DE102010010280A1 - Device for internal cleaning of heat exchanger pipes, has nozzle, which is positioned in heat exchanger tubes, from which scratches are loaded with pressurized water - Google Patents

Abstract

The device has a nozzle (9), which is positioned in the heat exchanger tubes, from which the scratches are loaded with pressurized water. The scratches are compressed through the heat exchanger pipes by pressurized water. The nozzle is provided with a water inlet pipe. A valve and a pump are provided for controlling the water flow.

Description

The invention relates to a device for internal cleaning of heat exchanger tubes, in particular of cooling tubes industrial cooler.

Such coolers occur, for example, in power generators or chemical plants. In power generation plants, the heat exchangers are used in particular as so-called capacitors. He serves there to liquefy the exhaust steam. This allows a closed coolant circuit. Contemporary capacitors in power generation plants exist as water-cooled surface capacitors. They have tube bundles. Through the cooling tubes of Abdampfkondensatoren cold cooling water is performed. The exhaust steam condenses on the outer surface of the cooling tubes. The number of cooling tubes in a condenser can be large. A number of 20,000 cooling tubes is not uncommon for the power plant capacitors. Depending on the design, heating of the cooling water in the cooling tubes should take place at 8 to 10 degrees Celsius.

The cooling water is usually taken from the environment. In order to limit contamination of the capacitors, the cooling water is cleaned before it flows into the cooling tubes.

Cooling of the vapor creates a negative pressure in the condenser, which is regularly referred to as a vacuum, although in the strict sense it is not a vacuum. This negative pressure is of great importance for the efficiency of the steam-powered power plant. The efficiency is determined to a large extent by the pressure gradient between the pressure (in the flow direction of the steam) in front of the steam turbine and the pressure behind the steam turbine. Since the cooling of the steam depends on the heat transfer in the cooling tubes, there is also a dependence of the negative pressure on the heat transfer. At the same time it should be noted that the heat transfer of the cooling tubes is reduced by contamination of the cooling tube inner surface. The contamination of the cooling tube inner surface is inevitable in conventional capacitors despite filtering the cooling water. Therefore, there is always a need for cleaning on conventional capacitors. Depending on the medium to be cooled or heated, which is passed through the cooling tubes, deposits are formed in the cooling tubes despite the filtering. This is true even with water. The main constituent of the deposits from the water is lime, unless the water has been previously descaled. But there are also significant deposits of manganese, iron and silica on cooling pipes made of steel, stainless steel, titanium or brass. Cooling tubes made of copper are also popular. Copper has significant corrosion problems. Upon contact with oxygen, copper oxides form. Oxygen is found in the cooling water, as well as in the steam.

The deposits usually lead to a deterioration of the heat transfer of the cooling tubes. As a result, the cooling performance decreases. However, deposits can be called corrosion or fouling. Therefore, a cleaning of the cooling pipes is not only useful for improving the heat transfer. If the corrosion is ignored, porous deposits form, which can increase the corrosion so that pitting can be talked about.

There are various cleaning devices for internal cleaning of the cooling tubes known, with which the heat transfer is to be improved again and with which the cooling capacity to be raised again. Such devices are described, for example, in: DE 69812512 T2 . EP 698423 A . US 2170997 . US 2,418,509 . US 2734208 . US 4281432 . DE 69507221 T2 . US 5153963 . SU 1414-482-A . US 5305488 . DE 69200433 T2 . US 1598771 . DE 698121511 T2 . US 3604041 , In these documents, scratches are disclosed, which are pushed one or more through the cooling tubes. The scratches have different shapes. Recurring is the shape of resilient hook, the hooks are connected at one end to the scratch and slide with the other, hook-shaped end on the inner wall of the cooling tube. The sharper the hooks, the better the cleaning effect. In part, the hooks at the contact ends are called blades.

In addition, the hooks at their end, with which they touch the inner surface of the cooling tube, adapted to this surface, that is, curved.

