JPS593217B2 - wick type oil combustor - Google Patents

Description

[Detailed Description of the Invention] The purpose of this invention is to provide an oil combustor that prevents the generation of tar, tin, and odor by improving the wick body of a wick-type oil combustor, and achieves ideal oil combustion with improved combustibility. This is what we are trying to provide.

The wick body for wick-type oil combustors is made of braided heat-resistant glass fiber5, which is the most common type used by all manufacturers. Fuel is soaked into this wick and air is sucked in by a natural draft for combustion, but the temperature distribution of the wick near the platter is such that it is easy to turn into tar.
Moreover, because the fuel (kerosene) remains for a long time, tar formation is further promoted, and the attached tar heats up over time and turns into hard carbon, resulting in poor combustion and a reduction in the amount of combustion. This causes a number of problems, such as a reduction in the ignition speed and the generation of foul-smelling tin, which significantly deteriorates the functionality of the oil combustor. In particular, if fuel contaminated with denatured oil or different types of oil is used, the above problem will occur in a very short time, and the wick will stick to the platter due to tar and carbon, causing wick height adjustment (burning amount adjustment). 20 It is connected to every problem and is the most important issue that must be solved.

At present, efforts are being made to solve this problem by improving the lamp wick body and improving the combustion section mechanism, but in any case, it has not yet been possible to solve all of these problems25.

The present invention uses an alkali metal silicate such as sodium silicate as a binder, and adds acidic metal phosphates such as primary phosphates and orthophosphates to the binder, and has a heat resistance of 30 to properly color the coating film. It is a type of paint composition in which pigments such as metal oxides with excellent properties are mixed and cured by reaction, and an alkali is added to provide an extremely excellent catalytic effect (tar suppression effect) to the inorganic heat-resistant paint. We discovered that the lamp wick had the same effect and coated the surface of the wick with this paint.
5-Coating (coating) to prevent tar adhesion and C (carbon) precipitation to achieve ideal oil combustion.

An embodiment of the present invention will be mainly described below.

In FIG. 1, numeral 1 denotes a wick held by a wick guide tube 2, 3 a combustion outer cylinder located on the outer periphery of the combustion part of the wick 1, and 4 a combustion cylinder located on the inner periphery of the combustor of the wick 1. The inner cylinder and the combustion outer and outer cylinders 4 and 3 have corresponding combustion holes 4',
3'.

Reference numeral 6 indicates a rectifying plate that forms a ventilation hole 6' and is attached to the lower part of the combustion inner cylinder 4, 7 indicates an air regulation plate that forms a ventilation hole 7/ and is attached to the upper end opening of the combustion inner cylinder 4, and 8 indicates an air regulation plate. A coil is wound around the outer periphery between the hot air diffusion plate 9 and the air regulation plate 7 using a holder attached to the plate 7, and is placed facing the upper opening of the air section formed by the combustion inner and outer cylinders 4 and 3. There is.

Reference numeral 5 denotes an outer cylinder located outside the combustion outer cylinder 3, which is equipped with a wire mesh 11 at its upper opening to cover the holder 8, the coil 10, and the hot air diffusion plate 9; Further, the outer cylinders 5 are held at a constant interval and are integrated by a mounting shaft 12 to form a combustion cylinder.

When surface treating (inorganic heat-resistant paint coating) the wick of an oil burner with a material that has a catalytic effect, the requirements include heat resistance, oil resistance, thermal shock resistance, and adhesion.

Regarding heat resistance, inorganic heat-resistant paints made of alkali metal silicates, acidic metal phosphates, and metal oxide pigments have already been applied to our gas stoves and burner cap trivets for stoves, and have a considerable amount of heat resistance. It's paint.

Burner caps are heated to about 500℃, and the tips of the trivets' claws are directly exposed to the flame, reaching a temperature close to red-hot. The color fading was only observed, and there was no problem with regard to heat resistance and long-term thermal stability. Furthermore, even if alkali is added to this heat-resistant paint, the paint itself is basic in its composition, so it is possible to mix the two at will, and it has been confirmed that there is no change in heat resistance after addition. .

The results of thermogravimetric analysis using a thermobalance of a paint containing 5 wt% of potassium carbonate (K2CO3) show that from the start of heating to around 200°C, the weight decreases slightly due to the scattering of contained moisture. It is acceptable, but if you further heat it up to 60
At about 0°C, no weight change is observed, and the addition of alkali has no effect on the thermal stability of the heat-resistant paint. Regarding oil resistance, we investigated changes over time in the hardness (crushing strength: using a Kiya manual hardness tester) of paints that were cured by immersing them in kerosene or diesel oil.

