Wear-resisting jet pipe

Abstract

The invention relates to a wear-resistant nozzle for catalytic decomposing devices and catalytic cracking devices of petrochemical plants, comprising a base tube, a wear resistant layer, a transition layer and center jet orifices. The invention is a metal-ceramic composite nozzle provided with a composite layer formed by the closely connecting of metal base tube, the wear resistant layer and the transition layer and center jet orifices of different shapes, wherein the total thickness of the wear resistant layer and the transition layer is 3-10mm and the end of the nozzle is in a flanging structure or embedded structure. The nozzle of the invention is produced by high temperature centrifugation or pressure self-propagating synthesis technology, wherein the base tube is made from austeniticstainless steel or carbon steel or low alloy steel or other metals and the basic material composition of the wear resistant layer is alpha-Al2O3 and the transition layer is made of Al2O3, Fe and other elements of metal and nonmetal. Due to high wear resistance and the structure of the composite layer, the invention has a wear resistance seven times higher than normal carbon steel and stainless steel and can be used for a long term at a temperature of 800DEG C, adapting to the high solid particles concentration and large mechanical impact, thus prolonging the service time of the nozzle from original three to four years to over six to eight years.

Description

technical field [0001] The invention belongs to petrochemical equipment, and more specifically, the wear-resistant nozzle of the invention is an important part and accessory widely used in catalytic cracking and catalytic cracking devices in petrochemical plants. Background technique [0002] Wear-resistant nozzles are important components and accessories widely used in catalytic cracking and catalytic cracking units in petrochemical plants. In different parts, the role of the nozzle is also different. For example, there are 100 to 1000 nozzles installed on the distribution pipe or distribution ring in the regenerator and reaction settler, which mainly play the role of fluidization and uniform catalyst bed. In this part, the concentration of the catalyst reaches 300-600kg / m 3 , The gas velocity of the nozzle hole is 10-150m / s, which is the part with serious wear. Due to the large number of nozzles and different degrees of wear, it often causes uneven fluidization of the b...

AI Technical Summary

Problems solved by technology

At the beginning of this century, high-temperature ceramic nozzles began to be used at home and abroad. High-temperature ceramics have better wear resistance than metal materials, but their toughness is too poor to withstand vibration and mechanical impact. During construction and installation, cracks or breakage are easy to occur.

Another fatal shortcoming of the nozzles prepared by the above technology is that since the ceramic nozzles and the metal sleeves are physically fitted, when these nozzles are used in the distributor or orifice plate of catalytic cracking, the metal at the end is exposed to the dust fluid. Under scour, so this part is easily damaged by abrasion, resulting in the cracking and falling off of the ceramic layer

[0004] Since the traditional centrifugal self-propagating method can only prepare composite pipes with round holes of equal diameter, it is currently only used for low-temperature powder transportation in the coal and metallurgical industries; while the composite pipes prepared by static self-propagating have low bonding strength and wear resistance, and poor surface quality. Bad question

Therefore, at present, the above two technologies cannot really realize industrial application in catalytic cracking and catalytic cracking units.

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