There are also scratches that are wholly or partially designed as brushes, as well as scratches, the first tear rips in the deposits in order to be able to remove one after the rest better

The scratches are preferably moved with pressurized water through the cooling tubes. For this purpose, the scratches are formed piston-like at one end. Piston-like, because there is no defined piston clearance. Rather, it must be considered that the deposits have different thickness. The piston-like end has to adapt to that. This is usually done with sealing lips at the end of the scratch. The sealing lips can be distributed at a small distance around the circumference. The permeability to the pressurized water associated with the distances may be beneficial in order to flush the deposits previously scraped off the hooks / cutters forward from the cooling pipe being cleaned.

For the application of pressurized water usually water pistols are used. The water guns have a front nozzle, with which the guns are pressed by hand into the opening of a cooling tube. At the same time pressed with a dome-shaped sealing part of the gun against the radiator plate in which the cooling tubes are held.

At a water pressure of up to 20 bar, depending on the water pressure, a force is required for sealingly pressing the gun, which depending on the area at which the pressure develops can easily correspond to a substantial part of the body weight of a cleaning man or even go far beyond that. Even if a gun is tilted in a cooling tube, and thus facilitates holding the gun, a tremendous physical effort remains for a cleaning man.

In addition, the physical effort increases as the posture becomes more difficult for the operator. From the difficulties arises a picture, if one realizes that the freedom of movement in front of the cooling tubes can sometimes be very small, for example only 500 mm and / or also requires an attitude of the pistol at head height and even overhead.

In practice, the operators have to pause again and again.

According to a proposal, the handling of the internal cleaning of the cooling pipes is facilitated by the projecting into the cooling tubes gun end or projecting into the cooling tubes / heat exchanger tubes part is provided with a spreading mechanism. By spreading the projecting into the cooling tube gun end the gun can be clamped and fixed there, so that the cleaning personnel is fully or partially relieved of the pressure described. With complete relief can be spoken of a complete self-clamping or self-locking against loosening.

The spreading mechanism can have different shapes.

An advantageous embodiment provides for the use of elastic, annular on the projecting into the cooling tube end material before. Compression causes a thickening, which clamps and locks the gun in the cooling tube. The elastic material may be rubber or compliant plastic such as elastomers. The elastic material can be used in the form of conventional O-rings. It is possible to arrange several rings in the axial direction one behind the other. Other profiles can also be used. Particularly advantageous are profiles that show an elongated cross-section in a running in the axial direction section. Such cross sections may, for example, have straight and / or round and angular surfaces. Rectangular cross sections and oval cross sections are included. Preferably find exactly rectangular cross-sections application. Such shapes, like other shapes of appropriate numbers, can be made economically. For small quantities, the molds can be cut from solid material with sufficient strength of the rubber or elastomer. A sufficient strength can be clarified by one or a few tests. For example, sufficient strength is provided by rubber and elastomer, which is standard for commercial hoses DIN 73411 Find application. For example, the molds of the invention may be formed by a tube section. In this case, hoses with a wall thickness of at least 1 mm, preferably of at least 1.5 mm and more preferably of at least 2 mm, and most preferably of at least 2.5 mm are favorable. Such hoses made of rubber and elastomers are commercially available, even with a fiber reinforcement. This prolongs the possible life and increases the usability. The commercially available hoses have nominal widths / wall thicknesses / outside diameters in mm of 10 / 3.5 / 17; 03/13/19; 16 / 3,5 / 23; 04/19/27; 25 / 4,5 / 34; 32/5/42; 38 / 6.5 / 51; 45 / 7,5 / 60; 50 / 7.5 / 65 These include, for example, commercially available cooling tubes with nominal diameters in mm of 15; 20; 25; 32; 40; 50; 65 opposite. After pollution, although the opening width of the cooling tubes is reduced. However, it can be assumed that the nominal diameter, because before positioning a gun in the cooling tubes first the scratches must be pressed into the cooling tubes and the cooling tubes are thereby released on a length required for positioning of the narrowing deposit. As a result, for example, tube sections with the following outer diameters can be used directly or indirectly after machining of the outer sheath for the spreading according to the invention in the tube opening: Tubing diameters Pipe size 17 15; 20; 19 20; 23 20; 25; 27 25; 34 32; 42 40; 51 50; 65 65;

When selecting the starting material for the described production of hose sections and a sufficient play of movement for the insertion of the gun must be considered in the pipeline. The movement can theoretically be small. Preferably, however, at least one clearance (here equivalent to a difference to the inner diameter / nominal diameter of the tube) of at least 0.5 mm, preferably at least 1 mm and more preferably at least 1.5 mm and most preferably provided by at least 2 mm.

