Salt bath furnaces

Fig. 1 shows the geometric dimensions of the specimen. The heat treatment conditions of the specimen is 830°C(vacuum) holding 15 minutes and 25 minutes for austenitisation, and then make it in the salt bath furnace immediately for tempering which the salt bath conditions were placed on each constant temperature of 290 °C, 310 C and 330 C for 30 minutes, 60 minutes and 120 minutes, then quench in the water. Each austempering conditions are coded by the salt bath conditions, such as 290°C-30m. 

This prepurified hydrogen may then be converted to UHg In the two-neck flask f, which is half filled with uranium turnings. These turnings must also be prepurified by treatment with dilute HNO3 (to remove the oxide film), washing and drying. Flask/is heated either with a nitrate-nitrite salt bath or an electric furnace. The temperature in the flask is 250°C. Two wash bottles, one empty and one filled with concentrated H O, are attached to flask /. 

When a piece of cold metal is suddenly immersed in molten salt, lead, zinc, or other molten metal, the molten liquid freezes on the surface of the cold metal, and heat is transferred by conduction only. After a very short time, the solid jacket, or frozen layer, remelts. From that time on, heat is transferred by conduction and convection. For that reason, discussion is postponed to the next section. Experimental determination of the heat transfer coefficient for heating metal solids in liquids is difficult, so practice is to record time in bath for good results as a function of thickness of strip or wire, as shown in section 4.7.1. on liquid bath furnaces. 

Perhaps the most common types of electrical equipment found in a laboratory are the devices used to supply the heat needed to effect a reaction or a separation. These include ovens, hot plates, heating mantles and tapes, oil baths, salt baths, sand baths, air baths, hot-tube furnaces, hot-air guns, and microwave ovens. The use of steam-heated devices rather than electrically heated devices is generally preferred whenever temperatures of 100 °C or less are required. Because they do not present shock or spark risks, they can be left unattended with assurance that their temperature will never exceed 100 °C. 

Plate (16 mm, or 0.640 In., thick) and bar (13 mm, or 0.5 in., diameter) were solution treated above the transus, water quenched, and aged at temperatures indicated in neutral salt baths or air circulating furnace with temperature control to 10 °C. Yield strengths varied from 65 to 1103 MPa (140 to 160 ksi). Tests were performed on standard Charpy specimens In three-point bending to determine plane-strain fracture toughness. 

The rare earth oxides of lanthanum, samarium and gadolinium were converted into soluble nitrate salts by dissolving them in the minimum amount of concentrated nitric acid. Then two sets were prepared by adding 2.0 ml of aqueous solution of La(N03)3.6H20 [0.2 M] and 0.01 ml of (n-BuO)4Ti to 25 ml of aqueous solution of Cu(N03)2 [1.0 M]. Similarly, two sets were prepared with Co(N03)3. Same procedures were followed for Sm(N03)3 [0.2 M] and Gd(N03)3 [0.2 M], One set of all these solutions were sonicated under ultrasonic bath (Model - Meltronics, 20 kHz, 250 W) for half an hour. The solutions prepared in normal and sonicated conditions were kept in muffle furnace (Model - Deluxe Zenith) first at 100°C for 2 h and then the temperature of the furnace was raised up to 900°C and calcined for 2 h. The solid composites prepared were then cooled to room temperature and treated as catalyst for phenol degradation. 

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