calculation for actual density

Oy Vey! Could you please format your question to use a little more white space and, perhaps, a paragraph break or two? It's very hard to read. Thanks.

dear anil

density of gas at x deg= (293/(293+x)*1.28)*(P b+fan tp/p ab)

where 293 k is at 20 deg c

1.28- density at 20 deg c

pb -barometric pressure

P ab - absolute pressure

fan tp-static pr+velocity pressure

air flow from high pressure side (atmosphere) to low pressure side (fan inlet or duct) is quite natural.and vice versa in case of outlet .so for make a flow of air the fan should generate a pressure more than pb in case of supply and less than pb in case of suction.

dear sundararavi, thanks for a reply, but what i wanted to know is not understood, let me explain it once again i am working in cement industry, and i am calculating the flow of gases thru a fan.As u know that density is available in actual cubic metre and normal cubic metre.For a standard gas the normal density is around 1.29kg/nm3 and i want to convert it to actual density in kg/m3,by certain temperature and pressure corrections. so the formula is kg/m3 = kg/nm3 *(273/273+temp measured)*(10275-Ps)/10336) lets me give data a) normal density is 1.29kg/nm3 b) temp measured at a point is 50 degree centigrade c) Ps (static pressure) at that point is -225mmwg d) at altitude of 47 metre , the pressure is 10275mmwg e) barometric pressure is 10336 mmwg, ok now what is troubling me is whether in the above formula it is ( 10275+Ps)/10336 or is it (10275-Ps)/10336. Some person told me that at suction side one should take it as negative and at discharge side as positive.Please can u clear my doubt anil

dear anil

if your fan is induced fan the sp = pb- sp. if it is forced draught fan then sp = pb+sp if you measure the velocity pr at inlet then fan sp=pb-vacuum pr(less than pb) created by fan(then only flow occure) where as if measure the vp at outlet then fan sp=pb+sp(then only flow occure) pls note that vacuum pr in the sense sp of fan to overcome the frictional +dynamic losses of duct system +fan losses.i hope it clear your doubt. for further detail you may refer buffalo forge fan engineering book

thanx sundararavi

Please give this assignment to one of your mining engineers esp with u/g experience.