The tube sections are bulged in the radial direction against the tube inner wall. This happens, for example, by axial compression. So that the end faces of the tube sections are gently pressurized when compressed, at the end faces of the tube sections are preferably provided with a metal cap. The metal cap can be made of thin sheet metal, for example with a thickness of less than or equal to 0.6 mm, preferably less than or equal to 0.4 mm and even more preferably less than or equal to 0.3 mm.

The metal cap preferably covers at least 50%, more preferably at least 70%, and most preferably at least 90% of the associated end face of the hose section.

It is also advantageous if the metal cap comprises the hose section at the associated end with an edge of at least 2 mm, more preferably of at least 4 mm and most preferably of at least 6 mm in the axial direction.

The annular elastic, expandable materials with the elongated cross-sections described above have no appreciable tendency to roll even under extreme water pressures occurring here.

Deformation of the resilient material may be effected by means of a power piston which presses the resilient material against, for example, a flange / flange fixed to the gun against a flange / flange fixed on the gun or the elastic material between two flanges movable on the gun. Squeezes stops or widening of the annular material from the inside causes. Each stop / flange forms a pressure surface and can be formed by existing or additional parts.

It is advantageous to provide a movable sleeve with a stop to provide a movable stop or to form the stop by the movable sleeve. The sleeve can at the same time completely or partially form the nozzle and / or completely or partially form the water pipe of the gun to the nozzle. Alternatively, the sleeve may be arranged in whole or in part on the nozzle displaceable and / or be arranged in whole or in part displaceably on the water pipe of the gun.

Preferably, the following embodiment is provided: the piston arranged in a cylinder. The pressure water supply is flanged in the direction of movement of the piston in front of the piston to the cylinder. The piston rod is hollow and serves as a water supply to the nozzle of the gun. The nozzle sits at the end of the piston rod protruding out of the cylinder. The piston rod penetrates the end wall of the cylinder. On the outside sit on the piston rod a movable sleeve. Between sleeve and nozzle a plurality of axially successively arranged O-rings are provided. The nozzle, the O-rings and the sleeve have an outer diameter which is smaller by so much than the inner diameter of the cooling tubes to be cleaned, as maximum with a contamination of the pipe inner surface is to be expected. A load of the piston with pressurized water causes a movement of the piston and a train over the piston on the piston rod, so that the train also acts on the nozzle and the nozzle moves against the O-rings, while the sleeve rests against the end face of the cylinder and can not escape, so that the O-rings deform under increasing the diameter and press against the pipe inner wall.

In the embodiment with the expansion of the expansion of the elastic, annular material, for example, a conical or a different inclined mandrel is suitable, which may also have a sleeve shape and in the central opening of the elastic and preferably axially fixed elastic material acts , The expanding mandrel can in turn be weaved with a piston or other mechanism. It also motors can be used. The motors may be pressurized water driven motors or pneumatic driven motors. The control of the motors can be carried out in the same way via the drive medium or via intermediate valves as in the other variants of the invention.

Optionally, the motor with water or another medium, eg. B. operated with compressed air.

When using water, it can be pressurized water that is generated by the same pump that also supplies the water to move the scratches or to flush the cooling tubes. When using the same water for the movement of the scratches and the operation of the piston valves in the line to the nozzle and in the line to the piston are advantageous, which allow a pressure adjustment. By adjusting the pressure in the nozzle and in the piston, the cleaning operation and the locking of the gun in the cooling tube can be optimized. A good attitude can already be found with a few adjustments. After knowing a good setting, a permanent pressure distribution between nozzle and piston can be used.

The use of a valve in the gun, although known from conventional guns, also the adjustability of the valve and the on-off function of the valve. However, not known is the diversion of pressurized water for the piston and the switching of another valve. Preferably, the diversion of pressurized water for the piston takes place before the valve for regulating the pressure water for the nozzle. As a result, the position of the gun regardless of the cooling tube can be maintained whether the pressurized water to the nozzle is started, interrupted, continued or canceled. If the valve can simultaneously assume an on or off position in the gun supply line to the piston, and if this valve, like the valve in the supply line to the nozzle, can be locked in the desired position, further advantages open up.

