NO160694B - SLIPEBAAND-MAGAZINE. - Google Patents

Abstract

1. Belt store, in which at least one belt reel having a central passage opening (4) has in the latter at least one bearing insert (6), which is provided with a pivot bearing surface (10) roughly coaxial to the reel axis and formed by an external circumferential surface for the rotary mounting of the belt reel on an angular bearing (3), the pivot bearing surface (10), whose diameter is at least approximately as large as the internal diameter of the passage opening (4), is essentially formed by an axial extension of the bearing insert (6) and in particular two separate pivot bearing surfaces (10) are located on either side outside the end faces (5) of the belt reel (2), characterized in that the belt reel (2) is formed by a wound abrasive belt and that the pivot bearing surface (10) is formed by the axial extension of a plug-in surface engaging in the inner face of the passage opening (4), bounded on at least one side by a collar (8, 9) and arranged in such a way that it is approximately adjacent to the end face (5) of belt reel (2).

Description

Incinerator for municipal and/or industrial waste.

This invention relates to an incinerator for municipal and/or industrial waste, whereby inside the furnace for cooling the waste flue gases on their way from the combustion chamber to the exhaust gas cleaning device, one of a pipe system consisting of a heat exchanger is arranged, the pipes of which are coated with the waste flue gases and flowed through by a heat carrier .

Incineration plants for rubbish, whether urban rubbish or industrial waste, must incinerate the material so that the remains are as small as possible both with regard to weight and volume and, furthermore, the remains must be practically sterile, i.e. free of fermentable substances such as that they can be stored without the slightest risk of contamination of the surrounding air or groundwater.

In addition, the combustion process must be carried out in such a way that the ambient air is neither polluted by solid particles from the combustion gas, i.e. dust, nor is foul-smelling substances added.

In order to satisfy the two above-mentioned requirements, the combustion process must take place by practically complete combustion, which in turn requires a high temperature for the fuel material or the combustion chamber. To avoid air pollution by dust, the combustion gases must be subjected to a thorough cleaning process before they can be discharged into the atmosphere.

The rubbish, however, is an inferior combustible material that usually contains a relatively small proportion of combustible substances, while the rubbish usually has a high moisture content. In addition, the composition of the litter varies greatly according to place and time, and the litter has a peculiar tangled and inhomogeneous nature. For these reasons, the combustion can hardly be carried out in practice under optimal conditions, i.e. only approximately with the theoretical amount of combustion air which ensures a high fuel layer - or boiler room temperature, and incinerators must usually be run with an excess air ratio of 2 to 2.5. Under such conditions, the requirement for practically complete combustion and complete deodorization of the flue gases can only be satisfied by the combustion taking place in well-insulated combustion rooms, i.e. rooms that are not exposed to unwanted cooling. Under such conditions, the gaseous combustion products (flue gases) that flow out of the combustion chamber have temperatures in the range from 800 to 1000°C.

This fact, however, is in contrast to the above-mentioned other requirement regarding the exhaust gases' freedom from dust or purification, because at the state of the art this can only be carried out at reasonable temperatures, and also out of consideration for the large effective gas volumes and gas densities at high temperatures. In addition, it must also be taken into account that the temperature normally tolerated by aqueous exhaust gas cleaning devices, such as cyclones, fabric filters, electrostatic precipitators, etc., is limited upwards to approx. 350°C.

You therefore get a relatively strong cooling of the flue gases on the way from the combustion chamber to the flue gas cleaning device (dedusting) with a reduction of the flue gas temperature of 600 to 700°C.

In the case of ovens with direct heat generation, this is achieved, as is known, by switching on or installation of a steam or hot water boiler in the waste incineration plant, and the flue gases give off their sensible heat to the boiler's hot surfaces so that their temperature is reduced to the necessary extent in! dependence on this heat output.

In the case of furnaces without direct heat generation, the necessary temperature reduction for the flue gases has been achieved by injecting water and/or mixing air into the exhaust gases.

In the first case, the heat removal takes place by evaporation of the injected water and superheating of the same to the final temperature of the gas-steam mixture. However, this procedure is associated with significant disadvantages which will be explained in more detail below.

