Smooth operational flow

The well pubhcized JIT approach is a key driver of Lean Supply Chain and, as we have indicated earlier, it requires materials and products flow like water from the supplier through the production process onto the customer. The capacity bottlenecks are eliminated, the process times of workstations are balanced, and there is little buffer inventories between operations. Smooth operation flow... 

The smooth operation flow of materials and products are further enhanced by Lean Sigma methodology where the variances within processes and between workstations are minimized by the statistical techniques of Statistical Process Control (see Basu, 2004, pp. 151-157). 

Process characteristics Elimination of waste Smooth operation flow High level of efficiency Quality assurance Flexibility Market sensitivity A virtual network Postponement Selected lean supply chain principles... 

The use of dynamic pressure transducer in the combustor section, especially in the Low NOx Combustors ensures that each combustor can is burning evenly. This is achieved by controlling the flow in each combustor can till the spectrums obtained from each combustor can match. This technique has been used and found to be very effective and ensures smooth operation of the turbine. 

When all three draft tubes were operated at similar velocities, the pressure drops across all draft tubes and downcomers were comparable. However, solid particle velocities in outside downcomers close to the walls were substantially less due to wall effect and redistribution of downcomer aeration flow. Smooth operations under these conditions were possible. The solid particle velocities in outside downcomers can be increased by enlarging the downcomer cross-section or by increasing downcomer aeration through separate plenums to minimize wall effects. 

The process is continuous, allowing smooth product flow and requiring minimum human handling. Therefore, it is operable with low maintenance costs. 

Vibration interference is a common problem with dissolution equipment (23). Careful leveling of the top plate and lids is critical. Within the spindle assembly, the bearings can become worn and cause vibration and wobble of the shaft. The drive belts should be checked for wear and dirt. The tension adjustments for the belt should be optimized for smooth operation. Surging of spindles, though difficult to detect without closely scrutinizing the tester operation, can cause spurious results. Vessels need to be locked in place so that they are not moving with the flow of water in the bath. 

The key to smooth operation of a CFB system is the effective control of the solids recirculation rate to the riser. The solids flow control device serves two major functions, namely, sealing riser gas flow to the downcomer and controlling solids circulation rate. Both mechanical valves or feeders (see Figs. 10.1(a) and (d)) and nonmechanical valves (see Figs. 10.1(b) and (c)) are used to perform these functions. Typical mechanical valves are rotary, screw, butterfly, and sliding valves. Nonmechanical valves include L-valves, J-valves (see Chapter 8), V-valves, seal pots, and their variations. Blowers and compressors are commonly used as the gas suppliers. Operating characteristics of these gas suppliers which are directly associated with the dynamics and instability of the riser operation must be considered (see 10.3.3.2). 

In another publication (13) it was demonstrated that with proper maintenance and operating care each of two HPLC solvent delivery systems was capable of delivering smooth, precise flow rates of as low as a few microliters per minute. While not all chromatographers will desire this high degree of precision, it is clear that if people observe good laboratory practice,... 

Determination of the dimensions of the fluidized spout is based on operation experience. According to Li et al. (1982), the cone angle, 6, for smooth fluidized flow in the conical section may be taken as 6 = 10°. The minimum thickness of the spout is set by the requirement that the spout base area should not be less than the cross-sectional area of the interconnecting aperture. The diameter of the dipleg should be greater than four times the equivalent diameter of the aperture. These will ensure an aperture restriction capable of controlling solids flow through the valve. 

Feeding-rate control, for smooth operation. Setting control influences mainly product size and quality, while feed control determines capacity. Flow must also be synchronized with the feed requirements of downstream processes such as ball mills, and improved crusher efficiency can reduce the load on the more costly downstream grinding. 

Implementation hierarchy. Implement process control in a hierarchy based on frequency of decision making. The first level is protection (safety, environment, and equipment), and the second is smooth operation and stability (through control of flows, temperature, pressures, and levels and through alarms). The third level is product quality. The fourth level is protitabihty. The final level is monitoring and diagnosis. 

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