It can be several pistols operated by a cleaning person at the same time. This multiplies the performance of this cleaning person.

It is favorable if the valves are at the same time provided with a pressure limiter. The pressure limiter allows the gun to react automatically when a blockage occurs. Then the pressure limiter can respond to an increase in pressure and bring the valve in the off position, in which the pressure water supply to the nozzle is interrupted. Thereafter, an attempt can be made to eliminate the scratch by pulsating pressure and / or with an increase in pressure by valve actuation or valve adjustment before the scratch is otherwise shaken or even a cumbersome backward movement of the scratch is initiated.

Similarly, the pressure limiter can respond to a pressure drop when a scratch has fallen out of the cooling tube after the cleaning end. With such a pressure drop, the valve in the supply line to the nozzle is also triggered and the pressure water supply is interrupted.

The shaking loose the scratch can be done with two guns according to the invention, when the valves on both pistols, a valve position is provided in which the pressurized water supply is interrupted and in which the water supply to the nozzle is released. Then the second gun can be used at the cooling tube inlet and operated in alternation with the gun at the cooling tube inlet, so that the stuck scratches can be applied alternately from the one side and the other side with pressurized water. According to the invention, when the pressure is applied to the one side, a ventilation of the line to the nozzle on the other side is provided. Optionally, the valve actuation can be electrically / electronically controlled. With a chip, various functions of the valves can be controlled.

The controller can respond to specific operating pressures in front of and behind the valve. The controller can effect the necessary pressure changes for a shaking operation. The controller may also respond to the particular operating pressure discussed above, which occurs when the scratches are a cooling tube have migrated and have leaked out of the cooling tube. Then the controller can respond faster and safer than the operator and set the gun to Off, so that a pressure loss is avoided. This is important if a single cleaning person handles several guns at the same time.

The controller may also include a safety shutdown, which will be effective when a gun has not yet found a sufficient seat in a pipe. Then the gun with a high-pressure jet could pose a danger to the cleaners.

The controller may also visually and / or acoustically and / or by vibration indicate each operating condition. The optical displays can be formed by light-emitting diodes. The vibration through magnets, the acoustic through miniaturized speakers. In addition, with the help of pressure sensors each operating pressure can be measured and processed with the controller. Furthermore, the controller can be linked to displacement sensors. This can be used, among other things, to shut down the gun if the gun does not reach the correct position in a cooling tube.

Commercially available chips are able to accommodate the necessary programs. The power consumption of these chips is so low that a button cell is sufficient. The controller can be enclosed in the gun, permanent or openable. The power source in the form of the button cell or other form is preferably interchangeable and moisture proof in the gun. The moisture protection is achieved by means of appropriate sealing rings.

All guns can be supplied with pressurized water by the same pump. Conveniently, a pump system with a pressure vessel arranged between the pump and pistols. As a result, the pressure conditions even out with irregular demand for pressurized water.

In the variant, is provided for the operation of the piston compressed air, in addition to the specific nozzle for the pressure water supply to the gun still a compressed air supply to the piston of the gun is provided. The compressed air is generated by a compressor. An advantage is a compressed air tank between the compressor and guns. This equalizes the pressure conditions and facilitates the connection of different guns.

A further variant of the invention provides that, instead of pistons and rings in the front region, with which the gun projects into a cooling tube, provided an inflatable or inflatable bellows. The bellows simplify the construction effort of the guns. The bellows can like the piston with pressurized water or compressed air are applied and controlled.

Optionally, the guns according to the invention with the expandable region on the input side sit so far in the cooling tubes, that there is a distance from the input-side plate, in which the cooling tube are held together. Optionally, the seat of the guns according to the invention in the cooling tubes is also chosen so that the spreadable range extends beyond the input-side plate of the radiator. The result is a relief of the cooling tube from the spreading pressure, because the spreading pressure is absorbed to a substantial extent by the input-side plate.

