In October 2010, Allweiler AG fulfilled a large order for centrifugal pumps in China. The PET, glycol, and thermal oil pumps are part of expanded polyester production in Wujiang.
A large number of Allweiler pumps have been in operation at the site since 2003. Allweiler AG is a business unit of Colfax Corporation.
The order was for eight pumps for PET production, 140 glycol pumps, and 20 thermal oil pumps for the plant s primary and secondary loops. The pumps delivered to Wujiang will be used to expand a polyester production plant. According to Stefan Kleinmann, Vice-President of the Industry business segment and member of the Allweiler AG executive board: "Allweiler AG won this contract because the operator of the plant has been using our pumps with great success since 2003. The long-term and very effective support provided by our subsidiary in Shanghai was another reason."
The pumped liquid can reach temperatures as high as 280° C during production of synthetic yarns. For this reason, the pumps are manufactured from 1.4581-grade stainless steel, a highly heat-resistant material. The special metal bellows-type seals are also designed to handle these high temperatures. The CNH-B series pumps are equipped with supplemental heating because liquid polyester begins to solidify below 250° C. Capacity is 400 m³ per hour at a pressure of approximately 14 bar; drive power is 180 kW.
Allweiler s largest chemical-standard pumps from the CNH-B series in size 200-500 are used to move thermal oil in the primary loop. This series reaches a capacity of 1200 m³ per hour at a maximum pressure of 25 bar and a maximum delivery head of 147 m. Liquid temperature can be as high as 350° C. Pumps of types NTT and NTWH are used in the secondary loop, depending on the liquid properties. In this application, the "Therminol" heat transfer oil reaches temperatures of 330° C and higher.
Picture: Allweiler pumps of the CNH-B series comply with DIN EN 22858/ISO 2858/ISO 5199. (Photo: Allweiler)