1146.1

- 1 (Adopted October 5, 1990)(Amended July 10, 1992)(Amended May 13, 1994) ( September 5 , 200 8 )

RULE 1146.1 EMISSIONS OF OXIDES OF NITROGEN FROM SMALL

INDUSTRIAL, INSTITUTIONAL, AND COMMERCIAL BOILERS, STEAM GENERATORS, AND PROCESS HEATERS

(a) Applicability This rule applies to boilers, steam generators, and process heaters that are greater than 2 million Btu per hour and less than 5 million Btu per hour rated heat input capacity used in any industrial, institutional, or commercial operation.

( b ) Definition s ( 1 ) ANNUAL HEAT INPUT means the actual amount of heat released by fuels burned in a unit during a calendar year, based on the fuel's higher heating value. ( 2 ) ATMOSPHERIC UNIT means any natural gas fired unit with a non

- sealed
combustion chamber in wh ich natural draft is used to exhaust combustion

gases

. ( 3 ) BOILER OR STEAM GENERATOR means any combustion equipment fired with liquid and/or gaseous (including landfill and digester gas) and/or solid fossil fuel, used to produce steam or to heat water, and that is not used exclusively to produce electricity for sale. Boiler or Steam Generator does not include any waste heat recovery boiler that is used to recover sensible heat from the exhaust of a combustion turbine or any unfired waste heat recovery b oiler that is used to recover sensible heat from the exhaust of any combustion equipment. ( 4 ) BTU means British thermal unit or units. ( 5 ) HEALTH FACILITY has the same meaning as defined in Section 1250 of the California Health and Safety Code

. ( 6 ) NOx EMISSIONS means the sum of nitric oxide and nitrogen dioxide in the flue gas, collectively expressed as nitrogen dioxide. ( 7 ) PROCESS HEATER means any combustion equipment fired with liquid and/or gaseous (including landfill and digester gas) a nd/or solid fossil fuel and which transfers heat from combustion gases to water or process streams. Process Heater does not include any kiln or oven used for drying, Deleted: a

Formatted: Pattern: Clear

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Deleted: 2

Formatted: Underline

Deleted: 3

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Deleted: 4

Deleted: 5

Formatted: UnderlineProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 2 curing, baking, cooking, calcining, or vitrifying; or any unfired waste heat recovery hea ter that is used to recover sensible heat from the exhaust of any combustion equipment. ( 8 ) RATED HEAT INPUT CAPACITY means the heat input capacity specified on the nameplate of the combustion unit. If the combustion unit
has been altered or modified s uch that its maximum heat input is different than the heat input capacity specified on the nameplate, the new maximum heat input shall be considered as the rated heat input capacity. ( 9 ) SCHOOL means any public or private school, including juvenile detent ion facilities with classrooms, used for purposes of the education of more than 12 children at the school, including in kindergarten and grades 1 to 12, inclusive, but does not include any private school in which education is primarily conducted in private homes. The term includes any building or structure, playground, athletic field, or other area of school property, but does not include unimproved school property

. ( 10 ) THERM means 100,000 Btu. (1 1 ) THERMAL FLUID HEATER means a PROCESS HEATER in which a process is heated indirectly by a heated fluid other than water. ( 1 2 ) UNIT means any boiler, steam generator, or process heater as defined in paragraph ( b )( 3 ) or ( b )( 7 ).

(c) Requirements (1) On or after September 5, 2008

, t he owner or operat or of any unit subject to subdivision ( a ) shall operate such unit so that it discharges into the atmosphere no more than 30 ppm of NOx emissions or for natural gas
fired units 0.037 pound NOx per million Btu of heat input, as specified in the permit to op erate

.
(2) An owner or opera tor of any unit subject to subdivision (a) must select to comply with one of the following NOx emission limits specified in Table 1146.1

- 1 and apply for a permit to construct to operate such unit in compliance with the selected
emission limit and the corre sponding permit application and full compliance dates. Table
1146.1

- 1 Deleted: 6

Deleted: 7

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Formatted: Indent: Left: 0", Hanging: 1", Tab stops: 0.5", Right + 0.7", Right + 1", Left

Deleted: 8

Deleted: a
Deleted: 2

Deleted: a
Deleted: 5

Deleted: (b)

