A harp screen, also popularly known as a piano wire screen, is made using single strands of highly tensioned straight wires. These wires are connected at either end of the screen and have a sheet metal hook. The design of the harp screen is such that the longer wires are gripped tightly to each other at a somewhat large distance by a transverse bond. This process ensures that along with screening machine vibrations, even the screen itself is producing its own dissonant frequency. This helps in counteracting clogging and sticking of the screen meshes.
In harp screens, the key factor is that the longitudinal wires straight or crimped are secured with somewhat wide space cross supports. Due to this, every single wire is excited, not just because of the force of the screening machine but also because of the material to be screened. The additional vibrations caused helps to work against the risk of pegging and blinding or sticking.
Screen panels such as harp screens are the type of screens that are recommended for materials that are difficult to screen and tend to blind or stick the conventional wire, especially to wedge-shaped materials and moist.
Iseveno Harp
Iseveno harp consists of alternately arranged crimped and straight wires and they are crimped horizontally to the screen level. These crimped and straight wires form triangular screen openings. The wires are then fixed at a particular spacing by cross binding made using plastic bindings. The distance of separation can be adapted depending on the requirement.
Material: Stainless steel, spring steel
Application Temperature: maximum 800 C
Cross connections: ss or spring steel, PU
Max width of the screen: 2500 mm
Alternate Name: Veno-Flex-Harps
Isevier Harp
Isevier harp consists of crimped screen wires that are arranged one after other and hence building square meshes. To attain stability for the screen, the longitudinal wires crimped are linked at a particular spacing by PU bindings or wires.
Material: Stainless steel, spring steel
Application Temperature: maximum 800 C
Cross connections: ss or spring steel, PU
Max width of the screen: 2500 mm
Alternate Name: Serpa-Flex-Harps
N-Harps
N-harps are made out of crimped as well as smooth longitudinal wires. These wires are fixed at a particular distance through PU bindings or wires building by these long screen openings.
Material: Stainless steel, spring steel
Application Temperature: maximum 800 C
Cross connections: ss or spring steel, PU
Max width of the screen: 2500 mm
Alternate Name: Harpa-Flex-Harps
Benefits of Harp Screens
- Increase in productivity using cross harps. It results in increased tonnes per hour for each sqft of screen space than any other screen surface.
- Harp screen allows screening at smaller gaps than would otherwise be possible.
- Harp screens make screening of damp and stick materials possible where screening with a woven product would be difficult.
- High efficiency
- Self-cleaning effect
- Screening of hard-to-screen materials
Application field of Harp Screens
- Gravel Pits
- Quarries
- Sandpits
- Mines
- Asphalt production
- Recycling
Screening difficult and fine materials can be achieved using a harp screen. The harp screens are exclusively supplied with tensioning folds. They are necessary for the correct operation of the screen. The screen is also supplied with polyurethane braids or wire which helps in improving the efficiency of the screen and its lifetime. Harp screens are made such that they provide maximum performance under all conditions.
