INDUSTRIAL SAFETY – Boiler Safety Operation Standards
Boiler: A Steam Boiler
Boiler is a closed vessel where the combustion heat is flowed into water to form hot water or steam in the form of work energy. Water is a useful and inexpensive medium for transferring heat to a process. Hot water or steam at a certain pressure and temperature has an energy value which is then used to transfer heat in the form of heat energy to a process. If the water is boiled until it becomes cold, the volume will increase about 1600 times, producing power that resembles explosive gunpowder, so the boiler system is a device that must be managed and maintained very well.
Boiler Work Process
The heat energy generated in the boiler system has a value of pressure, temperature, and flow rate that determines the utilization of steam to be used. Based on these three things the boiler system recognizes the state of low pressure (low pressure / LP) , and high pressure (high pressure / HP) , with the difference that the utilization of steam coming out of the boiler system is utilized in a process to heat the liquid and run a machine (commercial and industrial boilers), or generate electrical energy by converting heat energy into mechanical energy then turning a generator to produce electrical energy (power boilers). However, there is also a combination of the two boiler systems, which utilize high-temperature pressure to generate electricity, then the remaining steam from the turbine with a low-pressure state can be utilized in industrial processes with the help of boiler heat recovery.
The boiler system consists of a feed water system, a steam system , and a fuel system. The feed water system provides water to the boiler automatically according to steam needs . Various taps are provided for maintenance and repair of feed water systems, feed water handling is needed as a form of maintenance to prevent damage to the steam system . The steam system collects and controls steam production in the boiler. Steam is flowed through the piping system to the user’s point. In the whole system, steam pressure regulated using a faucet and monitored with a pressure monitor. Fuel systems are all equipment used to provide fuel to produce the heat needed. The equipment required in the fuel system depends on the type of fuel used in the system.
Before explaining the diversity of boilers, it is necessary to know the components of the boiler that support the creation of steam , the following components of the boiler:
- Furnace
This component is a place for burning fuel. Some parts of the furnace include: refractory , fireplace room, burner , exhaust for flue gas , charge and discharge door .
- Steam Drum
This component is a hot water reservoir and steam generator . Steam is still saturated ( saturated steam ).
- Superheater
This component is a place for drying steam and is ready to be sent through the main steam pipe and ready to drive a steam turbine or run an industrial process.
- Air Heater
This component is a heating chamber that is used to heat the outside air that is absorbed to minimize the humid air that will enter the furnace.
- Economizer
This component is a heating chamber that is used to heat water from condensed water from the previous system and new feed water.
- Safety valve
This component is a steam exhaust in the event that the steam pressure exceeds the boiler’s ability to withstand steam pressure .
- Blowdown valve
This component is a channel that functions to remove deposits that are inside the steam pipe .
After knowing the short process, the boiler system, and the components forming the boiler system, it is necessary to know the diversity of the boiler. Various forms of boilers have evolved following technological advances and evaluations of previous boiler products that are affected by boiler exhaust gases that affect the environment and what kind of steam products will be produced. The following classification of boilers that have been developed:
Based on the pipe type:
- Fire Tube
Fire pipe boiler types have the following characteristics: produce low steam capacity and pressure .
How it works: the ignition process occurs in the pipe, then the heat generated is delivered directly into the boiler that contains water. The size and construction of the boiler affect the capacity and pressure generated by the boiler.
- Water Tube
The type of water pipe boiler has the following characteristics: high steam capacity and pressure .
How it works: the ignition process occurs outside the pipe, then the heat generated heats the pipe filled with water and before the water is conditioned first through an economizer, then the steam produced first is collected in a steam- drum. Until the pressure and temperature match, through the secondary superheater and the new primary superheater, steam is released into the main distribution pipe. In a water pipe, running water must be conditioned to minerals or other contents that are dissolved in the water. This is the main factor that must be considered for this type.
