Steam Requirements for Heating (Wet Steam Accumulator)

https://www.google.com/?gws_rd=ssl#q=%22steam+accumulator%22

20,200 results in 0.26 seconds.

Why wait? Save yourself the delay by using a set of Steam Tables to work it all out for yourself.

How lazy!

Assuming a specific heat of 0.5 for the fabric is probably conservative; the water is the main load anyway. Then compare the sensible heat of water and fabric with the latent heat of condensation of the steam, allowing some reserve.

Call the accumulator salesman, he should know...

http://www2.spiraxsarco.com/resources/steam-engineering-tutorials/the-boiler-house/steam-accumulators.asp

http://www.esmagazine.com/ext/resources/ES/Home/Files/PDF/0909Fultonwhitepaper.pdf

As a rough estimate

Cotton 1.5kJ/kgK so heating 1000 kg to 90C = 90,000 kJ

to 135C = 160,000 kJ

Water is 4.2 kJ/kgK to for 7000kg to 90 C = 1,760,000 kJ

to 135C = 3,090,000 kJ

So you can see that the assumption for the cotton is pretty much irrelevant.

What is much more important though is to ask if any water boils at 135C. You have a dye and cotton both of which will increase the boiling point but not by 35C - is the vessel under pressure? The energy needed to vapourise any water is significant.

I am going to assume that the pressures you quote for the steam are psi (gauge) but its not clear why there are two such different pressures. Do you generate steam at 130psig and then use it at 90psig. If so is it desuperheated en route or is it used as superheated steam?

Taking the worst case and using saturated steam

90 psig 6.2 barg Saturated Temp 166 C Latent heat 2061 kJ/kg

At 90 C Duty = 1,850,000 kJ => Steam Demand = 1850000/2061 = 900kg

At 135 C Duty = 3,250,000 kJ => Steam Demand = 3250000/2061 = 1580kg

Note that this calculation makes no assessment for losses. Heating a huge dye tank will have significant losses even if well lagged. You can reduce the losses by heating quickly but this requires a larger heater - you say if the heating is done by an external heater so I can believe you could carry out the heating quickly.

If the dye tank is open at the top then your heat losses will be huge.