whittier candle filters - veolia · 2018-03-05 · modern membrane technology. auto-pulse uses...
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Whittier® Candle Filters Auto-Shok® and Auto-Pulse™ Technology
WATER TECHNOLOGIES
Veolia Water Technologies offers effective candle filter technologies to meet the needs of industry in a variety of applications, including product filtration and water treatment.
Candle Filter DesignCandle filters are vertical vessels filled with tubes or “candles” suspended from a tube sheet near the top. Liquid flows from the outside of the tube to the inside. The filtrate flows up the inside of the tube through the openings in the tube sheet to the top head, which serves as a reservoir of filtered liquid and compressed gas. The filtered effluent flows from this reservoir at the top of the tank. The conical bottom of the tank serves to collect and thicken solids released from the membranes.
Veolia’s candle filters are available in two models: Auto-Shok® and Auto-Pulse™. These filters look much the same in outward appearance but differ in their tube coating, operation and application. Our product experts will recommend the model best suited to your needs based on the influent stream, flow and process goals.
Our candle filters are furnished in standard sizes from 26 to 1,239 ft2 of filtration area. Various metallic or plastic materials of construction and linings are available to meet any process requirement.
> Easy MaintenanceCleaning is accomplished when the flow is reversed and the tubes are backwashed with stored filtrate at the bottom of the reservoir. An air inlet at the top of the tank creates an “airbump” backwash utilizing the air/gas in the dome. This “bump and run” operation removes the filter cake quickly and effectively, minimizing downtime. No separate pumps or large volumes of sluicing liquid are required to provide fast and complete removal of the filter cake.
AIR INLET
OUTLET
INLET
PRESSURE TRANSMITTER
PRESSURE TRANSMITTER
TUBEELEMENT
DRAIN
B
A
C
PT
B
B
PT
D
> Shown above is a schematic of the candle filter with a cutaway indicating the position of the tubular filters inside.
Auto-Pulse™
The Auto-Pulse tubular back-pulse filter is designed to accomplish submicron filtration without the use of precoats or filter aids, making it possible to recover product from waste streams and return it to the process without contamination. To achieve this unique capability, Auto-Pulse combines proven filter design with modern membrane technology.
Auto-Pulse uses polymeric membrane tubes to accommodate a wide range of solids concentrations, from slurries as dilute as 0.002% to over 10% solids. The membranes accomplish immediate removal of 1-micron particles without cake formation, and even smaller particle removal once cake has formed. The membranes are manufactured from a highly permeable, very retentive material that has all the chemical and thermal characteristics of Teflon®.
> Flexible OperationAuto-Pulse operates similarly to the Auto-Shok in regard to the flow through the vessel and the “bump and run” cleaning. However, the smooth, non-stick surface of the polymeric membranes enable complete filter cake release. Because the membranes do not depend upon cake formation for fine solids removal, flow can be stopped and restarted without affecting effluent quality.
Because there are no precoats, polymers or other chemicals to store, mix, and feed, Auto-Pulse is less expensive and easier to operate than other designs. Its submicron filtration capability and tolerance to flow variations make it unparalleled in its application to a wide variety of process or waste streams.
> ApplicationsAuto-Pulse’s unique design has many applications previously addressed by clarifiers, thickeners, filters, cartridges or combinations of these separation technologies. Thanks to the conical bottom, it can be used for solids thickening as well as solids removal, depending on the characteristics of the solids.
The Auto-Pulse vessel can be fabricated of a variety of materials ranging from coated carbon steel to titanium. The tubular elements can be made of Teflon, HDPE, or other polymeric materials for very difficult applications in the chlor-alkali, chemical or textile industries.