Deleted: Applicability ¶

Deleted: This rule applies to boilers, steam generators, and
proce ss heaters that are greater than 2 million Btu per hour and less than 5 million Btu per hour rated heat input capacity used in any industrial, institutional, or commercial operation. ¶

Deleted: T

Deleted: b

Deleted: and no more than 400 ppm of carbon monoxide. For each unit, a selection must be indicated in the application for permit to construct and operate between the ppm NO x or pounds of NO x per million BTU heat input compliance option

Deleted: ¶Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 3 ( 3 ) For dual fuel co

- fired combustion units a weighted average limit calculated by Equation 1146 .1

- 1 may be used provided a totalizing fuel flow meter is installed pursuant to paragraph (c)( 7 ), for units burning a
combination of both fuels.

Weighted Limit =

______________________ Equation 1146 .1

- 1
Q A + Q B

Where:
CL A = compliance limit for fuel A

CL B = compliance limit for fuel B Q A = heat input from fuel A Q B = heat input from fuel B ( 4 ) The owner or operator of any unit(s) with a heat input capacity greater than or equal to 2 million Btu per hour shall not discharge into the atmosphere carbon monoxide (CO) emissions in excess of 400 ppm or for natural gas
fired units 0.30 lbs/10 6 Btu

. ( 5 ) In lieu of complying with the applicable emission limits specified in paragraph (c)(1) or (c)(2) any unit(s) subject to subdivision ( a ) in operation prior to September 5, 2008 , and with an annual heat input of less than or equal to 18,000 therms per calendar year, shall: Category Limit Submit Application for Permit to Construct on or before Unit Shall be in Full

Compliance on or before Any Units Fired on Landfill Gas 25 ppm January 1, 2014 January 1, 2015 Any Units Fired on Digester Gas 15 ppm January 1, 2014 January 1, 2015 Atmospheric Units 12 ppm or 0.015 lbs/10 6 Btu January 1, 2013 January 1, 2014

Any Units Fired on Natural Gas, Excluding Units Located at Schools and Universities

, Atmospher ic U nits

, and Thermal Fluid Heaters 9 ppm or January 1, 2011 January 1, 2012

Any Units Fired on Natural Gas Located at Schools and Universities

, Excluding Atmospheric Units, and Thermal Fluid Heaters 0.011 lbs/10 6 Btu January 1, 2013 January 1, 2014

(CL A x Q A ) + (CL B x Q B ) Formatted: Indent: Hanging: 0.44", Space Before: 6 pt, No widow/orphan control, Keep with next

Deleted:

Formatted: Tab stops: 0.85", Left

Formatted: Pattern: Clear

Deleted: 2

Deleted: Any

Deleted: b Formatted: Italian (Italy)Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 4 (A) be operated in a manner that maintains stack

- gas oxygen concentrations at less than or equal to 3 percent on a dry basis for any 15

- consecutive

- minute averaging period; or (B) be tuned at least twice per year, (at intervals from four to eight months apart) in accor dance with the procedure described in Attachment 1 or the unit manufacturer's specified tuneup procedure. If a different tuneup procedure from that described in attachment 1 is used then a copy of this procedure shall be kept on
site. The operator of any unit(s) selecting the tune

- up option shall maintain records for a rolling of twenty four month period verifying that the required tune

- ups have been performed. If the unit does not operate throughout a continuous six

- month period
within 12 month pe riod , only one tuneup is required for the twelve month period that includes the entire period of non

- operation

. For this case, the tune

- up shall be conducted within 30 days of start

- up. No tune

- up is required during a rolling twelve month period for any unit that is n ot operated during that rolling twelve month period ; this unit may be test fired to verify availability of the unit for its intended use but once test firing is completed it shall be shutdown. Records of test firings shall be maintained for a rolling twenty four month period , and shall be made accessible upon request from an authorized District representative upon request

.

