RU2031312C1 - Device for cleaning heat surface from ash deposits - Google Patents

Abstract

FIELD: heat power engineering. SUBSTANCE: device has combustion chamber 1 inside which jack 2 is disposed provided with powder charge 3. The jack is connected with strike pipe 5 by means of gas channel 4. Shutter 6 provided with handle is disposed at the side of powder charge 3. Electromagnet 7, needle 8 passing through hole of shutter 6 and cap 9 are connected in series and form initiation system. Strike pipe 5 is connected to combustion chamber 1 by means of clutch 10 and may rotate. EFFECT: improved reliability of operation. 5 cl, 3 dwg

Description

 The invention relates to a power system and can be used to clean the internal surfaces of boiler units, in particular economizers, convective bundles of pipes, etc.

 Currently, methods for influencing surface dusting by a shock wave are widely used for cleaning heating surfaces. For example, in gas-pulse cleaning, the formation of a shock wave occurs due to the combustion of a propane-butane mixture with air in a pulse chamber [1].

However, the pressure amplitude is low 1 ^. 10 ⁵ Pa, since the bulk energy density of gaseous fuels (for example, benzene + oxygen) is low and is about 18 kJ / l.

 Known gas-pulse devices [2], in which the cleaning occurs due to the kinetic energy of the hot combustion products. The pipe is filled with a mixture of combustible gas and air. In the detonation tube, the mixture is ignited. A detonation wave propagates through the pipe, leading to the appearance of weak shock waves and gas flow.

 The disadvantage of this device is the formation of several shock waves that excite vibrations in the casing, the lining of the boiler and produce further destruction.

 The closest in technical essence to the claimed device is the selected device for cleaning the heating surfaces of the boiler [3], selected as a prototype, containing a shock tube, a mixture pipe for supplying a fuel-air mixture, an igniter, an exhaust nozzle. The nozzle is mounted perpendicular to the duct wall. The shock tube is filled with a fuel-air mixture. A high voltage is supplied to the ignition plug. The flame, propagating towards the open end, forms a gas stream, accompanied by shock waves acting on a dusty surface.

 The design has the following disadvantages inherent in all gas pulse chambers. Due to the large diameter of the nozzle, the more so having the shape of a confuser, the walls of the shock tube are filled with ash during the non-working period. At the moment the device is turned on, ash and larger particles “shoot out” and work as an abrasive, destroying the opposite wall of the chimney, as well as heat transfer surfaces. The presence of gas supply pipelines makes the device bulky and explosive. The operation of the device is possible only in stationary conditions.

 The use of condensed explosives (defect) as an energy source opens up much broader possibilities. The volumetric energy density of nitroglycerin is 1000 kJ / l, which is 50 or more times higher than the energy density of liquid, and even more so gaseous mixtures. In this case, the formation of a shock wave of 100 or more atmospheres is possible, the power and amplitude of which is easily controlled by the amount of charge. The use of gunpowder allows you to design a more compact, with a smaller diameter of the shock tube, a cleaning device with a charge power identical to gas-pulse devices.

 The aim of the invention is to increase the cleaning efficiency.

 The goal is achieved in that in a device for cleaning surfaces containing a shock tube with an open outlet end and an initiation system, according to the invention there is a combustion chamber with a socket with a powder charge located therein, connected via a gas channel to the shock tube, and a shutter with a handle located from the side of the powder charge and associated with the initiation system. The shock tube is rotatably connected to the combustion chamber. The open end of the shock tube is made in the form of a bent knee or with an oblique cut. The initiation system is made in the form of a sequentially located capsule, needle and electromagnet.

 This embodiment of the device in the form of two chambers, in one of which the ignition and combustion of the powder charge takes place, and in the other, the formation of a shock wave, allows you to receive a shock wave with high parameters that exceed the capabilities of known gas-pulse devices, and, in addition, eliminates from gas pipelines with working gases, mixtures of which are always explosive.

 Comparative analysis with the prototype shows that the inventive device is characterized by the presence of a combustion chamber in which a socket with a powder charge is located, connected through a gas channel to the shock tube, and a shutter with a handle located on the side of the powder charge. The initiation system is made in the form of sequentially located electromagnet, needle and capsule.

