Refrigeration Air Dryer Manual

Refrigeration Air Dryer Manual

(Sep 11 2021 - Views: 504)

Following the instructions will help to avoid hazards, reduce repair costs and downtime, increase reliability, and extend the service life of the machine.

The operating instructions must also be accompanied by country-specific regulations on accident prevention and environmental protection. They must be available at all locations where the machine is installed. The operator must read and follow the relevant operating instructions carefully. For example, installation, maintenance (maintenance checks, repairs), and transport.

In addition to the operating instructions and the necessary provisions for accident prevention at the place where the machine is to be used, the general technical provisions relating to safety and normal operation must be observed.

How To Install The Refrigeration Air Dryer

  1. Standard requirements: it is not necessary to install floor screws, but the foundation level is required to be solid. Consider the height of the drainage system and the installation of a drainage trench.
  2. The distance between the dryer and the surrounding environment or the machine should be at least one meter. For easy operation and maintenance.
  3. Avoid placing it outside the house where it will be exposed to direct sunlight and rain, or where the temperature is high, ventilation is poor and dust is excessive.
  4. Avoid too long, too many bending angles, and too small pipe diameter when installing, so as to avoid pressure drop.
  5. Please install a bypass valve above the inlet and outlet of the air dryer for maintenance.
  6. Pay attention to the installation of power supply
    – The rated voltage within ±5% range.
    – The wire diameter of the power inlet wire will be determined by the current and the length of the line.
    – The dryer power supply line must be dedicated.
  7. The pressure of cooling water or circulating cooling water ≥ 0.15Mpa, water temperature ≤ 32 ℃ and softened.
  8. it’s better to install the main filter at the entrance of the refrigeration air dryer. To avoid the surface of the heat exchange copper pipe being polluted by solid impurities and oil mist ≥3μ, which affects the heat exchange performance of the dryer.
  9. The air dryer is best to be installed after the rear cooler and gas storage tank. To reduce the temperature of compressed air, which is related to the performance and life of the dryer.

How To Operate The Refrigeration Air Dryer

Check Before Startup

  • Check if the power supply voltage is normal AC220V ±5% /AC380V ±5% 50HZ/60HZ or others that can be used in your country.
  • Check the refrigeration system. Observe the refrigerant high and low-pressure table, the two tables reach a balance under a certain pressure. The balance pressure fluctuates depending on the surrounding temperature, generally 0.5Mpa~1.0Mpa.
  • Check whether the air pipeline is normal. The air inlet pressure should not exceed 1.0Mpa except for special models. The inlet temperature should not exceed 45℃ except for special models.
  • For the water-cooled type, check whether the cooling water is normal, the water pressure is 0.15Mpa ~ 0.3Mpa, water temperature ≤ 32 ℃.

Control Panel Description

  • Refrigerant pressure gauge (pressure dew point gauge). Indicates the saturation pressure value of the refrigerant in the evaporator.
  • Air inlet pressure gauge. Indicates the pressure of compressed air at the inlet of the dryer.
  • Air outlet pressure gauge indicates the pressure of the compressed air at the outlet of the dryer.
  • Press the Stop button, then the dryer stops working.
  • Press the Start button, then the dryer is connected to the power supply and starts to work.
  • The current overload protection tripping indicator light. This light indicates that the compressor working current is overloaded, the overload relay has been tripped and needs to stop and check.
  • Refrigerant high and low voltage protection tripping indicator light. REF.H.L.P This light indicates that the high and low voltage protection switch in the dryer has jumped off and needs to be stopped and checked.
  • Reverse trip light, if this light is on, it means the phase sequence is wrong.

Check Before Startup

  1. Turn on the power and the power indicator on the panel POWER (red light) is on!
  2. For the water-cooled type, open the cooling water inlet and outlet valve.
  3. Press the green button START, the contactor suction, operation indicator is on (green light), the compressor began to run.
  4. Check whether the compressor operates normal, without abnormal noise, refrigerant high and low-pressure table instructions are normal.
  5. If everything is normal, then open the air compressor or the valves to the air dryer, and close the air bypass valve, the air pressure gauge will show the air outlet pressure.
  6. After 5-10 minutes of observation, the air treated by the dryer can meet the requirements. And the refrigerant pressure gauge indicates 0.3-0.5Mpa, the refrigerant high-pressure gauge indicates 1.2-1.6Mpa, the dew point temperature gauge indicates 2-10℃. (Except for special requirements).
  7. When shutting down the machine, turn off the air supply, then press the red STOP button to turn off the dryer and cut off the power. Open the drain valve to drain the residual condensate.

Other Notes

  • Avoid long time operation of the dryer in the no-load state.
  • It is forbidden to start and stop the dryer continuously for a short time, to avoid damaging the refrigeration compressor.

How To Maintenance Refrigeration Air Dryer

Proper use and maintenance not only keep the dryer high efficiency but also extend its life.

External Maintenance for Refrigeration Air Dryer

The main thing is to regularly clean the exterior of the dryer

  • Wipe with a damp cloth, and then wipe with a dry cloth. 
  • Avoid direct spray washing, to avoid damaging the electrical part or its insulation reduced. 
  • Do not use gasoline and other volatile oils, thinners, and other chemicals for wiping, otherwise the shell will cause discoloration, deformation, and paint peeling.