( 6 ) An owner or operator that has installed or modified a natural gas fired unit prior to September 5, 2008 complying with the applicable BACT emission limit of 12 ppm or less of NOx may defer compliance with parag raph (c)(2) until the unit’s burner(s) replacement. ( 7 ) Any owner or operator who chooses the pound per million Btu of heat input compliance option in paragraph (c)(1)

, (c) (2), or (c)(4) for natural gas fired units or chooses the weighted average emission limit using Equation 1146. 1

- 1 under paragraph (c )( 3 ) shall install a non

- resettable, totalizing fuel meter for each fuel used on an individual unit basis, as approved by the Executive Officer. ( 8 ) On or after January 1, 2015, an owner operator of any land fill or digester

gas (biogas) unit co

- fired with natural gas shall not operate the unit in a Deleted: 4

Deleted: 8

Deleted: twelve

Deleted:

Deleted: a calendar year

Deleted: that calendar year

Deleted: thirty (

Deleted: )

Deleted: The ow

. er or operator of any unit(s) who chooses to comply with subparagraph (c)(2)(B) shall maintain a record for a period of two years verifying that the tuneup has been performed.

Deleted: calendar year

Deleted: calendar year

Deleted: of two years

Deleted: ; or

¶

Deleted: (C)

Deleted: meet the emission limits specified in paragraph (c)(1)

Deleted: (3)

Deleted: The owner or operator of any unit(s) subj ect to paragraph (c)(2) shall submit and have approved by the Executive Officer, a compliance plan that demonstrates compliance with paragraph (c)(2). Such plan shall contain: ¶

Deleted: (A)

Deleted: A list of permits of all units with the rated heat input capacity, anticip ated annual heat input; and ¶

Deleted: (B)

Deleted: For each unit listed, a selection of one of the three options specified in paragraph (c)(2) to achieve compliance with this rule; and ¶

Deleted: (C)

Deleted: Non

- resettable, totalizing fuel met er(s) specifications; date of

Deleted: installation; and recorded fuel usage since installation.

Deleted: 4

Formatted: Double underline

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Formatted: UnderlineProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 5 manner that exceeds the applicable landfill or digester gas emission concentration limits specified in paragraph (c)( 2 ), provided that the facility monthly average biogas usage by the biogas units is 90% or more, based on the higher heating value of the fuels used. (A) The Executive Officer may approve the burning of more than

10% up to : (i) 25% natural gas in a biogas fired unit at the 15 ppm (digester gas) or 25 p pm (landfill gas) NOx level, when it is necessary, if the only alternative to limiting natural gas to 10% would be shutting down the unit and flaring more biogas. (ii) 50% natural gas in a digester gas

- fired unit at the 15 ppm NOx level, when it is necessa ry as specified in clause (c) ( 8 )(A)(i) and for units installed on or after September 5,
2008 provided the unit has demonstrated compliance with the NOx limits in paragraph (c)( 2 ) applicable to units fired exclusively on natural gas. For units subject to t his subparagraph, the percent natural gas usage shall be based on the facility monthly average biogas usage by the biogas units and the higher heating value of the
fuels used. (B) Any bio gas

- fired unit burning more than the approved percent

natural gas as determined under subparagraph (c)( 8 )(A) shall comply with the weighted average NOx limit specified in paragraph (c)(3). (d) Compliance Determination (1) Owners or operators of any units shall have the option of complying with either the pound per million B tu of heat input or parts per million emission limits specified in paragraph (c) (1)

, (c)(2)

, (c)( 3 ) , or (c)( 4 )

. (2) All emission determinations shall be made in the as

- found operating condition, except no compliance determination shall be establish ed during unit start up, shutdown, or under breakdown conditions. Start up or shutdown intervals shall not last longer than is necessary to reach stable temperatures. In no case shall the start up or shutdown interval last longer
than six hours or the ti me specified in the permit to operate, whichever is
less. Start

- ups and shutdowns shall not last longer than is necessary to Formatted: Indent: Left: 1.75", Hanging: 0.38", Tab stops: 2.13", Left + Not at 2"

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Deleted: s
Deleted: and

Deleted: (C)Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 6 reach stable conditions

. An compliance determination as specified in paragraph (d)(6) shall be conducted at least 250 operating h ours, or at least thirty days subsequent to the tuning or servicing of any unit , unless it is an
unscheduled repair

. (3) All parts per million emission limits specified in subdivision (c) are referenced at 3 percent volume stack

