Practice of energy saving and consumption reductio

The practice of energy saving and consumption reduction of large carton board machines since entering the 21st century, China's carton board machines have achieved rapid development, and the production capacity has broken through a record high. According to the data of China Paper Association, China's carton board output in 2015 has reached 22.45 million tons, which will undoubtedly lead to fierce competition in the industry. Therefore, energy conservation and consumption reduction is the best choice for enterprises to improve their competitiveness. Jingxing paper machine 12 has been officially put into operation on September 23rd, 2007. The 350000 ton green environmental protection box paperboard project adopts the world's most advanced papermaking equipment in recent two years. This paper mainly discusses the energy-saving and consumption reduction measures in the crushing department, drying department and clean water system and the good economic benefits after implementation

I. energy saving and consumption reduction measures

1. Optimization of the vacuum system of the press department

the Press Department of the paper machine is composed of one press and two presses, one press is blind hole press (large roll diameter), and the other press is shoe press. There are 6 vacuum pumps in the vacuum system of the whole press, which are independent of each other

due to the need of the normal operation of the paper machine, the vacuum degree of the wool cloth suction tank on the first pressure and the second pressure is actually controlled at -35 - -40kpa, while the designed vacuum capacity of the 7 # and 8 # vacuum pumps is -45kpa (actually -50kpa), so it needs to be realized by opening the vent valve corresponding to the steam water separation of the wool cloth suction tank on the first pressure and the second pressure, which will produce a considerable waste of resources. Now through technological innovation, the vacuum system of the press department is re optimized

after the vacuum optimization of the press department, stop the No. 8 vacuum pump, connect the No. 6, 7 and 9 vacuum pipelines in series, and install the pneumatic control valve. During actual operation, close the vent valve corresponding to the steam water separation of the wool cloth suction tank on the first and second pressure, and ensure the vacuum required by the first and second pressure suction tanks by adjusting the opening of the pneumatic control valve

2. Reduce the steam consumption of the drying section

the drying section of the paper machine section is composed of 60 drying cylinders and 8 Wacker cylinders. It is divided into 7 drying zones, of which 1 drying zone and 2 drying zone are designed with single row cylinders, and 3 drying zone and 7 drying zone are designed with double row cylinders. As we all know, every 1% increase in the press dryness of the finished paper can save 5% of the steam consumption of the drying section. Therefore, improving the dryness of the press is the key to reduce steam consumption. Through the improvement of the parameters of the two press wool fabric, the warp of the wool base fabric is optimized from single yarn to 6-strand twisted yarn, the air permeability of the wool fabric on the second press is reduced from 62cfm to 57cfm, and the air permeability of the wool fabric on the second press is reduced from 57cfm to 54cfm; In addition, the model of boot cover is also optimized, and the broken groove boot cover is used. Through the above measures, the press dryness of the paper sheet has been significantly improved, and the press dryness of the paper sheet has been increased by 0.51%

in addition, the moisture content of the paper also directly affects the amount of steam used. The moisture control standard of box board paper is 6% - 10%. On the premise of stable physical indexes of paper, it is necessary to increase the moisture of paper as much as possible, so as to reduce the amount of steam

3. Reduce the unit consumption of clean water

there are certain problems in the original design of the water system. First, there are many dishes of white water, and the turbid white water has been overflowing. Second, the long fiber turbid white water will be short of water instantly after the shredding system is opened, so it needs to be supplemented with clean water; Third, AOCC is short of turbid and white water, which needs to be supplemented with clean water; Fourth, the white pool under the surface is short of water and needs to be supplemented with fresh water

description of water system process optimization:

(1) by detecting the white water ss of the white water system, it is found that the turbid white water SS under the white water multi pan is at white 40. In this way, the universal tensile testing machine can be better operated at about 0mg/l, while the AOCC turbid white water is about 350mg/L. Because the white water multi tray recycling is the damaged paper pulp and the white water under the paper machine, it is relatively clean. In addition, the concentration of the two kinds of white water is not different, and the turbid white water under the white water multi tray can completely replace AOCC turbid white water. Through pipeline connection, connect the outlet pipe of the computer pump to the AOCC turbid white water, and pump the excess overflow turbid white water to the AOCC turbid white water tank, which not only solves the water shortage of AOCC turbid white water, but also solves the problem of overflow of white water turbid white water

(2) after multi disc concentration of OCC short fiber, the concentration can be directly processed into products by ordinary thermoplastic molding method; Up to 10% - 12%, this concentration is relatively high, which can not meet the demand of beating concentration of about 5%. It needs to be diluted before beating. Originally, it was diluted with white water and multiple plates of clear water, but now it is directly diluted with low concentration (0.8%) short fiber light pulp, which can reduce the use of this part of clear water. Since the white water used in many trays is the damaged paper pulp and the white water under the paper machine, the quality of the clean water is relatively clean, and its SS is within 120mg/L. Detect that the SS of white water in the under surface white water pool is about 300mg/L. The white water under the surface layer will always be short of water, so it needs to be supplemented with fresh water. Therefore, it is completely possible to supplement the turbid white water under the face with white water under the multi plate. Through the pipeline connection, connect the outlet pipe of the white water multi pan clean water pump all the way to the under surface white water pool, so as to solve the problem of water shortage in the under surface white water pool

(3) long fiber turbid white water will be short of water instantly after the disintegration system is turned on. Through pipeline connection, connect the lower mixed white water pump all the way to the long fiber turbid white water, and part of the long fiber turbid white water also goes to the white water tower, which forms a cycle and solves the problem of instantaneous water shortage of long fiber turbid white water

second, economic benefits

take corresponding measures for the press department, drying department and clean water system of the paper machine to achieve the purpose of energy saving and consumption reduction. According to the comparative calculation results of the data before and after optimization, 955000 electricity costs, 2855000 steam costs and 225000 drainage fees can be saved every year. All this shows that the measures taken to save energy and reduce consumption have achieved remarkable results