In addition, potassium carbonate (K2CO3) is used as an alkali in the paint.
The sample was prepared by adding 5 wt% and adjusting it into a dice shape of 5 fins x 5 fins x 5 ml. In the continuous immersion test for 6 months, there was very little change in hardness, and the initial weight of 15 kg (average value when the number of samples was Ω = 10) was 13.8 kg (same) when immersed in kerosene, and 13.8 kg when immersed in light oil. It was confirmed that the strength of the paint was maintained at 5kfI (same), and there was no concern about the paint softening or collapsing even after long periods of immersion.

This means that there is no need to worry about it even if it is left immersed in fuel oil during the off-season.

In terms of thermal shock properties, the lamp wick undergoes repeated ignition and extinguishing during use, and is then subjected to sudden heat shocks such as instantaneous extinguishing, and we confirmed changes in hardness due to repeated heating and cooling.
The same sample used for evaluating oil resistance was used. 3
A total of 1000 cycles were carried out, with one cycle consisting of heating at 00°C for 8 hours and cooling at θ10-like C for 16 hours.
kg, which was extremely good.

Furthermore, regarding the thermal shock resistance of a coating film, a heat shock test was conducted by applying a coating material to which K2CO35Wt was added as an alkali onto a metal plate. The test piece is 2
011 x 50u thickness 11! It was created by applying 30μ of paint to SPCC.

Each sample was heated to 1000C, 200℃, 300℃, 350C.
One cycle consisted of heating to 0C and 400C and then rapidly cooling in water, and 10 cycles were repeated at each temperature to evaluate cracks and peeling of the coating film. As a result, no change in the coating film was observed at any temperature, and the thermal shock resistance and adhesion of the coating film were good regardless of whether or not alkali was added. Since this was the result when a coating film was formed on a metal plate, we also confirmed the adhesion when a coating film was formed on heat-resistant glass, which is the same material as the lamp wick. Evaluation method is 30]! Using a test piece coated with 30μ of a paint containing 5wt% of potassium carbonate (K2CO,) as an alkali on a 1x80U heat-resistant glass plate, the test piece was heated at 300℃8.
A total of 1000 cycles were carried out, with one cycle consisting of heating for a period of time, holding at room temperature, and cooling for 16 hours at 810°C.
Similar to the results when the coating was applied on a metal plate, no change in the coating film was observed, indicating good adhesion. As mentioned above, this heat-resistant paint has excellent heat resistance, long-term thermal stability, oil resistance, thermal shock resistance when changing the base material, and adhesion even when alkali is added. It has excellent performance and poses no practical problems.

Figures 4 and 5 show the results of oil resistance and impact resistance.

Next, we will discuss the tar suppression effect (performance) of this heat-resistant paint with alkali added.

FIG. 3 is a cross-sectional view of the reactor. In the figure, 13 is the main body of the device, 14 is an oil supply pipe, a primary air supply pipe 15,
A secondary air supply pipe 16 and a flame hole 17 are provided.
The main body 13 includes a vaporizing section 18, a premixing section 19, and a combustion section 20 having a flame hole 17. The primary air supply pipe 15 has a plurality of ejection holes 21 .

22 is a heating heater.

The device 13 is heated and maintained at a constant temperature by the heater 22, a constant amount of fuel is sent from the fuel supply pipe 14, and the air necessary for combustion is sent from the primary air supply pipe 15 and the secondary air supply pipe 16 to vaporize the fuel. The mixture is premixed as it rises, and is ignited and combusted in the flame hole section 17. The flame hole portion 17 also serves as a sampling portion for checking how the vaporized gas has changed and for collecting gas. The tar suppression effect was confirmed by spreading the tar over the entire bottom surface of the vaporizer 18, burning it in the reactor 13 for a certain period of time, and comparing the degree of tar and carbon that adhered to each part. The method of implementation was to heat and maintain the device at a temperature of 300°C, use light oil to quickly check for tar, and observe the tar attached to the vaporization part and around the combustion supply hole after 2 hours of combustion.
After cleaning with acetone and extracting the tar, we compared the effects based on the degree of acetone coloring (the solubility of tar).