With the water pistols according to the invention, the cooling pipes are accessible even in the narrowest space. For example, the pistols can be positioned with a rod or with long tongs. With the rod or extended pliers, the guns can also be operated from some distance.

• a) wegen der anschließenden Entsorgung der Ablagerungen
• b) wegen der Wiederverwendung der Kratzer
• c) zur Klärung, ob ein Kratzer aus einem Kühlrohr nicht ausgetreten ist und dort vielleicht sogar festsitzt.

The object of the invention has been found to facilitate the cleaning work even more and simplify. The invention has recognized that waiting at the outlet of the scratches considerable effort on the cleaning staff. At the outlet of the cooling pipes, dissolved deposits and the well-worn scratches accumulate in a heap. The scratches must be separated from the deposits for the following reasons:

• a) because of the subsequent disposal of the deposits
• b) because of the reuse of the scratches
• c) to clarify whether a scratch from a cooling pipe has not leaked and may even be stuck there.

Depending on the size of the cooler, the amount of deposits accumulated during a cleaning process can be much more than 1 tonne in weight. In the context of disposal, there is always the question of whether a residue is sorted by type. The scratches must be painstakingly picked out of the deposits. The wipers wade deeply through deposition and must be rummaged with the volumes in the deposits. At the same time the search through the confined spatial conditions at the outlet of the cooling tubes is many times more difficult. The tight constrictions at the outlet of the cooling tubes arise from the design of the radiator. The cooling tubes form namely a tube bundle, wherein the various cooling tubes are held upstream and downstream in common plates. The inflowing cooling water must be distributed over the different cooling tubes. This happens in a low-volume chamber upstream of the cooling tubes. The effluent cooling water is either bundled and discharged in a line or the cooling water is subjected to further cooling in a downstream further cooler. In the case, a small-volume intermediate chamber or transfer chamber is provided between the two chambers. This chamber has not just structural reasons. An advantage of this chamber and the merging of the cooling water and the subsequent redistribution of the cooling water to the cooling pipes of the downstream cooler include an advantageous mixture of the cooling water. Even if no further cooler is connected downstream, there is a chamber at the radiator outlet. Their task is then collecting the effluent cooling water and its derivative.

The upstream chamber of a cooler and the outflow chamber are usually accessible only through small manholes.

According to the invention, a simplification of the cleaning work and a relief is achieved in that the emerging from the cooling tubes together with water and deposits scratches are sieved from the mixture. It is ideal if the extraction can be done before the mixture collects on the bottom of the chamber.

It may be advantageous to make a screening in different heights. As far as the cooling tubes end at a relatively short distance from the container bottom, it may be necessary to make the screening in the small distance.

According to the invention is optionally provided to screen off the scratches. In this case, the screen can be put together from various stable elements that can be mounted through each manhole in the chamber. During assembly, a distance is preferably left down so that the discharged from the cooling tubes deposits can fall through the sieve. It is also advantageous if between the container wall of the cooler and the sieve a device is provided, with which the fallen down deposits can be removed. These are for example conveyors that are moved back and forth over the container bottom. The reciprocating motion can be generated, for example, with a rod to which flaps are hinged so that the flaps collapse in one direction of motion and allow the material to lie down and fold out in the other direction of motion and take the material with it.

In a conventional drain at the bottom of the chamber, it is advantageous if the device, starting from the sequence in the one circumferential direction has a different conveying direction than in the other circumferential direction. This is then used to convey from each circumferential direction to the process can. That is, the hinges of the flaps are arranged so that they fold during a movement, which is directed away from the drain, and unfold during a movement, which is directed towards the drain out.

With a round container, the rod can be provided with the same rounding as the container. Then the rod can perform the reciprocating motion in the circumferential direction despite the rounding.

The cleaning of the intermediate chamber of deposits can be supplemented by a slot-shaped drain, which extends as far as possible over the whole or a substantial part of the axial length of the intermediate chamber.

If the container of the cooler do not have sufficient flow, the deposits to be disposed of can even be promoted to the manhole when the device is eingeschacht in the region of the side wall of the container.

