This animation shows the working principle of an Alfa Laval liquid/liquid 2-pass gasketed plate-and- frame heat exchanger where the fluids run counter-currently through the heat exchanger. The turning plate in the middle of the plate pack directs the flow into the two passes.

The hot liquid (illustrated in red) enters through one of the connections in the frame plate. The fluid runs through the heat exchanger in two passes and then leaves through one of the connections in the pressure plate. The cold liquid (illustrated in blue) simultaneously enters through one of the connections in the pressure plate and leaves through one the connections in the frame plate.

As the fluids pass through the heat exchanger, heat is transferred from the hot media to the cold media. Countercurrent flow enables maximum heat recovery possibilities and very close temperature approach can be achieved. Temperature cross is also possible, meaning that the hot outlet can reach a lower temperature than the cold outlet. This can only be achieved to a limited extent with tubular heat exchangers making plate-and-frame heat exchangers more thermally efficient. The fluids enter through the connections and portholes of the heat transfer plates. Specially designed sealing gaskets located between the plates direct the fluids so that the hot and cold fluids pass counter-currently in alternating channels.

When the fluid enters between the plates, it passes over the distribution area. Alfa Laval offers two types of distribution areas: our patented CurveFlowTM and the chocolate pattern. Alfa Laval’s well-designed distribution area is one of the most important features of a plate heat exchanger. Its main purpose is to ensure an even flow of fluid over the entire plate while maximizing heat transfer efficiency and minimizing maldistribution and fouling. In the animation you can see that the distribution area helps the fluids to quickly fill up the entire cross section of the plates.

The animation shows the flow principle of a conventional gasketed plate-and-frame heat exchanger with a 2-pass configuration, but additional passes are possible. It is also possible to have a different number of passes on each side of the heat exchanger. For bigger models with higher flow rates, reinforcing partition plates are sometimes used which are not shown in the animation. Specialized ranges of the gasketed plate-and-frame heat exchanger are also possible such as our semi-welded and WideGap. For very heat sensitive media, co-current flow is used in gasketed plate-and-frame heat exchangers. The benefit with this design is that the coldest fluid meets the hottest fluid when entering the heat exchanger, minimizing the risk of overheating or freezing sensitive media. In the animation, you can imagine reversing the cold fluid so that both fluids are entering at the frame plate connections. Alfa Laval has an extremely broad range of gasketed plate-and-frame heat exchangers which are used in all types of industries. The number of sizes, plate and gasket materials and available options are enormous.

Our Portable Compressors are built to last. And they’re also able to cope with lockdowns, including periods of inactivity. Even so, to ensure a smooth re-start, do the 12-point check-up. 

1. Any leaks in your systems? No? Double-check!
2. Drain water from the fuel filter and fuel tank.
3. Drain water from the compressor oil vessel.
4. Check the oil and coolant levels. Of both your engine and compressor. Top up when necessary.
5. Check the air filter element for dirt and oil residue. Replace when needed.
6. Check the non-return valve in the fuel (return) line.
7. Check the electrical systems and cables.
8. Check the electrolyte level and terminals.
9. Check the torque on critical connections.
10. Inspect the fan belt. Adjust it when necessary.
11. Make sure the regulating valve functions smoothly.
12. Check the tire pressure.

You’re ready for a smooth restart!
Load the unit. Build up pressure steadily. Keep monitoring the parameters.