Roll separating forces

F Roll separating force dyn Itf U Spouted-bed inlet gas velocity cm/s ft/s... 

The most important factor that must be determined in a given apphcation is the pressing force required for the production of acceptable compacts. Roll loadings (i.e., roll separating force divided by roll width) in commercial installatious vary from 4.4 MN/m to more than 440 MN/m (1000 Ib/in to more than 100,000 Ib/in). Roll sizes up to 91 cm (36 in) in diameter by 61 cm (24 in) wide are in use. 

Calendering problem with a Newtonian viscosity polymer. A calender system with R = 10 cm, w = 100 cm, h0 = 0.1 mm operates at a speed of U =40 cm/s and produces a sheet thickeness In = 0.0218 cm. The viscosity of the material is given as 1000 Pa-s. Estimate the maximum pressure developed in the material, the power required to operate the system, the roll separating force and the adiabatic temperature rise within the material. 

We can also compute the roll separating force, F, and the power required to drive the system, P,... 

From the pressure distribution we can now compute the roll separating force using F/W = mR F(n) (6.201)... 

The roll separating force has been calculated from roll deflection (admittedly... 

Roll-separating force, RF, is calculated from eqn. (2) where F is determined from Fig. 5.9. 

The roll separation or compaction forces are expressed by equation (104) which can be rewritten for briquetting rolls as " ... 

Figure 242. Effect of roll diameter on roll (separation) force. Briquetting pressures 1. 100 000 lb in" (approx. 6.9 x 10 Nm" ). 2. 50 000 lb in 2 (approx. 3.4x 10 Nm ). 3. lOOOOlbin" (approx. 6.9xl0 Nm 2)...

A calendering system (R of 0.17 m. Ho of 0.006 m, roll speed of 0.1 m/s) processes a material whose viscosity is 1 X 10 N s/m. For this system, find the sheet thickness, maximum pressure, and roll-separating force. 

---