Table 1.1. Boiler advantages and disadvantages based on pipe type.
| No. | Boiler Type | The advantage | Loss |
| 1 | Fire Tube | The installation process is easy and fast, does not require special settings | Steam operating pressure is limited to 18 bar low pressure |
| The initial investment of this boiler is cheap | Steam capacity is relatively small (13.5 TPH) when compared to a water tube | ||
| The shape is more compact and portable | The kiln is difficult to reach for cleaning, repair and condition checking. | ||
| Does not require a large area for 1 HP boiler | The efficiency value is low, because a lot of heat energy is wasted directly into the stack | ||
| 2 | Water Tube | Large steam capacity up to 450 TPH | The construction process is more detailed |
| Operating pressure reaches 100 bar | Initial investment is relatively more expensive | ||
| The efficiency value is relatively higher than the fire tube boiler | The handling of water entering the boiler needs to be maintained, because it is more sensitive for this system, it needs supporting components for this | ||
| The furnace is easy to reach for inspection, cleaning and repair. | Being able to produce greater steam capacity and pressure , the construction requires a large area |
Based on the fuel used:
- Solid Fuel
Solid fuel boiler types have the characteristics: the price of combustion raw materials is relatively cheaper compared to boilers that use liquid and electric fuels. The efficiency value of this type is better when compared to electric type boilers.
How it works: heating that occurs due to combustion between mixing of solid fuels (coal, baggase, rejected products, municipal waste, wood) with oxygen and heat sources.
- Oil Fuel
The type of liquid fuel boiler has the following characteristics: the price of the most expensive combustion raw material compared to all types. The efficiency value of this type is better when compared with solid fuel and electricity boilers.
How it works: heating that occurs due to combustion between the mixing of liquid fuels (diesel, IDO, residues, kerosene) with oxygen and heat sources.
- Gaseous Fuel
The type of gas fuel boiler has the following characteristics: the price of the combustion raw material is the lowest compared to all types of boilers. The efficiency value of this type is better when compared to all types of boilers based on fuel.
How it works: combustion that occurs due to mixing of gas fuel (LNG) with oxygen and heat sources.
- Electric
This type of electric boiler has the characteristics: the price of heating raw materials is relatively cheaper compared to boilers that use liquid fuel. The efficiency value of this type is lowest when compared with all types of boilers based on fuel.
How it works: heating that occurs due to a source of electricity that supplies a source of heat.
Table 1.2. Boiler gains and losses based on fuel.
| No. | Boiler Type | The advantage | Loss |
| 1 | Solid Fuel | Raw materials are easy to get. | Residual combustion is difficult to clean |
| Cheap construction. | Difficult to get good raw materials. | ||
| 2 | Oil Fuel | Not much combustion left over and easier to clean. | The price of the most expensive raw materials. |
| The ingredients are easy to get. | Expensive construction. | ||
| 3 | Gaseous Fuel | The cheapest fuel prices. | Expensive construction. |
| The best value is its efficiency. | Difficult to obtain raw materials, there must be a distribution channel. | ||
| 4 | Electric | The easiest maintenance. | The worst value efficiency. |
| Easy construction and easy to get the source. | The lowest combustion temperature. |
Based on the use of the boiler:
- Power Boiler
This type of power boiler has characteristics: its main use is as a steam generator as a power plant, and the remaining steam is used to run industrial processes.
How it works: the steam produced by this boiler uses a type of water tube boiler, the resulting steam has a large pressure and capacity, so it is able to turn steam turbines and generate electricity from generators.
- Industrial Boiler
Industrial boiler types have characteristics: their main use is as a producer of steam or hot water for running industrial processes and as an additional heater.
How it works: steam produced by this boiler can use the type of water tube or fire tube boiler, the resulting steam has a large capacity and moderate pressure.
- Commercial Boiler
This type of commercial boiler has characteristics: its main use is as a producer of steam or hot water as a heater and in addition to running commercial operations.
How it works: steam produced by this boiler can use a type of water tube or fire tube boiler, the resulting steam has a large capacity and low pressure.
- Residential Boiler
This type of residential boiler has characteristics: its main use is as a producer of steam or low pressure hot water that is used for housing.
How it works: the steam produced by this boiler uses the type of fire tube boiler, the resulting steam has a low pressure and capacity
- Heat Recovery Boiler
The type of heat recovery boiler has the characteristics: its main use as a producer of steam from unused hot steam. The results of this steam are used to run industrial processes.
How it works: steam produced by this boiler uses a type of water tube boiler or fire tube boiler, the resulting steam has a large pressure and capacity.
