Oil mist separation efficiency test bench

Quality assurance and the development of filters/separators/collectors should ideally be conducted under test conditions relevant to the actual conditions encountered. Therefore, oil separators must be tested at high temperatures up to 120°C and, depending on the application type, at high pressures.

Using the modular test system HMT 1000. oil separators (e.g., for separating leaked aerosols in internal combustion engines or for separating oil mist downstream of compressors) can be characterized quickly and accurately, and successfully tested under real-world conditions via isothermal particle measurements up to 120°C:

• Staged separation efficiency

• Load/holding time

• Total separation efficiency/weight analysis

• Pressure loss

Due to the modular layout, individual components of the test bench, such as the high-resolution heated light scattering spectrometer Promo® 1000 H, the heated dilution system KHG 10 D, and the heated aerosol generator PLG 2100. can be easily removed from the HMT 1000 and used for other applications, such as direct measurements on the engine.

At the heart of the HMT 1000 is the Promo® 1000 H light scattering spectrometer, which is used to simultaneously and independently measure particle size and particle number (and thus concentration). With the Promo® 1000 H, very fast, clear, reproducible, and isothermal measurements are possible.

Standard

GB/T 6165-2021

Technical parameters

Advantages

Grading and Separation Efficiency and Feed Measurement and Evaluation

Isothermal and Isobaric Measurements

All Components Can Be Heated to 120°C

High Reproducibility of Test Methods

Internationally Comparable Measurement Results Due to the Widely Used Measurement System

Customer-Initiated Cleaning and Calibration

Easy to Operate; Even Untrained Personnel Can Quickly Use the Equipment

Modular Layout Offers Greater Flexibility

Validate the Functionality of Individual Components and the Entire System During Pre-Delivery Acceptance Testing and Upon Delivery**

Reliable Operation

Short Setup Time and Extremely Low Maintenance Costs

The Equipment Will Reduce Your Operating Costs

Figure 1: Promo® 1000 H

Advantages of Optical Particle Measurement over Pure Gravimetric Analysis:

Traditional quantitative gravimetric analysis is often not fast or sensitive enough and cannot provide information about particle size distribution. Due to the excellent correlation between quantitative distribution measurement and gravimetric analysis, very rapid and volume-dependent testing of oil separators can be ensured. The concentration of clean gas can be determined in 1 minute using the Promo® 1000 H system.

Why Use Isothermal Measurement?

The viscosity of oil – and therefore the size and concentration of particles in the oil mist – varies as a function of engine temperature. Therefore, oil separators must be tested at different temperatures, for example, with different particle sizes (up to approximately 5-8 µm) and particle concentrations (approximately 10⁵-10⁷ particles/cm³), as well as different volumetric flow rates, in order to clearly characterize their separation capabilities. Variations in separator separation characteristics, such as due to changes in volumetric flow rate, temperature, filter load, etc., must be clearly determined through reliable online or field measurements. To avoid condensation and the effects of evaporation on the HMT 1000. the entire aerosol conduit (including the preparation, sampling, and measurement volumes) can be heated to 120°C. This allows for isothermal measurements of fractionation efficiency. Isothermal in-situ measurements, such as on an engine, are also possible.

The HMT 1000 testing system is mobile and features a modular layout. Therefore, individual components can also be used for other tests and particle measurements, such as in-situ measurements on an engine.

Figure 2: Isothermal particle sampling and field measurement using Palas® FTControl software for automated measurement data acquisition.

The software has been tested and validated with particles and enables fully automated characterization of oil mist separators. This means results are independent of the operator of the test bench (see the "Software" product group: FTControl). Test Bench Control:

• Automatic control of volumetric flow rate

• Automatic activation of the aerosol generator

• Automatic switching between feed gas/clean gas measurement points

• Automatic temperature control

• Evaluation and recording of measurement signals such as Dp, relative humidity, temperature, volumetric flow rate, absolute pressure, etc.

Automatic Measurement Process:

• Automatic evaluation of pressure loss curves

• Automatic measurement of fractionation efficiency

• Automatic evaluation of pressure loss curves under different feed conditions, including fractionation efficiency measurement

Figure 3: Comparison of Different Oil Separators

Application Areas

Quality Assurance of Oil Separators

• New and further developments in oil separators, such as coalescing separators, cyclone separators and other inertial separators, electro-filters and filter combinations, for example, for:

- Leaking aerosols

- Downstream oil mist in compressors

- Cooling lubricant for machine tools

- Minimal lubrication aerosols