Circulation heating system for steam heater

Abstract

The invention relates to a circulation heating system for a steam heater. The system comprises a main liquid supply box, a circulation heating pump, the steam heater, a pneumatic cut-off valve, a temperature sensor and a stirring device, wherein the stirring device is arranged in the main liquid supply box; a pipeline between the main liquid supply box and the steam heater is provided with a flowsensor; the main liquid supply box is provided with a circulation heating liquid outlet F1 and a liquid return port F2; a saturated steam pipe is provided with a branch pipe with a second pneumatic cut-off valve; the first pneumatic cut-off valve, the second pneumatic cut-off valve, the circulation heating pump, and the flow sensor and the temperature sensor are under interlocking control of a programmable logic controller PLC; the installation position F3 of the temperature sensor is positioned below the lowest operating liquid level of the main liquid supply box; and the temperature sensor is immersed in a heated medium. The system has the advantages of improving the circulation heating efficiency of emulsion, enhancing the safety, treating the fouling, blockage and the like of the heater and the like, along with convenient operation; and the system can protect the circulation heating pump under the condition that the heater or the pipeline in the heating system is blocked.

Description

technical field [0001] The invention relates to an emulsion system of a cold tandem rolling mill and an alkaline cleaning circulation system of a cold rolling mill, and is an improved circulation heating system of a steam heater. Background technique [0002] In the emulsion circulation system of the rolling mill, temperature control is very important. In order to ensure that the temperature in the emulsion supply main tank is controlled within the range required by the oil product (set from T1 to T2, T2 > T1), the emulsion of the rolling mill adopts The circulation heating method is the heating of the liquid supply main tank. [0003] Emulsion circulation heating refers to a method in which a circulation heating pump, steam heater, pneumatic shut-off valve, temperature sensor and other devices are installed next to the emulsion supply main tank (such as figure 1 Shown), in the figure 11 is the liquid supply main tank, 12 is the circulating heat pump, 13 is the steam hea...

AI Technical Summary

Problems solved by technology

[0006] When the temperature of the emulsion in the main liquid supply tank is greater than the T2 value, according to the control requirements, the pneumatic shut-off valve is closed and the steam heater stops heating, but there may be leakage when the pneumatic shut-off valve is closed. When the pneumatic shut-off valve leaks If the circulating heating pump is running normally, the temperature of the emulsion in the liquid supply main tank will continue to rise, exceeding the required T2 value, and until the temperature alarms, the manual valves before and after the pneumatic shut-off valve must be manually closed to slow down the temperature rising trend. The increase in temperature affects the quality of the emulsion, thereby affecting the quality of the strip product

[0007] When the pneumatic shut-off valve is automatically closed according to the control requirements, the pneumatic shut-off valve leaks and the circulating heating pump stops running due to failure or other reasons (that is, the steam heater and its pipeline are filled with emulsion and are in a static state). In this case, the leaked steam heats the heater and the emulsion in the inlet and outlet pipes. As the temperature of the static emulsion becomes higher and higher, a physical change of gasification will eventually occur. With further leakage of steam, gasification The area of ​​the closed pipeline is getting bigger and bigger, causing the emulsion in the pipeline to start to gasify. At this time, this part of the emulsion has been completely damaged. At the same time, the emulsion in the closed pipeline is gasified, causing the pipeline to expand and stretch violently. The bracket vibrates violently. Under normal circumstances, most of the pipeline bracket is welded on the main tank of the emulsion supply and the overall steel structure platform. The vibration of the pipeline drives the vibration of the main tank of the liquid supply and the overall steel structure platform, forming a potential safety hazard.

[0008] As the heater runs longer, scaling or even blockage will occur on the emulsion side of the tubular steam heater, which will easily cause the circulating heating pump to hold the pump, cause the motor to overheat, and damage the equipment. This cannot be detected in the conventional circulating heating system. Due to this change, corresponding protection measures cannot be taken

Images