FEATURE TEST & MEASUREMENT
Deaerator level measurement solutions T
he deaerator is a key, yet oftentimes overlooked, component of the
steam generation cycle, regardless of the scale of your process. Whether it is part of commercial power generation or a packaged boiler system, the deaerator has a crucial role to play. Although serving a primary role of
removing non-condensable gases (O2 and CO2
) from boiler feed water to
prevent corrosion for improved hardware longevity, the deaerator also provides additional support functions which, along with its core benefit, require high-quality instrumentation with accurate level controls to ensure optimal performance in its assigned tasks. Here are some of the support functions that deaerators provide: preheating boiler feed water for improved efficiency; reduces fuel requirements; effective removal of dissolved gases (O2
and CO2
Deaerators require high-quality instrumentation with accurate level controls to ensure optimal performance. Magnetrol has several instrument options that are fit for this purpose
A deaerator in the field ) from boiler
feed water; minimises corrosion for improved hardware longevity; ensuring adequate head pressure for boiler feed pumps; increases hardware longevity/lowers maintenance; managing deaerator storage/inventory; and, ensures sufficient supply to meet steam production demands.
LEVEL MEASUREMENT CHALLENGES AND CONSIDERATIONS As with all level measurement, the first obstacle is working around the effects process dynamics have on the fundamental technology. Another difficulty is the complexity of the measurement system relative to hardware installation, software
Aurora Magnetic Level Indicator integrated Guided Wave Radar monitors critical deaerator level
corrections and its perpetual need for calibration. Eliminating variables in the level measurement equation is the easiest method of optimising your deaerator level. Furthermore, inadequate level controls can inhibit the deaeration process. If the level is too high, this prevents the temperature from meeting minimum
requirements for removal of dissolved O2 and CO2
. On the flip side, if the level is
too low it can reduce or shutdown feed water flow to the boiler, affecting end use steam needs. The former affects hardware longevity and efficiency, while the latter risks production losses and possible damage to pumps. Do not ignore the fact that any
appreciable gain in boiler feed water achieved by leveraging the heat exchanger aspects of the deaerator reduces the amount of fuel required at
the boiler - every 10.8°F (6°C) rise in boiler feed water amounts to a one per cent savings in fuel cost.
LEVEL MEASUREMENT SOLUTIONS Magnetrol addresses the measurement challenges of deaerator level control with several instrument options. For point level, the company has introduced the Model B35 external cage float-actuated switch for low level alarming. For continuous level there is the Eclipse Model 706 guided wave radar transmitter for aggressive steam applications. For visual indication and continuous level, you can choose from the Atlas or Aurora magnetic level indicator with integrated guided wave radar - these can be supplied with switches.
Magnetrol
eu.magnetrol.com/Home.aspx
LEVEL MEASUREMENT SOLUTIONS FOR CONDENSATE DRIP LEGS
Level control of condensate tanks is critical to optimise condensate and waste heat recovery, as well as protect hardware. Each component of the steam generation and condensate recovery cycle has its own unique challenges and considerations when it comes to selecting level instrumentation. This is especially true when it comes to applications that are intended to keep the rest of the equipment safe, such as condensate drip legs. Placed along super-heated steam lines, condensate drip legs (or drip traps) collect particles of moisture and drain off the accumulated condensate. Employed as a preventative measure against turbine water induction, drip legs can be placed along main steam lines, hot and cold reheats and steam extraction lines. When a level switch senses the upper level in a drip leg, it opens a dump valve to remove the accumulated condensate. If particles of moisture escape condensate collection systems and enter the turbines, significant damage can result. Proper level controls should
prevent any moisture from entering the turbine, no matter how small the amount. Level controls used in condensate drip legs must also contend with the high temperatures and pressures associated with these devices. They must be able to provide accurate and reliable measurement despite these challenging conditions. Magnetrol has two level measurement solutions for condensate drip legs: the Model B40 float-actuated switch and the Model B35 external cage float-actuated switch.
Magnetrol
eu.magnetrol.com/Home.aspx
22
FEBRUARY 2018 | INSTRUMENTATION
/ INSTRUMENTATION
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95