The screen is preferably made of wire mesh on which the discharged from the cooling tubes deposits can not find a substantial hold and fall through. The screen preferably has a mesh size smaller than the diameter of the scratches to be collected, preferably less than 0.7 times, more preferably less than 0.5 times the diameter of the scratches to be collected. This is to prevent jamming or settling of the scratches in the sieve. On the other hand, the mesh size be as large as possible to ensure falling through the discharged from the cooling pipes deposits.

The drive of the device can be done by means of conventional Hubmotore. For example, chain drives, spindle drives, rack and pinion drives as well as crank mechanisms and eccentric gearboxes are suitable for this purpose.

The motors can be driven hydraulically, with compressed air or electrically. Pressurized water is available because of the above-described cleaning with scratches and pressurized water. An adjustment permissible pressures can be done with pressure relief valves. In the case of large operating systems, compressed air is usually also available, which can optionally be used for the drive. Alternatively, compressed air can be generated with a portable compressor. The same applies to electricity that can optionally be generated with a portable generator.

Preferably, the screening is done with a highly flexible net that can be easily passed through the manholes. The mesh preferably has the same mesh size as the sieve. The net can be mounted in different ways. Mounting aids can be magnetic strips and / or other mechanical clamps or hooks. Optionally, the net is also laid out on the tank bottom and raised at intervals to collect the well-worn scratches from the net before the accumulation of deposits on the net is too large to be able to raise the net by hand.

The interim cleaning of the intermediate chamber or the downstream of a cooling tube bundle chamber under the wire or under the network can be omitted in whole or in part if the chamber volume is increased under the wire or net, especially if the drain is funnel-shaped. Preferably, a funnel opening is provided which extends at least over 50% of the axial length, even more preferably at least over 70% and most preferably over at least 90% of the axial length. Preferably, the funnel circumferentially extends over a circumferential angle of at least 10 degrees, even more preferably over at least 20 degrees, and most preferably over at least 30 degrees, based on a circumferential angle of 360 degrees for the entire circumference.

The structural measures for the design of the intermediate chamber or the chamber downstream of a cooler are easier to implement in new construction measures than in the case of modification measures. With an enlargement of the chamber under the sieve / net, the sieve / net can remain at least during the entire cleaning process, if the volume of the chamber under the sieve / net is large enough to take up all discharged deposits. The sieve / net can even be arranged permanently in the chamber if deposits falling through the sieve / net are adequately discharged from the device described above and / or due to the effect of the described funnel.

In the drawing, an embodiment of the invention is shown.

The cleaning device according to the invention only roughly reminds us of conventional water pistols for cleaning cooling tubes. In the drawing is a cooling tube 15 shown in dashed lines. The cooling tube 15 belongs to a variety of identical cooling tubes, which are arranged together in a radiator. This is the right end of the cooling tube in the view 15 held with the same ends of the other cooling tubes in a plate, not shown, of the radiator. The cooling tube 15 is shown shortened in the view. The left end of the cooling tube in the view 15 is held with the same ends of the other cooling tubes in another plate. In the exemplary embodiment, the cooling tubes are traversed by water inside and flows around the outside of flue gases of a combustion, not shown.

The flue gases emit a significant part of their heat through the cooling pipes to the water. During the cooling operation, deposits occur in the cooling tubes, which necessitate internal cleaning of the cooling tubes. For internal cleaning scratches, not shown in the right in the view of the end of the cooling tube 15 pressed, as in the DE 69507221 T2 are shown. The scratches are filled with pressurized water through the cooling tube 15 pressed until the scratches on the left end of the cooling tube 15 from the cooling tube 15 fall out.

The pressurized water is mixed with one in the cooling tube 15 self-clamping device in the cooling tube 15 pressed. The self-clamping device includes a cylindrical housing 16 with a pressurized water connection 12 , as well as with a pipe 17 that has an entrance opening 18 for the pressurized water and into the cooling pipe 15 to a conical nozzle 9 enough. The nozzle 9 has a larger outside diameter than the tube 17 , It is a screw connection of the nozzle 9 with the pipe 17 provided for a replacement of the jet 9 allowed. The replacement is required to adapt the device to other cooling tubes that have a smaller or larger inner diameter. The parts to be replaced also include O-rings 5 and passport sleeves 10 and 19 , These parts also sit on the tube 17 , The fitting sleeves determine the position of the O-rings and their distance to the housing 16 established. For cooling tubes with low strength, the O-rings 5 be moved in the area of the input-side plate in which the cooling tubes are held. This plate then takes a substantial part of the forces from the clamping of the device in the cooling tube 15 on.

