Wedge wire screen filter

What is a wedge wire screen filter

Wedge wire screen, also known as trapezoidal wire screen, Johnson Screen, is formed by winding and welding of stainless steel triangular wire or stainless steel trapezoidal wire. There are two main types: Screen tube and Screen plate. The smooth surface of the filter element is the filtering surface, and the gap is strip-shaped, which belongs to the surface filtering form. Its finished products have the characteristics of high strength, high hardness, wear resistance, corrosion resistance, uniform gap, good seepage, easy cleaning and reverse cleaning. The material can be SS304, SS316, SS316L, Hastelloy, etc., or customized according to user requirements.

Why choose wedge wire screen?

As a commonly used metal filter element, wedge wire mesh is widely used because of its own advantages.
1. Easy to leak, wear-resistant and corrosion-resistant, the mesh section is trapezoidal, and the gap is narrow at the top and wide at the bottom.
2. Good wear resistance and long service life. The wedge-shaped net structure design is more perfect. Its service life is more than double that of similar products.
3. The maintenance workload is small. The sieve surface is divided into multiple sieve plates and assembled, and a single damage can be replaced individually.
4. Low cost of use. Although the price is slightly higher than other types of screen products, due to its long service life, the total cost of users is greatly reduced.
5. The screen hole design is reasonable, the mesh surface manufacturing process is unique, the particles of the limit size will not block the screen hole, and the screening efficiency is high.

Wedge wire screen filter you may need

structure

The structure of Johnson screen is welded by the parallel arrangement of screen wires and the support strips of vertical screen strips. The lower end is a sharp corner, which is fused with each other when the support bars are spot welded.

Several forms of wedge wire screen

The wedge wire screen mainly has two filtering methods: from the outside to the inside and from the inside to the outside.

1. From the outside to the inside: the water enters from the outside and flows out from the inside, the smooth surface is outside, the reinforcing ribs are inside, the gaps are arranged vertically, the reinforcing ribs are horizontally inside.

2. From the outside to the inside: water enters from the outside and flows out from the inside, the smooth surface is on the outside, the reinforcing ribs are on the inside, the gaps are arranged horizontally, the reinforcing ribs are vertical on the inside.

3. From the inside to the outside: the water enters from the inside and flows out from the outside, the smooth surface is inside, the reinforcing rib is outside, the gap is horizontal, and the reinforcing rib is vertical on the outside.

4. From the inside to the outside: water enters from the inside and flows out from the outside, the smooth surface is inside, the reinforcing ribs are outside, the gaps are vertical, and the reinforcing ribs are horizontal outside.

5. From the inside to the outside: water enters from the inside and flows out from the outside, the smooth surface is inside, and the reinforcing ribs are also inside.

Connection Type

1. Threaded connection
There are two types of threaded connections: external thread and internal thread, and there are various threaded connection forms such as metric (M), pipe thread (G), NPT (N) and Whitworth thread, which can be made according to user needs.
2. Flange connection
If it is a flange connection, you must figure out what type of flange, what standard flange, diameter and pressure resistance. If there is no standard, then be sure to figure out the inner diameter, outer diameter, thickness, mounting hole diameter, number of mounting holes and the diameter of the PCD of the flange.

Standard sizes

Diameter of triangular wire: 0.75×1.5mm, 1×2mm, 1.5×2.5mm, 2×3mm, 2.2×4.2mm, 3×5mm, 4×7mm, 5×8mm
Trapezoidal wire diameter: 2×3mm, 3×4mm, 3×5mm, 4×5mm, 6mm round wire, etc.
Material: stainless steel wire, low carbon steel wire, galvanized iron wire
Diameter: 25mm---1000mm
Gap: 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.20mm, 0.25mm, 0.3mm and so on.
Length: 500mm, 1000mm, 1500mm, 2000mm, ....., 6000mm
Joint way: welding ring joint, threaded screw joint, flange joint
Filtration method: inner filtration, outer filtration (outside, reverse roll, wrap wire eversion)

Features

1. High strength. 
The cross section of the V-shaped screen is larger than the width, and the screen itself has strength. Every point of contact between the screen bar and the support bar is fixed by welding, so that the screen bar is formed as a whole.
2. High opening rate.
Generally, the opening rate of the perforated plate is less than 30, because the bridges between the openings have a width, otherwise the bridges are easy to break, but the Johnson screen is not subject to such restrictions. The bridges of the Johnson screen are the screen bars. The processing method and cross-sectional shape make it not easy to break, the hole bridge can take a relatively narrow size, reduce the width of the screen bars or expand the gap between the screen bars, which can increase the opening rate of the Johnson screen.
3. Not easy to block. 
The V-shaped sieve bars are arranged together. From the cross-section, the openings are bell mouths. Once the broken catalyst particles pass through the gaps of the sieve bars, they will be taken away by the fluid immediately, because the particles are only in contact with the edge of the sieve bars at two points. There is very little chance of getting stuck in the slits of the strip. The contact area between the hole edge of the perforated plate and the particles is large, and the particles may get stuck.
4. Can filter fine particles. 
The Johnson screen can control the gap between the screen bars by the density of the screen bars. Lehler uses computer numerical control to modulate the gap, and the small gap can be 15 microns.

Application of wedge screen filter element

1. Malting machinery: It is suitable for the use of selection machines, hair teeth and drying furnaces in malt factory It has the advantages of high ventilation efficiency and good heat dissipation effect.
2. Beer machinery: It is suitable for use in the filter tank of the brewery, with the advantages of high porosity and long service life.
3. Mining machinery: used for desliming and dehydration of coal preparation in coal preparation plants. Environmental protection: It is used to fill oil, gas and water wells with sand and gravel, which can prevent the formation of sand and protect the downhole and surface equipment. It has the advantages of high opening rate, large filtering area, fast filtering speed and long service life.
4. Chemical industry and others: used for sewage treatment in sugar and paper mills; material filtration and dehydration in fertilizer plants and supporting use in various paint booths;
5. Starch filtration in food factories: ventilation for grain storage.
6. It can be used with deep well pumps and submersible pumps, and can also be used in water treatment equipment, environmental protection, desalination of seawater into industrial water and domestic water, tap water treatment, water softening treatment, petrochemical industry: petroleum products Terminal filtration and filtration of chemical acid and alkali liquids, recovery and filtration of organic solutions such as alcohol.

Application of wedge wire screen in self-cleaning water filter

The wedge-shaped mesh filter cartridge is an important part of the self-cleaning water filter, which can usually be seen after opening the filter cover, or part of the screen can be seen through the water inlet or outlet. The inside of the wedge-shaped mesh is suitable for use in self-cleaning filters because of its smooth surface and long service life. When the water containing impurity particles passes through the wedge-shaped screen, the particles are intercepted on the inside of the filter screen. When the impurities continue to accumulate and the internal pressure increases, the filter will start the automatic cleaning function, and the motor drives the steel brush or scraper to rotate to remove the inside of the wedge-shaped screen. The particles are cleaned up, and the particles are discharged from the sewage outlet by washing the water to complete the cleaning action.

Origin of Johnson screen

Johnson Screen is a V-shaped wire welded filter developed by Johnson Company in the United States to solve the problem of solid-liquid separation. It is widely used in oil, gas, well sand control, refining, food filtration, etc. around the world. In the field, its position in the nuclear power industry and petrochemical hydrogenation units is particularly prominent, because of the excellent performance of this product, it is used in many fields.