RU2293274C1 - Method of cleaning members of heating systems and hot water supply systems from solid deposits and device for realization of this method - Google Patents

Abstract

FIELD: cleaning internal surfaces of heating systems and hot water supply systems of single-storey and multi-storey buildings from solid, mainly silt deposits; cleaning of heating radiators and water supply equipment.

SUBSTANCE: proposed method includes generation of shock waves in system filled preliminarily with water by means of compressed air pulses for breaking deposits and removing them by flow of water. Shock waves are generated by action of vacuum and pulses of compressed air of exponential shape at considerable steepness of leading edge. Pressure of compressed air for generation of shock wave is selected not above rated working pressure in system to be cleaned and water in system is accelerated during action of pulse to velocity causing cavitation effect by portion of air fed to system. Device for realization of this method includes system to be cleaned, pipe lines, hydraulic unit and shut-off fittings. It is additionally provided with receiver and pulse valve which are structurally combined in single unit with commutator connected to it; commutator is so mounted that system to be cleaned may be connected with pulse valve and with drain main.

EFFECT: improved quality of cleaning components of systems; reduced labor input; enhanced safety in servicing equipment.

3 cl, 2 dwg

Description

Technical field

SUBSTANCE: group of inventions relates to cleaning the internal surfaces of systems and elements of central water heating of buildings from solid, mainly silty deposits and can be used in municipal services for cleaning clogged and clogged central heating radiators, risers and piping, for cleaning autonomous water supply systems and internal surfaces heat exchange equipment.

State of the art

It is well known that the formation of scale from water when it is heated in heat-exchange equipment reduces its heat engineering parameters, worsening heat transfer due to the low heat conductivity of scale and reducing the cross-sections of heat exchangers.

In heating systems, scale does not form, since the reverse process takes place in them - heat transfer from the coolant to the air. However, due to the low flow rates of the coolant, solid particles present in the water are deposited in the radiators and pipelines, gradually decreasing the flow cross-sections of pipelines and radiators and making it difficult to circulate the coolant in the system. These phenomena lead to the formation of stagnant zones, redistribution of the coolant flow, a decrease in the circulation rate, and, as a result, to uneven heating of heating elements and a general decrease in the efficiency of the heating system.

A known method of cleaning the inner surfaces of heating radiators of domestic heating systems and a device for its implementation (1). The method includes disconnecting radiators from the heating system, filling them with water with an air cushion and creating water hammer. In the known method create zones of water hammer, form them with compressed air in each section of the radiator in the lower part in two directions towards the vertical cavities and trap the air-water liquid with destroyed deposits through the upper part of the radiator, after which it is separated from the deposits and the liquid is returned to the lower part of the radiator, moreover, pulses of compressed air are fed after processing the previous section in turn to the next section and control the zone of hydraulic shock under the vertical cavities of each section.

The disadvantages of this method are the need to disconnect the heating battery from the heating system for cleaning, the complexity and cumbersome equipment for cleaning, the inability to clean the remaining elements of the heating system (risers and piping). The cleaning process is lengthy, since each section of the battery needs to be cleaned sequentially.

There is also a method of cleaning heat exchange elements (2). The method consists in immersing the heat exchange element in a container with water and exposing it to electro-hydraulic shocks by means of an electrode system. In addition, in the known method, the water-filling element is filled with water by no more than 90%, and energy is supplied to the middle electrodes 1.5-3.0 times lower than to the end electrodes, while high-voltage electrodes are placed on two opposite sides of each heat exchange element, and the effect of electro-hydraulic shocks is combined with immersion of elements in a container with water and extraction from it.

The disadvantages of this method are the great complexity when disconnecting heating batteries from the heating system and their reinstallation, sophisticated equipment and a long cleaning process, the inability to comprehensively clean the heating system.

Closest to the claimed technical solution are a method of cleaning the internal surfaces of pipelines from contamination and a device for its implementation (3). The method includes generating shock waves in a liquid by a sharp supply of compressed air pulses under high pressure. In this case, a shock wave is generated in the immediate vicinity of the inlet to the pipeline in the valve body, and filling the pipeline with a working fluid and discharge of contaminants is also carried out through the valve body in one closed cycle.

A device for implementing the method comprises a pneumatic ram with a source of compressed air and a hydraulic unit in the form of a cross, communicating with one pair of nozzles with a pneumatic ram and a pipeline, and the other with a source of working fluid and a drain tank. The valve body is made with the possibility of alternating pairwise connections "pneumatic ram - pipeline", "working fluid - pipeline" and "pipeline - tank for discharge". The pipe in communication with the pipeline is equipped with a flange nut with an adapter for connection to pipes of various diameters, and the remaining pipes are equipped with ball valves.

The disadvantage of this method of cleaning the inner surface of pipelines from contaminants is the impossibility of cleaning them efficiently while observing safety requirements, since an increase in pressure in the system being cleaned due to exposure to high air pressure can lead to damage to the system being cleaned and the risk of injury at work.

The problem solved by the invention

The problem solved by the invention is to improve the quality and speed of cleaning, reducing labor costs, ease of operation and improving the safety of equipment maintenance.

