RU32711U1 - Fume hood - Google Patents

Abstract

1. An exhaust hood including a work table with a worktop and a working chamber fixed on it, placed in the housing, the width of the worktop being greater than the depth of the working chamber, while an opening is made in the front wall of the working chamber, closed by a movable frame with a transparent insert, and located inside the chamber a screen mounted with a gap relative to the countertop and configured to change the size of this gap, and the upper part of the working chamber is made with a bevel from the back wall, characterized in that the inside of the chamber above the first screen has an additional screen located obliquely and with a gap relative to the first screen and the top of the working chamber, the lower edge of the additional screen being placed in the space between the first screen and the rear wall of the working chamber, while the lower edge of the opening is provided with a visor protruding beyond the front edge of the countertop. 2. A fume hood according to claim 1, characterized in that a recess is made in the countertop under the screen. 3. A fume hood according to claims 1 and 2, characterized in that a through hole is made in the countertop connected to the recess.

Description

in about

EXPLOSION CABINET

The utility model relates to ventilation technology, namely, devices designed to remove harmful substances directly from the place of their formation, and can be used when working with chemical reagents in laboratory conditions.

Fume hoods are known that are used as laboratory workstations (see, for example, USSR Aviation Administration JV21759485, published September 7, 1992, Russian PM Certificate No. 19486, published September 10, 2001, US Patent No. 5318473, class B08B 15/02, published on 06/07/1994).

The bottom of such cabinets is a desktop with a worktop, and the top is a working chamber with an exhaust pipe. An opening is made in the front wall of the working chamber, which is closed by a movable frame with a transparent element inserted in it, for example, glass.

IPC: V08V 15/02

allowing to observe what is happening in the working chamber process. The exhaust pipe is connected to the ventilation system. Due to the rarefaction of air created by the fan, harmful substances formed in the working chamber are removed through the exhaust pipe without entering the laboratory premises.

These fume hoods are characterized by the presence in their design of a large number of metal elements (metal working chamber, metal fasteners, etc.), which causes their significant disadvantages, namely:

- limited scope.

Such cabinets can only be used for working with chemicals that are neutral with respect to the metal used in the construction of these cabinets.

- the fragility of the design.

Over time, metal structural elements corrode, the mechanical functions of these elements are violated.

Fume hoods are also known in which the working chamber is made of glass, see the prospectus of the American company LABCONCO Protector Class Mate Hoods, 2000 (A copy of the analogue is attached).

solely for illustrative purposes, for example, for the demonstration of chemical materials in training laboratories.

A fume hood is known, including a work table with a worktop and a working chamber placed on it, placed in a corus, moreover, an opening is made in the front wall of the working chamber closed by a movable frame with a transparent insert, and a screen is provided inside the chamber equipped with fastening elements to the rear wall of the working chamber cameras, see prospectus of the Spanish company Flores Valles Fume Cupboards, Mod. 521. (A copy of the link is attached). The worktop and the fume hood chamber are made of plastic, neutral with respect to the action of the aggressive working environment, i.e. those harmful substances for which the device is intended to work. In comparison with the analogues described above, such a fume hood has a significantly higher durability.

However, it also has significant disadvantages:

-the width of the desktop countertops in this technical solution is less than the depth of the working chamber. In this regard, for the convenience of the laboratory assistant, the countertop is additionally equipped with a painted metal visor, which under the influence of chemicals is corroded and destroyed over time;

fastened with a sealant, which, like metal elements, over time is destroyed by the action of harmful substances;

-the opening in the front wall of the working chamber is made over the entire width of the working chamber, therefore, between the working chamber and the metal case, as well as the fastening elements of the frame with glass, a gap is formed in which harmful things inevitably fall; substances from the working chamber, thereby reducing the efficiency of the exhaust cabinet and polluting laboratory premises;

-the screen is fixed permanently on the back wall of the working chamber, with gaps fixed relative to the top and top of the working chamber, which does not allow optimizing the working conditions of the fume hood with the degree of volatility of the removed harmful substances.

