Oil-free gas pumps for the emissions monitoring of tomorrow

This year’s CEM conference is all about emissions monitoring. At the virtual event, international experts will discuss the latest regulations and future challenges in connection with practical application, standards and quality procedures. Taking place from March 2–4, the online exhibition will also showcase equipment, new products and technologies. KNF will present powerful measurement technology solutions, including the N 630, N 922, and N 96 oil-free gas pump series, which meet the highest durability requirements and allow for customization.

Versatile series of gas pumps series for emissions monitoring in Ex and non-Ex areasRobustness, durability and long service life characterize this series. All Ex and non-Ex versions are available as a single-headed model or with twin heads connected in parallel or in series. Users who wish to double down on leak-tightness can do so by choosing a model featuring an additional double diaphragm. This is typically needed for noble gas or hazardous gas applications. An optional water- cooling system can also be installed to enhance non-Ex versions to handle environment and media temperatures of up to +60 °C.

The non-Ex versions are equipped with either an EPDM or a PTFE-coated diaphragm, the Ex-version with a PTFE-coated diaphragm. Pumps from the N 630 series can achieve flow rates of up to 68 l/min, an ultimate vacuum of up to 25 mbar abs as well as pressure of up to 12 bar g. The protection class of the pump section is IP20, and the motor offers IP55 protection. It can be used at 50 or 60 Hz and is designed to be operated with a frequency converter. This allows the pump’s rotational speed to be set to any operating point.

Easy-to-service pump series simplifies emissions monitoring
The chemically resistant and oil-free N 922 vacuum pump transfers media reliably and with low maintenance requirements. Depending on the area of application, the diaphragm and the valves of the N 922 only need to be replaced about once a year. Few wearing parts, long periods between required maintenance work and low inspection costs all add up to advantageously low operating costs.

The gas transfer pump is now also available in two new non-Ex versions and a new Ex version, all with stainless steel pump heads, making it suitable for even more applications. The new models are highly leak-tight in keeping with KNF’s standards, and they feature substantially higher values in all the key areas compared to previous PTFE pump head versions, with a flow rate of up to 25 l/min, up to 110 mbar abs depth of vacuum and up to 6 bar g of pressure. This makes them particularly convenient as sample gas pumps for stationary emissions measurements.

To allow for geodetic discharge of condensates, the compressor housing in the N 922 can be moved in increments of 90 degrees separately from the motor.

In non-Ex versions, users can choose from three separate AC motors. With the IP20 protection class, the single-phase AC motor with a terminal box covers a broad voltage range of 100–120 V at 50/60 Hz, as well as 200–240 V at 50/60 Hz. An additional IP54 protection class single-phase AC motor with a terminal box covers a voltage range of 100–120 V at 50/60 Hz, 230 V at 50 Hz, as well as 220 V at 60 Hz. Another IP54 protection class motor is the three-phase AC motor for 230/400 V and 50/60 Hz that can be operated with a frequency converter. The Ex de motor with protection class IP66 is ATEX-compliant and certified to IECEx (incl. CCOE, NEPSI, KOSHA).

Gas sampling pumps for complex operating profiles
Small, light and high-performance – key qualities that manufacturers of portable measurement, monitoring and analytical systems require from pump technology. What’s more, the N 96 gas sampling pump also accommodates complex operating profiles. This dynamic profile is made possible by an efficient, brushless DC motor featuring a PWM control loop setup. The N 96 emits relatively little heat itself while being suited for use at ambient temperatures of up to 50 degrees Celsius. The pump can start up without discharge in the range of 2.5 bar relative pressure / 100 mbar abs vacuum. The flow rate is as high as 8.5 l/min. If necessary, the maximum positive pressure can be increased to up to 4 bar g.

When used for gas analysis, the pump transfers reliable and precise liquid or gaseous samples for evaluation. The EPDM- or PTFE-coated diaphragm ensures safe use with aggressive and/or corrosive media. Its chemically resistant design and very high tolerance of vapor and condensate means the N 96 can be used with a broad spectrum of media at temperatures of up to 70 degrees Celsius. These pumps can transfer, evacuate and compress media oil-free and without contamination.

The N 96 pump series features compact versions with AC/DC converter and PPS, stainless steel or aluminum pump heads. This allows for a broader range of applications, now encompassing the handling of valuable or hazardous gases such as tritium. Demanding media which may require optionally greater gas tightness – such as hydrogen, nitrogen and helium – can also be handled safely.

The wide-range power supply unit mounted to the compressor housing enables the pump to be used across the globe, regardless of the local power grid specifications. The pump head can also be rotated in 90-degree intervals, allowing for the connections to be positioned as needed. Fastening holes located on the side of the pump housing facilitate tubeless connection via o-ring adapters attached to a manifold.