Chemical Engineering June 2018 - 79

without a steam balance, and this
requires a complete understanding
of the system. The easiest and best
way to truly understand the steam
system is to create a steam balance
flow diagram.
The steam-balance flow diagram
can be accomplished in many different
ways, such as a fully devolved
document completed in different
technical software systems, or a
simple flow diagram completed with
a basic graphics program. The key
point is to develop a steam-balance
document that plant personnel can
use.
End results of a steam balance
Implementing a perfect steam balance
- one that accounts for steam
generation, distribution, end-user
requirements and condensate recovery
- can be an extremely challenging
goal in any industrial steam
plant operation. An industrial plant
can have several different steamgenerating
sources and a multitude
of end users with varying steam
WHAT A STEAM BALANCE
PROVIDES
1. Improved knowledge of the steam and
condensate system
2. Ability to set a roadmap for change to
improve system performance
3. Increased energy efficiency
4. Reduced emissions
5. Increased reliability
pressure and steam flow demands.
The steam turbine operation for electrical
generation or drive units plays
an important part of the balance, and
the operation of the steam-pressureletdown
valves (pressure-reducing
valves) needs to be minimized to
ensure maximum steam flow to the
steam turbine operation.
Four types of condensate-recovery
systems are typically added into the
balance, making the system dynamics
even more complex. To meet
production requirements, plants typically
continue to update and make
process changes over time, and all
such changes will affect the steam
balance. Therefore, steam balancing
must be viewed as a continuous program
- not a one-time effort.
A proper steam balance will also
eliminate the waste associated with
venting
" unusable "
low-pressure
steam to the atmosphere, by instead
balancing the steam flow more effectively
to the end users (steam
turbines, heat exchangers, reboilers)
and then discharging the condensate/flash
steam to the downstream
steam cascade systems. This results
in a final steam process that has
the correct amount of low-pressure
steam. If such a cascade system
cannot be accomplished, then the
operator may opt to use a thermocompressor
to upgrade the lowpressure
steam to medium-steampressure
grids until the desired
balance is achieved in the system.
Steam balance Example 1. The following
steam balance (Figure 1) was
accomplished in a simple software
graphics program format, but it resulted
in a substantial reduction in energy and
emissions. The steam balance indicated
that a pressurized condensate system
could easily be instituted into segPROTECT
PUMPS
DRY RUNNING * CAVITATION * BEARING FAILURE * OVERLOAD
MONITOR PUMP POWER
* Best Sensitivity
* Digital Display
TWO ADJUSTABLE SET POINTS
* Relay Outputs
* Adjustable Delay Timers
4-20 MILLIAMP ANALOG OUTPUT
COMPACT EASY MOUNTING
Only 3.25 " x 6.25 " x 2 "
* Starter Door
* Raceway
* Panel
* Wall
UNIQUE RANGE FINDER SENSOR
* Works on Wide-range of Motors
* Simplifi es Installation
WHY MONITOR POWER INSTEAD OF JUST AMPS?
Power is Linear-Equal Sensitivity
at Both Low and High Loads
NO LOAD
FULL LOAD
NO LOAD
No Sensitivity
For Low Loads
FULL LOAD
PUMP POWER
PUMPING
VALVE CLOSING
VALVE OPENING
NO FLUID
CALL NOW FOR YOUR FREE 30-DAY TRIAL 888-600-3247
WWW.LOADCONTROLS.COM
For details visit adlinks.chemengonline.com/70307-37
70
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
JUNE 2018
POWER
AMPS
http://WWW.LOADCONTROLS.COM http://adlinks.chemengonline.com/70307-37 http://WWW.CHEMENGONLINE.COM
Chemical Engineering June 2018

Table of Contents for the Digital Edition of Chemical Engineering June 2018
