The choice of electric heating tube should consider the power:
The calculation of the power of the electric heating tube can be conveniently carried out in the following three steps through standardized and unified calculation:
1. Calculate the actual power required to maintain the temperature under the premise of maintaining the temperature of the medium
2. Calculate the power required to heat up to the set temperature within a specified time from the initial temperature
3. According to the above two calculation results, select the model and number of heaters. The total power is taken as the maximum value of the above two powers and the coefficient of 1.2 is considered.
Formula:
1. Maintain the power required for the medium temperature pump
KW=C2M3△T/864+P
Formula: M3 increases the amount of medium kg/h per hour
2. The power required for initial heating
KW = ( C1M1△T + C2M2△T )÷ 864/P + P/2
Formula: C1C2 is the specific heat of the container and the medium (Kcal/Kg°C)
M1M2 mass of container and medium (Kg) respectively
△T is the difference between the required temperature and the initial temperature (°C)
H is the time required for the initial temperature to heat up to the set temperature (h)
P: Heat dissipation of the container at final temperature (Kw)
Performance curves are often used in electric heating tube calculations.
The selection of electric heating tube needs to consider the voltage:
The voltage specifications of the electric heating tube must be confirmed before purchasing. The confirmation of this step is equal to the fixed resistance value on the equipment, the greater the voltage, the greater the power, and it is especially easy to let the voltage exceed the load of the electric heating tube after being elected wrong, causing the resistance wire to blow and even the problem of electric heating tube breakdown. Conventional voltage specifications: 24V, 36V, 48V, 110V, 220V, 380V, usually the voltage we refer to is the rated voltage.
Rated voltage of electric heating pipe:
The rated voltage of the electric heating tube refers to the voltage specified at the time of redesign and marked on the electric heating tube shell. Or to put it another way, the rated voltage is the voltage given when the customer asks us to process and produce. Generally, there are 24V, 48V, 110V, 220V, 380V and so on.
Operating voltage of electric heating tube:
(1) Multiple series power supply, for a group of electric heating pipes or electric heating pipes connected in series to the power supply, the working voltage of the electric heating tube refers to the voltage specified in the design of this group of electric heating pipes.
(2) Single support power supply, for a single electric heating tube connected to the power supply, the working voltage of the electric heating tube refers to the voltage connected to the component specified at the time of design, that is, the rated voltage.
Note: This involves the question of whether multiple electric heating pipes are connected in series or parallel. Therefore, when judging the voltage, if multiple electric heating tubes need to be connected, it is necessary to consider whether to connect in series or parallel to determine the voltage of a single electric heating tube.
Effect of voltage on power:
In the case of determining the power of the electric heating tube, if the voltage is less than the voltage at the time of design, it will lead to a decrease in power and a decrease in heating efficiency; If the voltage is greater than the design voltage, it will lead to increased power, excessive load, and the possibility of internal heating wire blowing and even breakdown of the electric heating tube
