(1) preventive measures for breaking during smelting operation
(1) Reasonable distribution structure: the distribution of all kinds of scrap steel in the basket and the condition of adding into the furnace shall be reasonably configured to avoid the light and thin steel materials from forming a cluster on the top of the furnace and difficult to descend, and avoid the large scrap steel from falling and breaking the electrode.
(2) During smelting, especially when it is close to the melting point, carefully observe the distribution of the raw materials. If the bridge structure has been formed, the furnace burden should be allowed to collapse under the condition of power failure and the electrode has been raised to a high level by blowing oxygen or physical shaking or shaking, so as to avoid the electrode from being broken.
(3) The electrode shall adopt the strength suitable for the process requirements. The connecting electrode shall be provided with nuts of appropriate strength, cleaned and clamped with special tools. The lifting ring must be fastened before lifting the replacement electrode to ensure that the lifting ring and the electrode are in close contact. In order to ensure the cleanness of the interface, it is required to keep the end cap of the new electrode until the lifting ring is installed.
(4) The electrode holder shall avoid being caught in the white line between the electrode connections. The electrode connection cannot be above the electrode holder. The electrode holder cannot be clamped on the open socket or the socket with the lifting ring.
(2) preventive measures during control
(1) After high-voltage power transmission, observe whether the no-load voltage of the secondary short network is balanced (determined by the insulation resistance of the three-phase short network to the ground, and the unbalanced voltage should be within 10%).
(2) Before the electrode automatically descends, confirm that there is no non-conductive object in the scrap layer directly below the electrode.
(3) Observe whether the secondary voltage of the first phase electrode immediately drops after the first phase electrode drops to contact with the scrap steel.
(4) When an arc occurs at a phase electrode, whether the secondary current display of the phase electrode can be seen (the pointer of the ammeter swings greatly).
(5) Regularly check whether the braking force of the electrode hydraulic driving mechanism and the system delay coefficient change.
In terms of the internal quality of the electrode, the influence of the key technical indicators of the electrode (joint) on the electrode breaking in the smelting process has been studied in detail by many scholars. It is worth noting that the China Carbon Industry Association has conducted spot checks on the product quality of its member enterprises, and compared the test indicators of the spot checks with the national standards and the enterprise standards of well-known foreign enterprises. From the inspection indicators, most of the inspected products meet the yb-2000 standard, and some indicators have reached or approached the standards of foreign companies. However, the actual smelting effect of domestic ultra-high power graphite electrode is obviously different from that of foreign products of the same specification. Therefore, it is one-sided to judge the quality of electrode (joint) only by the physicochemical index of electrode (joint). It is necessary to fully consider the compatibility of our products with the smelting process, furnace structure, smelting steel grade and other comprehensive factors of different customers and establish a scientific and reasonable electrode production and technical use scheme.