Sustaining Mechanical Integrity of Evaporative Condensers

Evaporative condensers are an environment friendly and cost-effective warmth rejection resolution for numerous functions — meals and beverage refrigeration, industrial equipment cooling and HVAC. And a complete program of routine preventive upkeep will preserve these techniques acting at peak effectivity, maximize system working life and cut back unplanned downtime attributable to tools failure. Common inspections are, in fact, key and needs to be carried out in accordance with the producer’s suggestions and plant preventive upkeep schedule.

For every inspection, it is very important doc the inspection course of and all findings, the date of the inspection, the title of the individual performing the inspection and any actions taken. Digital pictures are a helpful technique for documenting current situations and demonstrating adjustments over time.

To make sure employee security, all correct lock out-tag out procedures for the unit and any website security procedures should be adopted previous to starting inspection or upkeep work. Moreover, measures should be taken to substantiate there isn’t any refrigerant left within the coil. That is often carried out by using a vacuum system previous to getting into or servicing the condenser. All the time comply with business greatest practices concerning using correct PPE and “one in-one out” procedures.

Most individuals carry a smartphone with a great digital digital camera, which is a useful gizmo for photographing or recording inspection findings. Different really useful instruments embody an infrared thermometer, an infrared digital camera, an ultrasonic metallic thickness meter, a vibration meter (ultrasonic or accelerometer), a laser alignment instrument, a multimeter for voltage and amperage, a micrometer depth gauge, and a dye penetrant take a look at package to detect cracks. Importantly, an entire inspection package can even embody the producer’s set up, operation and upkeep manuals and lock out-tag out varieties.

The next are basic pointers for the areas of inspection that needs to be a part of any efficient evaporative condenser preventive upkeep program. These pointers cowl inspections in 10 areas. Though upkeep frequency will depend upon quite a lot of components — e.g., situation of circulating water, cleanliness of ambient air and the unit’s working setting — every space of inspection needs to be carried out no less than yearly and extra incessantly as really useful by the producer for a specific element or as circumstances warrant.

1. Sufficient anchors and helps for unit
A complete upkeep program begins with a visible inspection of the elemental structural integrity of the system. This step contains inspecting the condensing unit’s helps and anchors to make sure it’s securely put in. An inspection also needs to be fabricated from any improperly supported piping, which might overstress coil connections and trigger a leak. Every help needs to be visually examined, on the lookout for cracks, lacking or unfastened fasteners and any corrosion.

2. Corrosion of enclosure, tubes, piping and helps
Condensers needs to be inspected for corrosion no less than yearly and extra usually as situations require. If left untreated, pitting can degrade the wall thickness of a tube or pipe, probably resulting in leaks and burst pipes.

Extreme tube scale causes misplaced condensing capability and decreased efficiency. Visually examine coil surfaces with a flashlight or digital digital camera. When additional examination is critical, particularly of areas that will not be readily seen, a versatile, lighted borescope might be useful. Wherever attainable, measure the depth of enormous pits with a micrometer depth gauge.

3. Scale build-up on tube bundle
Guarding in opposition to scale is critically necessary to sustaining the capability of the condenser, which is why condensers needs to be repeatedly inspected for scale build-up. Infrared cameras are efficient for measuring thermal degradation attributable to scale.

4. Cracks in fan assemblies
As a mechanical element, fan assemblies must be inspected no less than yearly. Fan blades can break off and trigger harm to surrounding areas. A loosened motor mount may cause a fan meeting to fall, which can end in intensive harm to the condenser.

Throughout inspection, look and hear for any vibrating components — bigger sheet metallic components will often be essentially the most noticeable. Watch the fan in operation, on the lookout for any vibration because it rotates. Hear for sudden adjustments in noise ranges or tones, and visually examine the fan assemblies for cracks.

5. Shafts, bearings, motor mounts, belts, and fasteners
A complete inspection contains detection of overheated bearings, belts or motors utilizing an infrared digital camera and conducting a visible seek for cracked or frayed belts and lacking fasteners. A rotating element might fail so comply with really useful upkeep procedures within the producer’s operations and upkeep guide to keep away from harm and mechanical points.

6. Scale or dust construct up in drift eliminators and the water sump
Visually examine the mist eliminators and basin for organic progress, scale build-up or dust accumulation. These situations trigger decreased airflow, leading to elevated working temperature and stress, which can trigger the spray water pump to clog and thereby prohibit or cease the stream of water over the coil bundle. If needed, drain the basin, take away any overseas materials and both clear or change mist eliminators as wanted.

7. Security gadgets
Verify that any security gadgets, comparable to vibration switches, are functioning correctly. Observe the producer’s directions for the frequency of, and process for, testing every system. Malfunctioning or lacking security gadgets might end in unsafe operation of the unit. For instance, a disconnected vibration change might fail to detect a vibrating fan meeting, which might end in catastrophic fan failure and mechanical harm.

8. Electrical connections
Wiring additionally must be inspected for unfastened connectors or indicators {of electrical} overheating (black marks), in addition to for melting or cracking wire insulation. Visually examine electrical connectors and use an infrared digital camera to determine overheating electrical elements that might fail or catch hearth. Contact an electrician to restore or change faulty electrical elements that present indicators of damage.

9. Spray nozzles
Visually verify that spray nozzles usually are not plugged and are delivering a uniform spray sample. Poor water spray to the coil floor might end in larger working temperature and condensing stress and compromise efficiency. All the time use spray nozzles from the unique tools producer to make sure optimum water protection.

10. Isolation valves and purge valves
Isolation valves needs to be checked to make sure they’re functioning and in good situation. Visually examine the valves to verify they’re free from indicators of main corrosion and take a look at the valves to verify they function accurately — opening and shutting correctly with out leaks. Substitute valves which are malfunctioning or displaying extreme corrosion.

Bear in mind, don’t wait till the condenser fails to carry out upkeep. To maximise the working lifetime of a system, preventive upkeep is essential. Effectively-maintained tools will maximize uptime and effectivity and assist to maintain a system hygienic and protected.

Steve Kline, P.E., is product functions supervisor at Baltimore Aircoil Firm.