General knowledge of maintenance

Release time:



General knowledge of maintenance
1. Matters needing attention in cooling tower design and selection
About setting up location:
1. Cooling towers should be installed in a clean and well ventilated environment, and the towers should be installed at a certain distance to ensure that they meet the design requirements.>
2. cooling towers should be installed in ventilated places. Avoid installing as far as possible in higher temperature, near heat source, dust, corrosive gas, debris 
concentration, there are dust, acid exhaust, high temperature exhaust and steam more places. Especially after inhaling a large amount of soot, not only cooling towers, piping and other equipment will also be corroded.>
3. If there are obstructions between the shutters and the walls, or if there are fewer spacing, the air inhalation will produce impedance, resulting in insufficient cooling 
capacity. You can consult our technical department.>
4. the location of the cooling tower must be reserved for pipeline configuration and equipment maintenance.
5. Distribution of pipes according to the specifications. Pay attention to several intake pipes of our company. Customers should pay attention to the corresponding pipes when purchasing solenoid valves.>
6. piping and water pumps must be installed below the operating level of the cooling tower, otherwise it will cause air inhalation.
Two. Matters needing attention in setting up cooling towers.
Basic considerations:
1. refer to the operation weight of the cooling tower and the design safety factor, and check the foundation bearing capacity.
2. The cooling tower foundation shall be designed and constructed according to the size specified in the design scheme or the foundation drawing provided by the factory, and the steel plates shall be embedded in the required size, and the foundation planes shall be on the same horizontal plane.>
3. After the cooling tower is installed on the foundation, the installation feet are straightened and the diagonal line of the measuring bottom frame is fixed, and the 
foundation bolts or welding are locked. When commissioning, please reconfirm whether the foundation bolts are locked or welded. When the steel frame is on the foundation, 
please lock the bolts or welding of the steel frame.
4. When equipped with shock-proof device, confirm whether the foundation or steel frame, shock-proof device and cooling tower are locked, and confirm according to the 
assembly essentials of shock-proof device instructions.
5. Concrete mixing strength shall be adopted in accordance with the current national standard "Code for Construction and Acceptance of Concrete Structures" (GB50204).
6. all steel plates were leveled horizontally with a level of + 2mm; the central axis deviation of all embedded steel plates was 4mm.
Three, pay attention to the main points before cooling tower operation.
1. When installing, please refer to Pipeline Installation Instructions, and select the appropriate pipe length, number of gate valves, number of elbows, links, connectors for direct connections, and so on. Other hose connections should be based on the actual situation in the required field, do not forget the possibility and necessity of these >installations.>
2. the connection of the circuit can refer to our electrical wiring and water supply and drainage instructions.
3. prepare the start-up of the pump ahead of schedule.
Rotate the blades of the motor to ensure that the impeller can operate flexibly without any blockage or bad friction or failure.
Open the intake valve and intake valve, let the liquid cover the whole internal space of the pump, then turn off the intake valve.
The pump oil is added to the surface of the mechanical seal to lubricate.
Start the motor for a moment to ensure that the motor is running in the right direction. >
Start work:
Fully open the inlet (or oil) valve;
Close the drain valve of the pipeline.
Start the motor to ensure the pump works normally.
If a flow meter or pressure gauge is installed at the pump outlet, the open water outlet valve shall be adjusted to allow the pump operating conditions to be within the rangeof the quality parameters listed in the rate table. During this period, the motor current shall be tested to ensure that the current setting is No excess of its power, >
prevent pump overload work burned motor.
Checking the leakage of mechanical seals should normally be controlled at less than 3 drops per minute.
Check motor temperature and bearing temperature rise and fall to ensure 
that their temperature is less than 70 degrees Celsius.
Stop working:
Turn off the pipe inlet and drain valves.
Stop the motor and turn off the power.
If the cooling tower does not work for a long time, the pump needs to be cleaned and maintained in a good condition.
