SE461609B - SEAT AND POWER PLANT FOR OIL OIL IN A FLUIDIZED BED - Google Patents

Description

461 609 2 THE INVENTION According to the invention, a satisfactory temperature distribution is achieved by adding the oil in the form of a water / oil emulsion. delays combustion. A heating zone and a nozzle are obtained around a nozzle outside a combustion zone within a larger bed volume. The water bursts at evaporating the fuel so that it spreads within the bed. A power plant there the invention applied includes except in such plants normally existing equipment also an equipment for preparation of oil emulsion and control equipment for driving it.

A suitable oil emulsion contains 5-40 X water, preferably 0-2 Z emulsion. and the rest oil. Appropriate water content depends on the oil contained in the fuel.

FIGURES The invention is described in more detail with reference to the accompanying figures.

Fig. 1 shows the course of events during the combustion of an oil droplet.

Figures 2 and 3 show the combustion zone at an oil nozzle at small and large, respectively oil drops.

Pig 4 combustion at sparsely placed nozzles and temperature gradient _ horizontally and vertically in a bed. ' Fig. 5 combustion at tightly placed nozzles and temperature gradient vertically in a bed.

Fig. 6 problems with oil accumulation at the bed bottom.

Fig. In the course of events during combustion of an oil emulsion.

Fig. 8 combustion around an oil nozzle during firing with an oil emulsion.

Fig. 9 combustion in a bed during firing with an oil emulsion and temperature tour gradients horizontally and vertically within the bed. 3 461 609 At time 0 on the time scale 1 in Fig. 1, an oil drop 2 leaves a mouthpiece. piece, volatile constituents denoted by 3 leaves the oil drop and burned and a coke residue 4 is obtained. The process is second-rate. Boil- the remainder 4 is then incinerated. Coal combustion takes place in principle_in the same way but due to the lower content volatile constituents occur the combustion is slower and smoother within a fluidized bed.

Figures 2 and 3 show nozzles 5 and 6. Small oil droplets are burned in one small intensive combustion zone 7. large droplets in a larger combustion zone 8. Especially with small drops, it is very difficult to achieve the desired value even temperature distribution in a bed.

In Fig. Q, 10 denotes a boat vessel with a bed 11 of particulate material and steam tubes 12 for cooling the bath 11. In the bottom 13 of the combustion chamber there are sparsely placed oil nozzles 14 and air nozzles 15 for supply of air for fluidizing the boat 11 and combustion of supplied oil. Due to the high content of volatile constituents, combustion rapidly in restricted combustion zones 16 and may contain some of the the firing takes place in the freeboard 17 of the combustion chamber 10. The unsatisfactory the distribution of the combustion means uneven temperature within the bed 11 with low temperature in areas 18 between the combustion zones 16. Combustion in the freeboard 17 can mean that the temperature becomes very high. The uneven the temperature distribution within the bed vessel 10 means that harmful thermal stresses of the included structural details, such as the tubes 12. occurs. Curve 19 below the bed vessel 10 shows the temperature variation in a W horizontally and the curve 20 next to the bed vessel 10 shows the temperature the variation in a vertical section through the bed vessel 10.

Even horizontal temperature distribution within the bed can be achieved with dense cation of oil nozzles 14 in the bottom 13 of the well chamber 10 As shown in fig 5 then the combustion takes place within a limited height and becomes the combustion zones 16 low. Temperature gradient of the kind shown by curve 21 obtained. Farbrmmmgegeeeme kylee ned 1 een ev fi ubeme 12 ßuaeae kyl- zones. The low temperature of the gases leaving the combustion chamber means low efficiency of a gas-powered turbine. The vertical temperature the gradient involves thermal stresses of the material. 461 609 4 Fig. 6 shows another problem that can arise during oil firing. At insufficient decomposition of the oil. ie large drops of oil, when it leaves nozzle 4, the oil droplets can form agglomerates 22 and collect at bed the bottom 13. of the vessel 10. This is depleted of volatile constituents and eventually coke and forms a slag that interferes with combustion and hinders or prevents the discharge of residues from the incineration from bed bug 10. It can also prevent or impede restart or put again nozzles.

Is the oil fuel supplied to the bed 11 of the combustion chamber 10 as a water / oil emulsion, the above-mentioned olefins are substantially eliminated.

The course of events during the introduction of the fuel into the bed is illustrated in Fig. 7L and 8. The water content of a fuel drop 2 delays the heating and the departure of volatile substances. Fuel 2 is spread in the bed. After a time volatiles emit and the water evaporates and bursts the fuel drop 2 in smaller drops 2a. This results in good distribution of the fuel and prevents accumulation of oil agglomerate 22 at the bottom of the combustion chamber. Pasta carbon particle 4 are formed which are spread in the bed 11 and incinerated.

In a zone 23 (Fig. 8) around the nozzle, the fuel droplets 2 are heated zone boundary, the fuel droplets 2 begin to decompose by gasification of the volatile constituents of the fuel and by evaporation of the water content.

The water content thus means that the fuel is better distributed so that the firing zone 16 is widened.

The invention expands the combustion zone around and over a fuel nozzle so that even distribution of combustion is obtained throughout the bed and Even temperature and insignificant temperature gradients are obtained even in sparse placement of oil nozzles. This is illustrated in Fig. 9. Curves 25 and 26 below and next to the bed vessel 10 shows the temperature distribution in the bed in a horizontal and a vertical section through the bed 11. Temperature the tour is almost jam and the temperature gradients are insignificant. 'a

Claims (3)

461 609 PATEHTKRAV 1. A method of controlling the temperature distribution and avoiding the accumulation of oil in the bottom of a fluidized bed of particulate matter when burning oil is characterized by the oil being added to the bed in a water / oil emulsion. 2. A method according to claim 1, characterized in that the water / oil emulsion contains between 5 and 40 Z of water, less than 2 X of emulsifier and the remainder oil. 3. A method according to claim 1, characterized in that the water / oil emulsion is fed to a fluidized bed where the combustion takes place at a pressure exceeding the atmospheric pressure. Power plant for carrying out the method according to one of Claims 1 to 3, characterized in that the plant, in addition to conventional equipment for such plants, comprises equipment for the production of a fuel consisting of oil, water and emulsifiers and control equipment. for regulating the composition of the emulsion.