Sulphur furnace

Fig. 25.11. Sankey energy flow diagram for a 1000ton/day sulfur-burning double absorption sulfuric acid plant (feed gas 10% S02). A Blower B Sulphur furnace C Waste heat boiler D Catalyst bed 1 E Steam superheater F Catalyst bed 2 G Boiler H Catalyst bed 3 J Intermediate heat exchangers K Intermediate absorber L Converter bed 4 M Economizer N Final absorber O Air dryer P Acid coolers. (Courtsey Lurgi GmbH, Frankfurt, Germany.)...

Sulphur Furnace and Vestibule Fixed and roller supports, inner air distribution, peepholes and manhole position, location of thermocouples, hydraulic tests for sulphur feed line, and sulphur spray gun for the furnace ... 

Molten sulphur (150 C) from storage is pumped to the sulphur furnace where sulphur is converted with an excess of oxygen from the process air to SO2 (4-7% SO2 by volume in "air"). The fiimace outlet temperature of the S02/air varies with the percentage of SO2 in air between 600 and 700 C, indicating the strong exothermic character of the reaction. The S02/air flow is cooled in an indirect air cooler from 6(X)-700 C to about 420 C. 

Calculate the outlet temperature of the SOj/air mixture leaving the sulphur furnace. 

Design a double hairpin ("trombone") cooler to cool the S02/air ex sulphur furnace to a temperature of 430with ambient air flowing counter-current through the jacket of the trombone cooler inlet cooling air temperature 30 "C, outlet 250 C. Mean SOi/air flow velocity in tube 25 m/s, mean cooling air velocity in jacket 20 m/s. 

In the 21st century an attempt is made in this presentation of a new, unconventional and innovative approach to produce sulphuric acid and sulphonating agent without a sulphur furnace, multipass converters, heat exchangers or expensive towers. A special feature of this process will be zero emission of sulphur dioxide, eliminating more than one million tonnes of acid rain at the current production of Sulphuric Acid in the world. 

A BLOWER B SULPHUR FURNACE C WASTE HEAT BOILER D CATALYST BED 1 E STEAM SUPERHEATER F CATALYST BED 2 G BOILER H CATALYST BED 3 J INTERMEDIATE HEAT EXCHANGERS K INTERMEDIATE ABSORBER L CONVERTER BED 4 M ECONOMIZER ... 

It consists of a stepper motor drive system and a valve coupled with stepper motor. The drive system accepts 4-20 mA current signal from the controller and generates proper sequence of position signals proportional to the modulus of the deviation of the control signal from 12 mA. The stepper motor operated valve has been used successfully for primary and secondary air control in a sulphur furnace, condensates control in desuperheater, SO2 control in sulphiter, imbibition water temperature control etc. 

The Micro-TEIMAC system was installed and commissioned covering a number of most important temperature points including juice clarification, evaporators, pan crystallizers, boilers and sulphur furnaces. The system has worked reliably in the industrial environment. All the temperature data points value has been simultaneously displayed on the display panel and updated after every 24 seconds. The control status and deviation indicator for each process point is mounted near the manually operated valve of the process point. The operator finds the presence of these indicators near the control valves very useful in the process of maintaining the temperature within the limits. 

The successful application of nickel-chromium-iron alloys as structural components of industrial furnaces and as chambers and containers in chemical processing under conditions of exposure involving sulphur substantiates their good resistance to this form of corrosion. These materials are used for service temperatures in the range 750-1 200°C, the upper limit of serviceability being determined largely by the chromium content of a particular alloy. Results of corrosion tests (Table 7.24) on cast nickel-... 

The furnace scales which form on alloy steels are thin, adherent, complex in composition, and more difficult to remove than scale from non-alloy steels. Several mixed acid pickles have been recommended for stainless steel, the type of pickle depending on the composition and thickness of the scale For lightly-scaled stainless steel, a nitric/hydrofluoric acid mixture is suitable, the ratio of the acids being varied to suit the type of scale. An increase in the ratio of hydrofluoric acid to nitric acid increases the whitening effect, but also increases the metal loss. Strict chemical control of this mixture is necessary, since it tends to pit the steel when the acid is nearing exhaustion. For heavy scale, two separate pickles are often used. The first conditions the scale and the second removes it. For example, a sulphuric/hydrochloric mixture is recommended as a scale conditioner on heavily scaled chromium steels, and a nitric/hydrochloric mixture for scale removal. A ferric sulphate/ hydrofluoric acid mixture has advantages over a nitric/hydrofluoric acid mixture in that the loss of metal is reduced and the pickling time is shorter, but strict chemical control of the bath is necessary. 

Inconel (typically 76 per cent Ni, 7 per cent Fe, 15 per cent Cr) is used primarily for acid resistance at high temperatures. It maintains its strength at elevated temperature and is resistant to furnace gases, if sulphur free. 

Any chemical derived from petroleum, the main refining processes being fractional distillation, catalytic cracking and platforming (reforming the constituents with the aid of a platinum catalyst). Since sulphur may be recovered from petroleum refining and since SBR, furnace black and processing oils are all petrochemicals it is... 

Heating the Tube.—Place the iron case with its tube in a bomb or tube furnace in such a way that the end with the capillary is raised somewhat and directed towards the wall on which a shield is fixed and close the furnace. Several tubes may be heated simultaneously. Light all the burners and heat gradually to the desired temperature, regulating the gas supply at the main tap. For aliphatic halogen compounds (and many sulphur compounds) this temperature is about 250°, for the aromatic compounds (and sul-phonic acids) it is about 300°. Most substances are completely oxidised after three to four hours, but in the case of aromatic compounds the heating is continued for some hours longer. 

The objectives of Aho s study [8] were to investigate the effects of peat type, particle density, diameter and moisture content, and oxygen concentration on the flue gas emissions of nitrogen oxides and sulphur dioxide from a homogenous countercurrent batch bed combustion using a pot furnace. His aim was to simulate the interaction of chemistry between the fuel bed system and the combustion chamber of a overfired batch bed. However, he also presented some results on the combustion heat rate. 

A second pyroreactor has been added to the system as back-up, to minimize the system down-time due to furnace heating element failure. The system has been expanded to also perform sulphur determination by oxidative combustion with UV fluorescence detection. The current sample load for the system is greater than 12 000 samples per year with a maximum capacity of the system, operating under optimum conditions, of greater than 40 000 samples per year. 

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