Special Maintenance - Hitecsa EQU-PF 233 Manual De Instalación, Uso Y Mantenimiento

II.9.1.4 Inspecting and washing the tube and shell
heat exchangers
DANGER!
The acids used for washing the heat exchangers
are toxic. Use suitable personal protective
equipment.
Plate heat exchangers do not get dirty in nominal operating conditions.
The working temperatures of the unit, the speed of the water in the
channels and the suitable finish of the heat exchanging surface reduce
fouling of the exchangers to a minimum.
Any fouling of the exchangers can be noted by measuring the pressure
drop between the inlet and outlet pipes, using a differential pressure
gauge. Any sludge that may form in the water circuit or any silt that
cannot be trapped by the filter, as well as extremely hard water
conditions or high concentrations of any antifreeze solution used, can
clog the exchanger, thereby affecting the heat exchanging efficiency. In
this case, the heat exchanger must be washed with suitable chemical
detergents. Pre-existing systems must be provided with adequate fill-up
and drain connections.
Use a tank containing weak acid: 5% phosphoric acid or if the
exchanger must be cleaned often: 5% oxalic acid. The liquid detergent
must circulate around the exchanger at a minimum flow rate of 1.5
times higher than the nominal work flow.
II.9.2

Special Maintenance

These are all those repairs or replacements that allow the machine to keep on working in standard conditions. The spare parts must be identical to the
previous ones. Namely, they must have equivalent performance, dimensions etc. according to the specifications provided by the manufacturer.
Control
Electrical system
Check power consumption of the unit
Electric motor of fans
Checking gas charge and humidity in circuit
(with unit running at full capacity)
Make sure there are no gas leaks
Check the operation of the maximum and
minimum pressure switches
Bleeding air from the chilled water system
Drain the water system
(if necessary)
The first detergent cycle removes the worst dirt and the final cleaning
cycle is completed with clean detergent. Before starting up the system
again, rinse abundantly with water to get rid of any traces of acid and
bleed any air from the system; if necessary start up the utility pump.
1.
2.
3.
4.
5.
6.
Frequency
Besides checking the various electrical components, the electrical
insulation of all the cables and their correct tightening on the terminal
Every 6 months
blocks must be verified, paying particular attention to the earth
connections.
Every 6 months
The motor must be kept clean with no traces of dust, filth, oil or other
impurities. These could cause it to overheat due to low heat
dissipation.
Every 6 months
The bearings are usually watertight with permanent lubrication and
sized in order to last approximately 20,000 hours in standard
operational and environmental conditions.
Every 6 months
Every 6 months
To be performed only by skilled personnel from workshops
Every 6 months
authorised, qualified to operate on this type of product.
Every 6 months
The unit must be drained if it remains idle during winter.
Every 12 months
In alternative, a glycol mixture can be used according to the
information provided in this manual.
24
SECTION II: INSTALLATION AND MAINTENANCE
EQU-PF –EQUH-PF;
Auxiliary cock;
Shut-off gate valve;
Wash pump;
Filter;
Acid tank.
Notes