Liquid flow furnaces

Continuous liquid flow furnaces include boiler furnaces, fluid heaters (such as Dow-therm heaters), evaporators, cookers, and many liquid heaters used in the chemical process industries. (See figs. 1.12 and 4.25.) The tubing through which the liquid fluids flow is often built as an integral part of the furnace, for which many textbooks are readily available therefore, they will not be discussed at length here. 

The furnace is tapped about every forty-eight hours. The liquid flows first into a receiver, in which the fluorides carried over are retained in the solid state, and from this vessel into moulds, giving ingots which can easily be divided. 

For many readers, the term "construction principle may mean much more than a twinning the calorimeter can also be built liquid or aneroid, closed or open, in a Dewar, with a liquid thermostat or a furnace, with thermopiles or thermistors, with a batch or liquid flow mixing system, with a steady flame or a bomb combustion device, with a sample drop facility and with a multi-sampler). 

Most of the preceding discussions related to liquid flow heaters in which the liquid was inside tubes and the furnace gases outside the tubes. Figure 4.27 shows some fire-tube boilers wherein the opposite is the case that is, furnace gases inside tubes that are surrounded by liquid water. These are mostly used in smaller boiler installations. 

The frimace and its associated infrastructure (offgas cooling, bag house, etc.) are controlled by an upgraded Programable Logic Control (PLC) system. Several monitors located in the control room display all process variables associated with the operation. Field instruments which comprise the furnace control system provide 4—20 mA inputs and outputs to indicate gaseous as well as liquid flows, pressures, temperatures and levels. The displays include snapshot indications, controllers, process trends and alarms as well as griqihics. 

Phases Gas plus reacting solid. Solid particle diameter 8-300 mm. Gapacity 0.2-1 kg/s. Can operate as a shaft furnace where the product is a solid, the furnace has countercurrent gas-solid flow and the blast furnace where the product is hot metal liquid the furnace has countercurrent gas liquid solid flow. Blast fur-... 

Be that as it may Willson certainly tried to devise a route for the manufacture of calcium metal in quantity by heating calcium oxide (lime) with carbon (coke). He had moved to Spray in the autumn of 1891 and built a small hydroelectric plant and an electric-arc furnace. On May 2, 1892, the initial experiment was performed. At the high temperature of the arc a brown liquid flowed from the furnace and solidified on cooling. 

Centrifugal pumps are subject to mechanical damage when they lose suction pressure or when the discharge flow is blocked. Furnace tubes may overheat and fail when liquid flow through the tubes is greatly reduced. Low-flow trips protect process equipment against these failures. This trip may be used to shut down a pump or block off fuel to a furnace. To test an orifice-type low-flow trip, proceed as follows ... 

Binary liquid metal systems were used in liquid-metal magnetohydrodynamic generators and liquid-metal fuel cell systems for which boiling heat transfer characteristics were required. Mori et al. (1970) studied a binary liquid metal of mercury and the eutectic alloy of bismuth and lead flowing through a vertical, alloy steel tube of 2.54-cm (1-in) O.D., which was heated by radiation in an electric furnace. In their experiments, both axial and radial temperature distributions were measured, and the liquid temperature continued to increase when boiling occurred. A radial temperature gradient also existed even away from the thin layer next to the... 

Various hollow-cone simplex atomizers (Fig. 2.1) have been developed for combustion applications, differing from each other mainly in the way that swirl is imparted to the issuing liquid jet. In these atomizers, swirl chambers may have conical slots, helical slots (or vanes), or tangential slots (or drilled holes). Using thin, removable swirl plates to cut or stamp the swirl chamber entry ports leads to economies of the atomization systems if spray uniformity is not a primary concern. Large simplex atomizers have found applications in utility boilers and industrial furnaces. Oil flow rates can be as high as 67 kg/min. 

---