• Enables product recovery in some applications
• Semi-continuous operation with quick removal of filter cake
• Requires less power for low pressure, low cost filtration
• Efficient submicron particle removal
• Rapid cleaning cycles reduces downtime
• Small footprint simplifies installation and lowers costs
Auto-Pulse™ Advantages
Filter Model # Diameter (inches) Maximum # of Tubes Filter Area (ft2)
18AP-26-9-48 18 9 2624AP-55-19-48 24 19 5524AP-75-19-66 24 19 7530AP-89-31-48 30 31 8930AP-123-31-66 30 31 12336AP-138-48-48 36 48 13836AP-173-48-60 36 48 17342AP-199-69-48 42 69 19942AP-248-69-60 42 69 24848AP-285-88-54 48 88 28548AP-348-88-66 48 88 34854AP-392-121-54 54 121 39254AP-436-121-60 54 121 43660AP-456-141-54 60 141 45660AP-558-141-66 60 141 55866AP-645-199-54 66 199 64566AP-716-199-60 66 199 71672AP-781-241-54 72 241 78172AP-868-241-60 72 241 86878AP-917-283-54 78 283 91778AP-1018-283-60 78 283 101884AP-1127-313-60 84 313 112784AP-1239-313-66 84 313 1239
> Shown above is the candle filter tube assembly with cut-away to show the flow distribution grid.
> These candle filters use tubular filter elements to support filter cake and produce high filtrate quality in the dietary fiber manufacturing industry.
Auto-Shok®
Auto-Shok is a classic tubular filter with precoated plastic or metallic screen covering the tubes. This filter is ideally suited for chemical filtration, condensate, and applications where exotic materials of construction would be required in other designs. Various precoat materials can be specified to meet your needs; for example, a precoat layer of powdered ion exchange resin is available for condensate filtration.
Filtration continues until a pre-determined pressure drop is achieved. The forward filtration is stopped. The filter is then pressurized from an external source, usually the feed pump. Once the vessel is pressurized, the quick-opening drain valve is opened, creating a sudden reverse flow that releases the cake, allowing the solids and liquid to drain.
> ApplicationsDesigned in standard sizes from 40 to 450 ft2 of filtration area, this filter has been used for many applications including brine filtration and condensate polishing. It is suitable for any hign flow rate, low-solids liquid influent. The large surface area in the vertical vessel enables the use of various precoat filter aids such as diatomaceous earth, cellulose, powdered ion exchange resin and more.
Because Auto-Shok has minimal metallic parts and its components can be alloy, coated or rubber lined, it is the technology of choice in the chlor-alkali industry due to its capacity to deliver excellent filtrate quality. When precoated with powdered ion exchange resin as a filter aid material, Auto-Shok is also used in condensate applications in the power and petrochemical industries.
• Self-contained internal backwash liquid source
• No external backwash pumps or tanks required
• Rapid cleaning cycles minimize downtime (which may eliminate the need for an additional filter)
• Entire tube bundle is removable as a unit for easy replacement and/or maintenance
• Small footprint minimizes installation costs and facilitates retrofits
• Minimum auxiliary equipment reduces costs and eases installation
Auto-Shok® Advantages
Filter Model # Diameter (inches) Maximum # of Tubes Filter Area ft2
18AS-26-9-48 18 9 2624AS-55-19-48 24 19 5524AS-75-19-66 24 19 7530AS-89-31-48 30 31 8930AS-123-31-66 30 31 12336AS-138-48-48 36 48 13836AS-173-48-60 36 48 17342AS-199-69-48 42 69 19942AS-248-69-60 42 69 24848AS-285-88-54 48 88 28548AS-348-88-66 48 88 34854AS-392-121-54 54 121 39254AS-436-121-60 54 121 43660AS-456-141-54 60 141 45660AS-558-141-66 60 141 55866AS-645-199-54 66 199 64566AS-716-199-60 66 199 71672AS-781-241-54 72 241 781
72AS-868-241-60 72 241 86878AS-917-283-54 78 283 917
78AS-1018-283-60 78 283 101884AS-1127-313-60 84 313 112784AS-1239-313-66 84 313 1239
