2 Automatic dosing pumps for Emission Reduction


Selective Non-Catalytic Reduction (SNCR) plays a crucial role in the reducing of harmful emissions such as Nitrogen oxides (NOx) from industrial plants. It is a technology designed to reduce emissions through the injection of urea or adblue via a lance into an emission stack.

It is a tried and tested technology that’s been working successfully around the world since 1974.As well as being used extensively in the electric power industry, SNCR is also being adopted to control nitrogen oxides (NOx) emissions from a range of combustion sources including industrial boilers, cement kilns, pulp and paper power boilers, thermal incinerators, steel industry process units, refineries and more.

Client Need

An emissions specialist contacted North Ridge who were looking for 2 automatic metering dosing pumps to administer AdBlue at high pressure through an injection lance.

The system was being designed to help an industrial manufacture reduce its emissions and meet Net Zero Targets. The system helps this by converting nitrogen oxides (NOx) into harmless nitrogen (N2) and water vapour (H2O). It does this by using ammonia or urea injection at high temperature directly into the upper furnace or convective pass of a boiler using water as a carrier. 

It’s the simplest and most economical form of nitrogen-reducing technology, ideal for applications where a reduction of 30% to 40% of harmful emissions is required. 

The automatic metering dosing pumps we specified were electric diaphragm dosing pumps with locally mounted controls which enable accurate and complete control of fluid dosing via the screen or remotely via wifi. 

The pump head contains a diaphragm housed in a chemically resistant material which in this case was polypropylene. The PTFE diaphragm is compressed, and opened via a polyethylene (PEUHMW) piston, with ball valve on the suction and discharge ensuring that the pump can self prime and repeatedly dose at the required pressure.

Diaphragm compression and the associated dosing rate of the pump is controlled via the motor speed and rate at which the eccentric movement of the gearbox compresses the diaphragm via the piston rod. As the design is positive displacement, the pressure generated will remain consistent with only the flow varying. 

The spraying nozzles on the urea injection lance ensure the NH3-Water solution is injected into the flue gas at the required pressure, and spray pattern. The water which acts as a carrier evaporates, leaving the gaseous NH3 to react with the NOx.

Exact pump specifications

The metering dosing pumps we manufactured were designed to achieve flows of up to 11L per hour and pressure up to 15 bar. They would be remotely controlled via their 4-20ma input for full automatic dosing control.

In addition, these automatic dosing pumps had advanced controls to provide proportional dosing using a variety of methods:

  • Manual: flow adjustment using the on-board controls and display
  • Analogue: dosing proportional to a 0/4-20mA signal
  • Proportional to flow: dosing according to water flow
  • Proportional to pulses: stroke frequency proportional to input pulses via a flowmeter or other device
  • Volume batch control: dosing a defined volume, after a manual, remote or timed pre-set start
  • Timed batch control: dosing for a set time, after a manual, remote or time pre-set start
  • ModBus: full dosing control through ModBus on-site control protocol. 

If you have a chemical transfer application involving the transfer of aggressive chemicals, solutions or solid laden liquids, visit www.northridgepumps.com or speak to North Ridge Pumps on 01773 302 660 to see how we can help.


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