilogram of water passing through it ... 

ECONOMIZER - A series of tubes located in the path of flue gases. Feed water is pumped through these tubes on its way to the boiler in order to absorb waste heat from the flue gas. 

The plant should trip in the case of a low water level in the boiler due to the electrical interconnection provided with air blower-sulfur feed pumps. This should be checked regularly. 

Rankine cycle A cycle of operations in a heat engine. The Rankine cycle mote closely approximates to the cycle of a teal steam engine that does the Carnot cycle. It therefore predicts a lower ideal thermal efficiency than the Carnot cycle. In the Rankine cycle (see illustration), heat is added at constant pressure Pi, at which water is converted in a boiler to superheated steam the steam expands at constant entropy to a pressure pz in the cylinder heat is rejected at constant pressure pj in a condenser the water so formed is compressed at constant entropy to pressure p, by a feed pump. The cycle was devised by William Rankine (1820-70). 

Boiler Feed Water System—Check the demineralised water plant units, water piping, operation of water pumps, condensate recycle lines, deaerator tank, drain lines, calibration of Boiler Feed Water tank, operation of level indicator, external insulation, location of temperature indicators, etc. Get examined the hydraulic test certificates for all pressure parts and subsequentiy obtain permission from Statutory Boiler Inspection Authority to commission the boiler. Note BFW pumps shall be run one by one to feed water into the boiler. Backpressure shall be created by throttiing overflow from WHB. Water flow... 

Reverse flow— Non-return valves are to be provided in boiler feed waterline to prevent reverse flow of steam/water from boiler into the pumps. 

Less/no flow of feed water to boiler—Provision of electrical interlocks for tripping of air blower (and consequently the sulphur feed pump also) when water level is very low in WHRB when there is very less or no flow of feed water to the boiler. 

Less supply of demineralised DM feed water to WHRB Danger to boiler Standby BFW pumps and storage of DM water Sufficiently large separate tanks for WHRB and absorption tower... 

Canal navigation interested him too, and it was in this connection that he made his first invention. In 1840 he had an experimental steam canal-boat in operation which was fairly successfiil except that when the boat was stopped it became necessary to resort to a hand pump to keep the boiler supplied with water. Worthington invented an independent feeding pump to overcome this deficiency automatic in its action and controlled by the water level within the steam boiler. 

---