Table 1.3. Boiler gains and losses based on utility.
| No. | Boiler Type | The advantage | Loss |
| 1 | Power Boiler | Can produce electricity and the remaining steam can run industrial processes. | Initial construction is relatively expensive. |
| Steam produced has a high pressure | Safety factors need to be considered. | ||
| 2 | Industrial Boiler | Easier boiler handling. | Steam produced has a low pressure. |
| Initial construction is relatively inexpensive. | |||
| 3 | Commercial Boiler | Easier boiler handling. | Steam produced has a low pressure. |
| Initial construction is relatively inexpensive. | |||
| 4 | Residential Boiler | Easier boiler handling. | Steam produced has a low pressure. |
| Initial construction is relatively inexpensive. | |||
| 5 | Heat Recovery Boiler | Easier boiler handling. | Steam produced has a low pressure. |
| Initial construction is relatively inexpensive. |
Based on boiler construction:
- Package Boiler
The type of boiler package has characteristics: boiler assembly is carried out at the manufacturing plant, direct delivery in the form of a boiler.
- Site Erected Boiler
The type of site erected boiler has the following characteristics: boiler assembly is carried out at the site where the boiler is to be built, deliveries are carried out per component.
Table 1.4. Boiler gains and losses based on construction.
| No. | Boiler Type | The advantage | Loss |
| 1 | Package Boiler | Easy shipping. | Limited pressure and work capacity. |
| It takes a short time to operate after sending. | Boiler components depend on the boiler manufacturer. | ||
| 2 | Site Erected Boiler | Work pressure and capacity can be adjusted according to desire. | Difficult to send, expensive cost. |
| Boiler components can be integrated with other manufacturers. | It takes quite a long time after the boiler stands, after the shipping process. |
Based on boiler working pressure:
- Low Pressure Boilers
Low pressure boiler type has characteristics: this type has an operating steam pressure of less than 15 psig or produces hot water with pressure below 160 psig or temperature below 250 0 F
- High Pressure Boilers
High pressure boiler type has characteristics: this type has an operating steam pressure above 15 psig or produces hot water with pressure above 160 psig or temperatures above 250 0 F
Table 1.5. Boiler gains and losses based on working pressure.
| No. | Boiler Type | The advantage | Loss |
| 1 | Low Pressure | Low pressure so that the handling is not too complicated | The resulting pressure is low, it cannot generate electricity. |
| The area required is not too large, and the construction cost is not more expensive than a high pressure boiler | |||
| 2 | High Pressure | The resulting pressure is high so that it can generate electricity and the rest can be recycled to operate industrial processes | High pressure so that the handling needs to be considered safety aspects. |
| The area required is large and the construction cost is more expensive than a low pressure boiler |
Based on how to burn fuel:
- Stoker Combustion
Stoker combustion type has the following characteristics: this type utilizes solid fuel to ignite, solid fuel is put into the combustion chamber via conveyor or manually. This type has combustion residue that must be handled in the form of bottom ash or fly ash which can pollute the environment.
- Pulverized Coal
How it works: this process destroys coal with a ball mill or roller mill so that coal has a size of less than 1 mm. then this powdered coal is sprayed into the combustion chamber.
- Fluidized Coal
How it works: this process destroys coal with a crusher, so that coal has a size of less than 2 mm. In this process combustion is carried out in a layer of sand, coal will immediately burn if it hits the sand.
- Firing Combustion
Firing type has characteristics: this type utilizes liquid, solid, and gas fuels to do combustion, heating which occurs more evenly.
How it works: liquid fuel used as preliminary firing fuel is put into the combustion chamber through an oil gun . After reaching the appropriate temperature, combustion is taken over by coal nozzle or gas nozzle .
Table 1.6. Boiler gains and losses based on combustion.
| No. | Boiler Type | The advantage | Loss |
| 1 | Stoker Combustion | The construction is relatively simple. | More waste is produced by combustion |
| The resulting heat is less even if there are no supporting components. | |||
| Relatively low efficiency | |||
| 2 | Pulverized | Relatively high efficiency | The construction is complicated and requires expensive investment funds. |
| The combustion process is more evenly distributed in the furnace. | |||
| 3 | Fluidized Bed | Relatively high efficiency | The construction is complicated and requires expensive investment funds. |
| The combustion temperature does not reach 1000 0 C so it does not cause NO X | |||
| 4 | Firing | Less waste produced by combustion | Construction is relatively complicated, it needs a nozzle. |
| The heat is produced more evenly | |||
| Relatively better efficiency |
Based on the boiler constituent material:
- Steel
The type of boiler made of steel has characteristics: the main raw material for boilers is made using steel in the steam area .
