DE1041621B - Heating oil - Google Patents

Description

GERMAN

The invention relates to heating oils which give ash when burned. When using such Heating oils, in particular residual heating oils with an ash content, in combustion power plants, e.g. B. Gas turbine and furnace, occurs as a result of the action of the ash components, such as vanadium and / or Sodium compounds, very often a corrosion or oxidation of the metals of the systems. Even opposite Materials that are very resistant to heat, e.g. B. nickel-chromium-iron alloys are used by the Combustion products of such residual heating oils with a high ash content attacked.

In most cases, the ash formed also has a relatively low melting point and therefore adheres to the surfaces with which it comes into contact, for example the turbine blades. The encrustations formed as a result strongly increase the effectiveness of such a system down. In the modern power generation systems with high operating temperature, these disadvantages are the use of residual heating oils even more so.

A wide variety of options has already been proposed to remedy the difficulties mentioned Substances such as magnesium oxide, zinc oxide, barium carbonate, silicon dioxide and some silicates, to be used as additives in the combustion of heating oils. These compounds are said to be the ash constituents partially render it harmless in the form of vanadates and partially simply as thinner heating oil

have an effect.

It is also known to use silica and calcium carbonate in an amount for the same purpose use that corresponds to at least half the vanadium content of the fuel. Likewise was The addition of magnesium sulfate and calcium naphthenate to diesel oils has already been recommended to prevent corrosion in internal combustion engines to counteract.

While some of these additives actually reduce corrosion, so does the amount the ashes increased and the advantage achieved was nullified again.

It has now surprisingly been found that a heating oil which produces ash on combustion, but contains a smaller proportion of magnesium silicate or a mixture of magnesium oxide, hydroxide or carbonate with silicon dioxide, not only counteracts corrosion, but at the same time significantly less precipitated amount of ash results. It is important here that the silicate or the mixture of the listed magnesium compounds and silicon dioxide is free of other metals apart from magnesium, i.e. in addition to the applicant:
"Shell" Research Limited, London

Representative: Dr. K. Schwarzhans, patent attorney,
Munich 19, Romanplatz 9

Claimed priority:
Great Britain June 22, 1953 and May 7 , 1954

Alun Lewis, Little Sutton, Wirral, Cheshire,
and Robert Patrick Taylor, Wallasey, Cheshire

(Great Britain),
have been named as inventors

Magnesium does not contain more than 5 percent by weight of the same.

Although the present invention refers to any fuel oil, which results in ash on combustion, it may with special \ ^r orteil be applied to residual fuel with a high ash content. The expression “residual heating oils with a high ash content”, as used in the present description, is understood to mean liquid oils with an ash content of at least 0.005 percent by weight, measured according to the IP - 4/44 method (see “Standard Methods for Testing Petroleum an its Products «published by the Institute of Petroleum, 10th edition, on pages 22 and 23) and have a viscosity of at least 1.779 ° Engler at 37 ° C, and which consist of or contain a residual petroleum.

Such residual heating oils with a high ash content can be made from petroleum residues alone or as a mixture with other liquid fuels such as distilled or cracked hydrocarbon fuel oils. The invention is particularly valuable in connection with residual heating oils which are used in combustion result in an ash that is rich in vanadium and / or sodium compounds.

For economic reasons, the amount of the additives according to the invention used should as much as possible be small, but it should be sufficient to minimize the harmful effects of the ashes and to reduce the amount of ash deposited in the facility to the required level. In general, 0.01 to 1.0 weight

809 659/384

percent and preferably 0.1 to 0.5 percent by weight, based on the weight of the fuel oil, is used.

The magnesium silicate used in the present invention can be either natural or synthetic manufactured magnesium silicate. So are talc, asbestos flour, enstatite, hectorite, olivine and the like naturally occurring magnesium silicates suitable for commercially available soils with a high magnesium content. Suitable synthetic magnesium silicates or mixtures of those with silicon dioxide can by Addition of a magnesium salt to an aqueous sodium silicate solution can be prepared, wherein it in in the form of gels and in this form are particularly suitable for incorporation into heating oils.

Similar mixtures of silicon dioxide with magnesium oxide, hydroxide or carbonate can also be used can be used, and in this case too, the mixture ingredients can be natural or be of synthetic origin. So the silicon dioxide can be in the form of quartz or kieselguhr or in the form of a synthetic silica produced by precipitation from a silica gel was available.

The magnesium silicate and the above-mentioned mixtures are preferably in a very finely divided form State when they are added to the heating oils or injected into the combustion apparatus will.

The magnesium silicate or the mixture of magnesium oxide, hydroxide or carbonate and silicon dioxide can be dispersed in the fuel oil. In general, the dispersions should be from 1 to 75 percent by weight, preferably 5 to 50 percent by weight of the additive. Such concentrated dispersions are for injection into heating oil supply lines, air supply lines or combustion chambers or suitable for addition to heating oils for the purpose of producing the heating oils according to the invention.

The following examples are intended to illustrate the present invention in more detail, with the specified parts Parts by weight are.

example 1

A residual heating oil with a viscosity of 65.0 ° Engler at 37 ° C and an ash content of 0.07 percent by weight, with approximately 60 percent by weight of the ash consisting of vanadium pentoxide, was in the combustion chamber of a gas turbine at a speed of 11.3 kg per hour burned. Finely divided talc was added to the air stream in a ratio corresponding to 0.5 percent by weight of the fuel is sprayed.

