Feed ports

FIG. 18-50 Intermeshing corotating twin screw extruder (a) drive motor, (h) gearbox, (c) feed port, (d) barrel, (e) assembled rotors, (f) vent, (g) barrel valve, (h) kneading paddles, ( ) conveying screws, (/) splined shafts, (k) blister rings, (APV Chemical Machinery, Inc.)... 

The wet eore that remains in the feed port is blown baek with air for 20-30 seeonds to ensure that the diseharged eake is eompletely dry. 

In an effort to determine the cause of low yields from a reactor network, your technicians have carried out some tracer studies in which 4.000 kg of an inert material are quickly injected at the feed port. The tracer levels leaving the reactor at various times after injection were as follows. 

Figure 7.7. Plate and frame press. A-inlet passage. B-feed ports. C-filtrate outlet. D-frames. F-plates...

Smith, W.S., Sickles, R.A., Miller, LA., and Womer, T.W., An Experimental Investigation into Solids Feeding Characteristics of a Single Piece Barrel with Integral Feed-port Design vs a Standard Two Piece Water Cooled Feedblock and Barrel Configuration, SPE ANTEC Tech. Papers, 53, 390 (2007)... 

Figure 17 Loading the fluid bed through the product in-feed port and unloading through...

Fig. 2. Internieshing co-rotating twin-sciew extruder A, motor B, gear box C, feed port D, clam shell barrel E, vent port F, screw shafts G, conveying screws H, kneading paddles I, barrel valve and J, bHster rings. Courtesy of APV Chemical Machinery Inc.

The spiral die, commonly used to extrude tubular blown films, eliminates weld line effects and produces a thermally and geometrically homogeneous extrudate. The polymer melt in a spiral die flows through several feed ports into independent spiral channels wrapped around the circumference of the mandrel. This type of die is schematically depicted in Fig. 3.18. 

Fig. E6.3b Side view of a hollow cylinder pump with feed port at one end of the shaft and discharge at the other end.

Fig. E6.6b The synthesis of the free rotating flight pump from building block 2. (a) an annular channel is created between the rotating shaft and hollow cylinder (b) the channel is twisted and extended into a helical spiraling channel (c) the channel is formed by a spiral that rotates between a stationary shaft and stationary barrel, with a feed port and exit port machined into the barrel.

The system consists of three subsystems the feed port, the screw, and the pelletizing plate, which are connected in series. Therefore, for steady state operation with atmospheric inlet and outlet conditions, the mass flow rate in each subsystem G,- is constant... 

Fig. 9.2 Schematic view of a melt extruder. The extruder is equipped with a feed port and a pelletizing plate.

However, experimental studies (50), using either powder feed or pelletized feed with some recycled melt over the channel block into the feed port, have not exhibited drag removal melting but a dissipative mix-melting mechanism, discussed in Chapter 5. As... 

Fig. 9.50 Schematic view of a three-chamber co-rotating disk devolatilizer. The molten inlet feed is deposited on the disk surface of the first chamber by a spreading block (SB). The film is exposed to vacuum via the vacuum port. The melt is collected at the channel block (CB) and forced to flow over the top of the disk to the feed port of the second chamber. Similarly, the melt is fed into the third chamber from where the devolatilized melt exists.

It is worth noting that the method used by Vergnes et al. in experimentally obtaining the relative viscosity equation parameters, a and ft in Eq. 10.3-6. They worked with two almost identical PP homopolymers, one in 4-mm mean pellet diameter form, and the other in the form of small, 750-pm-diameter beads (Solvay Eltex HL 101). A 21-mm Co-TSE was fitted with a rheometric slit of length L = 52 mm, width w = 28 mm, and an adjustable gap spacing 1.5 < h < 2.5 mm. The polypropylene in pellet form was fed at the feed throat and melted. Just before the die, a second feed port introduced the PP in bead form at various rates, resulting in different effective values. Two pressure transducers at the die were used to record the slit pressure drop AP(relative viscosity was then expressed as... 

Vent-Port Staging Analysis of a 42% polychloroprene - 58% CCI4 Undergoing Devolatilization in a JSW TEX 65 Counter-TSE Examine the experimental results obtained by Sakai et al. (33), shown on Fig. 10.27 in terms of equilibrium stage analysis. The results indicate that the incoming 58% CCI4 stream concentration is reduced to just above 7000 ppm after the second vent port downstream of the feed port. What does vent port equilibrium analysis ... 

In the case of flash degassing, the polymer solution is first heated under pressure to above the boiling point of the volatile components and decompressed directly into the ZSK. The polymer and solvent (monomer) spontaneously separate from each other inside the ZSK and the majority of the volatile components are released via the back venting system. Depending on the pressure and the temperature, up to 90% of the solvent can be removed in this way. Efficiency depends on the temperature of the polymer solution at the feed intake, the pressure drop in the back vent, and the material properties of the feeding system. The back vent is located upstream from the polymer or polymer solution feeding port (see Fig. 10.2). In this case, there is no melt in the screw channel so that the entire screw cross-section is available for the removal of gas or vapors. 

Through-hardened design especially for housing with several feed ports, e.g., made of wear-resistant tool steel or wear- and corrosion-resistant chrome steel. This design is often constrained by the size of the component because heat treatment can cause stress cracks in cross sections with thick walls. 

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