Disclosure of invention

To solve this problem, a method is proposed for cleaning elements and systems of heating and hot water supply from solid deposits by creating a cleaned system in pre-filled with water, using pulses of compressed air, water hammer and cavitation effect to destroy deposits and remove them from the cleaned system with a water stream. Moreover, according to the invention, the shock wave is generated by exposing the water to the filling system with a vacuum and pulses of exponentially compressed air with a large steepness of the leading edge, while the pressure of the compressed air for generating the shock wave is chosen not higher than the calculated working pressure in the system to be cleaned, and for mixing destroyed sediments with water, the water in the system during the impact of the pulse is dispersed by the portion of air supplied to the system to speeds that cause a cavitation effect.

Compressed air forms a water-air mixture in a water-filled system and accelerates it to high speeds, which leads to the appearance of a cavitation effect at the water – sediment – wall interface. The shock wave front and cavitation destroy the deposits accumulated on the walls of the system, and the air-water mixture intensively mixes them and forms a suspension, which is removed through the switch from the system by the flow of water into the drain line. Thus, the method includes the creation by means of pulses of compressed air in the heating elements pre-filled with water and the heating system at the same time as water hammer and cavitation effect, which contributes to a more complete destruction of deposits and their removal from the system by the water flow.

To implement the method, a device is proposed (see FIG. 1), comprising a receiver 1 in the form of a sealed vessel for accumulating compressed air with a fitting 2 for supplying air and a pressure gauge 3 installed on it. Inside the receiver, to exclude connecting lines and, as a result, additional resistance , a pulse valve 4 is placed with a switch 5 connected to the outlet of the pulse valve providing connection of the receiver by means of nozzles 6 and 7 and locking elements 8 and 9 with the system to be cleaned or with a drain highway, respectively.

The pulse valve 4 (see Fig. 2) is a housing 10, inside of which a differential piston 11 and a spring 12 are placed. Under the influence of a spring, the differential piston with its smaller diameter 13 is pressed against the outlet of the valve 4 and closes it. The chamber 14 of the differential piston stage communicates directly with the internal volume of the receiver 1, and the chamber 15 under the piston communicates with a control valve (not shown) and through the throttle 16 of a small bore with the receiver.

The pulse valve operates as follows.

The pulse valve is closed in the initial state. In the receiver 1 create a pressure of compressed air. From the receiver, compressed air fills the differential chamber 14 and, through the throttle 16, the chamber 15 under the piston 11, creating a force equal to the product of pressure by the cross-sectional area of the outlet of the valve 4, in the direction coinciding with the force of the spring 12. When the receiver reaches operating pressure, the control valve is opened and report the chamber 15 under the piston to the atmosphere. Since the orifice of the control valve is many times greater than the orifice of the throttle, the pressure in the chamber 15 under the piston begins to decrease rapidly, while the pressure in the chamber 14 of the differential stage remains unchanged. The force arising from the pressure of compressed air on the differential stage of the piston 11 overcomes the force of the spring 12 and detaches the piston from the outlet of the valve 4. Compressed air begins to act on the small diameter of the piston 11, the force of action is summed with the force on the differential stage, and the piston with acceleration moves from the outlet. At the same time, compressed air acts on a column of water located in the outlet of the valve, excites a shock wave in it and, displacing water, penetrates the system being cleaned. As a result of the penetration of air into the system to be cleaned, the pressure in the receiver and in the differential chamber, as well as the force exerted on the piston, decrease, the piston moves under the influence of a spring to the valve outlet and closes it.

The implementation of the method

Ball valves are installed on the system to be cleaned at the connection points of the device and the system is filled with water. A pipe is connected to a ball valve at a selected point in the system, the second end of which is connected to the switch. In the initial state, the ball valves of the switch and the system being cleaned are closed. A hose is connected to the switch to drain the water from the system, and a pressure hose is connected to the receiver from the source of compressed air (compressor). Using a compressor, air pressure is created in the receiver, controlling the value according to the pressure gauge on the compressor or on the receiver. When the operating pressure in the receiver is reached, open the ball valve at the entrance to the system to be cleaned, as well as the ball valves of the switch to remove air from the pipe and switch, fill the pipe with water and ensure contact of the water with the pulse valve. The presence of air in the switch and in the pipe negatively affects the process of formation and propagation of a shock wave in the system being cleaned, acting as a damper. After filling the pipe and the switch with water, close the drain valve of the switch and, using the control valve, turn on the pulse valve. A pulse of compressed air, acting on water, generates a shock wave at the air-water interface, which propagates through the switch, pipe and element to be cleaned through the system, gradually attenuating due to energy loss.

The front of the shock wave, moving along the system to be cleaned, causes the destruction of deposits, and the air entering the system displaces water and, partially mixed with water, forms a water-air mixture, accelerates it to such speeds that cause cavitation in the boundary layers of water - deposits - walls . Cavitation contributes to the further destruction of sediments, and the air-water stream intensively mixes them and forms a suspension, which is easily removed from the filled system by a stream of water when the switch drain valve is opened. After the water drained from the system ceases to carry out the destroyed deposits, it will “lighten”, the following elements are cleaned.

