Feed tank size

The pipe sizes for feed and return lines for the closed loop operation are much smaller than that for the open loop system which can also reduce the capital and operating cost. The feed tank size can also be much smaller for the closed loop which then allows shorter residence times for heat or shear sensitive products. 

Finishers. Magnetic finishing dmms are designed to produce the highest possible iron content in the concentrate. Typically, the feed size has been reduced to a nominal size of —74 fim (—200 mesh) or —44 fim (—325 mesh) in a ball mill circuit. The feed tank and feed arrangement of the finisher separator is usually of the semicountercurrent design. The objective is to disperse the feed particles in order to obtain maximum rejection of nonmagnetic particles. Both 762 and 914 mm dia dmms have been used in finisher appHcations. Dmm covers frequendy are not used in finisher constmction because of the material size. 

Rotation speeds to 40 r/min are possible with cakes typically 3 to 6 mm (0.12 to 0.24 in) thick. Filter sizes range from 930 cm to 19 m (1 to 207 ft") with 93 percent of the area active. The slurry is fed into a conical feed tank designed to prevent solids from settling without the use of mechanical agitators. The proper hquid level is maintained by overflow, and submergence ranges from 5 to 70 percent of the drum circumference. 

Feedwater pipework will normally be gravity head suction from the hotwell or feed tanks to the pumps and at a pressure in excess of the boiler working pressure from the pumps to the boiler. Few problems occur on the pipework between pumps and boilers. However, inadequately sized suction lines can give rise to cavitation at the feed pump with subsequent boiler shutdown. The feed tank should always be positioned to suit the temperature of the feed-water and the pipework sized to give free flow at that head, taking account of bends, valves and filters. 

The design, size and siting of the boiler feed tank or hotwell must be compatible with the boiler duty capacity and system temperatures. They should be installed giving sufficient space for access to controls, valves and manways. 

The critical feed time t it depends on the location and number of feed pipes, stirrer type, and mixing intensity, and increases with increasing reactor volume. When a constant power-to-volume ratio is preserved, ta-u is proportional to and where D., is the stirrer diameter and Vr the reactor volume (Bourne and Hilber, 1990 Bourne and Thoma, 1991). The productivity of the reactor expressed as the amount of product formed per unit time becomes almost independent of reactor volume. The reason is that the reaction goes to completion in the zone nearby the stirrer tip. The size of this zone increases independently of the tank size it only depends on the velocity of the liquid being injected, the location of the nozzle, and the stirrer geometry and speed of rotation. Accordingly, for rapid reactions, the feed time will also be the reaction time. 

Method Cyanide is destroyed by reaction with sodium hypochlorite under alkaline conditions. System component Reaction tanks, a reagent storage and feed system, mixers, sensors, and controls two identical reaction tanks sized as the above-ground cylindrical tank with a retention time of 4 h. Chemical storage consists of covered concrete tanks to store 60 d supply of sodium hypochlorite and 90 d supply of sodium hydroxide. 

For key raw materials that can create significant hazards if overcharged the maximum possible charge should be physically limited by sizing the feed tanks to hold no more than the required quantity. 

Note Coating with a deterrent not only modifies the rate of burning of the propint, but it also renders the grains waterproof c)The slurry of coated grains is pumped to the feed tank from where it can be sent either to the rolls(if the grain web is to be reduced in size) or directly to the top-feed filters(if the rolling operation is considered unnecessary)... 

Preliminary experiments on such a strategy of coupled separation and photodegradation were carried out on a simplified experimental device schematically represented in Figure 25.15a. It consists of two tanks separated by a 1.8 pm pore size alumina microfiltration symmetric membrane with grains coated with an anatase layer. The feed tank contained methylene blue (MB) and the reception tank was initially filled with pure water. Under continuous UV irradiation, MB is completely destroyed as it arrives in the reception tank (Figure 25.15b). The quantity of destroyed MB per surface area unit is equal to 1.0 X 10 mol.s. m . 

The process illustrated here is a simple modification of a previous example. Shown in Fig. 7-25, this modified process prepares the crude ding as a slurry in a feed vessel. The slurry feed was continuously charged to a dissolver that was maintained at a temperature of about 50 C. The feed rate was controlled such that the slurry was put into solution in the dissolver, and the dissolved solution charged continuously to the crystallizer through an in-line filter to remove extraneous insoluble particles and traces of the undissolved product. The crystallizer contained the seed slurry with the correct form at a lower temperature, about 25 C. The crystallizer slurry was continuously filtered through a ceramic cross-flow Alter system with a pore size of 0.2 p-m, and the clear permeate was sent back to the dissolver for further solubilization of product. This was inn until the feed tank was empty and all supersaturation was relieved. The critical parameters for successful development of this process were solubilities of the polymorphs, seeding, and control of supersaturation. 

Essential equipment to a productive fermentation department are sterilizable tanks for nutrient feeds. Multiproduct plants usually require several different sizes of feed tanks (i) a small volume to be transferred once... 

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