Technical Field

The invention relates to a waste flue gas cleaning system for the cleaning of flue gas in the industries such as textiles, wood, packaging, oil where the chemical products are produced.

In particular, the invention relates to a waste flue gas cleaning system for cleaning waste flue gases from contaminants without using any chemicals, for recovering energy from said flue gas. Prior Art

Today, there is a waste flue gas outflow in the production facility in many sectors with heat treatment processes. The content of these flue gases is of high importance for both legal procedures and environmental safety. This brings a responsibility for said production facilities to control their flue gas contents. On the other hand, any failure to utilize the energy of these waste flue gases causes a loss for the production plant. Currently, there are various systems for cleaning the waste flue gas in the technical field. In the present cleaning systems, the principles of heat transfer are used to ensure that the heat of the waste flue gas passes to another fluid. However, contamination is observed on the surface, on which the heat transfer is made, due to the contaminants in the waste flue gas content. The shortness of the contamination period and the fact that this contamination makes the heat transfer difficult and even brings it to the stopping point cause problems in terms of production efficiency. It is very difficult to mechanically clean the region which is contaminated and makes the heat transfer difficult. Chemical cleaning operations, on the other hand, poses a serious burden on the production facility. At the same time, getting rid of the chemical and waste mixtures occuring after cleaning with chemical substances (Waste water treatment) also requires a purification process.

In the aforementioned systems, high-voltage electricity (electrostatic) is mostly used. The deposits of the solid particles, which take place in the waste flue gas content and cannot be fully cleaned, is ignited by the high voltage electric arc, causing the fire risk, which is one of the handicaps of the existing cleaning systems.

An overview of the existing flue cleaning system (M), which is the prior art, is given in Figure 2. There are two different alternatives to provide cleaning in the present flue cleaning system (M). In an embodiment of the state of the art, there is a particulate filter (100) by which rough cleaning of the waste flue gas to be cleaned is made, an air/air exchanger (200) and an air/water exchanger (300) for reducing the temperature of the waste flue gas, and an electrostatic filter (400) for removing hydrocarbons descended to the condensation temperature. However, the condensing paraffin due to a decrease in the temperature of the waste flue gas in said air/air exchanger (200) and air/water exchangers (300), the materials such as the oils and the production materials such as fibers adheres to the walls, which prevents the heat transfer. This reduces the lifetime of the existing flue cleaning system (M) up to 4-8 months, and the walls are required to be cleaned every 3-7 days in order to continue the production. The high costs of the chemicals used for cleaning purposes to prolong the lifetime and the difficulty of purifying these chemicals are among the technical problems of the existing flue cleaning system (M). In addition, the fires are caused by charging the electrostatic filter (400) before reaching the low temperature and the particles of waste flue gases without cleaning the particulars sufficiently. In a further embodiment forming the prior art, the waste flue gas are directed to the chemical hydrocarbon holders (500), in which the catalysts susceptible to said hydrocarbons are located, for cleaning the hydrocarbons, the waste gas is discharged from the flue gas without recovering any waste energy in said chemical hydrocarbon holders (500). The catalysts come to be satisfied in short time and their lifetime ends. In addition, there is a disposal problem.

As a result, due to the inconveniencies described above and the inadequacy of the existing solutions, it has been necessary to make an improvement and development in the relevant technical field. Short Description of the Invention

The present invention relates to a waste flue gas cleaning system which meets the aforementioned requirements, eliminates all disadvantages and provides some additional advantages. The primary object of the invention is to provide a waste flue gas cleaning system by spraying the liquid of high evaporation temperature on waste flue gas, resulting from the production in the furnace flues of the production facilities, in low temperature, thereby allowing the waste flue gas to be washed and enabling the heat transfer to be directly made. The main object of the invention is to prevent the heat transfer mechanism in the flue of the existing facilities from being incapable of operating due to contamination, and to eliminate the need for regular cleaning. In the system according to the invention, the contamination, which is observed in the heat transfer mechanism, is prevented by making the heat transfer by the way of spraying directly onto the waste flue gas. Also, since the invention eliminates the need for regular cleaning on the heat transfer surfaces, there is no need for the chemicals used for cleaning purposes and the process for releasing the heat transfer mechanism from the contaminations caused by the said chemicals.

