Chapter 1 of retrofitting a centrifugal blower.

1. UNIVERSITY OF THE EAST
CALOOCAN CAMPUS
COLLEGE OF ENGINEERING
MECHANICAL ENGINEERING DEPARTMENT
Retrofitting of Centrifugal Blower for ME Lab Use
IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS IN
METHODS OF RESEARCH
NME 427 – 1ME
Submitted by:
Allana, Christian D.
ADVISER:
ENGR. EDWIN S. BAUTISTA
DECEMBER 15, 2016

2. Retrofitting of Centrifugal Blower
Chapter 1: The Problem and It’s Background
1.1 Introduction
Centrifugal fans and blowers are widely used in applications ranging from
household ventilation system and also for the process industries. Their main function is to
generate a pressure to move the air or gases against the resistance caused by ducts, dampers, or
even the other components of it in a fan or blower system. These machines have been designed
with different configurations and geometries; radial, backward curves and forward curves.
Blowers can achieve much higher pressures than fans, as high as 1.20 kg/cm2.
They are also used to produce negative pressures for industrial vacuum systems. Centrifugal
blowers are look more likely as centrifugal pumps than fans. The impeller of it inside is typically
gear-driven and rotates as fast as 15,000 rpm. In multi stage blowers, air is accelerated as it
passes through each impeller. While the single stage blower, air does not take many turns, and
hence it’s more efficient. A centrifugal blower typically operates against pressures ranging from
0.30 to 0.70 kg/cm2, but it can achieve high pressures. The flow in a centrifugal blower is highly
complex and poorly understood due to its three dimensional nature and geometrical parameters
of the machine which can result major affliction in achieving high efficiency standards for the
blowers.
One characteristic of this is that airflow tends to drop drastically as system
pressure increases, which can be disadvantage in material conveying systems that depend on a

3. steady air volume. Simply, because of this, they are most often used in applications that are not
prone to clogging. The performance of a blower is greatly affected by the number of blades, their
shape, also geometry and operating conditions. Further, the diffusing elements downstream of
the impeller govern the flow through the machine, its range of operation and efficiency.
Conventionally, the impeller blades in a centrifugal blower are of constant
thickness made out of metal sheet; as the demand for the improvement of its performance and
efficiency of centrifugal turbo machines increases the blades with aerofoil sections and have
come to be used for centrifugal impellers, since it is well known that the aerofoil sections in the
turbo machines can guide and control the flowing of fluid with minimum losses.

4. 1.3 Statement of the Problem
This research focus more on retrofitting of the existing centrifugal blower test rig
in the mechanical engineering laboratory, to give the mechanical engineering students such
better information on how to deal with it when using in experimentations.
1.4 Objectives of the Study
General Objective
 To be able to identify the present status of Centrifugal Blower
Specific Objectives
 To transform the current centrifugal blower into a bigger one to maximize the
volume and to push a large amount of air.
 To protect the u-tube manometers from any violent reactions of the student(s) by
framing it.
 To adjust the pressure gage and other measuring devices for them to easily read
the values.

5. 1.5 Significance of the Study
This research is focused more on retrofitting of the actual centrifugal blower in
the mechanical engineering laboratory to become more efficient when it comes to its
performance, also for the good design to raise the pressure and throw a large amount of air or
gasses.
1.6 Scopes and Delimitations
The scope of this study will focus only on retrofitting of the existing Centrifugal
Blower inside the mechanical engineering laboratory and to identify the current status of the
other components of it if there is something needed to be change.

6. 1.2 Conceptual Framework
This research is focused more on retrofitting of centrifugal blower that will
provide further information’s for all mechanical engineering students and such give better ideas
to operate the existing centrifugal blower.

7. Chapter 2: Review of Related Literature
This chapter presents the assessment of related studies regarding the retrofitting of
the centrifugal blower inside the mechanical engineering laboratory. Acknowledgement of
different books, journals and research papers were conducted in order to complete the following
reviews.
A centrifugal blower is a mechanical device for moving air or other gases caused
by ducts, dampers, or even the other components of it in a fan or blower system. These fans
increase the speed of air stream with the rotating impellers. They use the kinetic energy of the
impellers or the rotating blade to increase the pressure of the air/gas stream which in turn moves
them against the resistance caused by ducts, dampers and other components. Centrifugal blowers
accelerate air radially, changing the direction (typically by 90̊) of the airflow. They are sturdy,
quiet, reliable, and capable of operating over a wide range of conditions. Centrifugal blowers are
constant CFM devices or constant volume devices, meaning that, at a constant fan speed, a
centrifugal fan will pump a constant volume of air rather than a constant mass. This means that
the air velocity in a system is fixed even though mass flow rate through the fan is not. The
centrifugal blower is one of the most widely used fans. Centrifugal blowers are by far the most
prevalent type of fan used in the HVAC industry today. They are usually cheaper than axial fans
and simpler in construction. It is used in transporting gas or materials and in ventilation system
for buildings.
Moreover, Centrifugal blowers are also used commonly in central heating/cooling
systems. They are also well-suited for industrial processes and air pollution control systems. It

8. has a blower wheel composed of a number of blower blades, or ribs, mounted around a hub. The
hub turns on a driveshaft that passes through the blower housing. The gas enters from the side of
the fan wheel, turns 90 degrees and accelerates due to centrifugal force as it flows over the fan
blades and exits the blower housing.