In the event of unprofessional atomization of the water or non-continuous i.e. intermittent operation, the heated refractory masonry parts of the oven can be exposed to dangerous sudden cooling. Furthermore, there is the danger that with acidic flue gases, such as SOs and SO3 from sulfur-containing waste, or HC1 (hydrochloric acid) from plastics, e.g. PVC, severe corrosion occurs due to local cooling down to below the relevant exhaust gas's dew point temperature. This danger exists particularly at and near the injection nozzles, which are therefore eaten up and which in turn causes poor atomization and indirectly the above-mentioned rapid cooling of the masonry. Furthermore, as a result of the water injection, the exhaust gases get an unduly high moisture content which, at low outside temperatures, can lead to unwanted impacts around the combustion plant's chimney.

Just opposite to what has just been mentioned, the cooling of the flue gases by means of air mixing is less dangerous, but due to the low specific heat of the air, the amounts of air to be mixed represent many times the quantities of flue gas that you have to deal with. This primarily requires a colossal over-dimensioning of the dedusting plant and the suction plant and the associated extra costs. A major disadvantage, however, is the fact that the ballast, due to the multiple air mixing, greatly reduces the controllability of the firing, more precisely so that an elastic adaptation of the firing to the instantaneous combustion conditions is hardly possible.

The purpose of the invention is therefore to provide a combustion plant of the type mentioned at the outset, where the above-mentioned disadvantages are avoided, while the above-mentioned requirements and prerequisites are satisfied in the most economical way, with a suitable heat removal in the furnace between the actual combustion -place in the combustion chamber and the place where the exhaust gases exit from the stove, and where the heat removal must be easily adjustable with regard to quantity and local needs.

According to the invention, this purpose has been achieved by the fact that the heat exchanger which limits at least one side of the combustion chamber of the waste incinerator designed for flue gas cooling without direct heat utilization and which consists of a radiation part and at least a convection part, is arranged as a primary heat exchanger in a closed circuit system for the heat carrier circulated in this system, which serves as a cooling medium for the waste flue gases, and that in the same circuit system, however, outside the waste incinerator for indirect heat utilization of at least part of the heat produced in the oven, one is arranged with its secondary part to a heat consumer connected to a further heat exchanger and a secondary heat exchanger connected after this exchanger which serves as a recooler for the heat carrier in the closed circuit system, that further in the two circuit systems for the primary and the secondary heat carrier there is arranged in each of them at least one of a control valve or/and a circulation pump consisting of a flow control device, and that the flow control device arranged in the primary heat carrier's circuit system for maintaining a predetermined temperature in the waste smoke gases exiting the waste incinerator while adapting the flow rate of the primary heat carrier to the current heat load of the waste incinerator The furnace can be controlled by means of a temperature sensor arranged in the flue gas outlet of the furnace via a control device in dependence on the flue gas outlet temperature and by means of the through-flow regulating device arranged in the secondary heat carrier's circuit system while adapting the secondary heat carrier's through-flow amount to useful heat removal by the heat consumer with the help of of a measurable quantity serving as a control quantity which is kept constant at a predetermined value, and where the flow regulation device arranged in the secondary heat carrier's circuit system is controlled rt by means of a temperature sensor arranged in the waste incinerator's flue gas nozzle above a control device and depending on the flue gas outlet temperature.

The invention shall be explained in more detail by means of an example with reference to the drawing which shows a vertical longitudinal section through an incinerator made in accordance with the invention.

Before discussing the only schematically shown design in detail, first, in order to facilitate the understanding of the furnace and its operation as well as advantages, some general heating technical assumptions must also be explained on which the conception of this furnace design depends.

When considering the closed circuit for the primary heat carrier, it is found that for the same exchanged amount of heat, the difference between the boundary temperatures tI)lul.a and tmin for the primary heat carrier depends on whether the heat carrier is subjected to a phase change or not, i.e. whether an evaporation and subsequent condensation, i.e. liquid formation in the heat carrier takes place, and where it must be assumed, to keep the consideration quite general, that such a change in the state of the aggregate takes place for part of the flowing quantity of the primary heat carrier.

In the consideration below, in which the possibility of overheating of the steam heat carrier is assumed to be eliminated, the following symbols shall be used: G total flow rate of the primary heat carrier in the closed circuit

per time unit (kg/h),

G' subset of the primary heat carrier which

was subjected to a phase change (kg/h),

r specific heat for the phase change (kcal/kg), c average specific heat in the heat carrier (kcal/kg/°C) and

Q exchanged amount of heat (kcal/h).

