Steam Boiler repair and maintenance:
In the boiler maintenance, the daily report of the high-pressure boiler enables information recording and review of control and safety devices.
Steam boiler test
Testing for better steam boiler maintenance:
Column and water-view glass – open their drain valve quickly so that the water inside the glass and column comes out.
When closing the mentioned valve, the water level should immediately return to its original place.
Fuel cutoff control when water is low and water level control – empty the floating container when the burner is working.
If the control works in the set, the fuel supply to the burner must be cut off and the feeding pump must work.
If the controls are of the type equipped with a probe, to test them, the water level inside the steam boiler must be lowered, never bring the water level to levels lower than the bottom of the water-viewing glass.
Regulation of steam boiler
steam Boiler adjustment for better boiler maintenance:
Regulating the steam boiler is one of the effective ways to increase efficiency and keep it high.
The first goal of regulating the boiler is to achieve optimal combustion with controlled excess air, reduce losses from dry combustion gases, and also reduce the power consumption of blowing and suction fans.
A daily report in which every boiler operator records the hourly readings and observations related to unusual events. It is valuable. The value of this daily report is increased by recording notes on readings and observations obtained from distant parts of the steam generating unit, which are seldom visited during normal operation.
A competent operator, while passing by the devices for reading, should never be inattentive to their condition.
The central reservoir of information, whose task is daily studies and recording of these reports, depends on the size of the steam unit.
In any case, the received reports should be carefully reviewed every day and then filed regularly for future references.
In order to check the efficiency and performance of the device in boiler maintenance, important readings, such as fuel consumption, evaporation rate and combustion gas temperatures, should be recorded in a curve.
A curve that shows the daily, weekly and monthly changes of these results should be installed in a place where all the people responsible for operation can see it, if a certain reduction in a device is out of sight during the inspection of the boiler; This drop is determined by the aforementioned action, which indicates gradual changes in the system’s performance.
It alone has a daily report to record the figures related to the operation and performance of control and safety devices.
Conducting the minimum tests and inspections shown in the table will help the boiler operator in determining whether the boiler and controls are in good working condition. The tests should be performed at certain intervals and in case of any The problem should be corrected immediately.
A boiler with a defective safety valve, incorrect water level control, or a broken fuel cut-off switch should be used before repairing or modifying such devices.
Lack of water, especially in automatic boilers, causes the boiler to shut down.
In order to prevent accidents caused by lack of water, the following three main areas should be checked and tested periodically.
1- Feed water system: This system should have the ability to maintain the water level of the boiler at the usual level.
2- Safety controls during low water: when the water level in the boiler drops below the set limit, these controls must work.
3- Fuel cut off triggers: these devices must be able to cut off the fuel flow when receiving a signal from the sensors related to low water condition.
Floating control tests
Periodic tests of floating controls in boiler maintenance are necessary to ensure their free movement in boiler maintenance.
In the case of power boilers that work continuously, this should be done in every work shift, for heating boilers, once a week is enough.
Note that the response of float controls often slows down when sediment has accumulated in the float bowl.
Avoid this problem by draining the water in the floating chamber daily.
Meanwhile, once a year, run the whole system and manually clean the deposits from the working mechanisms.
Another point is that after testing the floating controls, empty the fountain column and clean it completely during the annual inspection.
Electrode probe type controls require periodic review of the following points:
Inspect the insulators at the entry points of the electrodes into the shell or the fountain column, to ensure that they are not cracked or not connected to the shell due to the accumulation of dirt and moisture on them, for the maintenance of the boiler.
This issue can cause electric current to flow from the electrode to the shell and destroy the sensitivity of the electrode.
Follow up on the repair of broken electrical connections related to the electrodes, as well as the repair of contacted wiring or the body of the boiler and steam boiler.
These conditions can also limit the sensitivity of the detector.
Replacement of electrodes
When replacing the electrodes, make sure that the new electrodes have a suitable length. Otherwise, the installed electrode may sense a point lower than the safe water level.
In case the decomposing electrodes are installed inside the water feature column, minimize the sediments, silt, and settling materials inside this column to prevent the formation of an electric circuit that will cause a misleading reaction.
Daily report papers
The daily report sheets are a useful reminder to prevent future problems, and also a guide to the proper use of the boiler.
In the daily report, all the working information of the boiler, such as pressures and temperatures, as well as points that should be paid attention to.
Such as the working time of the soot cleaners and the emptying of the water column, as well as the working time of the drain valves, should be recorded.
With this method, a continuous history of work information and also important work done will be available if needed.
Also, when testing safety devices, it is important to enter the work done in the report.
Any unexpected accident or irregularity in the operation of the boiler should be recorded in a separate book and a description of the accident and the actions taken to correct it should be written in it.
Read the previous hours. By this means, they will be informed about what has happened before and how the orders have been issued for the next activities, as well as the points with problems.
Then they should fully study the matters for which they are responsible and become fully familiar with them.
Some insurance companies prepare daily reports for small low-pressure units and high-pressure industrial plants.
Most of the units themselves plan daily report sheets to record important information related to the special details of the units.