- Cast Iron
The type of boiler made from cast iron has the following characteristics: the main raw material of the boiler is made using cast iron in the steam area .
Table 1.7. Boiler gains and losses based on material.
| No. | Boiler Type | The advantage | Loss |
| 1 | Steel | Strong and durable. | Cost is relatively expensive. |
| Steam can be used for high pressure. | More complicated construction. | ||
| 2 | Cast Iron | The cost is relatively cheap. | Vulnerable and easily damaged. |
| Simpler construction. | Could be loaded with steam for a limited pressure. |
Boiler safety
600 MW PLTU boiler
Boiler Protection / Safety Function
Boiler safety is intended to maintain and avoid more serious interference with the boiler and its supporting tools, which results in a decrease in boiler capability, or damage to equipment.
The basis of boiler protection and its auxiliary equipment is that the safety device must be able to guarantee the continuity of the boiler’s steam production service.
Protection
A boiler needs safety to maintain the reliability of operation in a long period of time. This boiler safety system in general will describe the safety of the boiler from corrosion, overheating and thermal stress that is caused during the process of startup, normal operation and shutdown.
Boiler vent must be opened during the filling process so that air in the boiler tube can be removed, the aim is to reduce the possibility of corrosion due to oxidation of air trapped in the boiler tube other than air. It also can cause cavitation and water hammer. Before operating the boiler must be rinsed (purge) from the used gas that accumulates in the combustion chamber is important because the waste gas from the combustion that is not wasted will form a hot gas that can cause an explosion in the room at the boiler ignitor startup because during this period many combustible possibilities occur and explosive due to frequent ignitor ignition failures and unstable binding conditions.
Boiler areas that require special attention include:
Feedwater is not always added when raising the boiler pressure because the water in the boiler always circulates naturally. But without the presence of feedwater in the filling water will not flow to the economizer. Economizer is secured from the formation of feedwater evaporation in the tube, because the steam trapped inside can cause water hammer, thermal shock and can cause fluctuations in drum level control. To safeguard this problem there needs to be a continuous flow of circulation from the economizer inlet header to one of the downcomers. This valve must be opened when the boiler is experiencing interference with feedwater flow control, the aim is to avoid the evaporation process in the economizer tube due to the cessation of natural circulation. Economizer is subject to both internal and external corrosion. Internal corrosion can be prevented by maintaining PH feedwater between 8 and 9 by chemical injection. External corrosion can be caused by the occurrence of condensation between the low temperature of the feedwater and the high temperature of the combustion gases that pass through the economizer. Overcoming this problem by keeping the economizer in an area far from the dew point, this case must be avoided during the startup process and after the unit is loaded.
Furnace is a part that requires serious attention. Because it deals with the problem of vapor pressure and steam temperature and combustion chamber temperatures are very high. Factors of concern are:
–
Boiler operating pressure Boilers must not operate above their working pressure and never exceed their design pressure.
– Balance balance firing operation
This relates to the heat generated by combustion of the combustion chamber in the case of imbalance firing, which will cause disruption of the natural circulation process and interference with the tube due to overheating.
During normal operating conditions pressure on the drum and drum level and water quality must always be controlled. The surface of the steam drum is very high, so at startup and shutdown the temperature difference in this area must be considered, namely the difference between the top and bottom should be as small as possible in this case it is important to maintain the occurrence of thermal stress on the steam drum.
Limitations that must be considered include:
– When there is a change in the phases of water and steam in the steam drum.
– The difference between top and bottom does not exceed the maximum setpoint of 50 0C for startup and 100 0C for shutdown.
Superheater located in an area where heat transfer by convection induction attracts quite serious attention because it is related to the condition of the steam temperature and the safety temperature of the metal tube. overheating due to disrupted production and vapor flow while the combustion gas stream passing through the high induction convection area.
Superheater safety limits include:
– Main steam temperature must always be controlled
– Combustion conditions must be balanced firing / adjusted according to its formation
– Thermocouple superheater exit must be monitored
– Gas temperature superheater entry area must be limited during startup to normal operating unit conditions.
- Safety Valve
Before the boiler is declared ready for operation, the safety valve must be checked and if necessary reset in accordance with the working area. This procedure is very important considering that after the boiler firing will produce pressure. This vapor pressure can determine that the safety valve serves as a safety against the occurrence of excess vapor pressure produced by the boiler.
