The operating cost profile of any heating or cooling
system is directly related to understanding the thermal losses in the
plant and also the utilization of water. It is critical that every component
of the system maximize its usage of the water before it is directed
to the next user or discharged to sewer.
By performing a detailed study of the impurities in the
various water streams, cycles of concentration can be monitored and
more importantly, scale forming impurities tracked to ensure they are
at their maximum concentrations before water is released from the system.
Utilities Optimized utilizes and independent water testing
laboratory to track the impurity loadings in various treated water streams
to ensure that maximum concentrations are achieved and adequate chemical
inhibition treatments are present.
Through this study process, simple cross checking
of routine water treatrment field test processes can be applied to ensure
their accuracy and a focus of continual improvement is realized.
A major feedmill operation in South Western Ontario
needed to improve their Boiler Room layout to improve accessibility
to major equipment. Utilities Optimized was retained to redesign the
boiler feedwater system and install a Blowdown Heat Recovery system.
The existing horizontal boiler feedwater tank was replaced
with a vertical stainless steel unit. Boiler feedwater pumps were relocated
from underneath the existing tank to grade level beside the new feedwater
tank. All electrical panels were mounted on the wall behind the pumps,
allowing easy access to all components. The Blowdown Heat Recovery system
was installed in place of the existing blowdown flash chamber and well
water cooling system. Flash steam from the Blowdown Heat Recovery system
was routed to the new boiler feedwater tank and injected below the normal
water level with a stainless steel steam muffler system.
Picture illustrates initial boiler feedwater system and
blowdown flash chamber. Boiler feedwater pumps were located underneath
existing tank with electrical panels in front making accessibility extremely
Second picture shows new layout of the boiler feedwater
system and Blowdown Heat Recovery system. All components are on grade
level with ample open space around each section for easy access and
maintenance. Flash steam comes off top of Blowdown Heat Recovery unit
via 1-inch line to steam muffler.
Make-up water is routed through storage section of Blowdown Heat Recovery
tank, picking up thermal energy normally lost to sewer.
Make-up water temperature has increased from 55oF to
over 110oF, consistently. Boiler feedwater temperature has increased
and average of 30oF with less steam flow from the steam heater system.
Blowdown water going to sewer averages 75 - 80oF with no additional
Overall savings have been calculated to be greater
than $11,000 annually as a result of the Blowdown Heat Recovery system.
Utilities Optimized personnel were request by
a regional natural gas supplier to provide a detailed water mass balance
evaluation of a Utility Plant in the Niagara area. The gas supplier
would be responsible for detailed combustion studies and a third consulting
engineer was responsible for electrical and gas consumption evaluation
and compiling the final report.
The plant utilizes Welland Canal water, which is essentially
considered “free”. An arbitrary “pumping cost”
of $0.10 per cubic meter was assessed to provide a basis for evaluating
subsequent treatment costs.
Utilities Optimized was charged with determining the
flow pattern through the site, document operating costs associated with
each aspect of treatment and provide a concise evaluation of water consumption,
system losses, current boiler blowdown losses and projections on savings
Based on the treatment process and associated losses,
for regeneration, chemicals, leaking pump seals etc., the cost of boiler
feedwater was determined to be 146% more expensive than the “free”
influent canal water. This increase in cost provided justification for
what was considered minor/insignificant repairs and also more appropriately
designed heat recovery. Additional savings initiatives in regenerant
water recovery were identified for future consideration.
The attached schematic roughly defines the steam
plant water path. Utilities Optimized personnel also performed a thermal
evaluation and several heat recovery initiatives were further documented.
The final report was incorporated into a detailed Project Study Report.
This report is being utilized as part of the basis for determining whether
this site is a candidate for co-generation and also a Utility Site,
selling both steam and electrical power to the main site user.