The exchanged amount of heat can therefore be expressed:

Under the aforementioned assumption that the evaporation of the primary heat carrier takes place without superheating the steam formed, the maximum temperature tmax of the heat carrier is identical to its saturation temperature ts, where the latter is dependent on the operating pressure p (i ata) which is selected for the closed circuit. On the other hand, it has been shown in practice that the lowest temperature tmjn, in order to avoid the harmful corrosions, must not fall below a certain minimum value which is approximately 150 to 200°C and which in this case should be denoted t,..

In this way, the equation (1) stated above yields: Q = G.c. (t3 —tc) + G'.r (la)

In practice, a sufficiently high operating pressure p (in ata) is chosen so that the saturation temperature ts is well above the minimum temperature t0 which must not be lowered. If you e.g. if water is used as the primary heat carrier, an operating pressure of 25 ata is sufficient in all cases, which ensures a ts value of 223°C.

The equation 1a shows that in the closed circuit the heat exchange achievable with the heat carrier can be changed within wide limits if the operating pressure p in the primary heat carrier and the heat carrier's circulating quantity are kept constant. It is clear from the equation la that the vaporized partial amount G' of the primary heat carrier is, for any value of the exchanged heat quantity Q, a function of the heat carriers' total flow rate G, so that in the end Q becomes only a function of G, i.e. Q = f(G). From this it follows that by increasing or decreasing the total flow rate G of the primary heat carrier per unit of time in the closed circuit has been given the opportunity to adapt the primary heat exchange system's working method according to the relevant heat load of the furnace, respectively according to the turnover of the fuel material (in kg/h) and the heat value (in kcal/kg) of the waste, e.g. e.g. garbage, to be incinerated.

This adaptability of the exchanged amount of heat at a constant, uniformly selected operating pressure p, as expressed in the equation la, allows for a specific furnace size a standard design of the heating and cooling system located in the primary circuit, as this only needs to be dimensioned according to the relatively nominal heating capacity of the furnace performance. This means a significant rationalization of production, because the primary heat exchanger that serves for heating the heat carrier and the other heat exchanger that serves for cooling back can be produced as standard designs with relatively low production costs, which represents a significant technical advance in the area.

The heat consumer that is to be connected to the incinerator has a heat absorption capacity which is to be denoted by Q" (kcal/h). In the case of the incinerator proposed here, however, this quantity of heat .Q" must be supplied to this consumer indirectly through a secondary heat carrier, where this is circulated in a closed or open circuit, namely with a turnover per

unit of time to be denoted by G" (in kg/h) and

with an inlet and outlet temperature t", respectively t"2, denoted on the heat consumer. This gives the following equation:

where c" denotes the average specific heat in the secondary heat carrier. In practice, it often happens that the heat consumer consists of a heating device, where the hot water is used as a secondary heat carrier (with an average specific heat c" = 1 kcal/kg °C, where the flow temperature t", = approx. 70° C and the return temperature t"2 = approx. 40° C. At these relatively low temperature values, which are far below the values for the limit temperatures that must be relevant in operation, namely ts and t0 for the primary heat carrier, it is completely impossible to make a direct withdrawal of a partial flow from the primary heat carrier's circuit in order to supply the heat consumer indirectly with the heat carried by the primary heat carrier.

For this reason, in the furnace design according to the figure, a further intermediate heat exchanger is arranged in the primary heat carrier's circuit, and the secondary part of this heat exchanger, which can be in open or closed circuit, is connected to the heat consumer, and a secondary heat carrier that flows in this circuit , but which is heated in the additional heat exchanger emits its heat to the heat consumer. For obvious reasons, this additional heat exchanger is preferably arranged at such a place in the circuit of the primary heat carrier where the heat carrier has its greatest enthalpy, i.e. its greatest heat content (in kcal/kg), i.e. at a place where preferably the saturation temperature t3 is still found, i.e. close to the outlet of the primary heat carrier from the furnace.

For this additional heat exchanger, which also comes in addition to the secondary heat exchanger arranged outside the oven and located in the primary heat carrier circuit, a standard construction can now also be used. This heat exchanger is dimensioned for the stove's heat output (thermal nominal output in kcal/h) and the heat consumer's heat demand (in kcal/h), taking into account an adaptation of the emitted heat quantity Q" according to the heat demand that may occur, and then even under conditions of complete elimination of useful heat release (Q" = 0), which adaptation is already opened by the turnover quantity G" (in kg/h) in the secondary heat carrier according to the above equation (2) changing while the temperatures t"j and t "2 is kept constant. Therefore, this additional heat exchanger can be manufactured as a standard design in serial production with relatively low manufacturing costs.