- Relief Valve
Relief valve can be classified as a safety as well as a safety valve, but this relief valve serves as a limiting or maximum pressure safety in the liquid work area. The use of relief valve is placed in the following areas:
– Header reheat / HP bypass spray water
– Header auxiliary steam spray
– Ignitor oil level header
– Heavy fuel oil level header
- Pneumatic Valve
The pneumatic valve as well as the safety valve serves as a safety for over steam pressure on the boiler only equipped with a pressure sensor which is conveyed through an electronic signal to the electro mechanical to open the pilot valve.
- Safety Boiler Drum Level
Serves to control the level of water level on the boiler drum as a safety for the occurrence of “high level drum boiler trip” and “low level drum boiler boiler”.
The reason for securing a “high level drum trip boiler” is to secure the boiler drum from carrying over in the drum which will result in deposits in the superheater area and turbine blade. Deposits will inhibit the heat transfer of the superheater which results in overheating of the superheater tube and the turbine blade will cause unbalance and vibration of the turbine.
While the condition of “low level drum trip boiler” can cause disruption of natural circulation which will result in overheating in the steam drum and steam production is inhibited.
- Safety of the Boiler Furnace
Serves to control the pressure of the combustion chamber / boiler as a safety for the occurrence of:
– Furnace pressure & gt; max
– Furnace draft & gt; max
In connection with the type of boiler with a balance draft design where the design pressure allowed is -10mmWg, this is to ensure the stability of the combustion process. Transportation of coal fuel to the combustion chamber and the process of removing coal ash from inside the combustion chamber to a dust catcher etc. If the security limits are exceeded and distorted, the above process will be disrupted.Things that must be maintained to avoid the above conditions are by:
1) Check the water seal through level on the bottom hopper boiler must be in a position above the normal level. Check LCV and bypass valve water supply.
2) Check the boiler manhole condition before the boiler startup must be in a closed condition including desorvation door.
3) The water level at the SDCC boiler bottom is normal.
- Main Steam Temperature Boiler Safety
Its function is to control the high temperature of the main steam coming out of the second level superheater as a safety for the main steam temperature to exceed the allowable design limit.
This security is intended to avoid the occurrence of thermal stress in a first level turbine due to the temperature difference that is too high between the temperature of the main vapor entering with the metal temperature at the turbine blade. In addition to avoiding material fatigue in superheater tubes due to steam temperatures that exceed the maximum capacity of superheater tubes.
- Safety of Total Air Flow
Serves to secure the total amount of air entering the windbox / combustion chamber during the boiler purification process. At the time of boiler startup and normal operation must meet the total flow amount greater than the minimum (& gt; 30% when the boiler purge).
At the time of flushing the boiler we expect all the combustion gases that have accumulated in the combustion chamber and exhaust gases to be pushed / released by air in the amount of & gt; 30% or about 600 tons / hour to be discharged into the outside air at least gases remaining clean combustion within 3 minutes (design) then safeguarding at startup and normal operation Toral air plays a role as combustion air so that when the total combustion air is at least 30% then the amount of ratio between air and fuel will not we are absolutely certain that we are worried about repeated ignition failures and one of the causes of combusable in flue gas.
- Safeguarding the Air Pressure Header Instrument
Instrument air is a major requirement in the pneumatic power control system. The instrument air supply must be properly maintained and very special considering that the source of power for all turbine boiler controls and its assistants lies in the continuous reliability of the instrument air supply and its working pressure.
Considering the virtue and function of the instrument air as a source of power for all turbine boiler controls and assist equipment, if air pressure drops below its working point, this will cause all pneumatic control functions to cease and will cripple the operation of the boiler and turbine.
Anticipate when an instrument low pressure alarm occurs, including:
– Immediately open the SAC backup valve to the instrument air header.
– Immediately check the condition of the instrument air compressor and its supply process.
– Localize the possibility of instrument air leakage on all lines.
– Localize the possibility of an open air drain / vent valve.
- Security Pressure Cool Scanner
Its function is to secure the cooling system on the flame sensor scanner. The importance of flame detection in a boiler to ensure the existence of combustion, so that there will be no buildup of fuel due to failure of ignition. The flame detector is secured from the heat of the combustion chamber by providing cooling in the form of pressurized air seals on the entire surface of the fire detector.