- gas oxygen on a dry basis averaged over a period of 15 consecutive minutes. (4) Compliance with the NOx and CO emission requirements of paragraph s (c)(1) through (c)( 4 ) and the stack

- gas oxygen concentration requirement
of sub paragraph (c)( 5 )(A) shall be determined us ing a District approved contractor under the Laboratory Approval Program according to the following procedures : (A) District Source Test Method 100.1

- Instrumental Analyzer Procedures for Continuous Gaseous Emission Sampling (March 1989), or (B) Distri ct Source Test Method 7.1

- Determination of Nitrogen Oxide Emissions from Stationary Sources (March 1989) and Method 10.1

- Carbon Monoxide and Carbon Dioxide by Gas Chromatograph/Non

- Dispersive Infrared Detector (GC/NDIR)

- Oxygen by Gas Chromatograph

- Th ermal Conductivity (GC/TCD) (March 1989), or (C) United States Environmental Protection Agency Conditional Test
Method CTM

- 030, Determination of Nitrogen Oxides, Carbon Monoxide, and Oxygen Emissions from Natural Gas

- Fired Engines,
Boilers and Process Heat ers Using Portable Analyzers; or (D) ASTM D6522

- 00(2005) Standard Test Method for Determination of Nitrogen Oxides, Carbon Monoxide, and Oxygen Concentrations
in Emissions from Natural Gas

- Fired Reciprocating Engines, Combustion Turbines, Boilers, and Proc ess Heaters Using Portable Analyzers ( E ) any other test method determined to be alternative and approved before the test in writing by the Executive Officers of the District and the California Air Resources Board and the Regional
Administrator o f the United States Environmental Protection Agency, Region IX. Formatted: Underline

Formatted: Underline

Deleted: paragraph

Deleted: (1)

Deleted: 2

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Formatted: Indent: Left: 1", Hanging: 0.44", Tab stops: 1.44", Left + Not at 1" Deleted: in

Deleted: equivalentProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 7 Records of all source tests shall be maintained for a period of two years (five years for Title V facilities) and shall be made available to District personnel upon request. Emissions determi ned to exceed any limits established by this rule through the use of any of the above

- referenced test
methods shall constitute a violation of this rule. (5) For any owner or operator who chooses the pounds of per million Btu of heat input compliance op tion of paragraph (c)(1)

, (c)(2) , or (c)( 4 ) for natural gas fired units

, NOx emissions in pounds per million Btu of heat input shall be calculated using the procedures in 40 CFR Part 60, Appendix A, Method 19, Sections 2 and 3 and CO emissions in pounds

pe r million Btu of heat input shall be calculated according to the Protocol for the Periodic Monitoring of Nitrogen Oxides, Carbon Monoxide, and Oxygen from Units Subject to South Coast Air Quality Management
District Rules 1146 and 1146.1

. (6) Compliance de termination with the NOx emission requirements specified in paragraph (d)(4) shall be conducted once every five years. (7) Any owner or operator of units subject to this rule shall check NOx
emissions with a portab le NOx, CO and oxygen analyzer according to th e Protocol for the Periodic Monitoring of Nitrogen Oxides, Carbon Monoxide, and Oxygen from Units Subject to South Coast Air Quality Management District Rules 1146 and 1146.1 according to the following
schedule: (A) On or after July 1, 2009

, the owner or opera tor of units subject to paragraphs (c)(1) through (c)(4) shall check NOx emissions at least quarterly or every 2,000 unit operating hours, whichever occurs
later

. If a unit is in compliance for four consecutive required emission checks, without any adjust ments to the oxygen sensor set points, then the unit may be checked semi

- annually or every 4 ,000 unit operating hours, whichever occurs later, until there is a n emission check indicating noncomplian ce

. (B) On or after January 1, 2015 or during burner replaceme nt, whichever occurs later, units subject to paragraph (c)(5) shall check NOx emissions according to the tune

- up schedule specified in subparagraph (c)(5)(B)

. (C) Records of all monitoring data required under subparagraphs (d)( 7 )(A) and (d)( 7 )(B) shall be main tained for a rolling twelve Deleted: NO x

