Views:38 Author:Site Editor Publish Time: 2018-11-26 Origin:Site
After selling Lestov induction cooktops for many years, a problem is coming: how many steps does it take to boil a pot of water?
Yes, it is so easy, only 3 steps: Fill the pot with water; Open the switch of induction cooker; Boil the water.
Ok, we are not kidding. Instead, we are generalizing the knowledge of Lestov induction cooker, so how long does it take to boil a pot of water?
Take the model QX-Y800 automatic commercial induction soup cooker as an example.
The bucket is filled with 230 liters of water. Heat water at room temperature to 100°C.
●In China, the normal temperature of the project is calculated at 20°C. There is no national standard. It needs to be judged according to different seasons in different regions. For example, the normal temperature of Russian engineering is 10°C. In the boiler design calculation book, the normal temperature is 20 °C.
●The specific heat capacity of water is: 1 kCal = 4.2kJ / (kg•°C) (physical unit, that is: the heat required to increase 1°C per liter of water is about: 4.2kJ / 4.186 ≈ 1kCal.
●Electric energy output per KW per hour is about 860 kCal: 1kW•h=1000W×3600s=3600kJ=860kCal
--From the above basic data, to heat 230 liters of water from room temperature to 100 °C, it needs 18400kCal (230L×(100°C - 20°C)×1kCal =18400kCal)
--Assuming the QX-Y800 is running at full capacity, the hourly heat production is: 25kW×860kCal=21500kCal
To boil 230L water, it needs about 51 minutes: 18400÷21500) × 60 minutes = 51 minutes
About the calculation of the rice-steaming time for commercial foood steamer , there is a set of data here.
●The bulk density of rice is 0.75 kg/L, and the specific heat capacity of rice is about 0.45 kCal (c=1.87kJ/(kg•°C)≈0.45 kCal)
●The ratio of water to rice is 1.2 : 1.
Suppose that a conventional steamed rice pan is filled with 75% of rice ( Rice pan size: 600mm*400mm*50mm). The heating power required for each layer is 1kw,
How long does it take to steam the rice without calculating the heat loss? The calculation data is as follows:
--The mass of rice: (6×4×0.5) L×1×0.75≈9 kg;
--Heat required for rice: 9kg× (100°C - 20°C) × 0.45kCal = 324 kCal;
--Water quality: (6×4×0.5) L×1.2×1≈14.4 kg;
--Heat required for water: 14.4kg×(100°C - 20°C)×1kCal = 1152 kCal;
--The steaming time is about 103 minutes:
1152kCal+324kCal)÷(1kW×860kCal)×60 minutes≈103 minutes.
Calculation is a headache for me. It doesn't matter. There is a simplified version here:
--How to calculate the heating time?
Heating time (minutes) = 5.5*capacity (liters) / power (kw)
--How to calculate heating power?
Heating power (kw) = 5.5*capacity (liter) / heating time (minutes)
Have you fallen in love with Lestov induction cooktop? Welcome your sample order.