If the ambient temperature is below 0 C, all the liquid inside the pump should be discharged to prevent the pump from bursting due to freezing.
4. The proper piping water should be added to the tower, and then the pump should be run to clean the piping. After several days of operation, the piping water for the first time should be emptied; the whole tower can be used normally by adding soft water or distilled water to the whole tower.>
5. The water supply pipeline should be connected with the cooling tower water supply valve. The water supply should not be less than 2/3 of the total water supply (or decided by the automatic water supply valve). After operation, the spray tank should be cleaned regularly to ensure its spray effect.>
6. Before starting the machine, open all the valves that must be opened, pull down the "Pump Open" and "Fan Open" buttons (the corresponding indicator lights are displayed in the working state), and then check whether the pump runs smoothly and the water flow is in the direction indicated by the arrow, whether the water pressure gauge is normal, >whether there is any leakage and unusual. Then check the direction of the fan air volume, if there is unusual vibration sound. Please immediately solve these problems found, >if the problem exceeds your processing capacity, please contact our after-sales service department.>
7. Pull down the buttons "Pump off" and "Fan off" and the entire cooling tower will stop working. To ensure the full safety of the electrical appliances, its air switch 
should be set to "off" so that the power supply is completely cut off.
(caution: pumps are not allowed to open or work without adequate water supply).>
8. This soft water cooling system has its own temperature control device: it will automatically open the sprinkler pump and fan according to the customer's needs (when its outlet temperature reaches its set top temperature), and it will stop the sprinkler (when the outlet temperature cools to the preset temperature).>
9. for the fan motor and pump motor, the electronic control system has the function of overload relay.
10. check the liquid level on the water tank. If you find the water level is insufficient, please replenishment in time.
* * * others, please operate according to the cooling tower maintenance instructions. * * *
Four. Initial and seasonal start up
Before the equipment is turned on, check the following contents:
1. remove all debris, such as leaves and trash on style grille.
2. rinse the spray tank and wash away the sediment and dirt.
3. check whether the mechanical floating ball valve operates flexibly.
4. check the nozzle of the water distribution system and clean it if necessary. Check whether the nozzle is in the right direction. (no need to check this item for the firsttime. The cleanliness and azimuth setting of the nozzles have been completed before the factory.)>
5. check and ensure that the baffle is safely seated.
6. adjust the tightness of the fan and the screw of the water pump (if necessary).
7. lubricate fan bearings before seasonal start.
8. turn the blade to ensure that the rotor leaves normal and unimpeded.
9. visual fan blades. From the blade tip to the air duct, whether the gap is even, whether the blade plane is smooth. The blade should be securely fastened to the fan.
10. If there is retained water in the "dead corner" of the system and pipeline, the equipment should be disinfected before the fan runs.
11. water injection into the spray tank until the overflow is located.
12. For a closed cooling tower, the specified medium is filled into the heat exchange coil and the air in the system is exhausted by the exhaust hole at the inlet of the coil 
before pressurization.
After the equipment is turned on, check the following contents:
1. adjust the mechanical floating ball valve as required.
2. the water level of the unit should be at the normal working level.
3. check and confirm that the fan is in the right direction.
4. open the spray pump. Check and confirm that the rotation direction of the impeller is in the direction of the arrow marked on the front cover.
5. measure all three-phase voltage and current. The current should not exceed the full load current which is calibrated by the motor nameplate. The service factor should be 
6. adjust the drain valve to the appropriate flow rate. Please consult your local qualified water treatment company for the minimum discharge required.
7. For more fan and pump maintenance, please refer to "Common Problems and Solutions of Pumps" and "Common Problems and Maintenance of Fans"
Note: closed cooling towers can only be used for closed pressure systems. Continuous use in open system will cause corrosion in tube, resulting in shorter service life of 
cooling towers.>
Five. Maintenance and maintenance of cooling tower during operation
Cooling tower as an important cooling equipment, it should be maintained and managed by special personnel, maintenance and observation of operation, to pay attention to the current, water temperature changes, and pay attention to whether there is abnormal sound, if there are abnormal phenomena, should immediately stop to check.>
1. motor produces abnormal sound.