Formatted: Pattern: Clear

Formatted: Bullets and Numbering Formatted: Pattern: Clear

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Formatted: Pattern: ClearProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 8 month period of two years ( five years for Title V facilities) and shall be made available to District personnel upon request. An owner or operator shall not be considered in violation of the
emissions limits of this rule or in permit conditions if the owner or operator complies with requirements specified in paragraph (d)( 9 ). Any emission check conducted by District staff that finds excess
emissions is a violation. (D) The portable analyzer tests required under subparagraphs (d )(7)(A) and (d)(7)(B) shall only be conducted by a person who has completed an appropriate District

- approved training program in the operation of portable analyzers and has received a certification issued by the District. (8) An owner or operator shall opt to comply with the requirements as applied to CO emissions specified in paragraph (d)(6) or (d)(7). ( 9 ) A source test specified under paragraph (d)(6) or an emission check conducted under the requirements specified in paragraph (d)( 7 ) that finds
emissions in excess of those allowed by this rule or a permit condition
shall not constitute a violation of this rule if the owner or operator correct s the problem and demonstrate compliance with another source test or
emission check within 72 hours from the time the owner or operator knew of excess emissions, or reasonably should have known, or shut down the unit by the end of an operating cycle, whichever is sooner

. (10) A n owner or operator may opt to lower the unit’s rated heat input capacity.
The lower ed rate d heat input capacity shall not be less than 2 million Btu per hour and shall be based on manufacturer’s identification or rating p late or permit condition.

(e) Compliance Schedule

(1) O wners or operators of units shall comply with the applicable schedule specified i n paragraph s (c)(1) and (c)(2)

.

( 2 ) On or after January 1, 201 5 or during burner replacement , whichever is
later , no person shall operate in the District any unit subject to paragraph (c)( 5 ) which does not meet the emissions limits specified in paragraph (c)(1 )

. Formatted: Underline

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Deleted:

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Formatted: Space Before: 12 pt

Deleted: The owner or operator of units subject to this rule shall meet the followi ng increments of progress:

Deleted: For

Deleted: o
Deleted: subject to

Deleted: shall:

Deleted: (A)

Deleted: By January 1, 1993, submit required applications for permits to construct and operate, and ¶ (B)

Deleted: By July 1, 1994, demonstrate compliance with paragraph (c)(1). ¶ For owners or operators of units subject to paragraph (c)(2) shall: ¶ (A) By January 1, 1993, submit a plan pursuant to paragraph (c)(3), and ¶ (B) By December 31, 1993, demonstrate compli ance with paragraph (c)(2).

Formatted: Indent: Left: 0.5", Tab stops: Not at 1.5"Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 9 ( 3 ) If any unit subject to paragraph (c)( 5 ) exceeds 18,000 therms of annual heat input from all fuels used in any twelve month period, the owners or operators shall: (A) within 4 months after exceeding 18,000 therms of heat input in any twelve month per iod, submit required applications for permits to construct and operate; and (B) within 18 months after exceeding 18,000 therms of heat input in any twelve month period, demonstrate and maintain compliance with all applicable requirements specified in parag raphs (c)(1) through (c)( 4 ) for the life of the unit. ( 4 ) The Executive Officer shall grant a time extension to the full compliance date with the applicable NOx compliance limits for any natural gas fired
units specified in paragraph (c)( 2 ) f or any health facility as defined in Section 1250 of the California Health and Safety Code that can demonstrate that the Office of Statewide Health Planning and Development has approved an extension of time to comply with seismic safety requirements pursuant to Health a nd Safety Code Sections 130060
and 130061.5. The extension of time granted by the Executive Officer shall be consistent with the time extension granted pursuant to Health and Safety Code Section 130060 but not to exceed January 1, 2015 and shall
be consis tent with the time extension granted pursuant to Health and Safety Code Section 130061.5 but not to exceed January 1, 2020. Those health facilities granted a time extension shall submit a compliance plan to the Executive Officer on or before January 1, 20 1 0. Formatted: Indent: Left: 0.5", Tab stops: 1", Left + Not at 1.5" Formatted: Pattern: Clear

Formatted: Pattern: Clear

Deleted: (f)

Deleted: Exemption

Deleted: The provisions of paragraph (c)(1) shall not apply provided the owner or operator: ¶

Deleted: (1)

