Preventative Maintenance Keeps Plate Heat Exchangers Running Efficiently
The plate and frame heat exchanger (PHE) is an engineered piece of equipment that serves as a means of energy transfer. Heat transfer involves bringing two fluids at different temperatures closer to each other, so that one either heats or cools the other. This means that energy already paid for is simply transferred to another part of the process. This saves energy and reduces the overall environmental impact of the production or system.
Plates, gaskets and a frame are the three main components of a plate and frame heat exchanger. In addition to being used in a variety of applications in indoor climate control, they can also be used to recover excess heat in industrial plants and environmentally friendly climate control.
In this article we look at the maintenance requirements that Plate Heat Exchangers require.
Maintenance is a word that makes most industries shudder because maintenance calls for shutdowns and shutdowns cost money. The most common PHE issues are fouling or scaling of the plates, clogging of the plate pack, and gasket failure. With the right preventative maintenance plans, PHEs can operate at optimum efficiency, ensuring production and system uptime while avoiding equipment failure and unpredictable shutdowns.
The design of the plate heat exchanger plays a significant role in ensuring better performance and energy efficiency. Plate heat exchangers can be designed with a unique corrugated pattern that not only gives it strength and rigidity, but greatly increases the rate of heat transfer from the warmer medium to the metal wall and from the wall to the other medium. These patterns also induce a high turbulent flow. This turbulence gives strong resistance to the formation of deposits on the plate surface to certain extent.
Over time, however, the sub-micron particles can build up on the plates, resulting in decreased thermal performance and increased pressure drop. Ironically, a plate heat exchanger can become one of the best filters in a system. If it is connected to an open loop without a filtration system - such as open cooling-tower water, river water or seawater, the narrow gaps between the plates of the heat exchanger will trap all kinds of debris and materials including silt, sand, rocks, leaves and shells acting as an effective barrier between equipment and debris occurring in the water source. An adequate filtration system keeps the fluids clean and prevents clogging. Custom filter solutions developed just for the plate heat exchanger units are also useful.
Back flushing the plate heat exchanger once a week is one step to an optimally running unit.
Regularly inspecting the plates along the side and the bottom for leaks and inspecting gaskets for softness and elasticity are key factors in the PHE maintenance plan.
Mechanical cleaning of plate heat exchanger is required only every two to three years if the water is dirty and every five to ten years if the water is clean.
Change gaskets every five to 10 years (depending on the application, temperatures and fluids)
IWC offers a comprehensive service package to users of plate heat exchangers.
Maintenance of PHE’s is easy and uncomplicated, provided the necessary preventative measures are taken. A clean PHE produces less pressure drop on the system requiring less effort on the pumps and other components, which assists in lowering energy costs while maximizing the heat-transfer rate and making plant operations as efficient as possible.
IWC (Pty) Ltd., originally founded in 1986 as Industrial Water Cooling, specialises in evaporative water cooling and GRP solutions for numerous applications as well as on-site servicing of plate heat exchangers, plate inspection, re-gasketing and pressure testing.
With offices in Johannesburg, Durban and in Australia, IWC upholds quality standards (ISO 9001-2000 accredited company) and excellent customer service, while maintaining a competitive price structure.
With years of expertise and practical knowledge, IWC offers bespoke PHE maintenance solution at cost-effective and competitive pricing. Contact IWC on +27 (0) 11 466 0699