It is a further object of the invention to provide a system enabling the fabric fibers and solid particles such as wood powders in waste flue gas to be decomposed by the filters after they have passed to the liquid phase.

The invention aims to recover the energy by transferring the heat energy of the waste flue gas to another liquid or Organic Rankine Cycle. Thus, heat and cost are saved, which is resulting in the increased productivity and the reduced environmental impacts.

The invention also aims to minimize the risk of fire. In the present invention, the risk of fire that may be caused by the deposits of the solid particles decreases as high electric arc (electrostatic) is not required. It is a waste flue gas cleaning system comprising at least one spraying device for spraying oil and/or water onto the waste flue gas as a heat transfer fluid for use of cleaning waste flue gases in production facilities for fulfilling the objectives of the above-mentioned invention, comprising - at least one first wash and heat transfer unit wherein the oil and/or water, being heat transfer fluid, is sprayed onto the waste flue gas to provide heat transfer and washing,

- at least one second wash and heat transfer unit wherein the oil and/or water, being heat transfer fluid, is sprayed onto the waste flue gas to provide heat transfer and washing,

- at least one particulate filter for use of decomposing the solid particles contained in the structure of said oil and/or water leaving said first wash and heat transfer unit;

- at least one separation container for separating the contaminants from said second wash and heat transfer unit due to the density difference of said oil and/or water.

The structural and characteristic features and all advantages of the invention will be understood more clearly by the following figures and the detailed description drafted by making reference to these figures, and therefore the evaluation should be made in view of these figures and the detailed description.

Figures for Understanding the Invention

Figure 1 shows the appearance of the waste flue gas cleaning system according to the invention.

Figure 2 shows an overview of the flue gas cleaning system of the prior art. Reference Numbers of the Invention

S Waste flue gas cleaning system

1 First wash and heat transfer unit 2 Second wash and heat transfer unit

3 Particulate filter

4 Separation container

5 Heating battery

6 Circulation pump

7 Valve

8 Closed valve

9 Gas pipe

10 Fluid pipe

1 1 Organic Rankine Cycle

12 Spraying device

13 Flue gas inlet

14 Flue fan

Reference Numbers of the Prior Art M The existing flue cleaning system

100 Particulate filter

200 Air/air exchanger

300 Air/water exchanger

400 Electrostatic filter

500 Chemical hydrocarbon holder Detailed Description of the Invention

In this detailed description, preferred embodiments of the invention are described for a better understanding of the subject with no limiting effects.

The invention relates to a waste flue gas cleaning system (S), which provides cleaning of waste flue gas from the contaminants and recovery of waste energy, especially in furnace flues in production facilities where chemical production is performed.

In the waste flue gas cleaning system (S) structure, the flue gas inlet (13) is provided to allow the waste flue gas to enter the waste flue gas cleaning system (S).

The waste flue gas entering the waste flue gas cleaning system (S) through the flue gas inlet (13) circulates in the gas pipe (9). Said gas pipe (9) is a gas-bearing pipe embodiment which circulates throughout the entire waste flue gas cleaning system (S) starting from the flue gas inlet (13). A plurality of valves (7) are located on the gas pipe (9). Said valve (7) is a component functioning as a key which allows the waste flue gas to circulate in the gas pipe (9) or prevents the circulation. Said valves (7) can vary according to their duties or location. The closed valve (8) located on the gas pipe (9) serves to bypass the circulation of the waste gas during the maintenance of the waste flue gas cleaning system (S).