Deleted: Installs by January 1, 1992, or at the time the permit to construct for the unit is issued, a non

resettable, totalizing fuel meter for each fuel th at demonstrates that the unit(s) operate with an annual heat input at or below 18,000 therms per calendar year; and ¶

Deleted: (2)

Deleted: Has available for inspection by the Executive Officer by February 1 of each year, records listing cumulative annual usage of each fuel for the preceding calendar year. Records shall be maintained and made accessible to the Executive Officer or authorized District representative for a period of two years; and ¶

Deleted: (3)

Deleted: Demonstrates compliance with the requirements specified in subparagraphs (c )(2)(A) or (c)(2)(B), and (c)(3).

Deleted: (g)

Deleted: Loss of Exemption ¶

Deleted: If any unit subject to a compliance plan submitted pursuant to paragraph (c)(3) exceeds 18,000 therms of annual heat input in any calendar year after 1992, the owners or operators shall: ¶

Deleted: (1)

Deleted: Within 4 months after the end of the calendar year during which the unit exceeded 18,000 therms of annual heat input, submit required applications for permits to construct and operate; and ¶

Deleted: (2)

Deleted: Within 18 months after the end of the calendar year during which the unit exceeded 18,000 therms of annual heat input, demonstrate and maintain compliance with paragraph (c)(1) for the life of the unit; and ¶

Deleted: (3)

Deleted: Maintain compliance with requirements of paragraph (c)(2) until compliance with paragraph (c)(1). ¶Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 10 ATTACHMENT 1

A. Equipment Tuning Procedure 1 for Forced

- Draft Boilers, Steam Generators, and Process Heaters Nothing in this Equipment Tuning Procedure shall be construed to require any act or
omission that would result in unsafe conditions or would be in violation of any regulation or requirement established by Factory Mutual, Industrial Risk Insurers, National Fire Prevention Association, the California Department of Industrial Relations (Occupational Safety and Health Division), the Federal Occupational Safety and He alth Administration, or other relevant regulations and requirements.
1. Operate the unit at the firing rate most typical of normal operation. If the unit experiences significant load variations during normal operation, operate it at its average firing rat e. 2. At this firing rate, record stack gas temperature, oxygen concentration, and CO concentration (for gaseous fuels) or smoke

- spot number 2 (for liquid fuels), and observe flame conditions after unit operation stabilizes at the firing rate selected. If the excess oxygen in the stack gas is at the lower end of the range of typical minimum
values 3 , and if CO emissions are low and there is not smoke, the unit is probably operating at near optimum efficiency

- at this particular firing rate.
3. Increase co mbustion air flow to the furnace until stack gas oxygen levels increase by one to two percent over the level measured in Step 2. As in Step 2, record the stack gas temperature, CO concentration (for gaseous fuels) or smoke

- spot number (for liquid fuels), and observe flame conditions for these higher oxygen levels after boiler operation stabilizes. However, complete the remaining portion of this procedure to determine whether still lower oxygen levels are practical.

1 This tuning p rocedure is based on a tune

- up procedure developed by KVB, Inc. for the United States EPA. 2 The smoke

- spot number can be determined with ASTM Test Method D

- 2156 or with the Bacharach method. ASTM Test Method D

- 2156 is included in a tuneup kit that can be purchased from the Bacharach Company. 3 Typical minimum oxygen levels for boilers at high firing rates are: 1. For natural gas: 0.5%

- 3% 2. For liquid fuels: 2%

- 4%Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 11 4. Decrease combustion air flow until the stack gas oxygen concentration is at the le vel measured in Step 2. From this level gradually reduce the combustion air flow, in small increments. After each increment, record the stack gas temperature, oxygen concentration, CO concentration (for gaseous fuels) and smoke

- spot number (for liquid fu els). Also observe the flame and record any changes in its condition.
5. Continue to reduce combustion air flow stepwise, until one of these limits is reached:

a. Unacceptable flame conditions

- such as flame impingement on furnace walls or burner parts, excessive flame carryover, or flame instability.
b. Stack gas CO concentrations greater than 400 ppm.

c. Smoking at the stack.
d. Equipment

- related limitations

- such as low windbox/furnace pressure differential, built in air

- flow limits, etc.
6. Develop a n O 2 /CO curve (for gaseous fuels) or O 2 /smoke curve (for liquid fuels) similar to those shown in Figures 1 and 2 using the excess oxygen and CO or smoke

spot number data obtained at each combustion air flow setting.

