Application of the hottest steam jet heating techn

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Application of steam jet heating technology in the paper industry

in terms of energy conservation, China's energy consumption per unit of GDP is 4.4 times that of Japan and 2.4 times that of the world average. This paper introduces several steam jet heating technologies and equipment at home and abroad, which are used to accurately and efficiently heat pulp, starch pulp, green liquor, black liquor, anaerobic wastewater, etc. in the paper industry. They are effective cases to improve production efficiency, save steam and chemicals, and reduce production costs

control principle of ejector

the American hydroheater internal control heater is equipped with a steam nozzle. There is a high-precision rod needle in the steam nozzle, which can be moved back and forth to change the nozzle area, and can accurately control the steam flow, so as to control the temperature of the outflow liquid. Because the control point is close to the heating point, the steam partial pressure can be kept unchanged, ensuring the stable operation of the ejector in a wide range. Under normal conditions, the ejector can control the temperature of the discharged liquid within ± 0.25 ℃. Compared with the general direct heating equipment, the ejector temperature control response is fast, more accurate and more stable

Application of ejector in paper industry

ejector has almost become an indispensable basic equipment in the pulp and paper industry in the United States and Europe. The ejector reduces energy consumption, eliminates steam hammer, vibration and noise, and protects the safe operation of the equipment. Accurately control the reaction temperature of each section, improve the product quality, save chemical consumption and reduce the cost

1 heating and gelatinization of modified starch

the continuous starch cooking equipment is realized by the visual touch screen installed in the control cabinet, which does not need manual operation and operates automatically. The production capacity meets the needs of large-scale high-speed paper machines, and the quality is stable. It is the development direction of the starch cooking bioplastics system. The key equipment is the ejector that can heat the starch instantly, evenly and stably

2 bleaching of pulp

the structure of the heating pulp hydrothermal device is shown in Figure 7. The ejector can evenly heat the pulp with a concentration of 12%. The ejector has hundreds of steam holes on the relatively large nozzle surface, and the steam is ejected from each hole at the speed of sound. Such sonic steam flow can effectively penetrate the pulp to achieve the effect of uniform mixing

the effect of using the ejector in a large pulping plant in the Midwest of the United States: (1) optimize the bleaching process conditions, accurately control the withdrawal and more agile bleaching temperature. After using the ejector, the operating temperature of sodium hypochlorite in the bleaching solution is increased by 8.3 ℃, maintaining the whiteness of the pulp and reducing the amount of bleaching agent by 10%. The equipment investment can be recovered within four months when the force is applied. (2) The original bleach mixer is directly replaced by an ejector, and the energy consumption is reduced by 20%. (3) An ejector is used to replace a nozzle system with a steam consumption of 8.6t/h. The steam consumption of the ejector is only 7t/h, saving 116000 US dollars per year

alkali recovery black liquor and green liquor heating

1 black liquor heating

the improved design installs k412as ejector in front of the spray gun pipeline to accurately heat the black liquor to the optimal temperature, so that the shape and size of the ejected droplets are consistent, and the best combustion effect is achieved

2 green liquid heating

after the improvement, the k414as ejector is installed. The green liquid temperature is accurately maintained at 88 ℃, and all steam hammers and vibrations are eliminated

3 white water heating

branding paper company in glenrobbie, Minnesota, USA uses an ejector to quickly heat white water when starting up, so as to shorten the time required to reach the maximum speed. The heating system can raise the temperature of 200m3 of white water from 27 ℃ to 43 ℃ within 30 minutes, up to 88 ℃

4 improve the hydraulic pulping capacity

optimize the hydraulic pulping temperature to shorten the pulping time, increase the pulping capacity, and increase the white water temperature for pulping to improve the pulping efficiency. The 12m3 hydraulic pulper has increased the white water temperature from 40 ℃ to 65 ℃, and the total pulping time has been reduced by 2. As an important basis for the implementation of enterprise classification management, the production capacity has been increased by 20%. It has been applied in ONP and 0CC waste paper production lines in China

5 in high latitude areas, it is used to raise the temperature of anaerobic sewage in winter to ensure the normal operation of anaerobic.

using ejector to heat pulp and paper industry wastewater in winter is the best choice for energy conservation and consumption reduction. The heating of wastewater is realized in the heat exchanger. Usually, the problem of maintaining anaerobic temperature is solved by adding multiple heat exchangers

using ejector instead of ordinary spray gun can save steam by 35%. If it replaces ordinary tank heating, the effect of energy saving and consumption reduction is more significant

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