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SUPPLY AND SERVICES

Revamping

of the Fans

An interesting case-study
of a project in Mexico

Paolo Saccenti, BU Director,
Service & After Sales
Vincenzo Avolio, Engineering Specialist, Service
& After Sales
Boldrocchi S.r.l.

hat is a “revamping” of a fan? erosion/corrosion resistance performance, as a
It is the modification of the fan change of the wear plates of the impeller, is not
in order to increase the per- considered in this paper.
formances, i.e. capacity and
pressure, that are the parame- Revamping solutions
Wters related to the potential of
increasing the output of the process or to meet the The methods to do the revamping are the following:
operating conditions of a new plant arrangement.
The modifications on the fan must not involve the • Speed increase;
layout of the plant, in other words the following • Impeller blades tipping;
components must remain the same: • Impeller change.

• Foundations; The qualitative result of all the three fan modifica-
• Inlet/outlet ducts; tion methods may be seen in the figure 1. The
• fan casing (only minor modifications). curve A is the fan not modified, while the curve B
is the result of the modification. Note that the sy-
The fan components that could be involved in the stem resistance, indicated by the two parabolas,
revamping are: may change or not. The system resistance doe-
sn’t change when no additional components or no
-Impeller - Inlet bell - Shaft - Bearings components modification, except than the fan, are
-Coupling - E-motor - Casing (eventual modifications) provided. The increase of capacity and pressure in
case of no system modifications, curve “C” are ∆Q
A modification of the fan in order to improve the and ∆P, while ∆Q and ∆P are relevant to a system
1
1
mechanical reliability, as the change of the bea- modification, curve “D”. The new absorbed power
rings; or the operational life of the fan, as a chan- is W in case of no system modification while W in
2r
1r
ge of the rotor material; or the improvement of the case of system modification.
78 Impiantistica Italiana - Gennaio-Febbraio 2023