Formatted: Space Before: 12 ptProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 12 7. From the curves prepare d in Step 6, find the stack gas oxygen levels where the CO
emissions or smoke

- spot number equal the following values:
Fuel Measurement Value
Gaseous CO Emissions 400 ppm #1 and #2 oils smoke

- spot number number 1 #4 oil smoke

- spot number number 2 #5 oi l smoke

- spot number number 3 Other oils smoke

- spot number number 4

The above conditions are referred to as the CO or smoke thresholds, or as the minimum excess oxygen level.

Compare this minimum value of excess oxygen to the expected value provided by the combustion unit manufacturer. If the minimum level found is substantially higher than the value provided by the combustion unit manufacturer, burner adjustments can probably be made to improve fuel and air mixing, thereby allowing operation with
less air.
8. Add 0.5 to 2.0 percent O2 to the minimum excess oxygen level found in Step 7 and reset burner controls to operate automatically at this higher stack gas oxygen level. This margin above the minimum oxygen level accounts for fuel variations, var iations Deleted: <sp>

Formatted: Space Before: 12 pt

Deleted: ofProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 13 in atmospheric conditions, load changes, and nonrepeatability or play in automatic
controls.
9. If the load of the combustion unit varies significantly during normal operation, repeat Steps 1

- 8 for firing rates that represent the upper and lower li mits of the range of the load. Because control adjustments at one firing rate may affect conditions at other firing rates, it may not be possible to establish the optimum excess oxygen level at all firing rates. If this is the case, choose the burner con trol settings that give best performance over the range of firing rates. If one firing rate predominates, settings should optimize conditions at that rate.
10. Verify that the new settings can accommodate the sudden load changes that may occur in daily op eration without adverse effects. Do this by increasing and decreasing load rapidly while observing the flame and stack. If any of the conditions in Step 5 result, reset the combustion controls to provide a slightly higher level of excess oxygen at the af

fected firing rates. Next, verify these new settings in a similar fashion. Then make sure that the final control settings are recorded at steady

- state operating conditions for future reference.
11. When the above checks and adjustments have been made, re cord data and attach combustion analysis data to boiler, steam generator, or heater records indicating name and signature of person, title, and date the tuneup was performed.

B. Equipment Tuning Procedure for Natural Draft

- Fired Boilers, Steam Generators, and Process Heaters. Nothing in this Equipment Tuning Procedure shall be construed to require any act or omission that would result in unsafe conditions or would be in violation of any regulation or requirement established by Factory Mutual, Industrial Ri sk Insurers, National Fire Prevention Association, the California Department of Industrial Relations (Occupational Safety and Health Division), the Federal Occupational Safety and Health Administration, or other relevant codes, regulations, and equipment m anufacturers specifications and operating
manuals.

Should a different tuning procedure be used, a copy of this procedure should be kept with the unit records for two years and made available to the District personnel on request.Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 14 1. PRELIMINARY ANALYSIS

a. CHECK THE OPERATING PRESSURE OR TEMPERATURE. Operate the boiler, steam generator, or heater at the lowest acceptable pressure or temperature that will satisfy the load demand. This will minimize heat and radiation losses. Determine the pressure or temperature that will be used as a basis for comparative combustion analysis before and after tuneup.
b. CHECK OPERATING HOURS. Plan the workload so that the boiler, steam generator, or process heater operates only the minimum hours and days necessary t o perform the work required. Fewer operating hours will reduce fuel use and emissions. For units requiring a tuneup to comply with the rule, a totalizing non

- resettable fuel meter will be required for each fuel used and for each boiler, steam generator, and heater to prove fuel consumption is less than the heat input limit in therms per year specified in the rule.

c. CHECK AIR SUPPLY. Sufficient fresh air supply is essential to ensure optimum combustion and the area of air supply openings must be in co mpliance with applicable codes and regulations. Air openings must be kept wide open when the burner is firing
and clear from restriction to flow.
d. CHECK VENT. Proper venting is essential to assure efficient combustion. Insufficient draft or
overdraf t promotes hazards and inefficient burning. Check to be sure that vent is in good condition, sized properly and with no obstructions.