Further, after the paint is cured, it is crushed and classified into a predetermined particle size, and a certain amount of the powder is used.

The degree of coloring was determined by measuring absorbance at a wavelength of 420 mμ using a spectrophotometer.

As mentioned above, this heat-resistant paint containing alkali metal silicates, acidic metal phosphates, and metal oxide pigments with excellent heat resistance has already been used in practical applications.
It has excellent heat resistance, impact resistance, and adhesion, and these properties must not be impaired by additives.

Particularly when applied as a coating, paintability as a paint is also an important factor, and it is most important to take into account the above-mentioned characteristics as well as performance. In Table-1,
Each composition evaluated is shown below. Among the inorganic heat-resistant paints with alkali added, the one with K2CO3 added was the best. Table 2 shows the absorbance measurement results at 420 mμ of acetone extracts for representative (good results) extracts. Here, the heat-resistant paints listed in Tables 1 and 2 are made of sodium silicate, in which metal oxide pigments such as Fe, Mn, and Cu are dispersed and mixed, as a binder, and monobasic aluminum phosphate. Polymerization ratio: 1/1
It was mixed and made into a paint at a ratio of .
(Both were extracted with 100cc of acetone.
) When liquid fuel is combusted, hydrocarbons are decomposed and tar and carbon are produced as by-products. This is because carbon is precipitated and attached by directly cutting the C--C bond and generating carbon. In these reactions, it is said from experience that it is possible to burn carbon etc. even at a fairly low temperature in the presence of an alkali etc.
It has been introduced and proposed in many literatures and patents. The effects of potassium carbonate (K2CO3) are not clear, but potassium is much more reactive with oxygen, hydrogen, carbon monoxide, or water vapor than other substances, and it is highly reactive with basic heat-resistant paints. It is presumed that this is due to a synergistic effect.
When other alkalis shown in Table 1 are added to paints, they are undesirable because they cause phenomena such as poor solubility, sedimentation, or rapid hardening, which impede paintability. . The effects of adding potassium carbonate (K2CO3) were compared when the amount added was changed. The results are shown in FIG. In particular, the addition of potassium carbonate has a very large effect on tar suppression, but from the viewpoint of performance, paintability, and physical properties, the appropriate amount to add is 1 to 20 wt% of the total amount; Performance also tends to deteriorate, and paintability and physical properties tend to be impaired.

A durability test was conducted by coating a lamp wick used in an actual portable kerosene stove with 5 wt% of potassium carbonate (K2CO3) added to this heat-resistant paint. As for the coating method, both dipping and air spraying are possible, and appropriate pretreatment (degreasing, removal of starch, etc. that adheres during spinning) is essential in order to improve the adhesion of the paint. In order to clarify the difference in effectiveness, we mixed 20% diesel oil into kerosene and conducted a combustion experiment with continuous combustion for 8 hours a day for 3 months (total combustion time 750 hours), and the results were extremely positive. Even the coloring of the wick was not observed, and tar was completely suppressed.

Furthermore, there was no decrease in combustion amount or change in ignition time, which solved the problems of conventional wick-type oil combustors.
It achieves ideal oil combustion and has extremely high practical value.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a combustion tube of a wick-type oil combustor showing an embodiment of the present invention, Fig. 2 is a partially cutaway perspective view of the main part of the wick body, and Fig. 3 shows the tar suppression effect. Figure 4 is a diagram showing the hardness change due to immersion in kerosene and diesel oil, Figure 5 is a diagram showing the hardness change due to heat shock test, and Figure 6 is a diagram showing the amount of K2CO3 added and the tar suppression effect. FIG. 1... Lamp body, 2... Lamp guide tube, 3
... Combustion outer cylinder, 4... Combustion inner cylinder.

Claims (1)

[Scope of Claims] 1. Consisting of an alkali metal silicate, an acidic metal phosphate, a metal oxide pigment, and as an alkali, an alkali metal or alkaline earth metal oxide, hydroxide,
Or a wick-type oil combustor using a wick whose surface is coated with an inorganic heat-resistant paint containing one or more selected from the group of carbonates. 2. The wick-type oil combustor according to claim 1, which uses a wick whose surface is coated with an inorganic heat-resistant paint containing potassium carbonate (K_2CO_3). 3. The wick-type oil combustor according to claim 1, which uses a wick whose surface is coated with an inorganic heat-resistant paint containing potassium carbonate in an amount of 1 to 20% by weight.