Principles of Food Sanitation

centrally installed equipment because of
the potential labor savings and reduced
maintenance.

Centralized High-Pressure,
Low-Volume Systems
This system, which uses the same princi-
ples as the portable high-pressure, low-vol-
ume equipment, is another example of
mechanical energy being harnessed and used
as chemical energy. Centralized systems uti-
lize piston-type or multistage turbine pumps
to generate desired pressure and volume.
Like the portable equipment, the cleaning
action of high-pressure spray units is prima-
rily due to the impact energy of water on the
soil and surface. The pump(s), hoses, valves,
and nozzle parts of the ideal centralized
high-pressure cleaning system should be
resistant to attack by acid or alkaline clean-
ing products. Automatic, slow-acting shutoff
valves should be provided to prevent hose
jumping, indiscriminate spraying, and wast-
ing of water. The centralized system is
more flexible, efficient, safe, and convenient
because there is no live steam to block vision
or injure personnel.
If improperly used, this cleaning system
can be counterproductive by blasting loose
dirt in all directions. Therefore, a low-pres-
sure rinse-down should precede high-pres-
sure cleaning. Most suppliers of these
systems provide customers with technical
assistance and match cleaning product and
cleaning equipment to obtain maximum
value.
The penetrating and cleaning action of a
centralized high-pressure, (boosted pressure
range) system is similar to that of a commer-
cial dishwashing machine. The system auto-
matically injects a cleaning compound into a
water line so that the hydraulic scouring
action of the spray cleans exposed surfaces
and reaches into inaccessible or difficult-to-
reach areas. Cracks and crevices where soil

has accumulated can be flushed out to

reduce bacterial contamination. Cutting and

scouring action is applied to all surfaces by

the jet, and chemical cleaning action is

improved through the water spray, which is

automatically charged with a detergent or

detergent-disinfectant solution. An example

of equipment components of a high-pres-

sure cleaning system is given in Figure 11–2.

The flexibility and major benefits of the

centralized high-pressure cleaning system are

realized if there are quick-connection outlets

available in all areas requiring cleaning. Sev-

eral detergents—acid, alkaline, or neutral

cleaners and sanitizers—can be dispersed

through the system, and mechanized spray

heads can be mounted on belt conveyors with

automatic washing, rinsing, and cutoff.

Centralized systems are far more expensive

than portable units because they are generally

custom built. The cost varies according to

facility size and system flexibility.

Factors Determining Selection of Centralized

High-Pressure Equipment

Generally, two types of central equip-

ment are most common: medium-pressure

Sanitation Equipment 197

Figure 11–2A centralized medium pressure, (boosted

pressure) system for a large cleaning operation. Cour-

tesy of JohnsonDiversey, Inc., Detroit, Michigan.