Abstract: In order to study the case of signal exported by the thermocouple wit h air pump after the signal as unit pulse imported by smoke temperature due to variational temperature in combustion chamber of lead column in Shaoguan Smelter, the loss of radiant heat in static state and the course of dynamic response about the measure head of thermocouple and the cover of thermocouple were deduced and analyzed. The results are revealed that reading error of the thermocouple in the course of dynamic response is mainly caused by the loss of radiant heat of the measure top of thermocouple and the cover of thermocouple, and their loss of radiant heat is restricted by their lagging time constant τ0; along with the process of dynamic response, reading error of the thermocouple is changed; when τ=3τ0, the process of dynamic response basically finishes, but the change due to ascending temperature will cause bigger reading error of t he thermocouple. The result of study will be more beneficial to on-line control of temperature in combustion chamber of lead column in Shaoguan Smelter.
Measurement error about temperature in combustion chamber of lead column in zinc refining
Abstract:
In order to study the case of signal exported by the thermocouple with air pump after the signal as unit pulse imported by smoke temperature due to variational temperature in combustion chamber of lead column in Shaoguan Smelter, the loss of radiant heat in static state and the course of dynamic response about the measure head of thermocouple and the cover of thermocouple were deduced and analyzed. The results are revealed that reading error of the thermocouple in the course of dynamic response is mainly caused by the loss of radiant heat of the measure top of thermocouple and the cover of thermocouple, and their loss of radiant heat is restricted by their lagging time constant τ 0; along with the process of dynamic response, reading error of the thermocouple is changed; when τ=3τ 0, the process of dynamic response basically finishes, but the change due to ascending temperature will cause bigger reading error of the thermocouple. The result of study will be more beneficial to on-line control of temperature in combustion chamber of lead column in Shaoguan Smelter.
Fig.1 Sketch of temperature gauging in combustion chamber of lead column1—Thermocouple with air pump and heat insulation cover; 2—Interior wall of combustion chamber; 3—Smoke; 4—Exterior wall of tray
Fig.2 Sketch of temperature gauging about thermocouple with air pump and heat insulation cover1—Measure head of thermocouple; 2—Smoke; 3—Heat insulation cover
Fig.3 Sketch of temperature about thermocouple with air pump in process of dynamic response (a) —Dynamic response to course of ascending temperature; (b) —Dynamic response to course of degressive temperature1—T1; 2—Tf; 3—T2; 4—TM; 5—0.632 (T2-T1) ; 6—0.950 (T2-T1)