Combustion

Combustion Activity

       To begin a Combustion activity, select Combustion from the Add_Step master pop-up menu.  Once selected, the Combustion dialog window will appear on the screen for entering the required information.  Generally speaking, a Combustion activity is used to model the emissions from a combustion process such as a boiler.  Emissions are calculated based on the amount of time that the combustion process takes place or the amount of fuel that was consumed and the associated compound emission factors.

An explanation of the data entry fields and requirements are described as follows:

· Activity Title: A single line of text which provides a brief reference to the process step being modeled and which will be used by the program as a Title Page entry.

· Vent I.D. Field: If the vessel, condenser, or other control device vent contains a vent identification number or code then this information may be entered in this edit field or selected from the drop down list.

· Equipment: This button is used to access the Equipment Database to select a combustion equipment item for use with this processing model.  If this activity step was pre-existing and is only being edited, the program will prompt the user to determine wether it should simple use the selected vessel (with or without) the previous emission factors.  The user may also select to have the program exchange the the newly selected vessel in every step involving the original vessel.

· Link: Process activities may be configured to be linked or not linked when the process is recalculated.  If this box is checked then the current activity will be re-evaluated during process recalculations.  If this box left unchecked then the mixture definitions will remain unchanged during process recalculations.  Occasionally, the process may contain a step that involves a chemical reaction or a liquid-liquid extraction.  Under these conditions, the user may wish for the mixture composition to remain constant during the process recalculation. 

· Duration (HR): Data entered in this field represents the amount of time that the Solids Drying process takes.  For example, an entry of 1.0 hr will cause the emissions from this Solids Drying model to take place over a one hour period.  The emission rate will be calculated by dividing the total emissions from this step by one hour.  The expression may be entered in minutes (15 min) or hours (0.25 hr).  A raw number (0.25) will be assumed by the program to be an entry in hours (0.25 will be converted to 0.25 hr).

· Pressure: Data entered in this field represents the vent discharge pressure and is normally set at 760 mm Hg or 1 atm. 

· Emission Temp: Enter the vent discharge temperature. 

· Fuel Consumption: Enter the amount of fuel that was consumed during the combustion operation.  Quantities may be specified in weight or volume.  

· Fuel Consumption Basis: Enter the comsumption basis to be used in conjunction with the emission factors.  Quantities may be specified in unit weight or volume.   For example, a quantity of 1.0 MMCF would imply that the emission factors are the actual emissions from the combustion of 1.0 MMCF of natural gas. 

· Fuel Consumption Emission Factors: If this combustion device has been  featured during an earlier step of the current file then this box will contain the last emission factors applied to this device.  Press the Factors DB or Edit button to define a new emission factor set or to modify the existing one.  

· Control Devices: A control device is an equipment item which, when installed in the process vent line, reduces the level of certain compounds in the final gas stream.  

· Non-Emitting: Check the Non-Emitting box if this activity will not have any vent emissions.  This condition can exist under certain processing operations.  For example, filling a vessel using residual vacuum in the vessel or filling a vessel when the process vent is tied directly back to the original charge vessel.  Other operations may involve charging material to an unvented vessel and allowing the pressure to build during the process. 

· Comments: Comments may help to document specific details that the user would like to make for this model.  Comments may be ented directly in the edit box or entered using the notepad like interface.