TY - JOUR A1 - Bäßler, Ralph A1 - Eberle, Arno T1 - Damage investigation on the explosive destruction of a tank at a chlorine liquefaction plant JF - Engineering failure analysis N2 - This paper summarizes the investigation of a serious explosion, which shattered the chemical facility of a chlorine/alkaline plant in Northern Germany in 1981. A pressure tank made from HSB 50 S steel and used as storage of liquid residues from a chlorine liquefaction process violently ruptured and the explosion threw parts of the tank approximately 100 m through the air. The local county government ordered an investigation to determine the root cause of this incident. The main objective of the investigation was to determine whether a nitrogen overpressure or a chemical reaction of residuals inside the so-called 'Taffy' receiver caused the explosion. A fracture mechanics based analyses evaluated the conditions the material was exposed to during the damage. Metallographic and mechanical tests confirmed that the material specifications were within the values specified by the guidelines but corrosion had reduced the wall thickness considerably. Analytical calculations to determine the minimum required pressure for the rupture and to cause plastic deformation to the tank confirmed that the failure did not occur due to nitrogen overpressure and therefore, a chemical reaction must have occurred. A detailed chemical analysis confirmed that the explosive disintegration of methylnitrate, which is highly sensitive to heat and impact, and its halogenated derivatives likely caused the incident. Due to the design and operational mode of the plant, impurities could accumulate and form explosive compounds in the Taffy receivers without control. KW - Chlorine liquefaction process KW - 'Taffy' pressure tank failure KW - Explosion by chemical reaction of residues of methylnitrate KW - Fracture of HSB 50 S (StE 36) PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2014.02.007 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 120 EP - 132 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-30635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -