Lummus Technology Heat Transfer Helixchanger™
RCR Stelform is a licensed supplier of Lummus Technology Heat Transfer (LTHT) Helixchanger™.
Licensed supplier of
LTHT Helixchanger™
Helixchanger™ Cost Benefits
HELIXCHANGER™, Initial Capital Cost is usually of the primary concern to project
management for new plants. On Lump Sum Turn Key (LSTK) projects, major effort is
made to control the capital costs of new equipment.
More HELIXCHANGER™
recently,
this approach is being re-examined by the project teams, since many end-users have
expressed concerns over the low reliability and availability of plant equipment
in operation for some time.
Analysis of Total Life Cycle Costs (TLCC) suggests that proper attention be given
to the total life cycle costs of equipment and not only the capital costs. HELIXCHANGER™, Low efficiency of plant equipment has also an adverse impact in meeting the environmental
regulations and consequently involves additional costs for corrective actions.
The following bar charts represent the results of a typical TLCC analysis representing
the relative costs involved with a bank of HELIXCHANGER� heat exchangers as compared
to the costs associated with using conventionally baffled heat exchangers in the
same services. HELIXCHANGER™
The following plots illustrate the HELIXCHANGER� Advantage over the conventionally
baffled heat exchangers.
The glossary of abbreviated cost terms is as follows:
- CAPEX 1: Represents the initial purchase price of the heat exchanger.
- CAPEX 2: Represents the costs for replacement of tube bundles and other associated
spare
HELIXCHANGER™ parts over the life of the heat exchanger unit.
- OPEX: Represents the operating costs for the heat exchanger, which includes the
pumping or compressor power costs, costs of chemical dispersants, anti-fouling agents
as well as loss of production costs associated with the downtime when the unit is
brought
down for bundle cleaning.
- MAINTEX: Represents the costs to clean the bundles during the life of the heat exchanger
unit as well as costs of tube plugging or replacement that may HELIXCHANGER™ be required due to corrosion and/or flow-induced vibration damage.
- DISPEX: Represents the removal and disposal of damaged tube bundles that cannot
be reused and must be replaced during the life of the heat exchanger unit.
Heat Exchanger Performance
Heat exchangers require scheduled maintenance for cleaning the tube bundles that
foul up over an operating cycle, which is often termed as the run length.
HELIXCHANGER� heat exchanger with its low fouling characteristics offers much longer
run length as compared to a conventionally baffled heat exchanger in identical service.
The drop in performance over an operating cycle is much slower in services where
HELIXCHANGER� heat exchangers are used (FIGURE-1).
Figure 1
Total Life Cycle Cost (New Heat Exchangers)
FIGURE-2 illustrates the typical Total Life Cycle Cost components as they are derived
for both the HELIXCHANGER� as well as conventional heat exchangers in identical
services. The comparison presented here is for new installations with each exchanger
unit consisting of relevant shell and tube bundle assembly.
HELIXCHANGER� designs save CAPEX 1 as well as CAPEX 2 over the life of this unit
due to the surface savings and lower fouling and consequently higher service life
of tube bundles. Lower shellside pressure drop saves operating costs when using
the HELIXCHANGER� designs. Longer run lengths with helical baffles translates into
lower maintenance costs and longer operating life of tube bundles saves the disposal
costs during the life span of the heat exchanger units.
As a result, in new installations, the HELIXCHANGER� option significantly lowers
the Total Life Cycle Costs of the heat exchanger banks.
Figure 2
Total Life Cycle Cost (Bundle Replacement)
The comparison presented in FIGURE-3 illustrates the typical Total Life Cycle Cost
components as they are derived for replacement bundles, segmental versus helical
in an existing heat exchanger shell.
Initial capital cost, CAPEX 1, is slightly higher when a HELIXCHANGER� bundle is
replacing the conventional bundle, however, the secondary capital cost, CAPEX 2,
is smaller in the case of replacement with HELIX, primarily due to longer service
life of the HELIX tube bundle. Low pressure drops and reduced down times offer lower
OPEX with the HELIX bundle replacements. Lower fouling characteristic also reflects
in lower MAINTEX for the HELIX bundle and increased service life results in lower
DISPEX using HELIX bundle replacements.
Consequently, in bundle replacement cases also the HELIXCHANGER� option considerably
reduces the Total Life Cycle Costs of heat exchangers.
Figure 3
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