JPH02203913A - Method for removing moisture adhered to dust collecting filter - Google Patents

Abstract

PURPOSE:To prevent an increase of pressure loss by connecting electrodes to both end parts of a filter composed of porous ceramic and applying voltage to the electrodes when the supply of air to the filter is started to immediately eliminate the adhesion of moisture and dew condensation generated on the filter. CONSTITUTION:Electrodes 5, 6 are connected to both end parts of a filter 1 composed of porous ceramic and voltage is preliminarily applied to the electrodes when the supply of air to the filter 1 is started. When the adhesion of moisture is started, the moisture adhered to the filter 1 is evaporated by utilizing the Joule heat of the current flowing to the filter 1. That is, when the adhesion of moisture or dew condensation generated on the filter, it is immediately eliminated and trouble such as an increase of pressure loss is not brought about.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a method for removing adhering moisture from a dust collection filter, which can effectively prevent moisture from adhering to a filter for collecting dust in gas. It is about the method.

(Prior technology) Filters made of porous ceramic are generally used as filters to collect dust in high-temperature gas. It's normal.

However, when high-temperature gas comes into contact with a low-temperature filter, dew condensation occurs, resulting in excessive pressure loss due to ventilation. For this reason, the auxiliary equipment for ventilation requires high ventilation pressure, resulting in large size and cost problems. Further, even when the filter is in use, condensation may occur due to the temperature difference between the high-temperature gas and the filter, resulting in a large pressure loss. Furthermore, even in low-temperature gases, if the gas contains a large amount of moisture, the moisture may be adsorbed in the filter, increasing pressure loss.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems and immediately eliminates moisture adhesion or dew condensation on the filter, thereby eliminating problems such as increased pressure loss. This was completed with the aim of creating a method for removing moisture from dust collection filters that would not cause this.

(Means for Solving the Problems) The present invention, which has been made to solve the above problems, connects electrodes to both ends of a filter made of porous ceramic, and applies a voltage at least when starting ventilation to the filter. The filter is characterized in that when moisture adheres to the filter, the Joule heat of the current flowing through the filter is used to evaporate the moisture adhering to the filter.

(Example) The present invention will be described in detail below with reference to the drawings. In the drawing, (1) is a bottomed cylindrical filter made of porous ceramic having a porosity of 20 to 60%, and A large number of filters are vertically supported by the support plate (2) and the lower support plate (3) and are installed inside the casing C), forming a dust collection filter device. Filter (1)
Commonly used materials include silicon carbide, alumina, and cordierite. The contact parts of the upper support plate (2) and the lower support plate (3) with the filter (1) are electrodes (5) and (6), respectively, and at least when the ventilation to the filter starts, these electrodes (5), (
6) Apply a voltage of 200 V or more per meter of length of the filter (1) between them. However, since the filter (1) has a high resistance value, almost no current flows under normal conditions even when voltage is applied.

However, when a high-temperature gas or a low-temperature gas with a high moisture content is passed through the filter (1) as described above in order to start up such a dust collection filter device, since the filter (1) is at a low temperature, dew condensation and moisture adhere to its surface. and the filter (
1) The resistance value decreases. Along with this, the filter (1
), and the filter (1) is heated by the Joule heat, which evaporates moisture generated by condensation and adsorption. This type of action is naturally adjusted so that when the degree of condensation and moisture adsorption is small, the current is small, and when the degree of dew condensation and moisture adsorption increases, a large current flows. can be resolved. In addition, even after the ventilation starts, the electrode (5)
, (6), it becomes possible to immediately eliminate dew condensation and moisture adsorption that occur during use.

In the illustrated example, the upper support plate (2) and the lower support plate (3) are used as electrodes, but electrodes are glued to both the upper and lower ends of each filter (1), and cables are connected to each electrode. It is also possible to conduct the energization. In addition,
The reason why the voltage is set to 200 V or more per meter of length of the filter (1) is that a sufficient amount of heat generation cannot be obtained if the voltage is lower than this. In the present invention, the current value is filtered (1)
In order to quickly evaporate moisture, it is preferable to flow a current of 2 mA or more per cross-sectional area 1c of the filter, although it varies depending on the state of the filter.

Furthermore, if an ammeter (7) is connected to the power supply circuit as shown in the figure, the wet state of the filter (1) can be known from the outside based on changes in the current value, making it easier to perform predictive maintenance.

(Effects of the Invention) As explained above, the present invention has an extremely simple structure that makes it possible to prevent condensation and moisture adsorption on the filter, and in particular prevents condensation that inevitably occurs during startup. It is highly effective in prevention. Further, according to the method of the present invention, since the filter is heated from the inside, a reliable effect can be obtained even if filter dust is attached to the surface. Therefore, the present invention greatly contributes to the development of industry as a method for removing moisture attached to dust collecting filters that eliminates the problems of the conventional methods.

[Brief explanation of the drawing]

The drawing is a partially cutaway front view illustrating the present invention in detail. (1): Filter, (5), (6): Electrode.

Claims (1)

[Claims] Electrodes are connected to both ends of a filter made of porous ceramic, and a voltage is applied at least when ventilation begins to flow through the filter. When moisture adhesion occurs, the Joule heat of the current flowing through the filter is used to cool the filter. A method for removing attached moisture from a dust collection filter, which is characterized by evaporating attached moisture.