Plate hat exchanger for DX system

[Marcos Rogerio]

I will use a plate heat exchanger like evaporator. It will be semi-weld plates and dry expansion (DX) for R407C. I am afraid about the below items:
1 - Is it necessary a liquid distributor inlet of the heat exchanger? How can I garantee the correct distribuition of liquid for all plates?
2 - What the ideal velocity of gas inner of HE to oil return?

Some one have experience with this aplication?


Best regards

Marcos

[stuartt]

A liquid distributor is only used on larger heat exchangers, the manufacturer can determine if you will require a distributor if you give them the proper information. Alfa Laval and GEA are very reputable manufacturers.

Suction line velocities should be minimum 750 fpm for horizontal runs and 1500 fpm for vertical rises. 3000 fpm is the maximum velocity.

[RANGER1]

From my experience the small ones have inbuilt distributor which is a must or it will not equally distribute trough each plate circuit. As Stuartt mentions, tell supplier all you can for correct selection.

[Magoo]

As per all the above, and also specify double wall HX particularly for DX application.

[cool_tech]

I have used with swep hx s and they are pretty good with design. alfa lavel is another good company i have used.