Pre-Filters for Thermal Oxidizers to remove contaminants up steam. The plugging problem is exasperated due to the numerous types of contaminants plugging the oxidizer units which can be classified into the following categories:
- Solid organic particulate
- Solid inorganic particulate
- Condensable particulate
Solid inorganic particulate includes contaminants such as stone, dust, or Silicone dioxide, common to the asphalt roofing shingle, found in remediation of hazardous landfills and in processes where silicone based lubricants is used such as the manufacture of high temperature silicone fabrics. Mineral fillers used in numerous products including pharmaceutical intermediate. Solid or semi-solid organic particulate such as food/flour dust, tars, biomass are found in the condensable particulate is most commonly “smoke” found in part quench operations, asphalt production/storage, textile manufacturing and food processing.
The fact there is true diversity in the very nature of contaminates the solution for the right pre-filters have resulted in the adaptation of several filtration technologies which have been a part of Air Clear’s product line for years.
Coalescing Fiber beds – These “Candle Filters” have been and are still used in numerous applications to remove condensable hydrocarbons from exhaust streams. When applied as a pre-filter in the asphalt industry exhaust they remove a large portion of condensable hydrocarbons, which can be recycled, prior to entering the Thermal Oxidizer (RTO) greatly reducing the frequency of bake outs and media replacement.
When significant quantities of dry particulate are present in the exhaust, a conventional dust collector can prevent bed buildup in the RTO. When condensable are present in the exhaust, permanent pre-filters can be used to coalesce and drain the “Thick, Sticky” material. Because this material is self draining it has very low maintenance and filters last for many years.
When particulate loading is very high there are two (2) effective options:
Stationary unit with replaceable filters: The filter type and efficiency can be varied to meet the specific requirements. This system is a cost effective solution when the process is not 24/7/365 operation. Two (2) hours of downtime on a monthly basis should be anticipated.
Indexing Filter: Removes dirty media off the filter face and onto a “dirty” roll while bringing clean media off the “clean” roll. The media can run for several months without change out. In most cases the media can be changed without projection shutdown.
Pre-filtering of a contaminated air stream with a well thought-out and properly designed pre-filter has been proven to allow for the use of more energy efficient air emission equipment. These same pre-filters have been applied to existing thermal oxidizer equipment to greatly reduce and in some cases eliminate the need for expensive heat recovery media replacement. With numerous time tested application in various industries and numerous pre-filter options Air Clear, LLC can help improve your bottom line by reducing energy consumption and system maintenance.