A used filter element looks like a few canisters with oil on them, and on many sites they end up being treated as scrap. What they actually contain is not simple, and disposing of them carelessly sends back into the environment the very contaminants the machine removed for the customer.
What the elements have trapped
What the elements trap comes mainly from the oil itself: oxidation products and sludge, metal wear particles, free water and impurities, and possibly corrosion products. Inside the machine these are under control; once they are dropped into an uncontrolled environment, rainwater carries the oil-soluble fraction into the soil and the groundwater. The amount of metal particles is small, but they belong to the same category and have to be handled in the same way.
The adsorption media are similar. The adsorption media used in the TL-50 and TL-100 decolouring units have taken up the pigments and impurities from the oil, and the material taken out of the machine is oily itself. It is an oil-contaminated material and does not follow the route of ordinary industrial waste.
The test is therefore simple: these consumables are pollutants while they are in the machine, and they do not stop being pollutants when they leave it. They have only changed location.
The correct route for disposal
- Collect them by category. Consumables from different sources and with different degrees of contamination should not be mixed together, because that enlarges the contaminated area and raises both the difficulty and the cost of the treatment.
- Store them closed. The site needs a fixed place for them, covered, protected from rain and away from any run-off, not simply left on open ground or in an open woven bag.
- Hand them over for treatment in accordance with the requirements of the local environmental authority, to a company holding the relevant qualifications. Which category they fall into and what paperwork is needed follow the regulations of the place where the site is.
- Keep the handover record. The quantities, the weights, the time of handover and the receiving company are the only evidence available when the destination has to be explained.
- Do not mix them in with other waste. Oil, cleaning agents and oily rags belong to the same class of contamination, and mixing them into one batch makes the whole batch harder to treat.
What the equipment side should do
Before the disposal there is work on site that is worth doing, because it serves both the environmental requirement and the later analysis. The removed filter elements and adsorption media should be photographed, numbered and filed against the equipment number and the date of replacement. At handover, record the quantities, the weights, the time and the receiving company as well. These records are the only evidence available when the destination has to be explained, or when the consumption of elements has to be reviewed later, and once they are thrown away they are gone.
If the blockage was unexpected, keep the removed element separately and record the operating figures from that run. That is more reliable than any later recollection.
| Action on site | Why it is worth doing | Record to keep |
|---|---|---|
| Photograph the removed elements | To account for the disposal later and to trace the replacement | Photographs linked to the equipment number and the date |
| Record the differential pressure and the flow at replacement | To compare against the next change and judge whether the element reached the end of its life or was blocked abnormally | The replacement record sheet |
| Weigh or count before handover | The handover step needs a basis | The handover note |
| Store separately, do not mix | To avoid enlarging the contaminated area and raising the treatment difficulty | The log of the storage point |
Read together with the running data
The rate at which consumables are used is a curve that reflects the condition of the oil. The filtration accuracy of the ZYD-100 is ≤1 μm, the cleanliness corresponds to NAS class 5 (NAS 1638) and the water content is ≤3 ppm (GB/T 7600). When the replacement interval clearly shortens, or when metal particles are found in a removed element, the oil test results from that period usually explain why. Read in reverse, if the oil tests are normal and a filter element was blocked abnormally, the cause has to be looked for in the specification of the element and in the way it was fitted.
The standard configuration of the ZYD-100 is five 150-500-5 fine filter elements in parallel. When one of them is blocked the change in the overall differential pressure is not obvious, so the state of each branch has to be found by isolating them one at a time.
A removed filter element is evidence the machine hands over to the site; throw it away and the basis for judgement goes with it.
