When customers come to us to seek a plate heat exchanger offer, certainly more than to find us a, but in the end there must be a variety of questions, the common question is: why is yours much more expensive than others? I see that others can do this kind of working condition even if the version is smaller? Why do you choose a larger model for us? And the number of plates exceeds so much?
For this kind of problem, we have long been accustomed to, today simply a one-time answer, those selection calculations, in the end, what you do not know the traps hidden in the book.
1. Heat exchanger margin - affect the number of plates
General selection software, alfa laval, for example, the heat transfer margin is generally 10%, at least have to advise customers to control at 5%, absolutely can not not set the heat transfer margin. If you do not set, although the plate less, and even if your working conditions will not change, but sooner or later the medium will be in the heat exchanger scaling, will affect the plate heat transfer coefficient, which affects the heat transfer efficiency.
2. Pressure drop - affect the heat exchanger supporting facilities
Pressure drop can be understood as the medium in the import and export pressure difference, that is, the pressure loss, imagine the following, when the pressure is smaller, is not the liquid flow slower? You will need more power to help it heat exchange? It is the pump. If you unknowingly use a heat exchanger with 100kpa pressure drop, you are guaranteed to have a negligible pump, and you don't know where the culprit is.
3. Interface flow rate - also affects the supporting facilities
Before explaining this, let's take a look at the concept of pump head, wikipedia definition is: head is the height of the pump can lift the water, is an important performance parameter of the pump, also known as the pressure head. Can be expressed as the fluid pressure head, kinetic energy head and potential energy head increase. And the interface flow rate and head is proportional to the relationship, quickly go to see your interface flow rate is not more than 3? Running cost is not cost? You must keep your eyes peeled when you pick one!