 Comparison of the claimed device with the prototype made it possible to establish compliance with its criterion of "novelty." When studying other known technical solutions in this technical field, the signs that distinguish the claimed solution from the prototype were not identified, therefore, they provide the claimed technical solution with the criterion of "significant differences".

 In FIG. 1 shows a device for cleaning, longitudinal section; in FIG. 2 shows a shock tube in the form of a bent elbow; figure 3 - shock pipe with an oblique cut at the exit.

 A device for cleaning surfaces from ash deposits (Fig. 1) contains a combustion chamber 1 in which a socket 2 with a powder charge 3 is located, connected via a gas channel 4 to the shock tube 5. A shutter 6 with a handle is placed on the side of the powder charge. Sequentially located electromagnet 7, the needle 8 passing through the bore of the shutter 6, and the capsule 9 together constitute an initiation system. The shock tube 5 is connected to the combustion chamber 1 by means of a sleeve 10 and is rotatable. The open end of the shock tube is made in the form of a bent knee (figure 2) or with an oblique cut (figure 3).

 The device operates as follows.

 A charge 3 with a capsule 9 is installed in the socket 2 of the combustion chamber 1. The shutter 6 is closed using the handle. When you turn on the electromagnet 7, the needle 8 hits the capsule 9. The defect is ignited. In the free space of the nest 2 of the powder charge, the pressure increases to 100-200 MPa, which accelerates the combustion process. In the gas channel 4, the defect particles that are not burnt in the nest 2 are burned out. Through the gas channel 4, the combustion products enter the wider channel of the shock tube 5, in which the combustion products “push” the “air” plug, forming a shock wave. By this time, the vice burns out.

 An oscillogram recorded by a pressure sensor mounted on a pipe near a cut characterizes the pressure change in the formed shock wave. The pressure impulse is single with a steep rocky front and a gentle rear, pulse duration of 1-3 ms.

Further, when leaving the pipe, the wave propagates throughout its volume, its amplitude decreases in proportion to the square of the distance. Therefore, when a wave falls on cleaned surfaces, its amplitude decreases to ≈ 10 ⁵ Pa, which nevertheless exceeds the amplitude of the waves from the gas-pulse device. Behind the shock wave moves a high-speed gas stream. Energy is distributed as follows: 80% in a shock wave, 20% in a high-speed flow. To fully utilize energy, it is necessary to direct the pipe directly to the cleaned surface.

If the heating surfaces have a low temperature, of the order of 100-200 ^{° C,} is used for cleaning the stationary unit with the nozzle of a curved type. If the heating surfaces are in the furnace, the device is mounted on guides that enable the open end of the shock tube to be inserted and removed from the furnace space, while it is made with an oblique cut. The open end of the pipe is directed towards the heating surface and is located above it. This eliminates the possibility of drift of the walls of the shock tube with ash.

 Using the proposed device for cleaning loose deposits of economizer surfaces provides the following advantages compared to existing gas-pulse devices. The presence of a source of energy of high concentration (gunpowder) can significantly reduce the diameter of the shock tube and, due to this, can clean any hard-to-reach spots. In addition, due to the small diameter of the shock pipe, it is possible to direct the pipe cut along the flue gas flow, which prevents ash from entering the pipe. In this regard, the destruction of the cleaned heat-exchange surfaces due to the action of firing ash particles is excluded.

Claims (5)

 1. DEVICE FOR CLEANING SURFACES OF HEATING FROM ASH DEPOSITS, containing a combustion chamber, a shock tube with an open outlet end, an initiation system, characterized in that the combustion chamber is equipped with a socket with a powder charge, a gas channel, through which the socket communicates with the shock pipe, in addition , the device is equipped with a shutter with a handle located on the side of the powder charge and communicated with the initiation system.  2. The device according to claim 1, characterized in that the shock tube is mounted to rotate around its axis.  3. The device according to claim 1, characterized in that the section of the shock pipe located closer to the output end is made in the form of a bent knee.  4. The device according to claim 1, characterized in that the output end of the shock tube is made with an oblique cut.  5. The device according to claim 1, characterized in that the initiation system consists of a sequentially located electromagnet, a needle and a capsule.

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