There are at least two units, the first wash and heat transfer unit (1 ) and the second wash and heat transfer unit (2) in order to ensure that the waste flue gas circulating throughout the gas pipe (9) by entering through the flue gas inlet (13) and passing through the valve (7) is washed and that the heat is removed. In the first wash and heat transfer unit (1 ), oil is used to wash and cool the waste flue gas, while in the second wash and heat transfer unit (2), water is used to wash and cool the waste flue gas. Base oil, thermal oil, glycol can be used as the oil in the first wash and heat transfer unit (1 ). In the first wash and heat transfer unit (1 ) and the second wash and heat transfer unit (2), the spraying devices (12) are provided for spraying oil and/or water onto the waste flue gas. Said waste flue gas enters the first wash and heat transfer unit (1 ). In the first wash and heat transfer unit (1 ), the waste flue gas and the oil sprayed through the spraying devices (12) move counter to each other. Thus, heat transfer between the flue gas and the sprayed oil takes place. The movement of the oil sprayed through the said spraying devices (12) in the first wash and heat transfer unit (1 ) is provided by the circulation pump (6) in the structure of the waste flue gas cleaning system (S). Apart from the said heat transfer in the first wash and heat transfer unit (1 ), some solid particles in the waste flue gas meanwhile pass into the oil sprayed through the spraying devices (12). Thus, the process of washing the waste flue gas is also made. The particulate filter (3) is located in the waste flue gas cleaning system (S) for the purpose of mechanically filtering the oil which takes its heat and some solid particles from the waste flue gas. Said particulate filter (3) preferably has a rotating disk and is responsible for separating and removing the particles from the oil. The oil transport between the first wash and heat transfer unit (1 ) and the particle filter (3) is provided by the fluid pipe (10).

There are two alternatives that can be used to transfer the energy of the oil in the waste flue gas cleaning system (S), which has the heat energy it has received from the waste flue gas and which has been separated from the solid particles in its structure. One of them is the heating battery (5). Said heating battery (5) is responsible for cooling the oil passing through the particulate filter (3) and releasing its heat energy to the fresh air. Another alternative is to transfer the temperature of the oil passing through the particulate filter (3) to the Organic Rankine Cycle (1 1 ). Organic Rankine Cycle (1 1 ) is a pressure cycle system that provides the recovery by converting the heat energy to the electrical energy. By cooling the heat to the heating battery (5) or the Organic Rankine Cycle (1 1 ), the cooled oil continues to cycle back to the first washing and heat transfer unit (1 ). The oil which cools by transferring its heat to the heating battery (5) or the Organic Rankine Cycle (1 1 ) continues its cycle by going to the first wash and heat transfer unit (1 ) again.

The waste flue gas which transfers its solid particles and heat in the unit (1 ) to the oil sprayed through the spraying device (1 1 ) in the first wash and heat transfer unit (1 ) enters the second wash and heat transfer unit (2) from the first wash and heat transfer unit (1 ). The water sprayed through the spraying device (12) and the waste flue gas coming from the first wash and heat transfer unit (1 ) move in the opposite direction to each other in the second wash and heat transfer unit (2). In the course of the movement of opposite direction, the heat transfer between said waste flue gas and said water takes place. The spraying device (12) is located in the upper part of the second wash and heat transfer unit (2). During the said heat transfer, some contaminants (mineral oil based substances) in the waste flue gas structure are mixed into the water by condensing as it is fallen below the condensation temperature. The water which has received the condensate contaminants contained in the waste flue gas and the heat energy of the waste flue gas is discharged from the second wash and heat transfer unit (2) by the fluid pipe (10) connected to the base of the second wash and heat transfer unit (2). Said fluid pipe (10) transfers water to the separation container (4). In the separating vessel (4), the minerals and oils, which are low in density and contained in the water, are decomposed from the water by remaining on the upper side. The remaining water is added to the heating battery (5) or Organic Rankine Cycle (11 ) for cooling by giving its heat.

In the second wash and heat transfer unit (2), the flue fan (14) is used to expel the waste flue gas, which is leaving as purified from the contaminants and released from its heat, from the waste flue gas cleaning system (S). The gas pipe (9) transmits the waste flue gas from the second wash and heat transfer unit (2) to the flue fan (14).

In one embodiment of the invention, both oil and water can be sprayed onto the waste flue gas from a single spraying device (12) to provide the washing and heat transfer.