Calculation of gas velocity
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Given that the flow rate of recycled hydrogen is 30,000 NM3/h, the dimensions of the high-pressure vessel are φ2000*7000 mm, and the system pressure is 1.5 MPa, how can the gas velocity of the recycled hydrogen as it passes through the high-pressure vessel be calculated?
This post was last edited by ylb913 on 2016-5-17 at 20:50. The unit for wind speed (flow rate) is m/s: it is obtained by dividing the flow volume of m3/h by 3600 s/h to get the flow rate per second, which is m3/s; then this value is divided by the cross-sectional area in m2 to arrive at m/s. The nominal value must be converted to cubic meters under actual operating conditions; the pressure should be expressed in gauge pressure, with 1.5 MPa equivalent to 16 atmospheres (gauge pressure). P1*V1/T1=P0*V0/T0, 16*V1/(273+50)=30000/273, V1=2218 m3/h=2218/3600=0.616 m3/s. With a diameter of 2 meters and a radius of 1 meter, the cross-sectional area is 3.14 m2. Gas velocity = 0.616/3.14 = 0.20 m/s
It’s because P0 is no longer present; the pressure under standard conditions is one atmosphere, so P0=1 (absolute pressure). Why write *1 as well?
Oh! I suddenly understood it – how is the space velocity calculated for those 50,000 NM3/h of coke oven gas passing through a 105 cubic meter catalyst? Could you tell me? Temperature around 220 degrees
This post was last edited by ylb913 on 2016-5-18 07:50. The unit for linear velocity is 1/h, which is m3/h divided by m3, that is, flow rate divided by the volume of the bed. The bed volume is 105 m3, and the flow rate is 50,000 Nm3/h; to convert this to m3/h under actual operating conditions, you haven’t provided the pressure. ——But I believe you can already do the calculation.
Thank you! Does the V here refer to flow rate or volume? ?
Flow rate, to be precise, is the volume that passes by per hour, or per second.