Distinctive features of the proposed method is that the system to be cleaned is pre-filled with water, and this eliminates the time loss for filling it during the cleaning process and allows you to clean the elements and heating systems of multi-storey buildings, starting from the upper floors. In the known as a prototype method, this function is not provided, since it is impossible to fill the element being cleaned through the valve body without filling the system below the cleaning point.

To generate a shock wave, an impulse with a large steepness of the leading front is required, however, the prototype proposes the use of a ball valve, which, due to the design features, cannot provide the required steepness of the front and the generation of the shock wave. When the valve is opened manually with any final speed, the flow area of the crane gradually increases from zero to the maximum value, which leads to the formation of a pressure wave with a gentle front.

It is theoretically possible to generate a shock wave by the method selected as a prototype using high air pressures, but in this case the shock wave is generated only at the initial moment of opening the crane, and the pulse energy is insufficient to destroy the deposits.

In the inventive method, a pulse valve is used to generate pulses, in which the shut-off element, tearing itself away from the saddle along the abutment plane, provides simultaneous action of compressed air on the water column over the entire cross section of the valve outlet.

At the moment of separation of the piston from the valve seat, a gap is also formed between the piston and the water column over the entire cross section of the column, which leads to the appearance of a vacuum zone at the gap. The emergence of a vacuum zone leads to an abrupt decrease in pressure at the piston-water interface and the excitation of a rarefaction shock wave in water.

The amplitude of the pulse of the rarefaction shock wave is (4, 5):

And ₁ = P ₀ - (P _in + P _a ),

where And ₁ - the amplitude of the pulse of the shock wave rarefaction;

P ₀ - the absolute pressure in the vacuum zone, close to "0".

P _in - the pressure of the water column at the piston - water section;

P _a - atmospheric pressure.

Next, the compressed air in the receiver begins to fill the vacuum zone, affecting the piston and column of water throughout the section. The pressure in the vacuum zone rises stepwise, if transients are not taken into account, up to the pressure in the receiver. The effect of compressed air pressure on a column of water causes an increase in pressure in it and excites a compression shock wave, which propagates through the system. The amplitude of the pulse in this case is (4, 5):

A ₂ = P ₀ + P _p

where And ₂ - the amplitude of the pulse of the shock wave compression;

P _p - absolute pressure in the receiver.

The resulting amplitude of the pulses will be equal to:

A ₂ -A ₁ = P ₀ + P _p - [P ₀ - (P _in + P _a )] = P _p + P _in + P _a .

As can be seen from the equation, the use of a pulse valve allowed us to obtain a compression shock wave with an amplitude equal to the sum of the pressures in the receiver and the system being cleaned, and not their difference, which is the case in the prototype, and allowed us to generate a shock wave sufficient for cleaning and such an intensity at pressure air in the receiver, which does not exceed the calculated operating pressure in the system being cleaned. This completely eliminated the risk of damage to the system due to high overpressure arising from the use of high pressure for the purification of compressed air, and protected personnel from injury.

Information sources

1. The method of cleaning the inner surface of the heating radiators of the internal heating systems and a device for its implementation. Patent RU No. 2201572 C2, F 28 G 7/00; (24) 02.02.2001; (46) 03/27/2003, Bull. No. 9; (71) Dzhigurda Oleg Petrovich; (72) Dzhigurda Oleg Petrovich; (73) Dzhigurda Oleg Petrovich.

2. The method of cleaning heat exchange elements. Patent RU No. 2064642 C1, F 28 G 7/00; (46) 07/27/1996, Bull. No. 21; (71) Gelfond Leonid Abramovich; (72) Gelfond Leonid Abramovich; (73) Gelfond Leonid Abramovich.

3. A method of cleaning the internal surfaces of pipelines from contamination and a device for its implementation. Patent RU No. 2179082 C2, 08 V 9/04, 9/032; (24) May 13, 1999; (46) 02.10.2002, Bull. No. 4; (71) X-STAR (US); (72) Kanonir Evgeny Yurievich (LV); (73) X-STAR (US).

4. R.R. Chugaev. Hydraulics. Ed. Energy, 1971

5. E.M. Mogendovich. Hydraulic impulse systems. Ed. "Engineering", L - d. 1977

Claims (2)

1. The method of cleaning the inner surfaces of elements and heating systems and hot water supply from solid deposits, which includes generating shock waves in compressed air pre-filled with water to destroy the deposits and remove them from the system to be cleaned with a water stream, characterized in that shock waves are generated by exposing the filling system to water with vacuum and pulses of compressed air of exponential shape with a large steepness of the leading edge, while the pressure of the compressed air to generate a shock wave is chosen no higher than the calculated operating pressure in the system to be cleaned, and the water in the system is accelerated during a pulse by a portion of air to speeds causing a cavitation effect. 2. A device for cleaning the internal surfaces of elements and systems of heating and hot water supply from solid deposits, including a system to be cleaned, pipelines, a valve body and shutoff valves, characterized in that the device is additionally equipped with a receiver and a pulse valve, structurally combined in one unit, connected to switch, and the switch is installed with the ability to connect the cleaned system with a pulse valve and with a drain line.

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