Filter Vessel Design and Material 1

[izhar7787]

Dear all,

1) Is there any specific codes and standards for designing a filter vessel apart from ASME 8 Div 1,2,3 ?

2) Why is most filter vessel's internals i.e. filter cartridges etc. are made of stainless steel? If my operating temperature is just 60 degrees celcius, can we just have a carbon steel internals?

 

[gr2vessels]

Depending on the operating conditions, if the pressure and temerature is elevated enough, the filter housing can/should be designed in accordance with a valid pressure vessel design code (eg. American, Chinese, European, Australian, etc.).
I don't agree with your statement that most of the filter cartridges are made of Stainless Steel. In fact, the SS is used only in mild corrosive environment.
Also, at 60 deg C the carbon steel material in OK only in neutral environment, otherwise the corrosion rate will be very high and your filter cartridge will disappear in the process flow in no time.
Cheers,
gr2vessels

 

[Gorostidi]

More and more GRP (Glass reinforce plastic) are being used. Internals are usually installed in PP. GRP offers good chemical resistance to corrosion.
in europe we use EN-13121-3 for design calculations

 

[izhar7787]

Dear all

Thank you very much for the replies

Dear gr2vessels, further query in reply to your response above:

1) Can you please define "elevated enough". How "elevated enough" is the limit before you need to start using a valid pressure vessel design code for the design of your filter vessel? Are you saying that a valid pressure vessel design code is not required if the pressure/temperature is not "elevated enough"?

2) Attached is the process specification for our filter vessel. With this, what is the best material for the vessel housing and also its internals i.e. filter cartridges, holding plates etc.?

 

[nuche1973]

ASME States that a vessel operating under 15psi is a non-codevessel. I use ASME Sections VIII and II as guidelines when calculating dust collectors and similar structures. The type of material is usually specificed by the customer. I've seen A-36 steel used as well as stainless steel. It all depends on the material, ambient conditions and industry. I've yet seen a standard design for collectors.

 

[gr2vessels]

izhar7787,
Judging by the size of the filter, I would think is rather an in-line strainer with a removable basket and fine mesh, than cartridge filter.
It can also be a cartridge filter with multiple removable/replaceable cartridges.
The size of this thing must be larger than 20", probably 30". Accordingly, given the design pressure and temperature, it should be designed as a pressure vessel in accordance with an internationally recognised pressure vessel code. I won't comment on the excessive design temperature and pressure, way above the operating conditions.
The housing and fixed internal should be carbon steel the type SA-516 grade 70. Having removable cartridges, it should have a quick opening in the top. There are many companies manufacturing standard filters of this type, these are much cheaper than the custom designed ones (a standard cost around $20,000 and a custom designed $60-80,000).
The filter elements are standard items, most likely with some stainless steel housing and synthetic fibre mesh. The number of elements shouldn't be high, given the confortably large allowable pressure drop. Also, ask the process engineers to account for some water in the diesel fuel, which may affect the selection of filter cartridge type.
Cheers,
gr2vessels

 

[Spoonful]

Hi,

From you flow rate of 650 m3/h allowable clean dP 0.35bar.

Assume use a basket of 30% open area with a fine mesh of 35% open area, the say your total open are is about 10%. Allowable pressure drop across basket about 0.09 bar you will need total screening area of 0.6 m^2, then say about 1000 x 600 rectangle, then your basket size is about dia. 300 x 600 length, then your vessel could be say 500NB or 600NB ( 20" or 24") then you work out your housing pressure drop and add up see if it still under 0.35 bar. I wont have a feeling of such thing custom made cost as much as $60k-80k, i would guess about half of this. Don't take any liability from my calculation, there are lots more things to consider than what i just did.

Your operating temp is about 35 degree C, but you design temp is 155 degree C. As far as i know most cartridges wont cant stand that high temp, you might need to use stainless steel or fiber glass cartridges, again, they could be quite expensive.