Boiler is a special equipment. It is different from other special equipment. It is not only common in factories, but also in our living areas, such as boilers used for heating in winter, and hot water used in dinning room, hotels, etc. Boilers and so on are closely related to our lives.

Boiler Maintenance Significance

For the normal operation of the boiler, three points depend on operation and seven points depend on maintenance. It shows the importance of boiler maintenance.

The specific performance is the following three aspects:

1. Affect boiler quality

Whether it is a steam boiler or a hot water boiler, if the boiler is not maintained for a long time, the quality of the steam or hot water of the boiler will be reduced, the boiler cannot operate efficiently, and the final quality will be affected.

2. Affect boiler energy saving

For boilers, we not only look at the quality of the boiler products, but also the operating costs of the boiler. For example, a hot water boiler that needs to operate 24 hours a day during winter heating. If the boiler is not maintained for a long time, it will cause the boiler Increased operating costs result in unnecessary waste of fuel.

3. Affect surrounding security

The boiler is a special equipment. If it is not maintained for a long time, it will cause aging and damage to all aspects of the equipment. This will lead to a decrease in boiler safety factor, and there will be a risk of boiler explosion accident.

Boiler Maintenance Methods

Daily Maintenance

In the daily use of the boiler, inspections, tests, measurements and records must be carried out in a planned and periodic manner to understand the status of the equipment. For the problems found, deal with them in a timely manner or formulate maintenance plans to solve them according to the situation.

(1) Inspection items

(2) Test items

1) Water level measurement and alarm interlocking device.

2) Automatic water supply equipment.

3) Fuel monitoring interlock mechanism.

(3) Instrument measurement items

1) Steam: pressure, flow, temperature (with superheater).

2) Water supply: pressure, temperature, water supply, return water, water quality analysis value.

3) Boiler water: water level, sewage volume, water quality analysis value.

4) Fuel: fuel consumption, oil heating temperature, oil pressure, air pressure, industrial analysis of coal and air pressure for combustion.

5) Ventilation: air flow, air door opening.

6) Flue gas: temperature, O2 and CO2 content, smoke and dust concentration.

(4) Record

Check the operation diary, analyze and deal with it.

Regular Maintenance

Find the problems that need to be solved in daily maintenance, and those that you cannot deal with immediately according to their importance and conditions of use, are included in the annual, quarterly and monthly maintenance plans, and implemented to ensure the perfect operation of the equipment.

Pressure Maintenance

Pressure maintenance is generally applicable to boiler that shutdown period does not exceed one week. Using the residual pressure in the boiler to maintain 0.05~0.1mPa, the boiler water temperature is slightly higher than 100℃, so that the boiler water does not contain O2, and can prevent air from entering the drum. In order to maintain the temperature of the boiler water, generate a slight fire in the boiler regularly, or use the steam of the adjacent boiler to heat the boiler water regularly.

Wet Maintenance

Wet maintenance is generally applicable to boiler that shutdown period does not exceed one month. After shutting down the boiler, drain the boiler water, remove the scale and soot, close all manholes, hand holes, valves, etc. Then add softened water to the lowest water level, and then use a special pump to inject the prepared alkaline solution into the boiler. The composition of the solution is sodium hydroxide or sodium carbonate or trisodium phosphate. After injection, turn on the water supply valve and fill the boiler with softened water until the water emerges from the air valve. Then close the air valve and the water supply valve, and turn on the special pump to circulate the water to make the solution evenly mixed. 

During the maintenance period, light a low-fire oven regularly to keep the outside of the heated surface dry. Turned on pump   regularly to circulate the water to make the concentration of the solution consistent. Regular testing is required, and if the alkalinity decreases, it should be supplemented. Take anti-freezing measures in winter.

Dry Maintenance

Dry maintenance is applicable when the boiler has been shut down for a long time. After the boiler is shut down, drain the pot water, remove the scale and soot, turn off the gas, water supply, and sewage wide, and then open the manhole to let the drum dry naturally. If the boiler room is damp, use low fire to dry the boiler body, furnace wall, and flue. Then put the desiccant (quick lime or anhydrous calcium oxide) on the grate with an open tray, and hoist it in the drum with a cloth bag to absorb moisture. Finally, close all manholes and hand holes to prevent moist air from entering the boiler and corroding the heating surface. In the future, check whether the heating surface is corroded every half a month or so, and replace the failed desiccant in time.

Inflation Maintenance

Charging maintenance is applicable to boilers that have been out of service for a long time. Generally, nitrogen and ammonia are charged from the highest part of the boiler and maintained at a pressure of 0.05~0.1MPa to force air to be discharged from the lowest part of the boiler, so that the metal does not come into contact with oxygen.

For boilers that not use for a long time, the outside of the heating surface should be painted with anti-rust paint after the soot is removed; The inside of the heating surface needs to be cleaned of scale and coated with boiler anti-corrosion paint. Clean the boiler auxiliary equipment completely, and the lubricating oil in the drum, induced draft fan and grate reducer should be drained. Rotate all movable parts once a week to prevent rusting. Maintain all electric equipment in accordance with regulations. 

Conclusion:

Insist on the above-mentioned boiler maintenance work can greatly reduce the boiler oxygen corrosion, extend the boiler service life, and ensure the safe and economic operation of the boiler equipment. There are many maintenance methods for boiler shutdown, but the implementation of various maintenance methods is closely related to the boiler structure, the boiler feed water quality, the boiler purpose and the length of the boiler shutdown time, etc., according to your actual situation, Use different maintenance methods corresponding to it respectively.

If you have any other questions about boiler maintenance, please contact EPCB, our professional service team will give you the greatest help.

EPCB, your private boiler system expert!

Boiler Use Guide：

Boiler Safety Guide |Comprehensive Boiler Safety Operation Manual

Boiler Energy-Saving Technology--Boiler Water Pump Power-Saving Transformation

Industrial Boiler Energy-Saving Transformation Case