A closer look at the two equations (la) and (2) will form the basis for the possibility of regulating the facilities, namely:

1. ) for the primary circuit system:

a) creation of constant operating pressure p with a predetermined value, e.g. 25 eight

for the treated case,

b) regulation of the flow rate G (in kg/h) in the primary heat carrier, in order to keep the temperature of the flue gases flowing out of the furnace at the temperature tfc which is approximately at 250 to 300° C or 150 to 200° C respectively and which does not must be undercut to avoid

harmful corrosions.

2. ) for the secondary circuit system: regulation of the flow rate G" (in kg/h) of the secondary heat carrier, to keep the flow temperature t'\ and, if it is a closed circuit, the return temperature t"2 at specific values, e.g. 70° C and 40° C respectively.

These regulations can easily be made automatic because the quantities that must be kept constant at pre-given values can be measured directly and can therefore be used as control quantities for the regulation.

In the subsequent description of the embodiment examples According to the figure, the different temperatures that occur are denoted by t -med the different index numbers >which indicate where the temperatures are measured or where they occur. In the design according to the figure, a closed circuit has been chosen for the secondary circuit system. As mentioned, however, an open circuit system can also be used here.

In the figure, 1 denotes an incinerator with three barrels with a grate firing as it is used for burning inferior materials such as rubbish, waste and the like, particularly at large municipal facilities for the destruction of rubbish. The combustible material, e.g. rubbish, is passed over a filling device 1a which is here designed as a filling chute and onto a grate 2. The fuel which is arranged in the form of several layers 3 on the grate is successively dried in a known manner in the same way, ignited and burned. The air required for combustion of the fuel 3 is supplied as leeward air from below and through the grate 2 and to the gas 3, as shown by the direction arrows 4 in the figure. During the combustion of the fuel 3 in the combustion chamber 5, gaseous combustion products are formed, which will below be referred to as flue gases, which flow through the successively arranged flue gas passages 6, 6' and 6" of the furnace 1, and which leave the furnace at the outlet point 7, as shown with the - continuous serpentine-shaped flow direction arrows F.

The flue gases exiting the furnace 1 at the outlet point 7 flow in a known manner through a dedusting system and then through a suction pressure system (suction fan) and finally into and through a chimney which, at a sufficiently high height under certain conditions, can replace the suction fan, after which the flue gases escape into the atmosphere.

The unburned residues formed by burning the material 3, i.e. slag, are removed from the furnace 1 at the outlet 8.

When the hot flue gases flow through the furnace's flue gas passages 6, 6' and 6", they give off their heat to three hot surface systems 10', 10" and 10"' which, viewed in relation to the flue gas path, are arranged one after the other in the furnace in the three flue gas passages 6, 6' and 6" and which together form a primary heat exchanger 10 which serves to heat a primary heat carrier and which limits one side of the combustion chamber 5. The heating surfaces 10', 10" and 10"' of this primary heat exchanger 10 consist of pipe systems through which the primary heat carrier flows and which are designed as pipe bundles or as pipe walls. This heating system for heating the primary heat carrier includes, in addition to the three subsystems 10', 10" and 10"', also the necessary inflow and outflow lines which are only indicated in the drawing at 21 and 22, respectively, as well as one appropriately arranged collecting drum as on the drawing is denoted by 16.

The primary heat exchanger 10 and its collector drum 16 are located in a closed circuit system through which the primary heat carrier flows and which is denoted by 30 in the figure. The heat carrier is circulated in the system's lines 31 by means of a mechanical circulation pump 23. This circulation could possibly also provided without a pump, e.g. by means of the well-known so-called •thermosyphon activation, i.e. by natural circulation.

Regardless of the way in which the circulation in the closed circuit system 30 is carried out, the primary heat carrier can be under any pressure because it flows in an intrinsically closed circuit system.

The pipes in the first heating surface system 10' of the primary heat exchanger 10 border the combustion chamber 5 and are exposed to heat radiation from the combustion chamber, while the pipe bundles in the two heating surface systems 10" and 10"' which are placed in the subsequent flue gas runs 6' and 5" on is effected by heat due to heat convection, i.e. by direct contact with the flue gases that flow along these tube bundles. These two hot surface systems 10" and 10"' thus form a convection part of the heat exchanger 10.

