Wedgewire screens are superior for retaining media, filtering, and sizing. In comparison with wire mesh and perforated metal, wedge wire continuous slot screens have more open area, have very precise openings, are stronger and more durable, are virtually non-clogging and reduce media abrasion. Wire mesh and perforated metal may be less expensive initially, but wedgewire screens offer easier installation and long-term operating and cost benefits. Wedge wire screens have maximum design flexibility, can be constructed in a wide variety of shapes and sizes from a variety of corrosion resistant alloys such as type 304, 316, 316L, 321, and 410S stainless steels, as well as nickel alloys such as C-276.
Wedge Wire Screens are All-Welded for Strength
Each intersection of rod and wire in a wedgewire screen is welded. The strength achieved by this method offers several vital benefits:
Wedge Wire has Precise Slot Sizes
- Reduced costs, since wedge wire screens have a very long life.
- Greater resistance to stresses of differential pressure and temperature cycling.
Precise slot sizes are available to meet system requirements. Screens can be fabricated with slot openings from 0.025mm to 12.5mm in 0.025mm increments to dependably retain catalysts, resins, or filter sands of even very small size particles.
Wedge Wire has Low Head Loss
The high open area of wedge wire screen contributes to low head losses through the screen surface.
Wedge Wire is Non-Clogging
Wedgewire screens are fabricated by helically wrapping parallel support rods with a continuous V-shaped wire. The uninterrupted slot formed with this procedure allows only two-point contact of particles in the screen slot to minimise clogging. This means:
- Maximum effective flow area and operating efficiency is maintained.
- Costly downtime for cleaning plugged screens is minimised.
Wedge Wire is Economical
Economy is achieved through the simple design, which results in a screen with low initial cost, minimum maintenance needs and simplified installation.
Reduced Installation Costs:
- Costly support media can be eliminated.
- Components are easily assembled.
Reduced Operating Costs:
Non-clogging slot design results in low head loss for lower operating cost.
Non-clogging slot design results in reduction of downtime caused by plugged screens.
High strength and durability reduces chance of screen failure and loss of media.
Reduced Maintenance Costs:
Due to the smooth surface and rigid construction, abrasion of media particles is eliminated, increasing the effective life of expensive media, resulting in longer intervals between cleaning cycles.
Screens constructed with wedgewire have significantly greater durability than perforated metal and wire mesh.
WEDGE WIRE FREQUENTLY ASKED QUESTIONS
Q. What is the open area?
A. Wedge screen open area ratio (OA) is calculated using the following formula (multiply by 100 for percent):
Q. What are the common wedge screen terminologies?
Q. What is the standard size?
A. Due to the near-infinite possible combinations of slot size, wire profile, wire length, rod profile and spacing, rod length, and alloy requirements for the immense variety of applications, wedge wire screens are all custom manufactured.
Q. How much does it cost?
A. Due to the near-infinite possible combinations of slot size, wire profile, wire length, rod profile and spacing, rod length, and alloy requirements for the immense variety of applications, wedge wire screens are all custom manufactured. Therefore, cost per unit varies widely and must be calculated on a per-job basis.
Q. What is the standard slot size? What slot sizes are available?
A. There are very few applications for which the slot size is 'standard.' Ion exchange applications (underdrain laterals, media traps) commonly have slots in the range of 0.15mm to 0.20mm. Intake screens for fish protection in Canada generally require 2.54mm slots; in USA 3.175mm slots (larger slots may be allowed, or smaller slots required, by local authorities). Otherwise, the rule of thumb for most applications is to size the slot at half the size of the smallest media particles, the exception being sieve bends where the slot is sized about twice the desired separation size. Screen can be manufactured with any slot from 0.025mm (with most wire profiles) up to about 10mm in 0.025mm increments; larger slots may be available constrained by wire profile and tooling.
Q. Why doesn't a well screen (long, small diameter) work as a surface water intake?
A. When a screen is buried in the ground, such as well screens or infiltration galleries, the surrounding pack provides distribution so that flows are nearly uniform over the entire screen surface. A screen in open water does not have a 'surrounding pack', and so must be engineered, like our StaticOrb� intakes, to balance the flow velocities. A long, small diameter screen may have the same screen area and therefore the same average velocity, but nearly all the flow will occur at the outlet end, with very little (or none) of the flow happening at the closed end. The high flow velocities at the outlet end are much higher than those allowed for fish protection, and suck debris onto the screen and clog it much more quickly. This causes the high velocities to migrate along the screen until they reach the end and have clogged the entire screen.
Flowline's sieve bend screening unit is the answer to many de-watering, sizing, and wastewater cleanup problems. Typical uses are sewage treatment, laundry wash water clean-up, poultry, fish, fruit and vegetable wastewater processing, minerals processing, coal preparation, paper production, textile plants, and many more. A sieve bend consists of a concave curved profile wire screen mounted in a frame with the screen openings perpendicular to the flow. A curved screen has greater capacity than a flat screen due to forces exerted as material flows against the curved surface.
Sieve bends are also known as DSM screens, after Dutch State Mines, who introduced the sieve bend as a static sizing screen having ten times greater capacity than conventional vibrating screens.
As slurry flows down the screen each wedgewire's sharp leading edge slices away a thin layer of water and small-particle solids. Larger particles continue down the screen surface, with much of the liquid removed. Separation size is considerably smaller than screen openings, usually about one half the opening size.
Flowline Sieve Bend Features:
Low Headroom - only 1.1 metres (44") tall for the 900 mm arc length unit.
Energy Efficient - operates with no moving parts and with no energy input.
Space Efficient - treats up to 122 litres per second per square metre of floor space.
Quiet Operation - no moving parts means no mechanical or electrical vibrations.
Accurate Sizing - can be used for sizing solid particles down to 0.2 mm (0.008").
Low Maintenance - the profile wire screen resists clogging by near-size particles, and the all-stainless steel construction ensures a long, corrosion-free installation.
Easy Screen Replacement - a typical screen can be replaced in 10 minutes with no tools.
Flexible Design - we can supply units with any features you may require.
Should you require assistance with regards to the correct application for your requirements, please contact us, alternatively you may request a quotation directly.