STEMM, based on the long experience of its engineers in the cement sector, has extended its already extensive manufacturing programme with electro-hydraulic clamshell grabs specially designed to work in this field.
Cement industry requires high performances and characteristics to face the harsh environmental circumstances of abrasion, wear, shocks and high temperatures.
Totally compact and multistable STEMM clamshell grabs specially designed to work in dusty and abrasive environments which is the case at cement plants where sand, clinker, limestone and minerals are handled.
Electrowelded structure built with high yield strength steels, subsequently stabilised and standardised to eliminate welding stresses.
Calculated by Finite Elements (F.E.A.) and S/DIN 15018 class H2-B4 and conceived for 6 million cycles.
Very fast grabs when closing and opening achieving a great production increase.
Clamshell grabs with optimal penetration and dragging that allows to always achieve complete filling in all operations; they also have a built-in anti-flip system so that the grab works inclined in all directions without affecting the operation of the pump and without any drop of oil escaping to the outside.
Very robust shells built with high elastic strength and anti-wear steels, with a standard progressive shell profile, which allows perfect and optimum filling.
Reinforced with nerves to withstand the most severe stresses and strains.
With Hardox reinforcements on the edges, anti-ware and anti-abrasive material, as sealing lips. These lips, made of HARDOX 500, have a 23º chamfer to allow adequate penetration and closure.
The closing path of the valves has a very special kinematics that ensures full filling, especially when handling materials of irregular shapes and granulometry, which is common in this cement sector.
The uniform movement of the shells during closing and opening is ensured thanks to a very robust double mechanical synchronism, which is placed on each side of the valves.
Optionally, penetration teeth can be welded to the lips, especially when handling stones and compacted materials.
Hydraulic cylinders: with metal protection
Special reinforced, double acting, tested to 400 bar.
Hardened, grounded and chrome-plated piston rods.
Protective flexible bellows to prevent dirt deposits on the piston rod surface.
With hydraulic cushioning and safety chamber.
Double seals on the guide.
Excellent front guiding to prevent stem buckling.
Double sealing joint and double lip scraper to prevent the entry of impurities.
Special, lubrication-free joints
The engineers of our R&D department have successfully developed maintenance-free and grease-free joints.
Our joints are additionally protected by double-lip polyurethane scrapers with high wear resistance, low deformation and high extrusion resistance.
These scrapers are suitable for severe working conditions and heavy dirt attacks and especially in dusty environments, preventing the penetration of dirt and water.
Variable speed motor pump unit
All valves, hydraulic and electrical components are top quality and world-renowned brands.
High pressure pump with automatically variable closing speed according to the resistance of the material to be handled.
Slotted pump shaft connected to the motor shaft by means of a steel-nylon-steel toothed elastic coupling.
This exclusive STEMM venting system avoids oil lamination and consequently also avoids oil overheating. It allows an important energy recovery on a daily basis.
The closing speed of our clamshell grabs is significantly higher achieving an important performance increase.
Electric cabinet
Integrated in the clamshell grab structure itself, with luminous status indicator lamps (such as oil and motor temperature, oil level, motor rotation direction ....)
Including WEID MULLER multipole plug (Male+Female)
Protected with metal guard and transparent viewing window.
