How to maintain the gas vacuum boiler after it is shut down

Boiler shutdown maintenance method.

During the shutdown of the boiler, if proper protective measures are not taken, the oxygen entering the boiler comes into contact with the moist metal surface, which can produce severe oxygen corrosion. In addition, the flue gas side of the heating surface often adheres to ash particles and combustibles during operation, and the corrosion of metal will be aggravated in a humid environment after the furnace is stopped. Corrosion during this shutdown is often more severe and more harmful than corrosion during operation.

Because it not only directly causes damage to the metal, but also the corrosion products replace the metal protective film, which deteriorates the water quality when the boiler is put into operation again, and greatly accelerates the metal corrosion. Because doing a good job in the shutdown and maintenance of the boiler is of great significance to ensure the normal operation and safety of the boiler, and to maintain and extend the service life of the boiler.

There are several methods for boiler shutdown maintenance:

1. Pressure maintenance.

When the furnace is stopped for less than one week, pressure maintenance can be used. That is, before the termination of the furnace shutdown process, the steam water system is filled with water, and the residual pressure is maintained at (, and the temperature of the pot water is maintained above 100, so as to prevent air from entering the boiler. The measures to maintain the temperature of the pressure inside the boiler are:

It is heated by the adjacent furnace or periodically by the furnace.

2. Wet maintenance.

When the boiler is out of service for less than one month, wet maintenance can be used. Wet maintenance is to fill the boiler steam water system with soft water containing lye, leaving no room for steam. This is because an aqueous solution with the right alkalinity forms a stable oxide film with the metal surface, thus preventing further corrosion.

During the wet maintenance process, a micro-fire oven should be used regularly to keep the outside of the heating surface dry. Turn on the pump regularly to circulate the water. Regularly test the alkalinity of the water, and if the alkalinity decreases, the alkaline solution should be added appropriately.

3. Dry maintenance.

When the boiler is out of service for a long time, dry maintenance can be used. Dry maintenance refers to the method of placing desiccant in the pot and furnace for protection. Here's how:

After the furnace is stopped, the pot water is cleaned, the boiler is dried by using the residual temperature of the furnace, the scale and slag in the pot are removed in time, and then the tray filled with desiccant is put into the pot barrel and the grate, and finally all valves and manholes and handhole doors are closed. Regularly check the maintenance situation and replace the failed desiccant in time.

4. Inflatable maintenance.

Inflation maintenance can be used for long-term shutdown maintenance. After the boiler is stopped, do not release water, keep the water level at a high water mark, take measures to deoxygenate the boiler, and then isolate the boiler water from the outside world. Nitrogen or ammonia is introduced to maintain the pressure after inflation at (.

Since nitrogen can form nitrogen oxide with oxygen, oxygen cannot come into contact with the steel plate. After ammonia is dissolved in water, it makes the water alkaline, which can effectively prevent oxygen corrosion, so nitrogen and ammonia are good preservatives. The effect of inflation maintenance is better, and it requires the boiler steam system to have good tightness.

The boiler needs to carry out a series of maintenance and maintenance during the shutdown process to prevent the corrosion of the boiler by the boiler water. Compared with ordinary boilers, vacuum boilers are much simpler to maintain. This is because the heat medium in the vacuum boiler is specially treated and completely sealed and does not come into contact with outside air.

Therefore, there is no need to worry about the occurrence of corrosion in the boiler after the furnace is shut down.

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1. Desiccant method.

The desiccant method is to drain all the water in the boiler when the temperature of the boiler water drops to 100 120 after the boiler is out of use, and the waste heat is used to dry the metal surface and remove the scale and slag deposited in the boiler water system. Then put desiccant in the boiler to keep the metal surface dry and dry to prevent corrosion.

The first check should be carried out one month after the desiccant is placed. If deliquescent is found, it should be replaced or dried immediately. It can be checked every three months in the future.

This method is suitable for a long period of furnace shutdown maintenance. The larger the proportion of the vapor volume to the total boiler water volume, the more convenient this method is.

2. Drying method.

This method is to discharge water when the temperature of the boiler water drops to 100 120 when the furnace is stopped. When the water is exhausted, the waste heat in the furnace is used to light a slight fire or introduce hot air into the furnace to dry the inner surface of the boiler.

This method is only applicable to the corrosion protection of the boiler during maintenance.

3. Nitrogen filling method.

It is to charge nitrogen into the boiler water system and maintain a certain positive pressure to prevent air from entering. Because nitrogen is very inactive and non-corrosive, it can prevent the shutdown of the boiler from corrosive.

Before shutting down the furnace, connect the nitrogen filling pipeline. When the pressure in the furnace drops to the gauge pressure, the nitrogen cylinder starts to send nitrogen to the boiler drum and economizer through the temporary pipeline.

There are two ways to maintain the hood of the gas boiler: 1. Dry maintenance: when the gas boiler is shut down, the water quality in the furnace should be discharged, the dirt should be cleaned, and it should be kept clean.

