Date: March 7, 2016 

To: Docket, EPA-HQ-OAR-2014-0738 

From: Andrew Bouchard

Subject: Meeting Record for January 7, 2016, Meeting Between the U.S. EPA and Zeeco

On January 7, 2016, representatives of the U.S. Environmental Protection Agency (EPA) 

participated in a conference call with Zeeco. The purpose of the call was to discuss the 

comments they submitted to the docket on the multi-point ground flare (MPGF) alternative 

means of emission limitation (AMEL) framework. The focal point of the discussion focused on 

the framework, and in particular the MPGF stability testing requirements. During the discussion, 

Zeeco raised concerns about the technical limitations of testing, including those that dealt with 

equipment size constraints, testing of gas mixtures which use a mix tank versus those that use an 

online mixer, onsite storage capacity and tanker truck capacity of the gas being tested/burned in 

the MPGF burner and the impact that all of these have on stability testing duration. In addition, 

Zeeco provided information to the Agency both in the meeting and with a follow-up email on the 

technical aspects of why flame stability testing could be further shortened from the 

recommended 15 minutes in duration that was proposed by the Agency in the initial framework 

discussion. See Attachment 1 for the names and affiliations of the meeting participants. See 

Attachment 2 for the follow-up e-mail from Zeeco.
Attachment 1 

Participants in January 7, 2016 EPA/Zeeco Meeting

Zeeco Representatives

Scot Smith

Doug Allen 

Sidney Cabbiness 

U.S. EPA Representatives 

Andrew Bouchard

Brenda Shine 
Attachment 2

Follow-up E-mail from Zeeco to the U.S. EPA After the January 7, 2016 Conference Call 
From: Doug Allen <bdallen180@gmail.com>

Sent: Monday, March 07, 2016 4:58 PM

To: Bouchard, Andrew; Shine, Brenda

Cc: Scot_Smith@zeeco.com; Sidney_Cabbiness@zeeco.com

Subject: Fwd: Duration Flare Test Points

Andrew, / Brenda,

Please see attached letter we have been discussing. If you have any questions or need further information please let me

 know.

From: Doug Allen [mailto:Doug_Allen@zeeco.com]

Sent: Monday, February 22, 2016 8:16 PM

To: Bouchard, Andrew <Bouchard.Andrew@epa.gov>; Shine, Brenda <Shine.Brenda@epa.gov>

Cc: Scot K. Smith <Scot_Smith@zeeco.com>; Sidney Cabbiness <Sidney_Cabbiness@zeeco.com>

Subject: Duration Flare Test Points

22-Feb-2016

Andrew, / Brenda,

Sorry for the delay in our sending this letter concerning test point length for AMEL testing on Pressure

 Assisted Flares. Zeeco would like to offer the following for your consideration. To sustain stable combustion a proper

mixture of fuel and air along with the three T’s of combustion, time, temperature and turbulence are necessary. With

 these variables remaining constant combustion will remain constant. This is true not only in open flare systems, but

 also in any of the combustion processes we design and test and supply, incinerators, process burners, power burners,

 pilots, etc. In a pressure assisted flare fuel is ejected from the tip at high pressure. This results in a high velocity gas

 stream that entrains the air required for the combustion process. Because the gas is exiting at high velocity the

 turbulence required for mixing is achieved. Temperature starts with a pilot for ignition. Once ignited this fuel/air

mixture stabilizes over low pressure zones designed into the flare tip. These low pressure zones provide the last T in

 the equation of time by slowing a portion of the mixture down and allowing it to burn just above the tip (basically at the

 point where the flame speed of the combustible mixture is equal to the speed of gases exiting the flare tip nozzzles /

 ports). This low pressure combustion zone burning continues the temperature requirement and allows burners without

 pilots to be stable as well. The combustion process will continue indefinitely unless one of these items is disrupted.

 Note in many testing environments, it is possible for the composition of the gases being burned to vary, or for the gas

 supply pressure to vary, or the environmental conditions to vary. In our testing, mix gases prior to testing, and we

 sample the gases during testing to ensure the composition is stable. We also try to perform testing at the extremes of

wind conditions, early in the morning when winds are stable / low, and in the afternoon when winds are highest. All of

 the variables are tied directly to the fuel flow exiting the burner tip. For this reason a properly designed pressure

 assisted burner once burning will remain burning until the gas flow stops or the composition changes to one that is not

flammable. External environmental conditions only influence the shape of the flame, they do not disrupt the

 combustion process.

An additional common characteristic to all burners (process burners, flare tips, incinerator systems, etc) is that

 stability tends to increase as the burner “warms up”. The radiant heat from the flame causes portions of the burner,

 all parts that are visible to the flame, to increase in temperature. The increased temperature of the burner aids or

 improves the stabilization of the flame. Our testing is for short periods of time to ensure that added stabilization is

not taken credit for in our design work. Usually the burner temperature is not stabilized or steady state until the burner

 has been operating for an extended period of time.

When pressure assisted flares are specified by end users/engineering companies they give the major extreme
 operating cases that will bracket all of the possible operating cases the flare will see. From this information, a test

 program is determined and the representative test fuels are selected. The flare tips are then tested to ensure they will be

 capable of being ignited by the pilot and cable of cross lighting from a piloted tip to un-piloted tip and from un-piloted

 tip to un-piloted tip over this range of fuels. As noted above the only way to disrupt the combustion process on a

properly designed burner is to interrupt the fuel supply or vary the gas composition LHV to one that is not flammable.

 Therefore once the test burner is lit and the flame stabilizes there is no reason to believe those conditions will change.

 So operating a test point for any longer than necessary to bring the burner to the test point operating conditions and

 record the test data is not necessary to determine stability. The amount of time to get the burner set and record data can

 vary from 1 minute or less up to 5 minutes depending upon the data required for the test. Therefore we can find no

reason to set any limit on the length of time a test point must be held to determine if the burner will be stable.

From the prior EER testing on pressure assisted flare tips, it was also obvious this type of burner was either

 operating in a “stable” condition, or it was simply not ignited (flame out). This is also the conditions we typically see

 in our testing work. The burner is either stable, and operating well, or the burner will simply not maintain a flame

 (goes out). 

If you have any questions on the above or would like any further information on this subject please let us

 know.

Best Regards,

Doug Allen

Chief Engineer-Flares

Zeeco World Headquarters | 22151 East 91st Street | Broken Arrow, Oklahoma 74014, United States

Main: +1 918 258 8551 | Direct: +1 918 893 8150 | Cell: 918 520 2789 | Fax: +1 918 251 5519

Doug_Allen@zeeco.com | zeeco.com