2. the fan vibrates violently.
3. fan blade and cooling tower wall.
4. tower sway.
5. tower body leaks.
6. the temperature of the pump is too high or the cooling water can not meet the cooling requirement.
5. check whether the fasteners are loose and ensure that the fasteners are locked.
6. keep the water tower clean and water treatment regularly. Circulating water turbidity generally does not exceed 50mg/L, short-term allowance does not exceed 100mg/L, circulating cooling water system should have water treatment measures, if there arealgae and moss breeding in the use process, should be removed according to the situation. >
It can be equipped with a dosing device, adding "liquid chlorine" or "new bromo" and other biocides.>
7. check whether there is any sundries in the water system, whether the water level is normal, and whether the circulating water quality can meet the water quality standard.
8. If the air volume is too large or too small, the blade angle can be adjusted, but the motor load should be checked at any time, such as the overloaded blade angle should be reduced.>
9. In the process of overhaul and maintenance, water receivers or PVC packing should not be trampled directly. If necessary, paving operation should be carried out.
Routine maintenance:
Daily maintenance of cooling tower is very important, it has a direct impact on the economic, safety and extended service life of equipment. Therefore, daily maintenance and 
repair work must be done conscientiously.>
The maintenance work of cooling towers is as follows:
1. regularly remove moss, dirt and debris in the flume, and sweep at least once a year in spring and autumn.
2. Check the water distribution system device regularly to keep the sprinkler filler clean. When the dirt is blocked, we should consult with the relevant units to find out the cause and analyze its influence, and then take necessary measures to restore good water quality.>
3. Valves and other transmission devices should be regularly refueled and maintained to keep their switches flexible. In addition to winter, it is advisable to rotate the 
valves of the cooling system in two directions every month for 2-3 turns to prevent rust from getting stuck.
4. regularly check whether the components are connected reliably, and the transmission system must be examined carefully.
5. Cooling towers are used in the north. Preparations for freezing prevention of coil pipes should be made conscientiously in autumn and relevant measures should be taken 
conscientiously in winter. When we stop, we must pay attention to emptying water.>
Maintenance of main components:
1. spray tank
Cold water pans should be thoroughly cleaned quarterly and inspected monthly or if necessary to remove dirt or sediment that is easily accumulated in the pans. The sediment will corrode the water dish and cause damage to the water disc material.>
After the first start-up of the equipment or equipment is discharged, the unit must be injected into the overflow. This is higher than the normal working water level so that there is enough water in the external pipes of the water distribution system and equipment.>
The water level should be kept out of the filter screen and suction inlet of the pump. Turn on the water pump, turn off the fan, and observe the water level through the inletgrille or the access door.>
2. sprinkler water distribution system
The water distribution system should be inspected every month to ensure its normal operation. Usually, the sprinkler system can be checked when the pump is turned on and the fan is closed (locked and marked). Our company is using three layers of sprinkler nozzle, actually will not plug, almost no need for cleaning and maintenance.>
If the nozzle is not working properly, this is a sign that the filter in the water pan is not working and that dirt or debris has accumulated in the water distribution pipe. 
A small pointed probe can be inserted into the sprinkler orifice and then pounded back and forth to remove the dirt clogged in the sprinkler nozzle.
When the accumulation of dirt or debris is particularly serious, the end cap of each branch can be removed and the dirt can be washed out of the main pipe. The sprinkler >
branch or connecting pipe should be removed only when absolutely necessary.
Master Cooling Manufacturing
3. water quality requirements
Water quality of cooling coil unit:
The recommended pH value of water quality is between 6.5 and 8.5.
