Furnace Connections

GC-MS Experiments. GC-MS pyrolyses were carried out using a Porapak Q column 6-ft (flow rate 35 mL/min) attached to a Finnigan 4000 quadrupole GC-MS. The sample was placed in a stainless steel tube 10 cm long connected to a 4 way valve. One of the outlets was attached to a Porapak Q column interfaced with the M.S. The stainless steel tube containing a portion of Au colloid film was placed in a furnace connected to a Variac provided with a digitial quartz pyrometer to measure the temperature. Three pyrolyses were performed at 100, 200 and 350°C with the Au-acetone film. 

Preparation of Molybdenum(VI) Oxide, a. Preparation of Molybdenum(VI) Oxide by the Thermal Decomposition of Ammonium Molybdate. Put a boat with 0.5 g of ammonium molybdate into a porcelain tube in an electric furnace. Connect one end of the... 

The thermal black process operates discontinuously and generally utilizes natural gas as a feedstock. A production unit consists of two cylindrical furnaces connected to one another, in which refractory bricks are piled one on top of another for heat storage with a large cavity in between. The two furnaces are operated alternately while the first furnace is being heated to the reaction temperature (ca. 1300 to 1500°C) with a stoichiometric mixture of air and combustible gas (mainly natural gas), natural gas is fed into the second already heated furnace and is thermally pyrolyzed. Since the reaction is endothermic, the furnace cools and the gas flows are switched when a critical minimum temperature is reached and the first furnace utilized, while the second is heated up again. The cycle time is about 5 minutes. 

Furnace—Furnace Connections—Experiments in Catalysis-Negative Catalysis—Detecting the Presence of Carbon... 

Pyrolyzer furnace connecting directly to the capillay column oulet. 

The reactor is surrounded by a small furnace connected to a programming controller which keeps the catalyst temperature constant or raises it linearly with time at various speeds. 

In addition to these techniques, analytical pyrolysis experiments were performed where 0.5-mg samples were batch pyrolyzed under flowing helium gas in a tube furnace connected to a hquid nitrogen cold trap. By wanning the cold trap, the pyrolysis products were transferred directly to a GC/MS system for identification. 

Power Supplies and Controls. Induction heating furnace loads rarely can be connected directiy to the user s electric power distribution system. If the load is to operate at the supply frequency, a transformer is used to provide the proper load voltage as weU as isolation from the supply system. Adjustment of the load voltage can be achieved by means of a tapped transformer or by use of a solid-state switch. The low power factor of an induction load can be corrected by installing a capacitor bank in the primary or secondary circuit. 

After it leaves the stoves, the hot blast enters a large refractory-lined busde pipe to distribute the gas evenly around the furnace. Multiple connecting pipes (tuyere stock) direct the hot blast to the blowpipes. At the ends of the blowpipes are the tuyeres, water-cooled copper no22les set into the refractory lining of the blast furnace. 

In practice, triple alloy is added to a clay graphite cmcible in a refractory-lined vacuum-tight chamber (Fig. 14). Power input is controlled by adjusting the appHed voltage until the charge is melted. A refractory cover is placed over the cmcible and sealed with sand. The furnace cover contains an opening which mates with a port connecting to a condenser. 

Heat Recovery and Seed Recovery System. Although much technology developed for conventional steam plants is appHcable to heat recovery and seed recovery (HRSR) design, the HRSRhas several differences arising from MHD-specific requirements (135,136). First, the MHD diffuser, which has no counterpart ia a conventional steam plant, is iacluded as part of the steam generation system. The diffuser experiences high 30 50 W/cm heat transfer rates. Thus, it is necessary to allow for thermal expansion of the order of 10 cm (137) ia both the horizontal and vertical directions at the connection between the diffuser and the radiant furnace section of the HRSR. 

After the waterwaH tubes deHver the saturated steam back into the top of the boHer dmm, moisture is separated out by a series ofbaffl.es, steam separators, and cormgated screens. The water removed drops down into the hot water contained in the steam dmm. The steam travels out through either a dry pipe, which leads to a superheater header, or a series of superheater tubes that connect directiy into the top of the steam dmm. The superheater tubes wind back into the top of the furnace and/or a hot flue-gas backpass section, next to the economizer, where heat from the combustion gases exiting the furnace superheats the steam traveling through the tubes. 

A typical 20-MW, a-c furnace is fitted with three 45-in. (114.3-cm) prebaked amorphous carbon electrodes equdateraHy spaced, operating on a three-phase delta connection. The spacing of the electrodes is designed to provide a single reaction zone between the three electrodes. The furnace is rotated to give one revolution in two to four days or it may be oscillated only. Rotation of the furnace relative to the electrodes minimizes silicon carbide buildup in the furnace. 

The failure took place in a large water-tube boiler used for generating steam in a chemical plant. The layout of the boiler is shown in Fig. 13.1. At the bottom of the boiler is a cylindrical pressure vessel - the mud drum - which contains water and sediments. At the top of the boiler is the steam drum, which contains water and steam. The two drums are connected by 200 tubes through which the water circulates. The tubes are heated from the outside by the flue gases from a coal-fired furnace. The water in the "hot" tubes moves upwards from the mud drum to the steam drum, and the water in the "cool" tubes moves downwards from the steam drum to the mud drum. A convection circuit is therefore set up where water circulates around the boiler and picks up heat in the process. The water tubes are 10 m long, have an outside diameter of 100 mm and are 5 mm thick in the wall. They are made from a steel of composition Fe-0.18% C, 0.45% Mn, 0.20% Si. The boiler operates with a working pressure of 50 bar and a water temperature of 264°C. 

After the initial hydrogenation studies were completed with WVGS 13407, all other liquefaction experiments were conducted in a larger, 3.8-liter bolted-closure autoclave fitted with an electrically driven magnetic stirrer arbitrarily set to provide mixmg at 1000 rpm. A temperature controller and power supply were connected to a three-zone furnace to control reaction temperature... 

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