HELP REQUIRED FOR DESIGN OF ac cab

[khadar]

Dear fndz...

This is my first post ...well..i have a problem 2 redesign ac path for cab of tractor , now the prob. is the tractor has 2 blowers & 5 inlets(diffusers) 2 let the air inside the cab ...but rite now ..the air from the blowers direclty fill the chamber which has 5 ports out 2 let the air out into the chamber . in this process the air from blowers directly hitz the walls of chambers then get distrubuted all along the chamber & then enters the cab....i think there is a energy lost when it hitz & circulates all over ...cant be direclty route all the 5 port from these 2 blowers ...please do help me ...help required urgently ....


Thannks in advance 2 all of U ...



Regards
Khadar

[Brian_UK]

If I understand you correctly you think that energy is being lost because the air path is not smooth.

In that case design better turns for the air within the ducting. Use round bends not hard corners, use turning vanes; all of these will help improve things.

Have you taken pressure measurements to find out what losses you have?

[khadar]

well....thank U brain for u r suggestion , i have taken up u r suggestions ...

but actually the problem now is ...all the 5 diffusers are not getting equal supply of air ...i mean the flow distribution is not proper ....

let me explain u in detail :::

There are four blowers in total . let us say A,B,C,D
& five diffusers to let the air inside the cab.

now A & D diffusers are connected for glass cleaning & B & C are used for cooling stuff in cab .

the flow is not uniform thru out the 5 diffusers ..so how can i make sure ..tht i can regulate this .

sorry brain ...will be posting the image in my next post ...

[Brian_UK]

You need to install small duct dampers (regulators) in the ductwork and measure the airflow from each outlet.

Now balance the airflow to your design requirements using the dampers.

Having balanced the system you could now measure the resistance of each duct and make a permanent restrictor for the ducts that have been dampered down.

[khadar]

hey brain ...

I am greatful 2 u for your valuable suggestions ..infact all of them properly worked with the data of my research & even my boss liked it ...

Finally, need a small help from you .

Do you have any gud article on electronic dampers which has these diodes it seems .. i have searched for it but could find only few data..

Will be very much thankful to you ..if you can get me any articles on these dampers.

Thanks in advance

Warm Regards
Khadar

[Brian_UK]

Do you have any gud article on electronic dampers which has these diodes it seems .. i have searched for it but could find only few data..

Are you asking about air duct dampers that respond to air volume or velocity ?

edit: I have used these in the past and they have proved reliable....
http://www.belimo.co.uk/pdf/e/Overview_VAV_en.pdf (2mb pdf)

They will control the airflow at a fixed rate but can be adjusted to vary the rate as required by electrical control.

[khadar]

hey ya ..itz exactly the same stuff ...i thnkful 2 u for being so helpful..

have a nice weekend , will get bak 2 u as soon as some breakthru happens in project

Merci
Khadar

[khadar]

Dear Fndz,

Thnkz the help you guys given from forum..especially brain...

well..Actually the duct design we proposed is succesfully accepted & we got a new task.need some info. on it

Ya, they need a duct which should have 2 legs (i.e) 2 outlets from a single source & it should be in such a way that when ever they require they can close one outlet so that all the air flows through only one leg.

Is such a costruction possible ..i heard that there are some 2 & 3 phase dampers which allows you to do so..is it ?

if any of you have any pictures of such duct's or dampers or any other info. please do send me ..

Thankz in advance ...

hope you guyz wont let me down again .

Regards
Khadar