If the PH value of water quality changes or scaling occurs after a long period of operation, the coil must be treated by chemical methods. The chemical agents must be 
suitable for the structural materials of the unit and other materials used in the system. The chemical agents must be accurately measured and accurately controlled. The chemical agents must reach evaporative cooling mode. Mix and mix slowly before the equipment. Chemical agents can not be added to the coil of evaporative cooling equipment in >batches.>
Sprinkler water quality:
The recommended pH value of water quality is between 6.5 and 8.5.
Due to the long-term use of the sprinkler, the PH value of the water pollution changes, and bacteria breeding, need to be regularly cleaned up.
Refer to Article 2 of the "Cooling Coil Water Quality" in Item 1 for chemical treatment of incoming water
4. water supplement valve
Mechanical floating ball valve is a standard component of evaporative cooling equipment. It can be easily contacted by the external repair door or the removal of the inletgate. The mechanical float valve controls the water flow through the filling outlet by the level of water. The flow rate increases when the water level reaches the bottom, >and the filling outlet closes when the water level of the flume gradually meets the filling water level.>
Please note the following points here:
1, please check the flexibility of mechanical floating ball valve every month.
2, please check the water supply pipe's water pressure regularly every week.
5. blowdown valve
Whether factory installation or site installation, the drain valve must be checked weekly to ensure that it works properly and is properly set up. It is necessary to keep the drain valve open unless the partial opening does not result in water concentration and corrosion in the water tray.>
6. main pump (provided)
The pump and pump motor shall be lubricated and maintained according to the instructions provided by the pump manufacturer. Circulating water pumps should not be used as a means of capacity control. Excessive start and stop will lead to scaling, leading to adecrease in dry and wet properties.>
If the pump unit is idle for too long, then it should be manually rotated pump motor blades and impellers (specific information refer to our company's related motor idle maintenance and pump solutions to common problems).>
7. drainage or sewage disposal
Closed-loop cooling equipment is cooled by evaporating part of the circulating sprinkler water, and saturated hot and humid air is discharged into the atmosphere. As this part of the pure water evaporates, minerals and impurities in the water and air-borne pollutants remain. These impurities and pollutants will continue to circulate in the >system and must be controlled to avoid fouling, corrosion, accumulation of dirt and biological contamination due to excessive concentration. Closed cooling equipment should >be installed in the sprinkler pump side of the drain pipe or drain pipe, in order to concentrate water in the system discharge.>
8. biological pollution control
The evaporative cooling equipment should be regularly monitored for microbial control, including the use of culture techniques to monitor microbial populations, and to 
visualize signs of biological contamination.
Poor biological contamination control can reduce heat transfer efficiency, increase the likelihood of corrosion, and increase the risk of pathogens (which may lead to Legionella disease).>
Specialized water treatment procedures should include routine operation, restart after periodic downtime, and system idleness (if any). If too many microbial contaminants are detected, more robust Mechanical flushing or water treatment procedures should be adopted.>
It is very important to keep all surfaces clean, dirty and residue inside the equipment. Besides, the dehydrator should be kept in good working condition.>
9. grey water and reclaimed water
The use of external recycled water may increase corrosion, biological contamination or scaling. Ash and reclaimed water should be avoided unless all hazards have been 
10. air pollution
When evaporative cooling equipment is running, the particulate matter in the air will be trapped in the unit when it is exhausted. Do not install the unit in the chimney, 
exhaust duct, ventilation holes, exhaust vents and other vicinity, so as to avoid the unit inhaled flue gas corrosion. In addition, the unit should be away from the 
building's fresh air intake to prevent the unit's exhaust into the building's air conditioning system. If the unit is installed in polluted industrial areas, such as chemical 
fumes, industrial smoke, saline alkali or serious dust pollution, the unit will be scoured by circulating water pollutants in the air and fouling, corrosion or accelerated 
biological breeding. The amount of impurities in the air will determine the frequency of equipment maintenance work, and sewage can improve the above situation. If there are any signs of corrosion, scaling or biological breeding, we should promptly contact experienced water treatment experts.>
Six. Recommendations for long term operation of cooling towers.