The pipe 17 at the same time forms a piston rod for a in the cylindrical housing 10 slidably arranged piston 20 , The piston 20 in turn has an O-ring that separates the gap between pistons 20 and housing 16 seals.

The housing 16 is at the left end in the view 3 openable or with a lid 4 locked. In addition, the piston protrudes 20 with a pen 11 through the lid 4 therethrough.

The device according to the invention also includes a control block with a switch 13 and an operating lever 2 that hinged to the switch 13 is held and in working condition on the pen 11 supported.

For a cleaning process, the device with the nozzle 9 in the cooling tube 15 pushed until the case 16 to the plate, in which the cooling tube 15 is held on the input side. Subsequently, the operating lever 2 placed in the position shown, opened in a valve, not shown, and pressurized water into the housing 16 flows. The pressurized water fills the housing interior and penetrates the pressurized water through the opening 18 in the tube designed as a piston rod, the pressurized water to the nozzle 9 passes. There, the pressurized water comes out of the nozzle 9 in the cooling tube 15 out. As soon as a pressure builds up, there is a piston movement in the view to the right towards the lid 4 out. The piston rod is moved along and become the O-rings 5 between the sleeves 10 and 19 pressed together. The can deform only due to their arrangement between the sleeves and on the piston rod outside. This causes a spreading of the device and a self-clamping of the device in the cooling tube.

Due to the self-clamping, the device according to the invention no longer has to be held by the cleaning staff during operation. This not only relieves the cleaning staff of the heavy physical work. This is especially true for hard to reach cooling tubes. It also opens up the possibility of parallel operation of multiple devices by a single cleaning person. In addition, you can work with water pressures that were previously uncontrollable when cleaning the cooling tubes. This applies, for example, for pressures greater than or equal to 30 bar.

2 and 3 show a chamber that connects two radiators together.

3 shows a section of the chamber connecting a downstream cooler with a front-flow radiator. The rear radiator has cooling tubes 39 that of a coat 42 are surrounded and together in a plate 31 are held. From the front cooler in the flow direction are cooling tubes 38 , a coat 37 and a plate 33 shown. Coat and plate 37 and 33 have the same function as sheath and plate 42 and 31 ,

Between both plates 31 and 32 is another coat 34 arranged by means of flanges 30 and 32 with the projecting edges of the plates 33 and 31 are connected. The coat 34 forms an intermediate chamber or transition chamber between the two coolers. In operation, cooling water is through the pipes 38 of the front radiator. At the same time, in an unillustrated form, exhaust steam is forced through the cavity inside the shell 37 and the cooling tubes arranged therein. The cooling tubes take up a part of the heat containing the exhaust steam and give the heat to the through the cooling tubes 38 flowing cooling water on.

The exhaust steam accumulates from the operation of a steam operation of a steam turbine with which a generator is driven, which generates electricity.

The cooling water emerging from the front radiator into the intermediate chamber is mixed in the chamber and re-distributed in the cooling tubes 39 of the downstream cooler pressed.

In the embodiment takes place at regular intervals, a cleaning of the radiator shown. With intervals is meant the number of operating hours. In other embodiments, a cleaning is carried out only after finding a decreasing negative pressure in the cavity of a radiator. In this case, the decreasing negative pressure is regarded as a concomitant of deposits in the cooling tubes, which hinder the heat transfer and reduce the efficiency of the cooler.

For cleaning, the cooler is taken out of service. This is usually synonymous with a business interruption of the power plant. The business interruption can be avoided, however, if the power plant still has a reserve cooling line, can be switched to the. When decommissioning the cooler not only the steam supply, but also the cooling water supply is switched off. The existing in the coolers cooling water is drained. This is done through drain holes at the bottom of the intermediate chamber. The drain opening is through a nozzle 36 and a flange 35 educated. The flange 35 is intended for connection of suitable cables or hoses.