Cleanliness in boiler facilities
Cleanliness in steam boiler facilities for maintenance and repair of steam boiler is possible to a certain extent and it is not possible to do more than that. However, in a dirty unit, the increase in operating, repair and maintenance costs, accidents and lost time due to boiler failure is predictable.
But if all logical steps are not taken to prevent the unit from getting dirty, boiler operation staff cannot be expected to observe cleanliness.
If after cleaning the boiler, dust and soot leaks from the external seams of the boiler and makes the environment dirty again, don’t be discouraged from cleaning it again.
Too much delay in repairs
Training of operating staff
The training of the operating staff is necessary in terms of dealing with unexpected events for steam production facilities and for better boiler maintenance.
In a small unit, individual training can be enough, but in larger units, for special cases, for example firefighter training, the operating staff should be trained in special centers for any emergency situation.
In relation to the emergency situation of the boiler, whether it is lack of water, failure in the auxiliary devices, or a defect in the interface system between the controls, or a rupture in the pressure system, each worker must have a specific position and a specific task.
Each person should understand the reasons for doing these tasks and how to do them quickly without any confusion and rework within the scope of his responsibility.
Some alarm systems are very valuable for warning of emergency situations.
But there is no danger notification system that can replace the instinctive prediction of most emergency situations by a knowledgeable and educated engineer.
Anticipating emergency situations
Emergency situations caused by water spilling from boilers and steam boilers.
Usually, it requires the reconstruction and repair of steam production unit devices, after selling the water level
Before the overflowed boiler is used again, the following provisions for the maintenance of the boiler should be implemented:
1- Safety valves:
Clean, lubricate, inspect and test the valves. Inspect the drain pipe for blockage with mud.
2- Fuel cut off keys when water is low:
Clean them and rewire if necessary. Replace mercury keys and fuses if necessary.
Then inspect and test them.
3- Limit controls:
Clean them, inspect them, and then test them. If necessary, replace them.
4- Flame protection devices:
Clean, inspect and then test them and replace them if necessary.
5- Electric motors, transformers, relays and wiring:
Electric motors must be cleaned and tested before starting.
Pipes containing wires, wiring harnesses and relays should be inspected by an experienced electrician.
Damaged components should be replaced. Failure to use safe methods in the use of electrical facilities can lead to fatal electric shocks or electrical damages such as burns and fires.
6- Refractory materials, bricks and insulation works:
After inspection and repair, all items must be before
Ignite the boiler
Dry as much as possible.
The initial firing should be slow and in short intervals, so as to gradually escape the moisture from the non-combustible materials used in the boiler, it puts pressure on it.
7- Internal inspection:
Boilers should be inspected from the inside, and any accumulation of mud and sludge should be emptied.
As soon as the steam boiler starts working, the following should be done.
Testing of flame protection devices, fuel cut-off switches when water is low, safety valves and limit controls.
After the boiler is put into operation, start preparing a daily report of it. Continuously monitor the operation of safety devices and controls.
In order to clean any leaks, inspect the dirty windshield, drain connections contaminated with mud, and similar contaminations caused by water overflowing from the boiler.
The forced withdrawal of the steam boiler from operation should normally be considered as a possibility.
Most of the units do not have an auxiliary boiler when the biggest boiler has an unexpected failure.
In emergency planning, a sufficient stock of spare parts, such as pipes, caps, sealing washers and similar parts that will help speed up repairs, should be considered.
In general repairs of a essential unit, it may be necessary to rent a boiler and steam boiler during the repair of the damaged unit.
If the engineers of these units plan the installation of water, steam, and fuel pipes for a rental boiler in advance, so that the rental unit can be quickly connected to the factory’s steam system, a lot of time can be saved. did
Study programs about steam boiler repair and maintenance should be expanded. The size of the steam production unit and the available facilities determine the best work method.
In large units, this may include periodic classes for operating personnel under the supervision of a capable manager.
In small units, this topic can be reduced to study at home for interested people.
Taking advantage of educational works
There are many institutions with a staff of power and operation engineers.
which has representatives in big cities and their goals are only training in boiler repair and maintenance.
It is highly recommended to take advantage of the educational and social work of such groups for better boiler maintenance.
Every year, the management should review the existing training programs for the employees of the steam production unit in order to be able to choose the program that is the best in relation to the desired goal.
Most of the engineers of the steam production unit or power plant specialists often experience similar events in their training as unusual events of the steam production unit; They create
This procedure is the best method of preparation against any possible incidents.
In case of an unexpected accident, an emergency boiler can be rented for the steam production unit to continue production.
An effective way to familiarize yourself with a new unit is to trace each of the important plumbing systems, and prepare a map of all valves and related equipment.
This should also be done for electrical systems.
Every boiler operator must be familiar with the relevant units. so that he can immediately go to the sensitive valves and controls when an emergency occurs.
All new operators must track and map each of the systems.
A file of all information related to machines, precision instruments and control systems, and devices in the steam production unit should be kept for study and review.
Also, a filing system should be prepared to keep the map of important devices. so that they can be accessed quickly if necessary.
Prepare a stock of sensitive spare parts so that they are always available
This warehouse includes pipes, parts and devices. which, if not present, will cause the steam boiler to fail.