RU1816927C - Method of cleaning the heating surfaces and set for its realization - Google Patents

Abstract

Usage: in the power system of various industries for cleaning heating surfaces. SUMMARY OF THE INVENTION: when filling the combustion chamber with a fuel-air mixture, jets of compressed oxidizer are fed in front of the nozzle at an angle to the direction of movement of the mixture. These jets enter the casing installed between the combustion chamber and the nozzle. 2 sec p, f-ly, 2-yl.

Description

The invention relates to a technique for cleaning heating surfaces of heat-exchanging equipment from loose loose deposits and can be used in the power system of various industries.

. The purpose of the invention is to increase the cleaning efficiency during rarefaction in the area of heating surfaces of more than 500 Pa.

In FIG. 1 schematically shows the layout of the installation that implements the proposed method of gas-pulse cleaning of heating surfaces; FIG. 2 is a section AA in FIG. 1 camera aerodynamic braking,; .:. ...-; . . / .-- .. /. .

The installation contains nozzles 1 and 2, respectively, for supplying fuel and an oxidizing agent, connected to the combustion chamber 3, connected by a pipe 4 with a nozzle 5 and equipped with a pilot 6 and a muffler 7. Between the combustion chamber 3 and the nozzle 5, an additional casing 8 is connected around the pipe 4 to the oxidizer source through

the pipeline 9, and in the wall of the pipe 4 inside the casing 8 is made inclined at an angle of 30-90 ° to the axis of the hole 10.

The supply of compressed oxidizer to the casing leads to the creation of an air curtain that provides a sharp decrease in the speed of movement of the gas-air mixture through the combustion chamber 3, which makes it possible to obtain an increased concentration of the gas-air mixture and, accordingly, the power of the shock wave exiting the nozzle 5.

The nozzle 5 is slotted and serves to direct a concentrated shock wave to the surface being cleaned.

An installation implementing the proposed gas-pulse cleaning method works as follows.

Fuel and compressed oxidizing agent are supplied to nozzles 1 and 2; after mixing, the mixture enters the combustion chamber. When the pipeline and the combustion chamber are completely filled with the gas-air mixture, the mixture is ignited using the pilot light 6. C

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Using the energy of expanding gases, a shock wave is generated in the combustion chamber 3. The energy of the explosion and the kinetic energy of the combustion products are directed through the slotted nozzle 5 to the zone of loose deposits, destroying and removing them from the heating surfaces. The effect of increasing the degree of purification is achieved due to the interaction of shock waves in the combustion chamber 3. When

collisions of compression waves in the combustion chamber

a pressure surge is generated that is several times higher than the pressure in the original wave.

Since the explosion of the gas-air mixture, the shock wave propagates in all directions, therefore, the back wave in the installation is damped in the silencer 7.

After the explosion and discharge of the combustion products onto the surfaces to be cleaned, the process is repeated. With a large resolution of H1 / 1 in the area of the surfaces to be cleaned, the process of filling the installation and moving the combustion products fundamentally changes. This is due to the fact that during the filling of the pipelines and the combustion chamber with the gas-air mixture, the latter moves with great speed through the installation, which leads to a decrease in the concentration of the gas-air mixture and, when ignited, due to the greater rarefaction in the pipe 4, the flame propagation velocity decreases, which leads to disruption of the combustion process and a drop in the power of the blast wave.

During the operation of the installation, when it is filled with a gas-air mixture, aerodynamic braking of the mixture moving through the pipeline 4 is carried out by introducing oxidizer jets through the holes 10 of the pipe 4. The introduction of oxidizing jets provides braking and increases the concentration of the gas-air mixture, which increases the power of the explosive shock the waves. The effect of aerodynamic drag is enhanced by the fact that the jet of oxidizing agent is introduced at an angle to the flow of the air-gas mixture. In this case, the injection of oxidizing jets is carried out in such a way that the boundary for equalizing the pressure of the gas-air mixture in the pipeline 4 and the introduced oxidizing jets is within the placement of the casing 8 or placed in front of the specified casing. Placing the pressure equalization boundary behind the casing is not practical. This is due to the fact that the oxidizing jets must be directed at an angle in the direction of movement of the gas-air mixture, which would reduce the braking effect and, consequently, the concentration.

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The optimal angle of inclination of the holes 10, made on the pipe 4, is 30-90 °.

The angle of 30 ° is determined by the technology of making inclined channels, as well as by the direction of action of the oxidizing jet. Since at an angle of less than 30 °, the oxidizer stream will blow out the gas-air mixture from the combustion chamber, which will reduce the power of the blast wave. If the angle of inclination of the channels is more than 90 °, for example 100-120 °, the effect of injecting a gas-air mixture from the installation will be observed, which exacerbates a known disadvantage.

An experimental verification of the proposed method of gas-pulse cleaning of the external heating surfaces from loose deposits was carried out on waste heat boilers PO Phosphates.

The implementation of the proposed technical solution eliminates the noted drawbacks and provides a positive effect;

- stabilizes the process of generating a powerful blast wave;

- improves the quality of cleaning the heating surfaces in the zone of high vacuum.

Thus, in the proposed technical solution, a positive effect is achieved by aerodynamic braking of the moving gas-air mixture by introducing jets of compressed air, the latter being supplied at an angle to the gas-air mixture flow. This provides an increase in the concentration of the gas-air mixture while decreasing its speed in the mixture pipe.

Claims (2)

1. The method of cleaning the heating surfaces from loose deposits by mixing fuel and oxidizer, filling the combustion chamber, igniting the mixture and ejecting combustion products from the nozzle in the form of a blast wave on the heating surface, which consists in that, in order to increase the cleaning efficiency when the rarefaction in the zone of heating surfaces exceeds 500 Pa, jets of compressed oxidizer are fed in front of the nozzle during filling of the combustion chamber with the mixture at an angle to the direction of movement of the mixture. 2. Installation for cleaning heating surfaces, comprising fuel supply pipes and an oxidizing agent connected to a combustion chamber in communication with a nozzle pipe and provided with an igniter, and a silencer, characterized in that, in order to increase the efficiency of the cleaning process, between the combustion chamber and the nozzle around the pipe an additional casing is installed, connected to a source of compressed oxidizer, and inclined at an angle of 30-90 ° to the axis are made in the pipe wall inside the casing. holes. Aa 3 (A $ o °