### Cameron Abney and Associates Blog Review Formulas and Conversion Charts

**Cameron Abney and Associates Blog Review Formulas and Conversion Charts**

**A. Boiler Formulas**

**Boiler Horse Power (HP):**

**BHP = (Lb/hr) * FE / 34.5**

**where Lb/hr is pounds of steam per hour and FE is the factor of evaporation.**

**Steam:**

**S=HP * 34.5 * t**

**where HP is boiler horsepower and t is time (h).**

**Cycle of Concentration of Boiler Water:**

**CYC=Bch / FCh**

**where Bch is ppm water chlorides and FCh is ppm feedwater chlorides.**

**Differential Setting (lb):**

**Delta S = P1 - P2**

**where P1 is the cutout pressure and P2 is the cut in pressure**

**Factor of Evaporation:**

**FE = SH + LH / 970.3**

**where SH is the sensible heat and LH is the latent heat.**

**Force (lb):**

**F=P / A**

**where P is pressure (psi) and A is area (in^2).**

**Horsepower (HP):**

**HP=(d * t) / (t * 33000)**

**where d is distance, F is force, and t is time.**

**Inches of Mercury (in):**

**InHG=P / 0.491**

**where P is pressure**

**Percent of Blowdown:**

**%BD=(PP - RP) / PP**

**where PR is popping pressure and RP is reseat pressure**

**Rate of Combustion (Btu/hr) RC=H / (Vf * t)**

**where H is heat released (BTU), Vf is volume of furnace (ft^3), and t is time (hr).**

**Return Condensate Percentage in Feedwater RC%=(MC – FC) / (MC – CC)**

**where MC is the makeup conductivity (μohms), FC is the feedwater conductivity (μohms), and CC is the condensate conductivity (μohms).**

**Static Head Pressure (lb)**

**SHP= Bpr * 2.31**

**where Bpr = boiler pressure (psi)**

**Temperature Conversions:**

**F to C**

**C = (F – 32) / 1.8**

**C to F**

**F = (1.8 * C) + 32**

**Total Force (lb)**

**TF = P*A**

**where P is pressure (psi) and A is the area of valve disc exposed to steam (sq. in.)**

**Water Column (in)**

**WC = P / 0.03061 where P is pressure (psi).**

**Flue gas analysis:**

** **

**Boiler flue gas analysis is used to determine**

** **

**combustion efficiency.**

** **

**Carbon Dioxide (CO2)**

** **

**Indicates complete combustion**

** **

**Carbon Monoxide (CO)**

** **

**Indicates incomplete combustion**

** **

**Oxygen (O2)**

** **

**Indicates the presence of excess air**

** **

**Oxides of Nitrogen (NOx)**

** **

**A product of high temperature combustion**

** **

**Combustibles**

** **

**Material that burns when exposed to oxygen and heat**

** **

**It is typical to target oxygen levels of 8% in low fire and 3% in high fire for gas fired burners.**

**It is typical to target oxygen levels of 6% in low fire and 4% in high fire for oil fired burners.**

**Johnston Boiler Company recommends no greater level than 200 ppm of Carbon Monoxide in its burner operation. The acceptable “Industry Standard” level is 400 ppm or less.**

**Johnston Boiler Company recommends zero combustibles for a gas fired burner.**

**Johnston Boiler Company recommends a maximum #2 Smokespot (Ringelmann Chart) in its oil fired burner.**

**For a burner originally adjusted to 15% air, changes in combustion air temperature and barometric pressure cause the following in excess air:**

** **

**Air Temperature**

** **

**Barometric Pressure (In. HG)**

** **

**Resulting Excess Air %***

** **

**40**

** **

**29**

** **

**25.5**

** **

**60**

** **

**29**

** **

**20.2**

** **

**80**

** **

**29**

** **

**15.0**

** **

**100**

** **

**29**

** **

**9.6**

** **

**120**

** **

**29**

** **

**1.1**

** **

**80**

** **

**27**

** **

**7.0**

** **

**80**

** **

**28**

** **

**11.0**

** **

**80**

** **

**29**

** **

**15.0**

** **

**80**

** **

**30**

** **

**19.0**

** **

**40**

** **

**31**

** **

**34.5**

** **

**60**

** **

**30**

** **

**25.0**

** **

**80**

** **

**29**

** **

**15.0**

** **

**100**

** **

**28**

** **

**5.0**

** **

**120**

** **

**27**

** **

**-5.5**

** **

*** Expressed as a percent of the Stoichiometric air required.**

**C. Energy Loss From Scale Deposits**

** **

**ENERGY LOSS**

** **

**FROM SCALE DEPOSITS IN BOILERS**

** **

**SCALE THICKNESS (INCHES)**

** **

**EXTRA FUEL COST (PERCENT)**

** **

**1/32**

** **

**8.50**

** **

**1/25**

** **

**9.30**

** **

**1/20**

** **

**11.10**

** **

**1/16**

** **

**12.40**

** **

**1/8**

** **

**25.00**

** **

**1/4**

** **

**40.00**

** **

**3/8**

** **

**55.00**

** **

**1/2**

** **

**70.00**

** **

**Related Articles:**

**http://www.boilerroomservices.com/**