e. COMBUSTION ANALYSIS. Perform an "as is" combustion analysis (CO, O 2 , etc.) with a warmed up unit at high and low fi re, if possible. In addition to data obtained from combustion analysis, also record the following:
i. Inlet fuel pressure at burner (at high & low fire)
ii. Draft at inlet to draft hood or barometric damper 1) Draft hood: high, medium, and low 2) Barometric Damper: high, medium, and low
iii. Steam pressure, water temperature, or process fluid pressure or temperature entering and leaving the boiler, steam generator, or process heater. Deleted: aboveProposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 15 iv. Unit rate if meter is available.
With above co nditions recorded, make the following checks and corrective actions as

necessary:

2. CHECKS & CORRECTIONS

a. CHECK BURNER CONDITION. Dirty burners or burner orifices will cause boiler, steam generator, or process heater output rate and thermal efficie ncy to decrease. Clean burners and burner orifices thoroughly. Also, ensure that fuel filters and moisture traps are in place, clean, and operating properly, to prevent plugging of gas orifices. Confirm proper location and orientation of burner diffuser spuds, gas canes, etc. Look for any burned

- off or missing burner parts, and replace as needed.
b. CHECK FOR CLEAN BOILER, STEAM GENERATOR, OR PROCESS
HEATER TUBES & HEAT TRANSFER SURFACES.
External and internal build

- up of sediment and scale on the he ating surfaces creates an insulating effect that quickly reduces unit efficiency. Excessive fuel cost will result if the unit is not kept clean. Clean tube surfaces, remove scale and soot, assure proper process fluid flow and flue gas flow.

c. CHECK WAT ER TREATMENT & BLOWDOWN PROGRAM. Soft water and the proper water or process fluid treatment must be uniformly
used to minimize scale and corrosion. Timely flushing and periodic blowdown must be employed to eliminate sediment and scale build

- up on a boil er, steam generator or process heater.
d. CHECK FOR STEAM, HOT WATER OR PROCESS FLUID LEAKS Repair all leaks immediately since even small high

- pressure leaks quickly lead to considerable fuel, water and steam losses. Be sure there are no leaks through the blow

- off, drains, safety valve, by

- pass lines or at the feed pump, if
used.
3. SAFETY CHECKS

a. Test primary and secondary low water level controls.
b. Check operating and limit pressure and temperature controls.

c. Check pilot safety shut off opera tion.
d. Check safety valve pressure and capacity to meet boiler, steam generator or process heater requirements.Proposed Amended Rule 1146.1 (Cont.) (Amended May 13, 1994)

1146.1

- 16 e. Check limit safety control and spill switch.
4. ADJUSTMENTS While taking combustion readings with a warmed up boiler, steam generator, o r process heater at high fire perform checks and adjustments as follows:

a. Adjust unit to fire at rate; record fuel manifold pressure.
b. Adjust draft and/or fuel pressure to obtain acceptable, clean combustion at both high, medium and low fire. Carbon Monoxide (CO) value should always be below 400 parts per million (PPM) at 3% 0 2 . If CO is high make necessary adjustments. Check to ensure boiler, steam generator, or process heater light offs are smooth and safe. A reduced fuel pressure test at both high and low fire should
be conducted in accordance with the manufacturers instructions and
maintenance manuals.

c. Check and adjust operation of modulation controller. Ensure proper, efficient and clean combustion through range of firing rates.
When a bove adjustments and corrections have been made, record all data.
5. FINAL TEST Perform a final combustion analysis with a warmed up boiler, steam generator, or process heater at high, medium and low fire, whenever possible. In addition to data
from com bustion analysis, also check and record:

a. Fuel pressure at burner (High, Medium, and Low).
b. Draft above draft hood or barometric damper (High, Medium and Low).

c. Steam pressure or water temperature entering and leaving boiler, steam
generator, or p rocess heater.
d. Unit rate if meter is available. When the above checks and adjustments have been made, record data and attach combustion analysis data to boiler, steam generator, or process heater records indicating name and signature of person, title, company name, company address and date the tuneup was performed.