Vacuum Drum Filter
Rotary Vacuum Drum Filter Overview
WesTech’s continuous Rotary Vacuum Drum Filters provide a wide range of liquid-solids separation for many types of industrial processing flow sheets. They offer the operating flexibility to handle dewatering, washing and clarification applications, or a combination of the two. WesTech drum filters are available with drums up to 13.5 ft in diameter and 36 ft in length and are built to customer specifications.
Rotary Vacuum Drum Filter Designs Include:
Scraper Discharge is the most common drum filter discharge. After dewatering, the cake is removed from the filter cloth by a scraper blade just prior to the re-submergence of the drum. The scraper serves mainly as a deflector to direct the cake, dislodged by an air blowback, into the discharge chute.
Precoat Discharge is best applied to processes which have relatively low concentrations of solids or produce filter cakes which effectively blind the filter media.
Roll Discharge is especially good for thin, sticky cakes which have the unique property of sticking to themselves. The filter cake on the drum is pressed against a discharge roll packed with filter cake so that the thin cake is pulled or peeled from the drum. Solids are removed from the discharge roll with a knife blade.
String Discharge best applies to thin cakes and materials that are unstable and if disturbed too much will change from a solid to a liquid. Most generally applied in the starch and pharmaceutical industries, it is a system of endless strings or wires spaced about 0.5 inches apart that pass around the filter drum but are separated tangentially from the drum at the point of cake discharge. The strings return to the drum surface guided by two rollers with the cake separating from the strings as they pass over the rollers.
Belt Discharge offers the ability to discharge filter cakes and wash both sides of the filter cloth with each drum rotation. Westech Belt Discharge Drum Filters offer the ability to discharge filter cakes and wash the filter media with each drum rotation. Many applications using this type of filter produce thin, sticky and wet filter cakes which are not easily discharged without the aid of a discharge roll.
Benefits and Features
- High speeds and minimal pressure drop
- Low submergence
- Superior knife advance system and longer-lasting knife
- Low maintenance
- Low power requirements
- Vacuum is constant around the drum
- No individual drum sections
- Adaptive to a wide range of solids
- High capacity
- No cake cracking
- No “sloughing off” of cake at beginning of precoat cycle
- Limited cake expansion and shrinkage
- Higher filtration rate per square foot of area
- Thinner precoat cuts
- Produces drier cake
- Metal Hydroxide Waste
- Gypsum (FDG)
- Municipal Waste
- Lime Softening Sludge
- Potato Waste
- Corn Gluten