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6.6.3. Heat tube recuperator
Maintenance on this type of recuperator is confined to
CLEANING since it does not have any moving parts.
Proceed as follows:
- every month check drain operation drain and remove
any deposits V
- clean the finned block using either warm water with
liposoluble detergents if necessary, or a compressed air
jet in the opposite direction to the airflow during normal
Unit operation.
6.7.
ACCESSORIES
6.7.1. Control air locks
TCF "SAL" control air locks do not require any particular
maintenance.
However, we recommend you check the alignment of the
gears and the movement of the fins, which must not in
any circumstance be deflected by the weight of the ducts.
6.7.2. External air intake grilles
These must be cleaned frequently to remove any deposits
obstructing the air passage which would comprise the
efficiency of the entire system.
6.7.3. Drip separator
Every month check that there are no deposits of dust or
scale that would impair separation efficiency Clean the
separator as follows:
- extract the drip separator from the Air Treatment Unit,
removing the panel and the screws
- completely dismantle the drip separator and clean each
single fin
- restore normal operating conditions, taking care not to
bend the fins during separator removal and reassembly.
6.7.4. Silencer
The silencers installed on TCF machines are of the
SOUNDPROOFED PANEL type.
They do not require any particular maintenance. Any dust
that forms on them should be removed with an ordinary
vacuum cleaner.
6.8.
TROUBLESHOOTING
The most common MALFUNCTIONS in Air Treatment
Units are:
- reduced flow rate
- increased flow rate
- reduction in heat exchanger efficiency
- reduction in heat recuperator efficiency
- reduction in humidifier efficiency
- abnormal noise
6.8.1 . Reduced flow rate
This is the result of an uncontrolled increase in resistance
in the air moving circuit which alters the fan's operating
point. The most frequent causes are:
- excessively clogged filters
- formation of frost or ice on the front surface of the
prefilters in particularly damp and cold climates on Units
operating entirely with external air
- blockage of the intake grille(s) (especially external air
intake)
- fully or partially closed control air locks
- activation of the dampers
- deposits on cell blocks and heat exchangers
- inefficient fan motor unit drive.
6.8.2. Increased flow rate
If the sum of the resistances in the air-moving circuit is
less than the value considered at the design stage, the
most common causes are:
- incorrect setting of any mechanical flow controls or zone
air locks
- non-replacement of filters after ordinary maintenance
operations
- open or partially closed inspection doors.
6.8.3. Reduction in heat exchanger efficiency
The most common causes are:
- clogging of finned block
- formation of air bubbles inside the exchanger
- feed fluids at temperatures lower than the design
temperature
- malfunction or breakdown of control valve actuators
- water flow rate below design values.
For steam-operated exchangers:
- malfunctioning of condensate drains
- reduced supply steam pressure.
For cooling gas-operated exchangers:
- malfunctioning of expansion valve
- reduced cooling capacity due to working temperatures
different from those envisaged.
6.8.4. Reduction in heat recuperator efficiency
For crossover flow recuperators the causes may be:
- dust and dirt on the heat exchanger block
- clogging due to the presence of foreign matter between
the heat exchanger fins
- abnormal bypass of air on recuperator
For two-phase gas recuperators the causes may be:
- dust and dirt on the heat exchanger block
- clogging due to the presence of foreign matter between
the heat exchanger fins
- abnormal bypass of air on recuperator
- loss of cooling capacity due to accidental failure
