Spray Starch System for Pulp and Paper

[mjar1989]

At our recycled paper mill we are planning to install a spray starch system to help with ply-bond .
http://www.freeimagehosting.net/t/1h2ie.jpg
The basic idea is to feed 14 % starch slurry and recycled water into a centrifugal pump. The diluted slurry then runs through rubber hosing, valves, filter, the shower bar and then returns to the inlet of the centrifugal pump to be recirculated.

How can I estimate:
1) Pressure drop across the shower bar
2) The filter/screen

 

[Navin A S]

size3) The flow rate of the pump1) To estimate the pressure drop across the shower bar, you need to know the flow rate and viscosity of the starch solution. You can then use the Darcy-Weisbach equation for calculating pressure drops in pipes. This equation is given by:P = (f*L*ρ*V^2)/(2*D)Where P is the pressure drop, f is the Darcy friction factor, L is the length of the pipe, ρ is the density of the solution, V is the velocity of the solution, and D is the diameter of the pipe.2) The filter/screen size will depend on the desired degree of filtration of the starch solution. You should consult a filter manufacturer to determine the best size and type of filter or screen for your particular application.3) The flow rate of the pump will depend on the pressure drop across the shower bar and the amount of starch that needs to be sprayed. Generally speaking, the more pressure drop and higher flow rate, the more starch will be sprayed. You can use the pump's performance curves to determine the flow rate at a given pressure drop.