The primary heat carrier is introduced into the system at the location designated 15, and after flowing through the primary heat exchanger 10, it leaves the latter above the collection drum 16. Thus, the heat carrier will, in addition to being heated by the flue gases from the inlet temperature t15 to the outlet temperature tJC, also be exposed to a partial or total phase change, as at least a partial amount G' (in kg/h) of the total amount G (in kg/h) of the primary heat carrier will, as a result of the heating in the heat exchanger 10, be transferred from a liquid aggregate state to a vapor aggregate state , i.e. evaporates.

The inlet temperature t15 for the primary heat carrier is the lowest temperature that occurs in the primary heat carrier's circuit system 30 (tmin), which temperature t15 with a view to possible corrosion cannot fall below the minimum temperature t(. which is in the order of 150-200° C The outlet temperature t16 of the primary heat carrier represents the highest temperature (tmax) in the closed circuit system, and this temperature t16 is preferably chosen, excluding the possibility of steam overheating, as the metnihgs temperature tB which is assigned to the operating pressure p.

As a result of the release of heat to the heating surfaces 10', 10" and 10"' and thus to the primary heat carrier, the flue gases coming from the combustion chamber 5 are cooled, so that their outlet temperature t7 at the outlet point 7 is significantly below the combustion chamber 5 combustion chamber temperature t3 (t7 <t,).

Thus, the primary heat carrier that flows through the primary heat exchanger 10, apart from its function of transporting the useful heat produced in the furnace 1 to the place of use, serves as a cooling medium for cooling the hot flue gases.

Since the primary heat exchanger 10's heating surface systems 10', 10" and 10"' only need to be dimensioned in accordance with the furnace 1's heat capacity and nominal performance, the heat exchanger 10 can advantageously be produced in serial production as a standard design.

A further heat exchanger 17 is arranged in the primary heat carrier circuit system 30 outside the furnace 1 so that the primary heat carrier, after leaving the collection drum 16, flows into the exchanger. The secondary part of this additional heat exchanger 17, denoted in the drawing by 17a, is connected via a flow line 17' and a return line 17" to a heat consumer 18 and thereby forms a closed circuit system in itself, which is denoted by 17b. In this closed circuit system 17b circulates as a secondary heat carrier, e.g. water, which is particularly often used in heating devices. This secondary heat carrier absorbs during the flow through the heat exchanger 17 a certain amount of heat (in kcal/h) from the hot primary heat carrier, so that the temperature of the secondary heat carrier rises to t' This heat is then emitted by the secondary heat carrier to the heat consumer 18, whereby the secondary heat carrier is cooled again so that its temperature drops to t"2. At this temperature t"2, the cooled secondary heat carrier flows again in the heat exchanger 17 of the secondary part 17a to be heated there to temperatures t"v. The flow temperature in this case can be t'\ — approx. 70° C and the return temperature t"2 can be approx. 40° C, which very often occurs in practice.

At these relatively low operating temperatures for the heat consumer 18, which are far below the temperature of the primary heat carrier (tmak9,<t>min), it is of course not possible to branch off or withdraw a partial flow from the primary heat carrier's closed circuit system 30 for direct heat supply to the heat consumer 18 For this reason, an additional heat exchanger 17 is arranged in the primary circuit system 30

whose secondary part 17a supplies the heat consumer

18 with heat. For obvious reasons then this one is

further heat exchanger 17 arranged at the place of the primary circuit system 30 where the primary heat carrier reaches its highest enthalpy, i.e. has its greatest heat content (in kcal/kg), i.e. at the saturation temperature ts, because a steam superheat should not occur. For this additional heat exchanger 17, as for the primary heat exchanger 10, a normal or a standard construction can be used, which is dimensioned for the nominal heat output of the furnace 1 and for the heat consumer 18's heat demand, taking into account the necessary controllability of the latter.

In a cooling system 11 which is suitably also equipped with pipes 11b for heat exchange and which is arranged outside the oven and seen in the direction of flow after the just mentioned additional heat exchanger 17 in the primary heat carrier's closed circuit system 30, the primary heat carrier emits the heat to the surroundings, where during that, phase changes can occur that are opposite to the phase changes in the primary heat exchanger 10, i.e. a transition from a vapor state to a liquid state. During this cooling in the cooling system 11, the enthalpy (in kcal/kg) and the temperature of the primary heat carrier decrease further so that a temperature tn is established for the primary heat carrier which is temporarily still above the temperature tri at the heat carrier's inlet to the furnace 1.