Maintenance for Automatic Drainer

  • Check the automatic drainer every day, clean the filter inside regularly to avoid clogging and loss of drainage effect.
  • When cleaning the drainer, use soap and water or detergent, it is forbidden to use gasoline, toluene, rosin, and other corrosive agents.
  • If the cooler is equipped with a drain valve, it should be drained more than twice a day at regular intervals.
  • Air-cooled condenser, the distance between its ribs is only 2-3mm, it is easy to be blocked by the dust in the air, causing poor heat dissipation. So clean it regularly, sprayed with compressed air, or brush with a copper brush.
  • Water-cooled condenser, the water filter needs maintenance.

Internal Maintenance for Refrigeration Air Dryer

Periodic vacuuming of internal components during downtime

Failure and Troubleshooting for Refrigeration Air Dryer

Failure Causes Troubleshooting

The dryer doesn’t work at all

  • No power supply.
  • Blown fuses.
  • Disconnection.
  • Loose thread.
  • Inspection of the power supply system.
  • Replacement of fuses.
  • Find the break and fix it.
  • re-strengthen.

The Compressor doesn’t run

  • The power supply is out of phase or the voltage is out of the allowable range.
  • Poor contactor, no suction.
  • High and low voltage protective switch defective.
  • Thermal Overload Circuit Head Release.
  • Mechanical failure of the compressor, e.g., seized cylinder.
  • If the compressor is a capacitor start, the starting capacitor is damaged.
  • Check the power supply so that the supply voltage is within the rated range.
  • Contactor replacement.
  • Adjust the pressure switch setting or replace the damaged pressure switch.
  • Thermal Overload Relay Replacement.
  • Find the loose threads and reattach them.
  • Compressor replacement.
  • Replacing starter capacitors.

Refrigerant high pressure, causing the pressure switch to trip

  • High air intake temperatures.
  • The condenser has poor heat dissipation due to poor ventilation or insufficient cooling water circulation.
  • The ambient temperature is too high.
  • Over-flushing of refrigerant.
  • Refrigeration system air mixture.
  • Increases the rear cooler to change the inlet air temperature to the required temperature.
  • Clean the condenser or water line and increase the cooling water circulation.
  • Improved ventilation.
  • Drain excess refrigerant.
  • Re-vacuum the refrigeration system and charge with an appropriate amount of refrigerant.

Refrigerant low pressure causes pressure switch trip

  • Compressed air does not flow for a long time.
  • Low load.
  • Hot gas bypass valve not open or defective.
  • Insufficient or leaking refrigerant.
  • Improved access to air.
  • Increased compressed gas flow and heat load.
  • Adjust the hot gas bypass valve or replace it if damaged.
  • Refill refrigerant or leak detection, fill and re-vacuum, fill the refrigerant.

The compressor operating current is too high, causing a trip in the thermal overload relay.

  • Excessive air load and high air inlet temperatures.
  • Excessive ambient temperature and poor ventilation.
  • The compressor has high frictional resistance.
  • Insufficient refrigerant, making it overheat too much.
  • Compression overload.
  • Main Contactor, Poor Suction.
  • Reduced heat load and high air intake temperatures
  • Improved ventilation.
  • Replace refrigerant oil or compressor.
  • Refrigerant charge.
  • Reduce the number of compressors starts.

The icing of condensate inside the evaporator

  • Too much airflow, too light a heat load.
  • Hot air bypass valve not open.
  • Clogged evaporator discharge, excessive water collection, and ice production, affecting airflow
  • Increasing the flow of compressed air.
  • Regulating hot air bypass valve.
  • Unclog the drain.

Dew point indicates too high

  • Too high an inlet temperature.
  • High ambient temperature.
  • If air-cooled, clogged condenser and poor heat dissipation.
  • If water-cooled, the temperature of the cooling water is too high or the circulation is insufficient.
  • Excessive air handling capacity but low pressure.
  • The air isn’t moving.
  • Increased aftercooling heat dissipation reduces intake air temperature.
  • Improvement of ambient temperature..
  • Air-cooled: cleaning the condenser.
  • Water-cooled: cleaning of condenser scale.
  • Improved access to air.
  • Improving compressor air operating conditions.
  • Dew point thermometer replacement.

The pressure drop of compressed air is large

  • Clogged filter in the pipeline.
  • The line valve is not fully open.
  • Too small pipe diameter, too many elbows, or too long pipeline.
  • Frozen condensate in evaporator clogging gas lines.
  • Clean or replace the filter.
  • Open all the valves through which air flows.
  • Improvement of air piping system.
  • Pre-treatment.

Work with low efficiency

Mainly due to changes in working conditions, so that the working state of the refrigeration system has changed, caused by refrigeration valve parts. In the adjustment of the refrigeration valve, the amplitude should be small, each rotation of the valve stem 1/4-1/2 circle, running about 10-20MIN, and then observe the refrigeration effect, if no change or change is not significant, can be readjusted.

We know that the refrigeration air dryer is composed of four major parts and many accessories. Thus, once the fault, we should not only focus on some local attention but have a comprehensive inspection of the entire system. Only in this way, we can eliminate the doubts one by one, and finally find the real source of the failure.

In addition, when we repair and maintain the air dryer, we should pay attention to the protection and avoid capillary breakage damage, resulting in refrigerant leakage.

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