FR2839306A1 - Smoke generator for optical experiments, uses liquid that generates smoke when heated, with liquid reservoir and heater housed in closed box - Google Patents

Abstract

The smoke generator (1) comprises a reservoir (2) for a smoke-generating liquid, a burner (3) to heat the liquid and produce smoke, and a hose linking reservoir to burner. The reservoir and burner are fixed inside a box (7). The reservoir has a cap (10) to allow filling. The burner is electrically powered through a socket (6). The smoke emerges from a hole (8) in the side of the box.

Description

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 The invention relates to a smoke generator, comprising a tank containing a smoke liquid, a burner for decomposing under the effect of heat the smoke liquid by producing smoke, and a pipe connecting the tank and the burner for supplying the smoke smoke burner.

 It is common in the context of the study of optical phenomena, especially in education, to use a cloud of smoke to highlight a light ray.

For this, the operator has two simple and inexpensive craft techniques: the first consists in projecting cigarette smoke into the zone where the light beam must be highlighted, the second consists in shaking above the same zone a cloth full of chalk powder. It goes without saying that the first technique, in addition to its harmfulness, is incompatible with prevention messages against smoking. The second method is particularly messy.

 In addition, these methods only generate a cloud of short duration. It is therefore often necessary to repeat the operation in order to allow time for each observer to fully see the phenomena highlighted.

 In addition, there are known, in particular in model making, compact smoke generators composed of a reservoir and a burner connected together by a pipe, a smoke liquid, stored in the reservoir, being broken down in the burner under the effect of heat by forming smoke. These generators are complicated to use in a classroom because of the different elements that must be arranged close to each other.

In particular, to ensure the supply of smoke smoke to the burner, it is necessary to fix the tank above the burner so that the liquid flows under the effect of gravity. So you need a support for the tank. To avoid this problem, it is possible to use a pump, but this often fragile and noisy accessory further complicates the assembly of the experimental device. In addition, the burner gives off a certain amount of heat and the teacher or a pupil may burn himself by touching it, especially after the experiment, when the absence of smoke suggests that the burner has already cooled down. A second support for the burner is therefore required.

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LUUJt-UU! UC 1 IIIVt:::lllIUII CSt UVIII UC Ut-VOUppCf UII yuriurclfdul UC 1 Ulllt:::t::: pVUVdfIt générer un nuage de fumée persistant, peu salissant, non nocif tout en étant facile à manipuler et sans danger de brûlures pour l'enseignant ou les élèves.

LUUJt-UU! UC 1 IIIVt ::: lllIUII CSt UVIII UC Ut-VOUppCf UII yuriurclfdul UC 1 Ulllt ::: t ::: pVUVdfIt generate a persistent smoke cloud, not very dirty, not harmful while being easy to handle and without danger of burns for teacher or students.

 This objective is achieved by the device according to the preamble in which the tank and the burner are fixed together in a housing. By positioning the tank so that the level of the smoke liquid is above the burner or by equipping the generator with a pump, we obtain a smoke generator that is easy to handle both during the experiment and during storage and without danger of burns since the burner cannot be touched.

Thanks to such a device, it is therefore possible to generate a durable smoke cloud, non-dirty and safe for observers located nearby.

 It is preferable to provide the tank with a supply opening which can be closed by a plug and accessible from outside the housing. Thus, the smoke fluid tank can be filled easily and safely.

 In a preferred embodiment of the invention, the burner is an electric burner. It is preferably supplied by a power cable connected to a socket fixed to the outside of the housing.

 The invention also relates to the use of a smoke generator according to the invention for displaying a light beam during geometric optics experiments.

 An example of a smoke generator according to the invention is presented below with the aid of FIG. 1 which shows the device in section.

 The smoke generator (1) consists of a tank (2), a burner (3) and a pipe (4) connecting the tank (2) to the burner (3). A smoke liquid, contained in the reservoir (2), flows into the burner (3) where it decomposes under the effect of heat producing thick smoke.

 To operate, the burner is supplied with 12 V by an electric cable (5) to which an electric supply socket (6) is connected.

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 In order to facilitate the use of the smoke generator, it is enclosed in a housing (7) An opening (8) is made in the housing through which the smoke generated in the burner (3) can exit. The reservoir (2) is provided with a filling opening (9) accessible from the outside of the housing (7). This filling opening (9) can be closed by a plug (10).

 The smoke liquid flows into the burner (3) under the effect of gravity. It is therefore not necessary to provide a feed pump. It is sufficient during use to open the cap (10) to bring the interior of the tank to atmospheric pressure. At the end of use, just close the cap. A low vacuum is then created in the bottle which interrupts the flow of the smoke liquid in the pipe (4), the burner is no longer supplied and the electrical supply can be cut.

 During optical experiments in class, the teacher will direct the smoke generator to the area where the optical phenomenon must be highlighted. It will obtain a homogeneous smoke during all the time necessary for the experiment.

List of references
1 smoke generator
2 tank
3 burner
4 supply line
5 power supply cable
6 power socket
7 housing
8 smoke outlet opening
9 filling opening
10 cap

Claims (5)

 1. Smoke generator, comprising a tank (2) containing a smoke liquid, a burner (3) for decomposing under the effect of heat the smoke liquid by producing smoke, and a pipe connecting the tank (2) and the burner for supplying the burner 3) with smoke liquid, characterized in that the tank (2) and the burner (3) are fixed together in a housing (7).  2. Smoke generator according to claim 1, characterized in that the reservoir 2) is provided with a supply opening (9) which can be closed by a plug (10) and accessible from outside the housing (7) .  3. Smoke generator according to claim 1, characterized in that the burner (3) is an electric burner.  4. Smoke generator according to the preceding claim, characterized in that e burner (3) is supplied by a power cable (5) connected to a socket (6) fixed to 'outside the housing (7).  5. Use of a smoke generator according to one of the preceding claims for displaying a light beam during geometrical optics experiments.