Essa® Linear Cross Stream Sampler

State of the art technology for the primary and secondary sampling of falling streams from belt conveyors.

Essa are pioneers of a range of electric motor driven ball screw samplers that find particular application in collecting a representative samples from the material stream being discharged over the head pulley of a belt conveyor. These are setting new standards of performance and reliability that traditional chain, pneumatic and hydraulic drive samplers can find difficult to match.

The ball screw sampler maintains genuine uniform cutter speed through the falling stream; even when wear eventually occurs. The concept has been long term field proven in a broad range of medium to extra heavy applications.

The ball screw sampler is of simple yet rugged construction designed for maximum operational availability with low maintenance, in even the most arduous applications.

The electric motor driven ball screw mechanism produces a very rapid acceleration and deceleration time and results in a constant speed drive, which does not slow down when confronted with the falling stream be sampled. It’s combination of a powerful directly coupled electric motor and the huge mechanical advantage produced by the ball screw and nut assembly ensures that sampler performance conforms most closely to recommended sample theory.

The installation of the falling stream (linear) sampler at the discharge end of a belt conveyor is an internationally preferred method of sampling the material being carried by that belt conveyor. Various international standards have been established to assure the sampler performs in a manner which assures that the collected sample is truly representative. One of the most relevant requirements of these standards is the sampling cutter must travel back and forth through the falling stream at a uniform rate. Sampling equipment manufacturers have traditionally used chain, pneumatic or hydraulic drives to satisfy this requirement. Essa have been pioneers in the use of this precision ground (square) screw thread and ball nut concept to drive falling stream samplers. This is a truly positive drive system, which by its very nature is obliged to travel through the falling stream at a uniform rate. It has none of the potential “elasticity” of pneumatics or hydraulics and will continue to operate at a uniform rate even when the mechanism eventually begins to wear. Essa’s simple, yet rugged, application of the concept assures maximum reliability and availability of the system.

Essa also offers a full range of complementary sampling and sample size reduction equipment and a design through to commissioning service for complete sampling stations and systems.