The new 50t/d liquefaction equipment of Liuzhou Iron and Steel (Group) Co., Ltd. is designed and manufactured by Sichuan Air Separation Equipment (Group) Co., Ltd., which adopts the medium pressure belt freezer process. The nitrogen compressor is a combined type imported from COOPER Company of the United States. The compressor and liquid storage system are two large-scale low-temperature storage tanks of 500m3. The configuration of the whole set of liquefaction equipment is currently relatively advanced in China. After the production device is started, the nitrogen gas from the raw material pipe network (the normal operation is condensed by the liquefaction device and the low pressure nitrogen gas is combined with the supplementary low pressure nitrogen gas) is pressurized to 0.3 MPa in the low pressure section of the combined nitrogen press, and then after the expansion machine The reheated nitrogen of the heat exchanger merges into the intermediate pressure section of the combined nitrogen press and is pressurized to 2.5 MPa and cooled, and then enters the supercharger driven by the expander, absorbing the work output by the expander, and simultaneously pressurizing . After the pressurized nitrogen gas is cooled, it enters the nitrogen liquefier E1 to exchange heat with the refluxing nitrogen gas. After the temperature is lowered to 260K, it is extracted from the middle of the nitrogen liquefier E1 and enters the low temperature freezer. The nitrogen temperature from the freezer is 245K. Then enter the nitrogen liquefier E1 and continue to exchange heat with the refluxing nitrogen to a temperature of 172K. Most of the nitrogen gas is about 9600m3/h, and the expander is exhausted. After expansion, it enters the nitrogen liquefier E1 as a reflux gas. After reheating, The cold box is sent out and enters the middle pressure section of the nitrogen press to start the next cycle. The other part of the gas continues to exchange heat with the returning nitrogen in the nitrogen liquefier E1. The temperature of the liquid nitrogen nitrogen liquefier E1 is 102K, and then exchanges with the liquid nitrogen after throttling in the liquid nitrogen subcooler E2. After cooling, it is throttled to 0.03 MPa and enters the oxygen liquefier E3. The oxygen is liquefied in the oxygen liquefier and subcooled, and then pressurized to 0.25 MPa by the liquid oxygen pump 11, and then sent out to the cold box. The cold source of the liquid nitrogen subcooler E2 is provided by the partial cooling of the liquid nitrogen after the supercooling. After the partial liquid nitrogen is vaporized, it is also reheated by the nitrogen liquefier E1, and then the cold box is vented or enters the low pressure nitrogen pipe network. Nitrogen is sent out through the liquid nitrogen subcooler E2.
With the water-sand blasting process, an abrasive agent is added to the high-pressure water, in order to enable efficient paint and rust removal from metallic surfaces. Dust contamination concerns mean that pure sand blasting is prohibited in many countries, or permissible only under strict conditions. Water-sand blasting is an alternative which enables the use of abrasive agents, such as sand, silica sand or ground blast furnace slag, in order to achieve different shot blasting results.
In comparison with purely abrasive agent shot blasting systems, this system has the advantage that no deformation (peening) arises in the shot blasted material. With the water-sand blasting process the heat is removed by the water so no form-changing heat concentration occurs in the shot blasted material. In addition, in case of paint removal with high pressure, the removed material is carried in the water and washed away.
In case of the water-sand blasting process, our AK600 HIGH PRESSURE GUN is provided with an injector, through which the abrasive additive is added to the water. With increasing operating pressure, the required quantity of abrasive agent reduces. Vice versa in comparison with pure water jets, a significantly lower pressure is required for a comparable result.
Hydro Blasting machine, water blasting machine, blasting machine ZHEJIANG BOTUOLINI MECHANICAL CO.,LTD , http://www.botuopump.com
eference example: Water-sand blasting process with paint-removal and rust-removal from ships