SU923908A1 - Air heater for thermoplastic films - Google Patents

Description

The invention relates to the food industry, in particular, to packaging equipment using ¹ heated air, used for packaging products in a thermoplastic film, mainly polyethylene.

Closest to the present invention is the air heater for thermoplastic films, containing a casing in which the heating elements and guides are located, forming channels for the passage of air [1] o

A disadvantage of the known air heater is an inefficient selection of heat from the heating elements, which leads to their overheating and failure, and also does not allow to increase the air temperature at the outlet. In addition, the design of the famous stove is complicated and cumbersome.

2

The purpose of the invention is to reduce the consumption of thermal energy, increasing the temperature of the air at the outlet and simplify the design.

This goal is achieved by the fact that in the air heater for thermoplastic films containing a casing in which heating elements and guides are located forming channels for air passage, a sleeve is installed inside the casing, and the guides are placed on it along helical lines.

At the same time, the adjacent guides at the end walls have windows for the passage of air from one channel to another.

The drawing schematically shows a stove for thermoplastic films, a general perspective view.

The heater contains a casing 1 installed in the last sleeve

ku 2, guides 3 “5 and heating elements 6. Guides 3-5

3 923908

four

placed on the sleeve 2 on the screw lines and form channels 7 “9 for the passage of air. The heating elements 6 are located inside the sleeve 2. In the end walls 10 and 11 of the casing there are ₅ holes 12 and 13 for the entry of cold air and for the release of hot air, respectively. Adjacent guides 3 and 4 at the end walls 10 and 11 of the casing 1 have windows 14 and 15 for the transition of air from one channel to another. '

The heater works as follows.

The cold air from the supply system, 5 air (not shown) flows through the opening 12 in the wall 10 and further into the channel 7 formed by the guides 3 and 5 and the inner wall of the casing 1.

The sleeve 2 and the walls of the guides 20 3-5 are heated by the heating element 6 and in turn in turn the air passing through them.

On channel 7, air will leak to the end wall 11 and through the window 15 25

goes into the channel 8 formed by the guides 4 and 5 and the inner wall of the casing 1. Then the air through the channel 8 reaches the end wall 10 and. through the window 14 passes into the channel 9 formed by the guides 3 and 4 and the inner wall of the casing 1. Next, the hot air through the channel 9 reaches the end wall 11 and through the opening 13 leaves the air heater ₃₅ into the working area (not shown).

Thus, the cold air, passing repeatedly through a large contact surface formed by the guides 3 “5 and the outer wall _{40 of the} sleeve 2, heats up to a given

heat and is efficiently used in this case, the heat removed from the heating element 6.

Since the walls of the guides 3 ~ 5 are low, the design of the heater itself is compact and simple compared to the known one.

Repeated passage of air in the casing eliminates the need to heat the heating elements to achieve a high leaving air temperature, which leads to a sharp decrease in electricity consumption and increase the reliability of the heating elements.

Claims (2)

Claim 1. Air heater for thermoplastic films, containing a casing in which heating elements and guides are located, forming channels for air passage, characterized in that, in order to reduce the consumption of thermal energy, increase the air temperature at the outlet and simplify the design, a sleeve is installed inside the casing, and the guides are placed on it along the screw lines. * 2. Air heater in π. one, ' characterized in that the adjacent guides at the end walls have windows for the passage of air from one channel to another.