New Stationary Gas Detector with Dust Explosion Protection

With the new Polytron 7000 type P3D, Dräger (Germany) has developed a stationary gas detector for use in dust explosion-hazard areas that allows to measure more than 100 different toxic gases, vapors, and oxygen. With an innovative housing made of robust aluminum and an integrated inlet, it is in conformance with the requirements of ATEX and IECEx for measurement in zone 20 and 21.

Polytron 7000 was developed in cooperation with customers from industry and can be modified modularly by means of different selectable electrochemical sensors to specific requirements. In the Dust-Ex zone the integrated inlet allows for monitoring, also in poorly accessible areas like in silos. The dust explosion protection is relevant for example in the production of plastic, fertilizer and pigments as well as in carbon storage. The electronics of the Polytron 7000 type P3D is located in an extremely robust, closed housing which is approved according to protection type "tD". The integrated pump and an upstream particle filter allow for the suction of the toxic gas or oxygen from zone 20, where combustible dust can be present constantly or over a prolonged period of time. The device itself can be installed in zone 21. This is what makes it significantly different from previous models.

Polytron 7000 type P3D was developed to meet the special requirements as of dust explosion-hazard areas in compliance with EN 61241-0 and EN-61241-1. For inertisation applications, it is also tested and the measuring performance is approved in accordance with EN 50104.

A data dongle provides the logging of the measurement values as well as event logging, and allows a subsequent evaluation on the PC. A sensor dongle activates the sensor self-test required for SIL2 applications. The sensor diagnostic dongle checks the remaining sensor life, thus ensuring the functionality of the device. This way, the gas detector signals the user a reliable gas measurement or indicates preventive service that may be necessary. As stationary gas detectors are often installed in poorly accessible areas like in silos, the HART communication allows remote access to the device parameters and the display thereof on the PC.

For an explosion to occur, there are three factors that must come together: A sufficient amount of a flammable substance, sufficient ambient air (oxygen), and a source of ignition. In terms of this so-called explosion triangle, the Dräger Polytron 7000 type P3D provides comprehensive protection when the flammable substance consists of dusts.

With its proven technology the gas detector meets the measuring requirements for the monitoring of toxic gases and oxygen with a dust particle size of at least 0.1 µm (micrometers).