When the system is shut down for a long time, the following operations should be carried out.
1. the water in the evaporative cooling equipment should be emptied.
2. rinse the spray tank.
3. the drainage of the cold water tray should be kept open.
4. the adjusting bolts for fan bearings and motor bases shall be lubricated. When the equipment is placed for a period of time, the item should also be checked when it is 
first started.>
5. Electric hotlines and insulating materials are used to wrap the water supply, overflow and drainage pipes, as well as the pump and the pump risers to the overflow level to solve the problem of residual water.>
6. check whether the corrosion protection layer of the unit is complete. Clean and re spray if necessary.
7. fan bearings and motor bearings need to be rotated at least once a month. After determining that the cut-off switch of the unit has been locked and marked, the fan blade needs to rotate for several weeks to check for abnormalities.>
8. Antifreeze Protection: If the recommended minimum flow through the heat exchanger coil is not achieved, and the coil has no other anti-freeze measures, in the ice season once the system pump shut down, or the media stopped flowing, the coil must be immediately emptied. The coil can be emptied through the drain valve and vent hole of the inlet >and outlet pipes of the closed cooling tower. And the diameter can ensure that thewater flows out of the coil quickly. This anti-freezing measure can only be used in >emergencies, and it is not recommended as an anti-freezing protection measure, nor can it be used as a routine operation. Coil should not be emptied for a long time, >
otherwise internal corrosion may occur.
Recommended maintenance for idle period
If the equipment is idle for a period of time, we need to do the following additional work besides maintaining all the components as required by the maintenance instructions:
Monthly rotating fan bearings and motor bearings. After confirming that the cut-off switch of the unit has been locked and marked, turn the blade of the machine for several weeks to check for abnormalities.>
If the idle period of the equipment is between two weeks and one month, the main pump, sprinkler pump and fan should be rotated before starting to check for abnormalities.
If the idle period of the equipment is longer than one month, the sprinkler flume should be emptied and the insulation of the motor should be inspected every six months and the lubrication of the bearing and the mechanical seal should be inspected monthly.>
Long term UN used towers should be covered and protected.
(Note: Before starting any maintenance, make sure that all power supplies connected to the unit are turned off, locked and marked!)
Seven. Circulating water quality requirements for cooling towers
Any good supply of water also contains slightly corrosive substances and insoluble substances such as calcium carbonate, and will be concentrated over time. This impurity is affected by air pollution, water rust and corrosiveness will gradually increase, and even cause failure. The following table is the standard for chilled air conditioner >
cooling water developed by the Japan refrigeration and air-conditioning industry association. Reference should be made to this water quality standard value to determine the >
flow rate of the basic fixed circulating water and whether water treatment chemicals are needed for proper treatment.
The cooling water quality standards for refrigerating and air-conditioning machines are as follows:
  Project Standard value of cooling water Standard value of make-up water Inclination
Corrosion Rust
Standard project ph(25℃) 6.5~8.2 6.0~8.0
Conductivity(mS/m)(25℃){uS/cm)(25℃) 80 below {800 below} 30 below {300 below}
Chloride ion(mgC1/1) below below  
Sulphate ion(mgso42-/1) below below  
Acid consumption(ph4.8)(mgCaCO₃/1) below below  
Full hardness( mgCaCO₃/1) below below  
Calcium hardness( mgCaCO₃/1) below below  
Ionic silicon( mgSiO₂/1) below below  
Reference project Iron(mgFe/1) below below
Copper(mgCu/1) below below  
Sulfide ion(mgS2-/1) Should not be detected Should not be detected  
Ammonia ion(mgNH4+/1) below below  
Residual chlorine(mgC1/1) below below  
Mono carbon(mgCO²/1) below below  
Stability index below -


Eight. Water supplement for cooling towers
Circulating water is reduced by the following (1) to (3) reasons. Supply should be reduced according to this reduction.
