WO2008149249A1

WO2008149249A1 - A cogeneration application in producing sanitary paper

Info

Publication number: WO2008149249A1
Application number: PCT/IB2008/051542
Authority: WO
Inventors: Ahmet Nezir Isiklar
Original assignee: Hayat Kimya Sanayi Anonim Sirketi
Priority date: 2007-06-04
Filing date: 2008-04-22
Publication date: 2008-12-11
Also published as: EP2155962A1; ATE486167T1; TR200703816A2; DE602008003222D1; UA95158C2; ES2355117T3; KR101058537B1; EG26087A; EP2155962B1; RU2009149646A; CN101730767B; CN101730767A; KR20100017946A; RU2437973C2

Abstract

The objective of the present invention is to realize a sanitary paper production method which eliminates problems that originate from the mains power supply and cause disruption in production, while enabling energy conservation in sanitary paper production. For this purpose, a sanitary paper production method is realized wherein electricity is produced from combustion gases by means of a turbine (1), the hot combustion gases emanating from the turbine are utilized by being used in drying (3) of sanitary paper and the gases emanating from sanitary paper drying process are cooled with an absorption chiller(5), and thus a solution has been provided to the problem.

Description

A COGENERATION APPLICATION IN PRODUCING

SANITARY PAPER

[ 1 ] Field of the Invention

[2] The present invention relates to a method for producing sanitary paper where the hot exhaust gases of the gas turbine are used by means of a process system and at the same time electricity is generated (cogeneration) in the sanitary paper drying process.

[3] Background of the Invention

[4] Drying of the paper is one of the procedures which require the most amount of energy in the production process of sanitary paper. In this procedure, the paper sheet is dried at the hood of the cylinder around which it is wound, by passing it over the hot air generated by the burners. Burners operate with natural gas or any other liquid fuel, and their only purpose is to generate heat. On the other hand, the steam sent to the Yankee cylinder is obtained from the steam boilers using fuel.

[5] A thin paper sheet, which is 3 to 5.5 meters wide, comprising 5% water, produced with a speed of 2000 meters per minute, is obtained by filtering the water of a mixture containing 99.8% water and 0.2% fiber. As disclosed above, this paper sheet is dried by being wound onto big heated cylinders called "Yankee Dryers". Steam passes also through the Yankee dryer. This procedure carried out on the Yankee is the most significant step of sanitary paper production in terms of energy consumption.

[6] As energy costs continuously increase nowadays, decreasing the costs by reducing high energy consumption in the said drying procedure is a desired improvement in the said process.

[7] Furthermore, in the state of the art, machines and devices which operate with electrical energy are used in most of the procedures within sanitary paper production plants. This situation leaves the plant processes unprotected before the decreases in efficiency occurring as a result of the power cuts in the mains. The high energy consumption and price increases and fluctuations being experienced in fuels do not make the operation of motor generators running with liquid fuel economic. Additionally, quality of the network electricity is another problem. Voltage drops in the mains impede continuous operation of most of the machines used in production, and may even cause some of them to fail. This situation leads to decrease in efficiency and disorder in the production plant, while the failed devices impose a further cost.

[8] In the electricity production plants, depending on the use of an engine or turbine, the electrical efficiency varies between 20 - 55%, and 45 - 80% of the energy input transforms into heat and is discharged to the atmosphere. Producing electricity with these known conventional systems, not only pollutes the environment but it is also not sufficiently economical since it loses a great portion of the energy input as waste heat.

[9] Cogeneration method, which can be defined as production of electricity with gas fired turbines and utilization of the heat in the hot exhaust gas emanating from these turbines in various production processes, is a method which is currently being used in many production sectors. 85 - 90% total efficiency can be attained by means of the gas fired cogeneration units which simultaneously produce heat and electricity.

[10] For example, the USA patent application No. US2005160618 discloses a cogeneration system used in drying of sanitary paper. However this application is about providing vacuum by using steam, rather than minimizing heat and electricity consumption.

[11] Summary of the Invention

[12] The objective of the present invention is to realize a sanitary paper production method which eliminates problems that originate from the mains power supply and cause disruption in production, while enabling energy conservation in sanitary paper production.

[13] For this purpose, a sanitary paper production method is realized wherein electricity is produced from combustion gases by means of a turbine, the hot combustion gases emanating from the turbine are utilized by being used in drying of sanitary paper and the gases emanating from sanitary paper drying process are first used in generating steam in steam boilers and then the cold water used in local cooling with an absorption chiller is obtained, and thus a solution has been provided to the problem.

