business relationship meant to last
We support and accompany our customers through all project phases - from the analysis of process data, the recommendation of filter media, to the monitoring of filter media in use. This guarantees our customers first class advice on all aspects of filtration.
We are continuously working on the improvement of our products in order to meet with the high market requirements. A close collaboration with our customers and suppliers is of great benefit here.
Installing a new set of filter bags
During the reinstallation phase, the team makes sure that the clean air casing is thoroughly clean, and especially the perforated plate, because the bags and pockets have to be correctly positioned to ensure a good seal. The services thus have a major influence on dust emission levels from the chimney. Gentle insertion of the baskets is also decisive in determining bag service life.
Precoating new filters for better airflow, longer filter life
When your dust stream contains a significant percentage (by weight) of submicron particles, precoating can reduce or prevent the premature failure of your new filter media. In the figure, you can see how the precoating material has built up an initial dust cake on the media, preventing dust particles from flowing into and blinding the media. Precoating ensures that air flows freely through the collector, improving filtering performance while extending the filter life. Typical service life for bag filters without precoating is 1 to 3 years and for cartridge filters is 3 to 12 months. Depending on the application, precoating can extend the filter life, potentially providing enormous cost savings in replacement filters and changeout labor.
Precoating new filters provides other benefits, too. By keeping particles on the filter surface, precoating improves the dust collector’s initial filtering efficiency at startup. Precoated filters are easier to clean and provide better dust cake release for applications with process air that contains moisture, hydrocarbons (oil), or both.
Laundering Needlefelt Filter Bags
The process of laundering Needlefelt filter bags is, in general, not recommended, but where it is considered essential or useful the following guidelines may be considered. It should be noted that the success of a washing process will be dependent on the nature of the product being filtered.
Very rarely will a washing process restore the filter fabric to its original specification and more normally the fabric performance will be degraded relative to a new bag, leading to a shorter period before blinding and failure.
Implication of Waste Oil on Aramid Filter Bags
General comment in respect of Aramid Filter Bag performance relative to the use of waste oil:
Within any fuels (waste derived or virgin) the main concerns for the filter plant focus around the Sulphur and Halide contents of the fuel.
On combustion and in the presence of water these two chemicals react to form acidic products.
A typical filter bag on an Asphalt Coating plant uses Aramid fiber. While aramid fiber has a particularly good temperature resistance it is susceptible to acid attack which degrades and embrittles the fiber.
In plants where the stone is alkali based (limestone) these acids are neutralized but where no free alkali exists then acid attack is possible when the filter is cooled through dew point conditions.
Recommended Felt & Filter Velocities