The heat indication from the primary heat carrier in the secondary heat exchanger 11 can, at a given ambient temperature t0, be increased in a known manner, e.g. by exposing the cooling system .11 to a cold air stream, as shown in the drawing where this is done with the help of an air fan lia. Of course, instead of air, water can also be used as a cooling medium for the secondary heat exchanger 11 which serves as a recooler for the primary heat carrier.

The regulation of the entire system explained above must be explained in more detail.

A regulatory body 19, e.g. a control valve, is arranged in the circuit system 30 for the primary heat carrier for adaptation by the heat exchange provided by the primary heat carrier to the instantaneous heat output of the furnace 1, while it must be ensured that the outlet temperature t7 of the flue gas is kept constant and that the minimum temperature tc for the primary heat carrier at the inlet to the furnace 15 (t15 = tc) must not be exceeded due to possible corrosion.

For this purpose, a temperature sensor is arranged at the flue gas outlet 7 which acts on a control device 25 which either controls the control valve 19 or the circulation pump 23 or both parts, i.e. the valve 19 and the pump 23 to regulate the amount of the primary heat carrier that is circulated in the closed primary circuit system 30 depending on the outlet temperature t7 of the flue gases leaving the furnace 1. If, for example the circulation pump 23 is an adjustable displacement pump, so the device 25 controls the flow rate in the closed primary circuit system 30 by regulating the displacement volume of the pump. If, however, it is desired that the transport performance of such a pump 23 does not fall below a minimal value, the control device 25 can under such conditions also control the control valve 19. If, on the other hand, the circulation pump 23 is made with unchanging, i.e. constant transport performance, then the control device affects 25 on the control valve 19 and opens or closes the valve in accordance with the flue gas outlet temperature t7 so that the flow rate in the closed primary circuit system 30 is regulated accordingly.

Furthermore, for regulation of the primary circuit system 30, one has the option of using the operating pressure p in the primary heat carrier, the pressure being kept constant at a preselected level, e.g. 25 ata.

In a similar way, a regulatory body 20, e.g. a control valve, for adaptation of the amount of heat effectively delivered to the heat consumer 18 (kcal/h) to its immediate heat demand arranged in the secondary heat carrier's closed circuit 17b, with the help of which the flow rate G" (1 kg/h) of the secondary heat carrier (e.g. e.g. hot water) can be adapted to the instantaneous heat withdrawal by the heat consumer 18. Here, under certain conditions, it is appropriate that the amount of heat (kcal/h) which is withdrawn for utility purposes by means of the regulating body 20 can be reduced to zero according to the immediate heat demand.

Thereby, the regulating bodies 19 and 20 arranged in the primary and secondary heat carrier's closed circuit systems 30 and 17b can be automatically regulated depending on the heat load of the furnace 1 or the removal of useful heat through the heat consumer 18, as it is easily feasible that these two regulating bodies 19 and 20 are controlled by means of measurable quantities in that these are kept constant at predetermined scale values. It has been described above that the control valve 19 is controlled in dependence on the outlet temperature t7 of the flue gases with the aim of regulating the flow rate of the primary heat carrier in the closed primary circuit system 30 to thereby keep the outlet temperature t, constant. However, a corresponding control device 32 can also be arranged for controlling the control valve 20, and furthermore, a circulation ion pump 33 controlled by this control device 32 can, if desired, be arranged in the closed secondary circuit system 17b.

The main advantage of the combustion of inferior fuel materials shown in the figure by an additional heat exchanger 17 is that a heat consumer 18 can now be supplied with useful heat from the incinerator 1, without the differences in the heat consumers involved and in their operating conditions in each particular -separate case requires a special device for dimensioning the heat exchange systems used in order to be able to provide a closed circuit for the medium that serves as a cooling medium for cooling the flue gases and as a heat carrier for supplying the heat consumer with heat. Thus, the expensive single production which is to some extent a special solution for the specific case at hand is not necessary.

In this case, no withdrawal of a specific amount of the heat carrier from the aforementioned closed circuit is made for the supply of heat to the heat consumer. This gives the additional advantage that a heating device can be supplied with heat from the waste incinerator also in the very frequent cases where the heat consumer or heat consumers consist of heating devices with hot water as the secondary heat carrier and where due to the very low operating temperatures (t" = approx. 70° C and f = approx. 40° C) a withdrawal of a partial flow from the primary heat carrier circuit system for direct supply of the heat consumer with heat from the primary heat carrier cannot be carried out at all.

Another advantage of the incinerator according to the invention is that corrosion due to the aggressive nature of the combustion gases

is avoided, which corrosion when withdrawing a partial current from the primary heat carrier's circuit

for the supply of a heat consumer occurs when an equal quantity of the same heat carrier must be fed into the circuit at a relatively low temperature which corresponds to the ambient temperature t0.

As already mentioned, the oven according to the figure can be made with the additional heat exchanger 17, but without the circulation pump 23, as the circulation in the primary heat carrier is then provided by the thermosyphon effect itself. It is taken into account that by increasing the pressure in the primary heat carrier's circuit system 30 (e.g. to 25 ata) the dimensions can be reduced, e.g. diameter of the collection drum 16, in this respect a relatively compact design is obtained.

If the heat consumer 18 were to have one

heat needs that the by means of the further

heat exchanger 17 draws so much heat from it

the primary heat carrier that this after the outlet

from the heat exchanger 17 already has the temperature determined as inlet temperature

at the inlet to the furnace at 15 (t15 = <t>min = <t>c),

then you can possibly waive it completely

secondary heat carrier 11 because in this case the additional heat exchanger 17 arranged for the heat consumer 18 can simultaneously serve as

recooler for cooling the primary heat carrier which in furnace 1 has been heated in it

primary heat exchanger 10 using the flue gases.

If necessary, you have the opportunity to run it

according to the figure constructed plant so that it

secondary heat exchangers 11 are only then put into operation

when the heat withdrawal at the heat consumer 18

from the primary heat carrier is relatively small,

while otherwise, i.e. in case of relatively large heat output, the air fan 11 and/or is started

leads the primary heat carrier over a bypass line past the secondary heat exchanger 11,

i.e. that the latter is not flowed through

the primary heat carrier.

Claims (2)

1. Incinerator for city and/or industrial waste, whereby inside the oven for cooling the waste flue gases on their way from the combustion chamber of the exhaust gas cleaning device is arranged one of a pipe system consisting of heat exchangers whose pipes are coated with the waste flue gases and flowed through by a heat carrier, characterized in that the heat exchanger (10) which limits at least one side of the combustion chamber (5) of it is arranged for a flue gas cooling without direct heat utilization garbage incinerator (1) and which consists of a radiation part (10') and at least one convection part (10", 10"'), is arranged as a primary heat exchanger in a closed circuit system (30) for the in this system (30 ) circulated heat carrier which serves as a cooling medium for the waste flue gases and that in the same circuit system (30), however, outside the waste incinerator (1) for indirect heat utilization of at least part of the heat produced in the oven (1) is arranged a with its secondary part (17a) of a heat consumer (18) connected to a further heat exchanger (17) and a secondary heat exchanger (11) connected after this exchanger which serves as return cooler for the heat carrier in the closed circuit system (30), that further in the two circuit systems (30, 17b) for the primary and the secondary heat carrier is arranged in each of them at least one of a control valve ( 19 respectively 20) or/and a circulation pump (23 or 33) consisting of a through-flow regulating device, and that in the primary heat carrier circuit system (30) arranged through-flow regulating device (19 or/and 23) for maintaining a predetermined temperature (t7) in those out of the garbage incinerator (1) exiting garbage flue gases during adaptation of the flow rate (G) of the primary heat carrier to the relevant heat load of the garbage incinerator (1) can be controlled by means of a temperature sensor (24) arranged in the furnace's (1) flue gas outlet nozzle (7) over a control device (25) depending on the flue gas outlet temperature (t7) and with the help of the flow-regulating means (20 or/and 33) arranged in the secondary heat carrier circuit system (17b) while adapting the secondary heat carrier flow rate (G ") for useful heat removal at the heat consumer (18) with the help of a measurable quantity serving as a control quantity which is kept constant on a predetermined tamed value, and where the flow control device (20 or/and 33) arranged in the secondary heat carrier's circuit system (17b) is controlled by means of a temperature sensor (24) arranged in the waste incinerator's (1) flue gas outlet nozzle (7) over a control device (32) and depending on the outlet temperature of the flue gas (t7). 2. Refuse incinerator according to claim 1, characterized in that the primary and the additional heat exchanger (10, 17) are laid out for the thermal nominal performance of the refuse incinerator (1).