[14] Detailed Description of the Invention

[15] The illustrative figures of the cogeneration application in sanitary paper production realized to fulfill the objective of the present invention are attached. These figures include;

[16] Figure 1 is the flow chart of an example embodiment of the inventive sanitary paper production method.

[17] Figure 2 is the table showing certain characteristics and performance values of the turbine employed in an embodiment of the inventive sanitary paper production method.

[18] The components in the figures are numbered individually where the numbers refer to the following:

[19] 1. Gas turbine

[20] 2. Burner

[21] 3. Paper drying cylinder

[22] 4. Steam boiler

[23] 5. Absorption chiller

[24] The inventive sanitary paper production method comprises a gas turbine producing electricity upon rotating by means of the energy of the combustion gases emanating from the combustion chamber, supply the produced electricity to the various machines and devices operating with electricity within the production process, drying of paper upon combustion gases emanated from the turbine which have relatively lost their energy being transferred to the paper drying cylinders and being applied on the paper wound onto the paper drying cylinder.

[25] The hot gases emanating from here and relatively comprising water steam are passed through the steam boiler to obtain steam and then cold water is obtained in the absorption chiller unit.

[26] The said turbine preferably operates with natural gas and it is "TBM-T70" type and

"TAURUS 70-10301 Axial" model manufactured by Turbomach or suchlike. In Figure 2, a table is provided which shows certain characteristics and performance values of the said turbine. The turbine supplies the air required to burn the natural gas from outside environment and the temperature of the exhaust gas emanating from the turbine changes depending on the temperature of the outside environment. For example, when the temperature of the outside environment is -1O⁰C, temperature of the exhaust gas emanating from the turbine is expected to be around 48O⁰C and the temperature of the turbine exhaust gas increases as the temperature of the outside environment increases.

[27] Turbine exhaust gas is transmitted to a channel type burner via pipes. The said burner also uses natural gas for fuel. In cases where the temperature of the turbine exhaust gas is not sufficient for using in the paper drying process, additional burning energy is provided in this burner to increase temperature of the gas to be transmitted to the paper drying cylinder. When the turbine exhaust gas does not contain sufficient amount of oxygen for combustion, it is possible to make additional air supplement from the outside environment. When temperature of the turbine exhaust gas is sufficient for using in the paper drying process, turbine exhaust gas passes through the burner without being subjected to any process. In another embodiment of the invention, in cases where the temperature of the turbine exhaust gas is sufficient for using in the paper drying process, turbine exhaust gas directly circulates by means of a bypass pipe and is transferred to the paper drying cylinder, while bypassing the burner.

[28] The gas with the sufficient temperature to be used in paper drying process is transmitted to the Yankee paper drying cylinder. Yankee paper drying cylinder is a cylinder which has an imperforate surface, has aqueous paper sheet wound onto the outer surface thereof and has a relatively big diameter. Heating is performed from within the cylinder with steam. At this point, the moisture within the paper is ensured to be evaporated by having the hot gas acting on the paper from outside of the paper drying cylinder and the steam heat acting on the paper from within the cylinder.

[29] Relatively chilled and moist gas emanating from the Yankee paper drying cylinder is transmitted to the steam boiler and absorption chiller. Absorption chilling method is a method known in the art, and steam and cold water is attained from the exhaust gas by means of chemicals like lithium bromide liquid. Thus, a cooling system is provided which is not dependent on electricity as it is the case in compressor cooling systems.

[30] The described course of the invention can be carried out via single serial equipment while it can also be performed via two or more serial equipments operating in parallel. The pipe systems in between the main equipments such as the said turbine, burner, paper drying cylinder, absorption chiller can be designed with design methods well known in the art, such that they will provide ease in use, safety and operation flexibility in accordance with the special system in which the method is to be applied.

[31] The flow chart of an example embodiment of the inventive method is shown in

Figure 1.

[32] All components disclosed in the inventive method are designed in external arrangement for saving in investment costs or existing closed area.

[33] Fundamental principles of the invention are described in this specification. Within the scope of these fundamental principles, it is possible to develop various embodiments of the invention. The invention is essentially according to the claims.

Claims

[1] A sanitary paper production method characterized with the steps of

- collection of the gases emanating from the combustion chamber of a turbine operating with natural gas,

- the turbine producing electricity upon rotating by means of the energy of the emanating combustion gases,

- supplying of the produced electricity to various machines and devices operating with electricity within the production process,

- transferring of the combustion gases, which emanate from the turbine and have relatively lost their energy, to the paper drying cylinders by means of the bypass pipe,

- applying thereof on the paper wound onto the paper drying cylinder,

- drying of the paper with the gas passing through the pipe,

- passing the hot gases obtained during drying through the absorption chiller unit,

- obtaining cold water from the absorption chiller unit.