The disruption of this cooling system will result in a melting point on the flame detector because there is direct contact between the device and the heat of the fire detected in the damage. The fire detector / scanner will signal the burners that are operating for the trip so that the boiler will trip.
If a low pressure alarm blower discharge flame scanner occurs, do the following:
– Check the standby auto start scanner’s blower select in the auto position.
– Check the air filter / filter blower inlet may be dirty.
– Check for possible leaks in the joint line.
- Drum Level
High Alarm : 50 mm ; Low Alarm : -50 mm
High Trip : 250 mm ; Low Trip : -250 mm
2. Temperature Main Steam & Reheat Steam
High Alarm : 550 oC ; High Trip : 570 oC (delay 60 second)
560 oC (delay 600 second) ; 550 oC (delay 6000 second)
3. Furnace Pressure
High Alarm : 50 mmWg ; Low Alarm : -50 mmWg
Furnace Draft High Trip : 225 mmWg ; Furnace Pressure Low : -225 mmWg
4. Boiler Safety Valve Main Drum
RV 39 : 3011 psi , RV 40 : 2975 psi , RV 41 : 3047 psi, RV 42 : 3064 psi , RV 43 : 2993 psi , RV 44 : 3029 psi
Secondary Superheater Outlet Header / Main Steam ; SV 13 : 195 kg/cm2, SV 14 : 196 kg/cm2, SV 15 : 197 kg/cm2
Reheat Outlet Header / Hot Reheat ; SV 92 : 57 kg/cm2, SV 102 : 57 kg/cm2 (SV=safety valve)
water that enters the boiler is always conditioned (mineral free water) so that it does not damage the material / pipes of the boiler iron, so the quality is always controlled, and each time a water sample is taken and injected with chemicals where the pH, conductivity, chlorine, phosphate, silica maintained within the allowable value. and if there is poor quality, it must be removed (blow down) and replaced with new water (make up).
Salt water quality : & lt; 20 usings; PH: 9.2 – 9.5 / Silica: & lt 0.0185 ppm / PO4: 0.3 – 3 ppm / Cl-: & lt; 0.5 ppm
so that the boiler works economically and efficiently in addition to the type of coal used, the combustion process is optimized to achieve perfect combustion. which boiler operator plays an important role to control, including the composition of fuel and combustion air, oxygen analyzer, chimney, sootblowing, etc. are always monitored.
auxiliary equipment on the boiler installed more than one (a pair or more), aiming that if one of these aids occurs interference then it will not be to stop the boiler but the stand-by will be the way to back it up. so that steam production remains available even if not with maximum generator loading.
The following picture is one type of boiler
The cause
- · Over Heating
- · Material grade
- · Gas Temperature
- · Internal Scale
- · Minimum Thickness (Minimum Thickness)
- · Fly Ash Erosion
- · Blowing Steam Erosion
- · Manufacture defact (manufacturer’s defects)
Impact: Lost of opportunity for production 3 – 5 days
The cause
Varies greatly
Impact
- Heat transfer is interrupted
- Boiler Efficiency
- Threatening Lost of opportunity for production 5 – 10 days.
Mill Explosion
The cause
- Explosive Mixture ( PA and PF)
- Uncomplete inertia
- Internal wear
| Operating Risks | Cause | Effect | Prevention |
| Oil Blast | |||
| High fuel temperature | Incorrect thermostat settings, Steam control valve is not biased open. Automatic electric controller can not be controlled.
Explosion |
Oil Gasification (phase change in oil)
Unstable flame, Explosions that cause damage to property and loss of life |
Periodically check the heater and the control instrument
Follow Manufacturing Instructions |
| Gas explosion | |||
| Repair of gas lines | Damage to the pipe or valve | Explosion.
Fire. Loss of life and property damage |
Use the right method for purging and refilling in gas lines. Follow NFPA 54 |
| Wet gas (wet gas) | Distillate in gas | Fire extinguishes and sparks suddenly.
