Environmental Engineering Reference
In-Depth Information
Motor
Gear reducer
Coupler
Top bearing
Screw
Bottom
bearing
figure 3.1 Archimedes's screw pump.
beginnings. The first fully functional centrifugal pumps were developed
in the 1800s. Centrifugal pumps can move great quantities of water with
much smaller units compared to earlier versions of pumps.
The pump is a type of hydraulic machine. Pumps convert mechanical
energy into fluid energy. Whether water is being moved from groundwater
or a surface water body, from one unit treatment process to another, or
to the storage tank for eventual final delivery through various sizes and
types of pipes to the customer,
pumps
are the usual source of energy
necessary for the conveyance of water. Again, the only exception may
be, of course, where the source of energy is supplied entirely by grav-
ity. Water/wastewater maintenance operators must therefore be familiar
with pumps, pump characteristics, pump operation, and maintenance.
There are three general requirements of pump and motor combinations.
These requirements are (1) reliability, (2) adequacy, and (3) economy.
reliability
is generally obtained by installing in duplicate the very best
equipment available and by the use of an auxiliary power source.
adequacy
is obtained by securing liberal sizes of pumping equipment.
economics
can be achieved by taking into account the life and depreciation, first cost,
standby charges, interest, and operating costs.
Texas utilities association (1988)
Over the past several years, it has become evident that many water-
works and wastewater facilities have been unable to meet their optimum
supply or treatment requirements for one of three reasons:
1. Untrained operations and maintenance staff
2. Poor plant maintenance
3. Improper plant design