Dry in the hearth over a slight heat and place the packed lumpy lime in the pot. Then check the manhole, hand hole and valve to make it sealed. Reminder, it is necessary to search for three months to make trouble, such as quicklime crushed into powder, and replace it in time.

2. Wet maintenance: When the water in the furnace is discharged after the furnace is stopped, it should be cleaned first, then refilled with water, and heated to 100 degrees, so that the gas in the furnace can be discharged out of the furnace and the valve should be closed. Gas boilers are also industrial boilers, which often exist during operation, if there are parts damaged, the boiler body leaks or improper operation, it will cause accidents, so maintenance measures should be taken during the long-term shutdown of the furnace and the leakage of the line.

Hello dear, it's a pleasure to serve you! How to maintain the natural gas boiler for ten days during the Spring Festival: Drain the pot water after the furnace is shut down to remove scale, impurities and soot; Close (or close with blind plates) the valves of each pipeline connected with the boiler body; The softened water is injected into the boiler to the lowest water level, and the prepared alkaline antiseptic liquid is injected into the boiler with a special pump; When all the antiseptic liquid is injected into the boiler, open the boiler feed valve to fill the boiler with softened water until the boiler water emerges from the drain valve, and close the drain valve and feed valve; Turn on the special pump to circulate the water of the boiler, so that the alkaline antiseptic liquid concentration in all parts of the boiler is mixed evenly; During the maintenance period, external inspections should be carried out frequently, and the water alkalinity of the pot should be tested regularly, and the alkalinity or liquid level of the liquid medicine should be found to be reduced, and the cause should be found out and dealt with in time, and the liquid medicine should be supplemented; Regularly turn on the pump to circulate the water to make the concentration of the liquid medicine consistent; During the wet maintenance of the boiler in winter, the ambient temperature of the boiler must be maintained above 5.

Wet maintenance is a boiler maintenance technique. In order to prevent [1] out-of-service corrosion of boilers and other equipment, fill the equipment with deoxygenated water and add sufficient deoxidizer, and use short-term deactivation and maintenance of boilers under pressure and sealing. Thank you for your patience and hope mine can help you and have a great day.

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I found it for you on the China boiler trading network, which is more professional, under normal circumstances, the furnace can be used for wet maintenance for no more than one month, and dry maintenance should be taken for more than one month. External maintenance of the furnace body of the boiler that has been out of service for a long time:

1. After the boiler is shut down for cooling, the ash on the heating surface and the ash on the upper part of the grate and the lower part of the furnace body must be completely removed.

2. Then keep the flue with a certain amount of natural ventilation. In general, in order to prevent moisture, desiccant should be placed in the furnace and flue. Quicklime should be replaced after it has become powdered.

If the location of the boiler room is low-lying, and the ground is seriously damp during the shutdown of the furnace, the combination of frequent low-fire baking and placing desiccant should be adopted. If the boiler is shut down for a long time, after the soot is completely removed, the outer surface of the metal of the furnace body is coated with red dantan oil or other anticorrosive paint.

After the boiler is stopped, drain the pot water, remove limescale and soot, close the valves on the hot water supply pipe, water supply pipe and sewage pipe, or plug it with a partition. Then open the manhole and let the pot stem dry naturally. If the boiler room is damp, it is best to dry the boiler body, as well as the furnace wall and flue with a slight fire.

Then the desiccant is placed in the pot barrel and furnace chamber, and then all the manholes and hand holes are closed to prevent moist air from entering the boiler. After that, check every half a month, and replace the invalid desiccant in time. Hope it helps.

I wonder how big your boiler is? What type of boiler? Please advise.

DLT 956-2005 "Guidelines for the Prevention of Corrosion of Thermal Power Equipment in Shutdown (Standby) of Thermal Power Plants".

Close the valve, butter the valve, and vacuum.

How often should a gas boiler be serviced during use? The following summarizes the precautions for maintenance and maintenance of gas boilers when they are in use. 1. Pay attention to the following points during the operation of the gas boiler:

1) The gas boiler is not allowed to burn under positive pressure or smoke from the furnace, because it is easy to burn out the coaling hole cover. (2) Do not accumulate water on the ground level at the bottom of the gas boiler to prevent moisture corrosion. 2. The gas boiler should be inspected every 2-3 weeks.

3. After every 3-6 months of operation, the gas boiler should be shut down for comprehensive inspection and maintenance. (1) Inspect the inside and outside of the gas boiler, such as the weld of the pressure part, whether there is corrosion inside and outside the steel plate, if it is found that the serious defect should be repaired in time, if the defect is not serious, it will be repaired when the furnace is stopped next time, if there is something suspicious, but it does not affect the safety of production, it should be recorded for future reference. (2) After the inspection is completed, the boiler primer can be applied on the water surface to prevent corrosion.

4. Gas boilers and boiler bases should be painted at least once a year. 5. The gas boiler should also be maintained under the condition that it is not used for a long time, and the maintenance method is as follows: there are two kinds of dry method and wet method, and the furnace should be stopped for more than one month, and the dry maintenance method should be adopted, and the wet maintenance method can be used for less than one month.