A load balancing device and balancing method for a fast cooling fan of a vertical continuous annealing furnace

Abstract

The invention discloses a load balancing device and method for a fast cooling fan of a vertical continuous annealing furnace. Furnace PLC control system and the transmission side frequency conversion fast cooling fan connected with the PLC control system, the operation side frequency conversion fast cooling fan, the transmission side pressure transmitter and the operation side pressure transmitter. The fast cooling fan load balancing method uses two interrelated pressure regulation loops to control the speed of two variable frequency fast cooling fans respectively, and selects the normal pressure setting value based on whether the actual speed of the fast cooling fan exceeds its upper limit value. Or the smaller of the normal pressure setting value and the pressure detection value on the overspeed fan side is used as the setting value of the pressure regulating circuit. The invention can ensure the balance of the extraction and blowing of the protective atmosphere in the fast cooling section, and at the same time, the air volume, that is, the load of the protective atmosphere blown by two fast cooling fans to both sides of the strip steel can be basically balanced and consistent.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, in particular to a load balancing device and a balancing method for a fast cooling fan of a vertical continuous annealing furnace. Background technique [0002] The function of the fast cooling section of the vertical continuous annealing furnace is to take away the heat of the strip steel by spraying protective atmosphere on both sides of the strip steel, so that the strip steel is rapidly cooled and the internal crystal structure of the strip steel is fixed. The nitrogen-hydrogen protection atmosphere is extracted from the fast-cooling furnace by two high-power variable-frequency fast-cooling fans, cooled by two water-cooled heat exchangers, and then re-blown into the fast-cooling furnace by two sets of fast-cooling air boxes. side while cooling the strip. [0003] The existing vertical continuous annealing furnace fast cooling fan control device generally controls the speed of two variable...

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Problems solved by technology

[0004] But even if the two fast cooling fan pressure controllers use the same pressure setting value, due to the constraints of the process pipeline layout, the length of the branch pipes of the two fast cooling fans, the resistance of the branch pipes (for example, due to the number of turns of the branch pipes, The pipe resistance difference caused by different turning angles) is different, the blowing volume of the protective atmosphere of the two fast cooling fans, that is, the load of the fast cooling fan will also be unbalanced, that is, the air volume blown by the two fast cooling fans to the protective atmosphere on both sides of the strip is inconsistent , so that the "tremor" phenomenon occurs when the strip steel travels in the fast cooling section and shakes back and forth. When it is more serious, one fast cooling fan will be in an overload state, while the other fast cooling fan will be in an underload state, and the fast cooling fan will be in an underload state. Overload work will seriously affect the service life of the fast cooling fan

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