Explosion Fire Loss of life or injury Damage to the boiler and property |
Follow NFPA 54 for the Wet Gas supply system |
| Drastic changes in the value of BTU gas | The difference between the gas source and the difference in heating value | Incomplete combustion (bad)
Explosion Boiler Damage Loss of life or injury |
Suitable alarm
Use a responsive combustion controller with BTU changes |
| Too high pressure | Malfunction of the gas regulator | Rich mixture of fuel
Explosion Boiler Damage |
Good supervision of the operation of the regulator
Periodically check the operation and pressure replacement settings Replace and repair the regulator |
| Steam leak | |||
| Steam leak | Damage or corrosion to pipes or other parts | Burns | Make sure all connections and pipes are strong
Make sure all personnel are aware of and aware of the dangers of superheated steam leakage |
| Steam explosion | |||
| Malfunction of the safety valve | Interference (barrier) between the boiler and valve
The valve is damaged or corrosion Interference with valve outlet |
When the pressure rises, the valve will not open so there is accumulation of pressure on the boiler
Break down the boiler Loss of life and property damage |
Repair or replace safety valves
Remove barriers Periodically test everything with ASME standards |
| Low water level | Low water preventative / low water preventive malfunction
Error operator The malfunctioning of the monitoring instrument |
The boiler surface overheats
The boiler broke Loss of life |
Make sure the operation of the water supply system to the boiler works well periodically in check
Properly train boiler operators Change the water level controller |
| Blast Furnace | |||
| The late inauguration | Inadequate lighter
Low fuel pressure Excessive air flow Low fuel temperature Water in fuel |
Side explosion
Fire Damage to the boiler |
Give adequate lighters
Improve the ratio of fuel to air Review instructions from the manufacturer |
| Fire | |||
| Fire | Explosion
Electrical or mechanical failure Error in operation of the tool |
Potential to injure or kill personnel
Damaging the tool |
Operate the device according to the method used by the manufacturer
Train operators to maintain good tools (goodhousekeeping) Train personnel to put out fires in an emergency |
Some things that must be considered
- Follow the instructions given by the manufacturer. Use the Operating standards that have been created and reference some jobs to the ASME standard
- Training – Workers must truly be given training in compliance in operating the equipment. Safety training should be a continuous process that aims to educate workers to recognize and maintain safety in their minds. The training program must be carried out continuously and supervised
- Cleanliness – environmental hygiene is very important for the safety and good conduct of operations in the factory. Low hygiene increases the risk of accidents
- Clothing and safety equipment – appropriate clothing must be worn at all times. Avoid exposed clothing and jewelry. Safety equipment must be worn for as long as necessary (for example: work caps, masks, earplugs, goggles, gloves, work shoes.) Never operate large equipment such as rotating equipment, automatic machinery, electrical machinery unless there is a safety device.
- Hot surfaces – a lot of hot surfaces are found in the boiler and even non-heating surfaces can be uncomfortable due to heat. Therefore, new workers must be made aware of this. Be careful when working, especially if you are in close proximity to the boiler. Never enter the boiler except until the specified stage.
- Monitor the remote controller – in factories many units use the remote controller. Note whether there are workers in the unit that will start up before the unit is properly turned on
- Noises occur in the factory and accumulatively cause illnesses for workers. Always use safety equipment, for example ear plugs
Engineering control
- Check the isolation of the boiler surface area and the pipe
- Automatic shutdown deviceschecking
- Check the fuel and air controller
- Check valves
- Check the water level controller
Administrative Control
- Tool operator training
- Review the tool control procedure
- Review of Operating Procedures
- Field Inspection
- Audit
- Check the boiler water content
External inspection is carried out by a certified boiler supervisor. The sections that find supervision include:
- Leakage
- Instrument indicator
- Safety instruments
- System controller
- Valve
- Cleanliness
- Label
- Piping
External inspection is carried out by a certified boiler supervisor. The sections that find supervision include:
Combustion Inspection Parts:
- Door gaskets
- Fire side insulation
- Tube sheet
- Tubes
- Blowers
- Stack
Water Parts Inspection:
- Tube bundle
- Scale buildup
- Condensate feed water tanks
- Chemistry control systems
- Level floats
Here are some tests that must be done regularly on the parts of the boiler
- Safety / Relief Valve Operational Test(monthly)
- Check System for Leaks (weekly)
- Low Water Fuel Cutoff (LWFCO) Rapid Drain Test (weekly and every start up)
- Burner Check (monthly)
- Water Chemistry Check (monthly)
- LWFCO Slow Drain Test (4 times a year)
- Circ and / or Condensate Pump Check (4 times a year)
- Safety Valve Setpoint Test (routine)
- Drain Water Gage Glass (as needed)