After draining the cooling water begins the top to 1 described cleaning the cooling tubes 38 of deposits therein. When cleaning the scratches occur at considerable speed from the cooling tubes 38 out. The same applies to the cleaning water. Water and scratches bounce against the opposite plate 31 and fall down more or less unpressurized. The water flows after contact with the mantle 34 to the drain. It also entrains deposits. The scratches and debris accumulate on a coarse mesh below in the intermediate chamber. From the net is in 3 the contour 30 shown in dashed lines. In 2 are also contours 40 the network shown in dashed lines.

The network is in the embodiment by magnetic strips 41 and 43 held in the position shown.

As soon as a substantial layer of deposits has formed on the network from the cooling tubes, the cleaning process in the exemplary embodiment is interrupted in order to take up the net and free it from the scratches collected therein. Subsequently, in the exemplary embodiment, the deposits lying in the intermediate chamber are pushed into the drain opening. In this case, a slider can be used. In the embodiment, the pushing is supported by a water flush. In other embodiments, the intermediate chamber is cleaned alone with a water rinse.

After cleaning the intermediate chamber, the network is clamped again in the intermediate chamber and the cleaning of the cooling tubes continued with scratches and with water.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69812512 T2 [0006]
• EP 698423A [0006]
• US 2170997 [0006]
• US 2418509 [0006]
• US 2734208 [0006]
• US 4281432 [0006]
• DE 69507221 T2 [0006, 0060]
• US 5153963 [0006]
• SU 1414482 A [0006]
• US 5305488 [0006]
• DE 69200433 T2 [0006]
• US 1598771 [0006]
• DE 698121511 T2 [0006]
• US 3604041 [0006]

Cited non-patent literature

• DIN 73411 [0016]

Claims (16)

Device for internal cleaning of heat exchanger tubes, wherein scratches or the like are pressed by means of pressurized water through the heat exchanger tubes and wherein the scratches and the deposits collect in a heat exchanger tubes downstream in the flow direction of the pressurized water chamber, characterized in that the scratches are screened from the deposits, the be discharged from the heat exchanger tubes. Apparatus according to claim 1, characterized by the use of a sieve or net, which is mounted before the internal cleaning and then dismantled, Apparatus according to claim 2, characterized by the permanent mounting of a sieve or net and a discharge of the falling through the sieve or net deposits from the part of the chamber. Device according to one of claims 1 to 3, characterized by a sieve of wires. Device according to one of claims 1 to 4, characterized in that the sieve or mesh has a mesh size which is smaller than the diameter of the scratches, preferably less than 0.7 times the diameter of the scratches, even more preferably less than 0.5 times the diameter of the scratcher is. Device according to one of claims 2 to 5, characterized in that the sieve is composed of several elements. Device according to one of claims 2 to 6, characterized in that a conveyor is provided under the wire or net, the conveying direction is directed against the drain provided there. Apparatus according to claim 7, characterized by at least one longitudinally movable rod with movable flaps, which fold in a bar movement against the conveying direction and fold out during a movement in the conveying direction Device according to one of claims 2 to 8, characterized by a clamping of the net or hook for the suspension of the network. Apparatus according to claim 9, characterized by magnetic strips for clamping the network. Device according to one of claims 1 to 10, characterized by an interruption of the cleaning process for an intermediate emptying of the screen or network of sieved scratches. Device according to one of claims 1 to 11, characterized by a chamber volume under the sieve or net, which receives the entire accumulating deposits during the cleaning process. Device according to one of claims 1 to 11, characterized by a funnel-shaped drain at the bottom of the chamber. Apparatus according to claim 13, characterized in that the funnel extends in the axial direction of the chamber at least over 50% of the chamber length, preferably over at least 70% of the chamber length and most preferably over at least 90% of the chamber length. Apparatus according to claim 13 or 14, characterized in that the funnel extends in the circumferential direction of the chamber over a circumferential angle of at least 10 degrees, preferably at least 20 degrees and most preferably at least 30 degrees, based on a Gesamtumfangswindel of 360 degrees. Device according to one of claims 1 to 15, characterized by a supplementary water flushing in the chamber for discharging the accumulated deposits in the chamber from the cleaning of the cooling tubes.

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