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Construction Steps Of Refractory Castable For Lining Of Two-stage Reformer Furnace
Feb 14, 2019

The way of refractory castable construction has been shared in many articles in the past, including blast furnaces, circulating fluidized bed boilers, etc. Today, the second-stage reformer in the petrochemical industry is used as an example. The construction of the material is a simple sharing.

The construction of the refractory castable for the second-stage reformer must be carried out after a series of construction preparations such as equipment preparation, material tool preparation, and steel formwork installation have been completed. The focus of its construction is on the mixing, pouring and curing of refractory castables. details as follows: 

1. Refractory pouring and stirring

(1) The mixer is stirred by a large forced mixer. The mixing procedure and the amount of water added are strictly in accordance with the construction instructions provided by the material manufacturer;

(2) The stirring water should be drinkable clean water, the water temperature and discharge temperature should be controlled within 10~25 °C, and the stirring time after adding water should not exceed 2 min;

(3) In order to prevent the castable from condensing in the mixer and the stringer, the mixer and the stringer should be cleaned frequently.

2, refractory castable pouring

(1) The ball arch support ring can be filled with water before pouring the cylinder to clean the castable when the casting body is poured;

(2) When pouring, the stringer should be moved symmetrically at 180°, and the material should be uniformly cut along the circumference. The stringer should not be fixed in one place;

(3) The pouring speed should be equal, preferably at a height of 350 mm per hour;

(4) When using the plug-in vibrating rod to vibrate the castable, the vibrating time should be strictly squeezed, and the vibrating should be stopped immediately when there is no bubble around the vibrating rod to avoid delamination. While vibrating, "lightly tap the template with a mallet;

(5) The vibration of the castable should be carried out in layers. The thickness of each cast is 150mm. When vibrating, the vibrating bar should cover 50mm of the lower castable, so that the new and old castables are tightly combined with pure calcium aluminate cement. The refractory castable shall be continuously poured, not exceeding 30 min at a time;

(6) The free fall height of the poured material during pouring should be within 1.3m. If it is too high, the particles of the castable will be separated. When using a stringer, it is best to use 800mm;

(7) Stop casting when the castable is poured to a distance of 100 mm from the top of the formwork, and pour after the installation of the lower formwork is completed;

(8) The ambient temperature of castable construction should be between 5 and 35 °C;

(9) The thickness of the lining is controlled by the thickness control top block. The thickness of the castable lining is ±5 mm.

3, maintenance

(1) After the pouring of the castable is completed according to the design requirements, since the lining of the second-stage reformer is continuous casting, the curing start time can only be judged according to the initial setting time of the castable, generally starting from 3~5h after construction to the formwork. The method of cooling and curing the water to the end of the exudation of the castable is not less than 24h. Close all nozzles during curing to reduce air convection and avoid evaporation of water.

(2) After curing for 24 hours, the mold can be demolished, and after the natural curing, the hammering inspection is performed, and a crisp sound is emitted to indicate that the structure is dense, and the lining surface has no crack. After the oven, the overall lining is inspected for quality, allowing small mesh cracks and no through cracks.


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