The gas stream exiting the combustion chamber collided with a series of plates that formed the Turbine blades should represent and were arranged at an angle of 45 ° to the gas flow. the Amount of precipitation on the blades could at any time by pulling out and weighing the Shovels are determined.

When spraying talc as described above, the average precipitation on the was Shoveling after 20 hours of operation 72 mg.

In order to be able to compare the invention as it was described in the above example The following 20-hour experiments were carried out under the same conditions:

a) without the injection of any additive;

b) Injecting 0.4 weight percent silica instead of 0.5 weight percent talc.

The average weight of precipitation on

the blades after 20 hours of operation was 104 mg in case a) and 170 mg in case b), whereby the surprising reduction in precipitation

use of talc is shown.

It can also be noted that in the

Cases a) and b) checking the presence of precipitates by diffraction of X-rays of sodium vanadyl vanadate shows that, however, this

ίο compound when using talc not in the ashes are present. Since sodium vanadyl vanadate normally causes corrosion in steels, it is reduced The use of talc not only reduces precipitation but also helps reduce corrosion too to decrease.

⁰ example 2

500 parts of asbestos flour were mixed with 350 parts of a heating oil that had a viscosity of 65.0 ° Engler

37 ° C and an ash content of 0.01 percent by weight and passed the mixture through a three roll color mill, 5 parts of aluminum stearate were mixed with 50 parts of the same fuel oil and heated to 140 ° C. The resulting Gel was mixed with the paste of asbestos flour and heating oil and the mixture through the again same mill run.

3 percent by weight of the resulting paste was with a residual heating oil with a viscosity of 65.0 ° Engler at 37 ° C and an ash content of 0.1 weight percent mixed, with the majority of the ash being vanadium pentoxide. This mixture was kept in an auxiliary tank with stirring at 90 ° C, from which it was fed into the main fuel line to a refractory lined combustion chamber of a gas turbine plant in dimensioned Crowd was directed. The same residual heating oil was passed through the main fuel line, and the above mixture was metered at such a rate that the burned fuel oil Contained 0.12 percent by weight of asbestos flour. The heating oil was burned at a rate of 10.4 kg per hour.

The gas stream exiting the combustion chamber was through a series of flat blades made of a nickel-chromium-iron alloy, which had a distance of 2.5 cm from each other and in stood at an angle of 60 ° to the gas stream. The gas velocity through the series was 183 m per second, and the temperature of the gas in the row was 600 to 610 ° C.

After operating the above arrangement for 20 hours, the ash deposit on the blades became measured by their weight gain, and the average precipitate was found to be 60 mg.

In order to be able to compare the invention as it was described in the above example, were following 20-hour experiments under the same conditions and using the same Residual heating oil carried out:

a) without any addition and

b) Injection of an aqueous solution of magnesium sulfate into the heating oil stream with such a solution

Speed that a concentration of 0.15 '% of magnesium sulfate obtained in the fuel became.

The average weight of precipitation on the blades after 20 hours of operation was im

Case a) 150 mg and in case b) 120 mg. It can be seen from this that the use of asbestos flour is a 6O% reduction in the amount of precipitation in comparison with heating oil without additives, whereas the simpler magnesium compound, magnesium sulfate, only gave a 20% reduction.

Example 3

Example 2 was repeated, but the mixture mentioned therein was fed into the main heating oil line introduced at such a rate that a concentration of 0.18 percent by weight Asbestos meal was maintained in heating oil. The average deposited weight per shovel was only 50 mg after 20 hours of operation, which is a 67% reduction in the amount of precipitation in the Comparison with the heating oil without additive corresponded.

Example 4

A paste of talc in fuel oil as described in the first paragraph of Example 2 was prepared. The paste was processed into a mixture and this was fed to a residual heating oil and that Burning fuel oil in a gas turbine system as described in the second and third paragraph of Example 2 became. The dimensioning was adjusted so that a concentration of 0.1 percent by weight of talc in the Heating oil was obtained. The average weight of precipitation per shovel after 20 hours of operation was 100 mg, which is a 33% reduction in the amount of precipitation compared with the heating oil without addition, corresponded.

To avoid the undesirable effect of substantial amounts of metals other than magnesium in the To show the additive used, Example 4 was repeated using a talc that was mixed with Calcium carbonate had been diluted so that the mixture contained 21.5% calcium. After 20 hours Operating using this additive has been found to be the average rainfall per blade was almost the same as when a fuel oil was burned without an additive.

Claims (3)

Patent claims: 1. Heating oil that produces ash when burned, such as a residual oil with a high ash content, which in particular consists mainly of vanadium and / or sodium compounds by a smaller proportion of magnesium silicate or a mixture of magnesium oxide, hydroxide or carbonate with Silicon dioxide, the silicate or mixture being essentially free of others Metals other than magnesium. 2. Heating oil according to claim 1, characterized in that the proportion of the silicate or the Mixture is 0.01 to 1.0 percent by weight. 3. heating oil or dispersion according to claim 1 and 2, characterized in that the magnesium silicate Is asbestine or talc. Considered publications:
German Patent No. 819 032;
Belgian patent specification No. 499 650. © «09 659 / Ϊ84 10.58