NOx Removal (SCR/SNCR) Nozzles


Reduction of NOx emissions in gas streams through chemical reaction with ammonia or urea reagents.


Nitrous oxides (NOx) are formed by combustion in high-temperature environments, such as power plants and large diesel engines. NOx causes air pollution by reacting with air in the presence of UV light from sunlight to form ozone, the primary component of smog. Therefore, it is crucial to limit NOx emissions in applications that produce large quantities of these gases.

In both selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR), spray nozzles are used to inject a reagent or series of reagents into the exhaust gas to combine and react with the gas (and potentially a catalyst) to remove NOx from emissions. SCR uses ammonia as the reagent while SNCR uses either ammonia or urea injected at a high temperature. BETE spray nozzles are designed to maximize efficiency in SCR/SNCSR injection applications as they atomize and distributes the reagent into the process stream which increases the reaction surface area that combines and reacts with the NOx. Spray nozzles coupled with BETE injection lances can distribute the reagents as evenly as possible within the process stream to ensure proper mixing and minimize bypass.
 

Selecting a NOx Removal (SCR/SNCR) Nozzle:

Important factors to consider:

  • Temperature and particulate content of gas stream
    • SCR/SNCR applications typically occur at high temperatures
    • Particulate in the gas stream has the potential to clog injection nozzles and catalysts
    • Injection lances may need to be designed to prevent flashing of the spray media prior to the nozzles or with protective / purge shrouds to prevent build-up
  • Process gas flow rates and velocities
  • Scrubbing fluid composition
    • Typically aqueous ammonia, anhydrous ammonia, or urea
  • Nozzle material of contruction for high temperature and corrosive environments
  • Available nozzle mounting locations and distance to catalyst
    • Nozzle arrangement is important in order to fully cover the flue gas and prevent bypass
    • Proper residence time is required to ensure mixing and vaporization of reagents
  • Available pressure drop (∆P) across the nozzle
    • ∆P = supply pressure at nozzle inlet - process pressure outside nozzle
    • Availability of compressed air, nitrogen, or other carrier/atomization gases
  • Our experienced engineers can help determine which nozzle will perform as required with your design details


Common NOx Removal (SCR/SNCR) Nozzle Uses and Industries:

  • Power generation industries
  • Petrochemical industry
  • Coal fired power plants
  • Gas turbines
  • Boilers
  • Exhaust gases of ships, locomotives, and other large diesel engines
  • Exhaust gases of passenger cars, trucks, construction equipment, and other smaller diesel engines
    • ISO 22241 standardizes a commercial urea compound (AUS 32, commonly known as Adblue) which is used as the agent for selective catalytic reduction of NOx

XAAD

  • Internal mix air atomizing nozzle
  • Wide variety of hardware configurations
  • Available with clean out and shut off capabilities
  • Nickel alloy and other 300 series stainless steels available by request
Nozzle Type(s):
Air-Atomizing
  • Air-atomizing nozzles provide the fine atomization and high turndown rates often required for SCR / SNCR injection applications
Spray Pattern(s):
Hollow Cone
Angle Range:
70°
Common Materials:
316, 321 / 347, 310
  • 321 SS, 347 SS, and 310 SS provide high temperature resistance to the environments found in SCR / SNCR applications

XAER

  • Air atomizing nozzle with external-mix design provides independent control of flow rate and drop size
  • Wide variety of hardware configurations
  • Available with clean out and shut off capabilities
  • Nickel alloy and other 300 series stainless steels available by request
Nozzle Type(s):
Air-Atomizing
  • Air-atomizing nozzles provide the fine atomization and high turndown rates often required for SCR / SNCR injection applications
Spray Pattern(s):
Full Cone
Angle Range:
10 - 30°
Common Materials:
316, 321 / 347, 310
  • 321 SS, 347 SS, and 310 SS provide high temperature resistance to the environments found in SCR / SNCR applications

PJ

  • Impingement nozzles provide some of the finest atomization of any nozzle type for lower flow rate applications
  • Impingement style nozzle with external pin
  • No whirl vanes or internal parts
  • Lower flow rates than P series
  • Multiple filter options available
  • Optional safety wire hole available
Nozzle Type(s):
Impingement
  • Misting nozzles provide the low flow rates and fine atomization required for efficient SCR / SNCR injection applications
Spray Pattern(s):
Mist
Flow Range:
.007 to 2.43 gpm
Typical Pressure Range:
50 to 400 psi
Angle Range:
90°
Common Materials:
316, 321/ 347, 310
  • 321 SS, 347 SS, and 310 SS provide high temperature resistance to the environments found in SCR / SNCR applications

Mist

Select a nozzle number below for performance graph, drawings, and to request a quote.
Nozzle Number Connection Sizes Spray Angles gpm @ psi     (density: 1 SG)
10 psi 40 psi 100 psi 1000 psi 2000 psi 3000 psi
PJ 6 1/8″, 1/4″ 90° - - .010 .030 .042 .052
PJ 8 1/8″, 1/4″ 90° - - .018 .057 .080 .099
PJ 10 1/8″, 1/4″ 90° - .017 .027 .085 .120 .147
PJ 12 1/8″, 1/4″ 90° - .023 .036 .115 .163 .199
PJ 15 1/8″, 1/4″ 90° - .037 .058 .185 .262 .320
PJ 20 1/8″, 1/4″ 90° .034 .067 .106 .335 .474 .581
PJ 24 1/8″, 1/4″ 90° .050 .100 .158 .500 .707 .865
PJ 28 1/8″, 1/4″ 90° .065 .130 .206 .651 .921 1.13
PJ 32 1/8″, 1/4″ 90° .090 .180 .285 .901 1.27 1.56
PJ 40 1/8″, 1/4″ 90° .140 .280 .443 1.40 1.98 2.43

These values are filtered based on search criteria or application and do not represent the full range of nozzles for this series. Click here to see all available series offerings.

L

  • Unique misting spiral design provides fine atomization in a durable clog-resistant design with no internal components
  • Misting nozzle with large free passage
Nozzle Type(s):
Spiral
  • Misting nozzles provide the low flow rates and fine atomization required for efficient SCR / SNCR injection applications
Spray Pattern(s):
Mist
Flow Range:
.139 to 3.82 gpm
Typical Pressure Range:
30 to 100 psi
Angle Range:
90°
Common Materials:
316, 321/ 347, 310
  • 321 SS, 347 SS, and 310 SS provide high temperature resistance to the environments found in SCR / SNCR applications

Mist

Select a nozzle number below for performance graph, drawings, and to request a quote.
Nozzle Number Connection Sizes Spray Angles gpm @ psi     (density: 1 SG)
10 psi 50 psi 100 psi 250 psi 500 psi 1000 psi
L 40 1/8″, 1/4″ 90° .139 .311 .440 .696 .984 1.39
L 48 1/8″, 1/4″ 90° .199 .445 .630 .996 1.41 1.99
L 54 1/8″, 1/4″ 90° .266 .594 .840 1.33 1.88 2.66
L 66 1/8″, 1/4″ 90° .376 .841 1.19 1.88 2.66 3.76
L 80 1/8″, 1/4″ 90° .541 1.21 1.71 2.70 3.82 5.41

These values are filtered based on search criteria or application and do not represent the full range of nozzles for this series. Click here to see all available series offerings.