Mechanical Engineering Laboratory II - Boiler Horsepower and Capacity - PDF

 Mechanical Engineering Laboratory II ME 152 Report 1 : Physical Study of a Steam Generating Unit Engr. Arjay C. Alcantara Instructor 1 d d  Objectives At the end of this discus...

 Mechanical Engineering Laboratory II ME 152 Report 1 : Physical Study of a Steam Generating Unit Engr. Arjay C. Alcantara Instructor 1 d d  Objectives At the end of this discussion, we will be able to answer the following: 1. What is meant by boiler horsepower and boiler capacity? 2. Define and illustrate through drawings the different classifications of boilers as enumerated above. 3. What are the importance and uses of an industrial boiler? 4. What is an air vent, how important is it and how it is done? 5. What is purging? 6. Define the following: descaling, backfiring, water hammer. 7. What is a water softener? Give details on its operation and standards. 8. What are the dangers associated in boiler operation? 9. What is the difference between economizers and preheaters? 10. What is the difference between design pressure and operating pressure? d d What is Boiler Horsepower and Boiler Capacity? d d Boiler Horsepower (BHP)  The Power Output of the boiler to generate steam.  Boiler horsepower is the amount of energy required to produce 34.5 pounds (15.65 kg) of steam per hour at pressure 0 psig(0bar) and temperature 212oF (100oC).  1 BHP =33479 btu/hr about (9.811 KW or 8441.587kcal/hr.)  The common computation of 746 watts – 1Hp does not apply on the Boiler Horsepower. d d Example : The ME Lab Boiler has a rated steaming capacity of 345 lbs/hr with 100% efficiency. Compute for BHP../ BHP =. / BHP= 10 d d Boiler Capacity  The Maximum amount of steam a boiler can produce per hour.  Often called steam generating capacity. d d Example : The ME Lab Boiler has a heat input of 334790 btu/hr with 100% efficiency. Given the Boiler Horsepower BHP is 10 Compute for the boiler capacity. Given : Heat Input = since 1bhp = 33479 btu/hr = 10 x 334790 btu/hr Boiler Efficiency =100% Solution : ( ) Boiler Capacity = = = 345.03 lb/hr (. / ). d d Boiler Classification  Fire Tube Boiler and Water Tube Boiler  Internally Fired or Externally Fired  Vertical Boilers or Horizontal Boilers  Natural and forced circulation boilers.  High ,Medium and Low-pressure boilers.  Single Tube and Multi Tube boilers  Coal, Oil, Crude Gas fired boilers d d Boiler Classification Fire Tube Boiler  Internally Fired  Single Tube or Multi Tube Boiler  High (100 Tons /Hr), Medium(20 to 50 Tons / Hr), Low pressure boiler(less than 20 Tons / Hr). From ASME CODE  Natural or Forced Circulation Type.  Coal, Oil, Crude gas fired boiler d d Boiler Classification Water Tube Boiler  Externally Fired  Single Tube or Multi Tube Boiler  High (100 Tons /Hr), Medium(20 to 50 Tons / Hr), Low pressure boiler(less than 20 Tons / Hr). From ASME CODE  Natural or Forced Circulation Type.  Coal, Oil, Crude gas fired boiler d d Boiler Classification Vertical Boiler Horizontal Boiler The two can be a fire tube and water tube boiler d d Boiler Classification Natural Circulation Boiler Forced Circulation Boiler - Water and Steam circulate naturally in the - A pump is installed in the closed flow loop system. steam boiler without needing a mechanical The pump's pressure differential helps manage the pump. water flow rate. A pressure reduction device (orifice or equivalent) is also commonly employed as an extra control mechanism. d d Applications of Boilers  Power Plants : Steam turbines use boiler steam to generate power.  Food processing: The food processing business uses steam for cooking, sterilizing, and other food preparation operations.  Commercial heating: Commercial buildings such as offices, retail stores, restaurants, and hotels utilize these boilers for heating purposes due to their compact size, allowing for easy installation in mechanical rooms or on rooftops.  Industries like textiles, pharmaceuticals, and refineries rely on boilers to provide high-pressure steam for tasks like sterilization, distillation, and heat exchange.  The main purpose is to produce steam coming from boilers. d d Why do we need air vents on our boilers?  To ensure the system's safety and lifespan, all interior gas- fired boilers require an exhaust vent to remove dangerous combustion byproducts.  Air vents serve to control the pressure inside the boiler. Boilers run at high pressure, and air vents allow any trapped air or gas to be released, preventing improper pressure maintenance. This helps to avoid harmful circumstances like overpressure, which can result in equipment failure or even explosions.  The exhaust stack helps control the temperature of the gases leaving the boiler. If these gases aren’t vented effectively, it could affect the boiler’s heat exchange system, lowering overall efficiency or causing overheating d d What is purging?  To clear ( a container or space) of something unclean or unwanted. To clear out unburned fuel also in the burner.  Purging is a boiler operation which the process of removing the air from it. The water inside the boiler must run freely through the tubes.  What will you do to purge the boiler. What are the connections you need to open to remove the unwanted materials in the boiler? d d De Scaling  Process of removing hardly scale minerals inside the boiler causing the tubes also to be clogged. Backfiring  An Explosion of prematurely ignited fuel or unburned gases in internal combustion engine. Water Hammering  (Fluid Hammering) is the loud, often violent banging or knocking noises produced when steam or water suddenly changes direction or pressure within the boiler system. d d What is a water softener?  a device used to treat hard water by removing the minerals that cause hardness, primarily calcium (Ca²⁺) and magnesium (Mg²⁺) ions.  To remove materials that can cause scaling. What are the operations in water softener?  Waters enter to the water softener  Water will be softened  Regeneration Cycle : Rinsing , Brine Solution and Backwashing d d What is a water softener?  a device used to treat hard water by removing the minerals that cause hardness, primarily calcium (Ca²⁺) and magnesium (Mg²⁺) ions.  To remove materials that can cause scaling. What are the operations in water softener?  Waters enter to the water softener  Water will be softened  Regeneration Cycle : Rinsing , Brine Solution and Backwashing d d What are the dangers associated in boilers?  Serious accidents caused by low water and flarebacks.  Improper opening and closing of control valves or orifice of the boiler.  Operations of flame burner of the boiler. Too much fuel or unburned mixtures of fuel may cause explosion if ignited.  Operating the boiler to its not allowable design or working pressure.  Operating the boiler without maintenance. That may cause to serious injury.  Corroded Parts. May cause fire or burns in the working area if the boiler will explode. d d What is the difference between design pressure and an operating pressure?  Design pressure is the maximum pressure a pressurized boiler can be exposed to due to the availability of standard wall thickness materials.  Operating pressure refers to the wall strength of a pressurized cylinder such as pipeline or storage tank and how much pressure the walls may safety hold in normal operation. d d Get in Touch With Us Send us a message or visit us City of Batac, Ilocos Norte, Philippines (63) 77-600-0459 [email protected] Follow us for updates facebook.com/MMSUofficial www.mmsu.edu.ph