In on-site operation and maintenance, when a plate-and-frame heat exchanger is shut down to drain the medium, if the equipment temperature has not dropped to near ambient temperature, rapid cooling will cause uneven contraction of the plates or gaskets. This is a common operational risk. To avoid such problems, the temperature variation range and the compatibility of plates and gaskets should be considered during model selection. The following answers address key selection points from an operation and maintenance perspective.
Record inlet and outlet temperatures, pressures, and flow rates every shift; check clamping bolts for looseness every week; compare pressure drop and temperature difference trends every month. If the pressure drop rises significantly or the temperature difference decreases, it may indicate scaling or blockage, and cleaning should be scheduled.
Plates are commonly made of 304 or 316L stainless steel; titanium or Hastelloy may also be selected according to medium corrosiveness. Gasket materials must match the medium temperature and concentration. For example, nitrile rubber is suitable for water-based media, EPDM has higher temperature resistance, and fluororubber has better corrosion resistance. During selection, provide the medium composition, concentration, and operating temperature to match materials properly.
When shutting down to drain the medium, wait until the equipment temperature drops to near ambient temperature before draining to avoid uneven contraction of plates or gaskets caused by rapid cooling. If emergency draining is required, cool down slowly or use a gradual draining method.
Determine the plate area and flow-pass combination based on heat transfer duty, allowable pressure drop, and medium characteristics. The BR-28 plate-and-frame heat exchanger is suitable for working conditions with small to medium flow rates and small temperature differences. Selection can be verified against actual parameters.