(1) evaporation loss
The cooling tower will evaporate part of the water to cool the circulating water. To this end, the amount of evaporated water will be reduced.
Evaporation E (%) = Delta t/R X100 delta T: temperature difference between circulating water inlet and outlet (degree Celsius)>L: circulating water quantity (kg / h)>
E (kg/h) =delta tXL/R: latent heat of water evaporation (kcal/kg) - - 575 (kcal/kg) at 37 degrees Celsius>
(2) water droplet loss
When the fan rotates, the amount of water released from the gas and the amount of water emitted from the free ventilation window are combined.
The loss of water droplet is C (%) = about 0.1% of the circulating water volume.>
(3) sewage disposal
Because the cooling tower often evaporates part of the water, so that the ratio of the concentration of the dissolved component in the circulating water to the concentration of the dissolved component in the supply water is called the concentration multiple of the circulating water.>
In order to make the circulating water operate under a certain 
concentration ratio, part of the circulating water is discharged from the outside to maintain the proper water quality. This work is called sewage disposal.>
The amount of sewage discharged should be lower than the concentration multiple set according to the recharging water quality, the setting environment and the use state. Generally, in >order to make the circulating water run below a certain concentration multiple, the discharge can be calculated according to the following formula.>
Discharge capacity: B (%) =E / N-1 - C N: concentration multiple (about N=3)>
(4) recharge volume
Water supply M (%) =E+C+BM (kg / h) =LX (E+C+B)>For example:>Evaporation is E=0.87%; water droplet loss is C=0.1%; discharge volume is B=0.3%.>M=0.87+0.1+0.3=1.27%>Generally >
speaking, the supply water is about 2% of the circulating water.
Nine. Freeze protection of closed cooling tower tray.
1. The simplest and most reliable way to freeze the heat exchanger coil is to use glycol solution. If conditions are impossible, an auxiliary load should be retained on the coil at all times so that the water temperature will not be lowered below 10 C when the cooling tower stops. In addition, a certain amount of traffic must be maintained.>
2. If no antifreeze solution is used, the water in the coil should be emptied immediately when the pump stops or the water flow stops. This can be achieved by automatic draining valves and bleeder valves connected to the cooling towers. We must pay attention to the proper pipe insulation and proper diameter, so that the water can flow out of >the coil quickly. This antifreeze method should only be used in emergency. The coil should not be emptied for a long time, otherwise the inner part of the coil will be >
corroded easily.
Ten, service, consultation
Quality assurance and quality commitment:
Our company guarantees that the labor force and all materials used in the manufacture of this equipment are of the highest quality.
If a mechanical failure occurs within one year from the date of operation (or within thirteen months from the date of delivery of the equipment in our factory), the quality inspector of the company determines that the equipment is due to the use of defective materials or poor workmanship. As a result, the company will maintain the equipment, or >immediately replace the same or equivalent parts of the equipment free of charge. The parts of the repair equipment or replacement equipment are delivered only by truck >outside the factory premises of the company and do not include transportation or labor costs.>
If it is confirmed that the failure of the parts of the equipment is caused by some external disturbance or that the failure of the parts of the equipment is caused by 
improper installation or artificial reasons, then our company has the right to stop providing any quality assurance and quality assurance. The company will not undertake any cost incurred in the maintenance without prior approval from our company.>
In any event, our company shall not be liable for any kind of consequential or accidental damage arising from the manufacture, sale, installation or use of this product.
1. make an appointment to install, guide and install the cooling tower products of our factory, undertake all kinds of old tower transformation business.
2. accept the consultation of various cooling towers in our factory.
3. provide all parts needed for this product maintenance.
4. design and trial manufacture of cooling towers with special requirements for users.
5. Maintain the interests of users, in the case of correct use, if the quality causes damage can be treated as "three packages".

Previous Page

Next Page

Previous Page:

Next page: