DE102009014805A1 - Energy recovery system for use in system of baking oven operated with gas- or oil burners, has heat exchanger chamber provided with inlet for oven waste gas or fumes, and cleaning chamber provided with outlet connected to chimney - Google Patents

Abstract

The system has a single module (1) provided with a housing comprising a heat exchanger chamber and a cleaning chamber. The heat exchanger chamber is provided with an inlet (3) for oven waste gas or fumes, and the cleaning chamber is provided with an outlet (4), which is connected with a chimney (6). The inlet and outlet of the module are connected with a short-circuit zone. A plate-type heat exchanger is arranged within the heat exchanger chamber. Mechanisms are provided for transformation of laminar flow into turbulent flow and designed as mobile chains and movable bars.

Description

The The present invention relates to an energy recovery plant for use in gas or oil burners Installations, in particular ovens.

With the use of such systems can, for example, in ovens Conventional design, by means of thermal energy recovery the energy requirement can be significantly reduced. At the same time, it is possible to condense the water contained in the swath and the Clean exhaust gases, in particular to reduce the fine dust content.

To the There are bakeries with individual ovens and secondly large-scale bakeries with a variety of ovens. It does not play for the invention Role, whether this as floor, continuous and / or other ovens are formed.

Usually Each oven is connected to a chimney, since the exhaust or Swath control exactly to the respective burner model of the oven and the local conditions must be coordinated, to ensure the best possible bakery quality.

furnace waste gases and swaths that are discharged to the environment included large amounts of heat. These amounts of heat get lost by the chimney. Oven exhaust gases leave the oven with temperatures of 200 to 300 ° C. The swath is with about 120 ° C, although only half as hot as the dry Flue gas, in contrast to this but almost with moisture saturated. The swath has, despite its low temperature a much higher energy content than the hot one Flue gas.

at However, a mixing of flue gas and steam reduces the dew point. With a saturated swath, the dew point is approx. 100 ° C, while diluted with flue gas Swaths only has a dew point of about 60 ° C, in whose Do not continue condensation at higher temperatures takes place.

A Variety of ovens is only with a flue gas outlet equipped, in which also the Backraumschwaden is introduced. However, to achieve optimal energy extraction is, however a separation of steam and flue gas makes sense.

For example, from the DE 28 03 091 A1 it is known to mix the flue gases of a flue gas circulation heating system and the baking fumes discharged from the baking space in continuous furnaces, to supply them together to a heat exchanger and to use them for steam generation. This type of heat recovery is very expensive in relation to the recoverable amount of heat. All the more so since the main part of the heat energy, the heat of evaporation, which is contained in the baking cloud, in this type of heat recovery can not or only to a very small extent can be used.

Of the Backwash consists of fresh supplied at the oven inlet Juice vapor and the water evaporated from the dough during baking, the so-called bake loss. The supplied at the kiln inlet Saturated steam requires about one third of its production the entire heat demand, which is used to make baked goods is required. The task of saturated steam is only in it, the surface of the dough pieces so long elastic to hold until they have reached their full volume. simultaneously it affects the appearance of the baked good. The juice vapor gets into the interior of the baking channel with the dough pieces a continuous oven, is overheated there by about 100 ° C. and falls, as described above with the Ausbackverlust as a baking cloud. This steam is basically not to the energy supply during baking, but contains a lot Energy in the form of condensation heat, the unused the Oven leaves.

Therefore is the energy recovery and saving from baking steam in continuous furnaces of particular importance.

The Solution is in proportion to the recoverable heat energy very expensive. The heat of vaporization as the main component the heat energy contained in the baking cloud becomes used at this facility only to a very small extent.

From the DE-AS 20 40 797 It is known to separate the exhaust gases from a baking oven and the steams withdrawn from the baking chamber separately from one another and parallel to one another by means of a heat exchanger in the form of a cylinder ring for the preparation of hot water. The interior of this cylinder ring is divided by a partition wall into two passage spaces, through one of which the exhaust gases and through the other the swaths are passed. The swaths condense on the associated area of the cylindrical heat exchanger. Also in this heat exchanger, the problem is that the exhaust gases are discharged at a relatively high temperature of about 440 to 450 ° K to the atmosphere.

From the DE-OS 26 25 099 is a method for recovering the waste heat of incinerators known in which the exhaust gases are cooled below their dew point. For this purpose, several on the exhaust side connected in series heat exchanger are provided. These different ones Heat exchangers are (obviously) supplied with different heat transfer medium, to each of which part of the exhaust gas heat is transferred. Thus, for example, in the first stage, in which the exhaust gases still have their highest temperature, the water of a building heating system from an inlet temperature of 50 ° C in the heat exchanger (corresponds to the return temperature in the heating system) to the usual flow temperature (for example, 60 to 70 ° C) heated. In the next stage, for example, the air recirculated in a ventilation system is heated from an inlet temperature of 35 ° C to a correspondingly higher temperature level. In addition, the water of a floor heating of 28 ° C can be heated to a higher temperature (usually 32 ° C), etc. (see page 6, penultimate section of DE-OS 26 25 099 ).

The specific problems of waste heat recovery in continuous tunnel kiln - where on the one hand steam for Swaths produced and the heat of vaporization contained in the swaths subsequently recovered as far as possible is to be, are not addressed in this known method and not solved.

Farther It is known from continuous tunnel ovens for baking purposes the flue gases on the one hand and the swaths on the other hand at several Remove consecutively in the direction of passage and a common exhaust pipe to supply a chimney.

One particular disadvantage of the previously known solutions is that used for each oven a fireplace which leads to a financial overhead.

The The object of the invention is a system for energy recovery to create or develop this so that with simple constructive Means a higher waste heat utilization possible is. Furthermore, in addition to the purification of the exhaust gases (desulfurization, Reduction of nitrogen oxides) the fine dust pollution of the environment the emission of the flue gases can be reduced.

According to the invention the object achieved in that the energy recovery system from at least two identical arranged on a base frame Modules exists. Each of the individual modules consists of a housing with a heat exchanger chamber and a cleaning chamber.

Within the heat exchanger chamber is a plate-shaped Heat exchangers arranged, being between the individual Heat exchanger plates Facilities for converting the laminar are provided in a turbulent flow. These can be as movable chains or staggered rods arranged as movable be educated. At the same time they serve to clean the plate surface.

The individual modules have corresponding inputs, the with the departure for the kiln exhaust or for the Blockades are connected. It is also possible, each Module to provide with multiple inputs, where then either the outlets for the kiln exhaust gases or the Departures for the baking steam of several ovens are connected.

The Outputs of the individual modules are via a line system connected to just a single fireplace. Inside the module is between the input and the output a short circuit path intended. This can be used in case of faults or during maintenance work continue to work on the system without interrupting production. about the short-circuit path can the kiln exhaust gases or the baking steam either directly or through the cleaning chamber be routed into the fireplace. The fireplace has a central Exhauster on to adjust the draft conditions. each single module has its own exhauster inside the Housing arranged at the outlet of the heat exchanger chamber is. With the help of this exhauster can be at the individual Ovens draft ratios / parameters set become.

The individual modules are on an expandable base frame at any time assembled. This can be done together with the modules both on the ground, be arranged on the wall as well as on the ceiling.

The individual modules have a cleaning chamber in which a scrubber, preferably a rotating washer, arranged is. Here the kiln exhaust gases or the steam are cleaned. It a flue gas desulfurization with neutralization and a Reduction of nitrogen oxides through the use of catalysts within the cleaning chambers. Furthermore, by intensive washing Particulate matter filtered out of the kiln exhaust gases or the backwash.

The above the plant recovered heat can be varied be used, including for the domestic water heating (Heating), the preheating of the intake air for the oil or gas burner, for generating absorber cold.

Based An embodiment of the invention is intended to be closer be explained.

It demonstrate

1 - Schematic representation of the energy recovery system

2 - Explosive representation of the module

3 - Side view of the module

The plant according to the invention 1 - For energy recovery from the kiln exhaust gases and the baking steam consists essentially of a frame 2 on the the modules 1 are arranged.

Each existing oven is a module 1 whose entrance 3 with the departure of the furnace exhaust, and a module 1 whose entrance 3 is connected to the swath trigger provided.

The exits 4 are over a pipe system 5 with the fireplace 6 connected. At the end of the fireplace 5 is an exhauster 7 arranged, which ensures the withdrawal of the furnace gases and the baking steam from the ovens in the event of an accident or maintenance. In this case, the kiln exhaust gases or the baking steam are over a short circuit path 8th - 2 - that the entrance 3 with the exit 4 connects, led directly to the fireplace, without the production process in the bakery must be interrupted.

All modules 1 The energy recovery system are identical. Every single module 1 consists of a housing 9 in which a heat exchanger chamber 10 and a cleaning chamber 11 are arranged. Inside the heat exchanger chamber 10 a plate heat exchanger is arranged, spaced in the spaces between each other chains 12 are provided. These ensure that the laminar flow is converted into a turbulent flow. By the movement of the chains 12 in the interstices, cleaning of the plate surface is achieved to some extent.

The entrance 3 the heat exchanger chamber 10 For example, the first module connects to the steam outlet of the first oven. The subsequent second module is then connected to the departure of the kiln exhaust gases of the first oven. But it is also possible, the Schwadenabgange or the outlets of the kiln exhaust gases of several ovens each with a module 1 connect to.

After passing through the baking steam or kiln exhaust gases through the heat exchanger chamber 10 , Where the heat exchange between the hot baking steam and the kiln exhaust gases and located within the heat exchanger plates exchange media, this is about the Exhauster 13 to the cleaning chamber 11 directed. The Exhauster 13 ensures appropriate draft ratios / parameters in the system oven / energy recovery system.

Inside the cleaning chamber 11 - 2 - is a rotating windscreen washer 14 , its shaft with a drive unit 17 is connected, arranged. The lower area of the cleaning chamber 1 is formed by a liquid filled bottom tray. The disk is immersed in about one-third of this fluid.

The discs of the washer 11 are very thin-walled and have small distances from each other. When moving the rotor (shaft) of the washer 14 In addition to the rotational movement, there is a "fluttering" of the disks, whereby solids present in the flue gas or in the swath are separated. As the disks reenter the liquid bath as the rotary motion continues, the adherent solid components are washed by the disks. In addition, the cooled kiln exhaust gases pass through a neutralization zone in which toxins are eliminated and neutralized.

Subsequently, the cleaned and cooled baking fumes or kiln exhaust gases leave the cleaning chamber 11 over the exit 4 and the pipe system 5 in the direction of the fireplace 6 ,

The plate heat exchangers are via the supply and return line 15 . 16 For example, connected to a service water or heating system. Alternatively, the recovered heat can also be used for the production of absorber refrigeration.

The frame 2 is designed so that, depending on space, the energy recovery system can be mounted on the floor, on the wall or on the ceiling of the bakery.

1

module

2

frame

3

entrance

4

output

5

line system

6

fireplace

7

exhauster

8th

Short track

9

casing

10

heat exchanger chamber

11

cleaning chamber

12

chain

13

exhauster

14

disk scrubber

15

leader

16

returns

17

drive unit

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 2803091 A1 [0008]
• - DE 2040797 [0012]
• - DE 2625099 A [0013, 0013]

Claims (9)

Energy recovery system for use in operated with gas or oil burners systems, especially ovens, in combination with the cleaning of the kiln exhaust gases, wherein the module is arranged in the exhaust system between the departure of the kiln exhaust gases and the swath of the plant and this leading to the outside chimney , characterized in that the system consists of at least two identical modules ( 1 ), the individual modules ( 1 ) from a housing ( 9 ) with a heat exchanger chamber ( 10 ) and a cleaning chamber ( 11 ) and the heat exchanger chamber ( 10 ) with at least one input ( 3 ) for the kiln exhaust gases or the baking steam and the cleaning chamber ( 11 ) with an output ( 4 ), with the fireplace ( 6 ) is provided. Energy recovery plant according to claim 1, characterized in that the input ( 3 ) and the output ( 4 ) of the module ( 1 ) with a short-circuit path ( 8th ) connected is. Energy recovery plant according to claim 1 and 2, characterized in that within the heat exchanger chamber ( 10 ) is arranged a plate heat exchanger, wherein means are provided for the conversion of the laminar flow into a turbulent flow in the interstices of the heat exchanger plates. Energy recovery system according to Claims 1 to 3, characterized in that the devices are in the form of mobile chains ( 12 ) are formed. Energy recovery system according to claim 1 to 3, characterized in that the facilities are designed as movably arranged rods arranged. Energy recovery plant according to claim 1 to 3, characterized in that at the outlet of the heat exchanger chamber ( 10 ) an exhauster ( 13 ) is arranged to adjust the draft conditions in the plant operated with oil or gas burners. Energy recovery plant according to claim 1 and at least one of the preceding claims, characterized in that in the cleaning chamber ( 11 ) a rotating washer ( 14 ) is arranged. Energy recovery plant according to claim 1 and at least one of the preceding claims, characterized in that the axis of the washer ( 14 ) on both sides with flanges for receiving a drive unit or for receiving a coupling member for connection to the windscreen washer of the subsequent module ( 1 ) is provided. Energy recovery system according to claim 1 and at least one of the preceding claims, characterized in that the individual modules ( 1 ) on a base frame ( 2 ) are arranged.