Plate & Shell Heat exchangers many benefits to Shell & Tube in the industrial gas sector

The strong benefits of Vahterus Plate & Shell Heat Exchangers (PSHE) have been proven in refrigeration installations over the years. For customers working in the refrigeration sector, PSHE brings safety and flexibility for the manufacturing of process skids. As there are clear similarities with the industrial gas sector, the benefits proven in the refrigeration industry also apply to this area of business. PSHE is a compact and flexible solution when designing and constructing process skids; particularly since with PSHE, condensate and/or inert removal can be done within the heat exchanger itself, and there is no need for an external separation vessel.

In the industrial gas sector, the materials used for the heat exchangers are predominantly stainless steel. This makes PSHE a more cost-efficient alternative with shorter delivery time, especially when compared to shell & tube technology. From a process point of view, further advantages are possible due to improved thermal efficiency, since it is possible to achieve close approach temperatures between the hot and cold side, whilst still maintaining a low gas side pressure drop. In addition, the PSHE construction copes very well with the low temperatures typically used in industrial gas processes.

The suitability of PSHE within the industrial gas sector has been proved, for example, in Hungary, where Vahterus has many years of experience and cooperation with Linde Gas Hungary Co. Cltd., who are a producer and distributer of a variety of industrial and medical gases. Particular references of note are in installations for nitrous oxide (N2O) production.

Linde Gas Hungary is responsible for designing and building complete N2O production process skids. The production process of nitrous oxide is based upon thermal decomposition of ammonium nitrate. Liquid ammonium nitrate is injected into the reactor, causing the evolution of gas, which is then cooled and from which H2O is condensed in the cooler/condenser unit. This gas is then refined in the purification towers, before being compressed to the liq- uefaction pressure. In the final stage of the process, the gas stream is liquefied before going to storage and delivery.

In the process described above, Vahterus PSHE are used for the gas cooler, condensing water, and in the liquefaction of nitrous oxide gas. Due to the corrosive nature of ammonium nitrate gas, the cooler-condenser and liquefier units in the process, are manufactured fully from stainless steel materials.

Previously, Linde Gas Hungary used shell & tube technology in their process. In 2004 a Hungarian design office introduced them PSHE-technology, which resulted in immediate interest.

“Vahterus PSHE technology gives us a clear advantage with its compact size. Compact size makes the product easier to handle and the final size of the process skid, smaller. It is also more economical for us considering the overseas shipping of our process skids. Plate & shell heat exchangers used in the skid are manufactured from fully stainless steel materials, so the price advantage of PSHE compared to shell & tube technology is clear” says Silóczki, the Plant Engineering Manager of Linde Gas Hungary.