The closest in technical essence to the declared one is a fume hood (see certificate on PM of Russia No. 25177, published on September 20, 2002), containing a work table with a worktop and a working chamber fixed on it, placed in the housing; the width of the countertop is greater than the depth of the working chamber; an opening is made in the front wall of the working chamber, closed by a movable frame with a transparent insert, and inside the chamber there is a screen installed with a gap relative to the table top and top of the working chamber and made with the possibility of changing the values of these gaps; top of the working

the camera is made with a bevel from the back wall. The rear wall of the working chamber is equipped with pockets designed to accommodate screen mounting elements to the rear wall of the chamber, and the pockets are arranged so that it is possible to change the gap between the screen and the tabletop and the gap between the screen and the top of the working chamber.

This technical solution is the prototype of this utility model.

The disadvantage of this technical solution is the fact that the condensate formed when using the cabinet is located both on the front and rear walls of the screen, as well as on the walls of the chamber and flows onto the countertop, which reduces the efficiency of the fume hood.

This utility model is aimed at solving the problem of increasing the durability and efficiency of using a fume hood.

According to a utility model, the problem is solved due to the fact that in a fume hood containing a work table with a worktop and a working chamber fixed on it, placed in a housing, the worktop width being greater than the working chamber depth, while the closed opening is made in the front wall of the working chamber a movable frame with a transparent insert, and inside the camera there is a screen installed with a gap relative to the countertop and made with

the possibility of changing the size of this gap, the upper part of the working chamber being beveled on the side of the rear wall, an additional screen is installed inside the chamber above the first screen, located obliquely and with a gap relative to the first screen and the top of the working chamber, the lower edge of the additional screen being placed in the space between the first screen and the rear wall of the working chamber, while the lower edge of the opening is provided with a visor protruding beyond the front edge of the countertop; a recess may be made in the countertop under the screen; a through hole connected to the recess may be provided in the countertop.

The applicant has not identified any technical solutions that have the same set of features as the claimed solution. This, according to the applicant, allows us to conclude that the claimed object meets the criterion of "novelty.

The proposed utility model is illustrated by drawings, which depict:

in FIG. 1 is a perspective view of a fume hood in a perspective view,

figure 2 is a General view of the camera in a perspective view,

in Fig.Z - camera, rear view in a perspective view,

figure 4 - distribution of air flow in the chamber.

a working chamber 3 is installed, placed in a metal corne 4. The countertop 2 and the chamber 3 are made of plastic and are rigidly connected, in this example glued together, forming a single whole. The width of the countertop 2 is greater than the depth of the chamber 3, due to which the front edge of the countertop 2 projects forward relative to the front wall (not indicated by a separate position) of the chamber 3, which is necessary for the convenience of the laboratory assistant. An opening is made in the front wall of the chamber 3 (not indicated by a separate position), closed by a frame 5 with tempered glass (not indicated by a separate position), mounted for movement along plastic guides 6. The opening width is less than the width of the front wall of the chamber 3, and the opening itself equipped with an upper and side visors 7. The side visors 7 are rigidly fastened through plastic guides 6 to the housing 4, and there is a gap between the upper visor 7 and the housing 4. On the rear wall 8 of the chamber 3, a screen 9 is mounted, made with the possibility of vertical movement. To place the fasteners and install the screen 9 on the wall 8, pockets are made 10. In the upper part of the working chamber, an additional screen 11 is made fixed from the same material as the screen 9. The screen 11 is located above the screen 9 obliquely relative to the screen 9 with a gap relative to him and the top of the working chamber 3; the lower edge of the screen 11 is placed in the space between

screen 9 and the back wall 8 of the working chamber 3 (goes beyond the screen 9). The lower edge of the nroyem is equipped with a visor 14 that extends beyond the front edge of the countertop 2. Between the screen 9, the screen 11 and the rear wall 8 of the chamber 3, an exhaust channel is formed (not denoted by a separate position) connected to the exhaust pipe 12 connected to the working chamber 3 and connected to ventilation system (not shown in the drawing). At the same time, the upper part of the chamber 3, on which the screen 11 is mounted, has a bevel 13 from the side of the rear wall 8. This form of the working chamber 3 makes it easy to fasten the screen 11 using plastic fasteners, without using metal ones. A through hole 15 is made in the corner of the chamber 3 in the countertop 2, in which there is a sink (sink), and on the rear wall 8 of the chamber 3 there is a faucet 16; they are intended for washing off reagents. In the countertop 2 under the screen 9, a recess (groove) 17 is made, connected to the through hole 15.

All structural elements of the working chamber 3, including the exhaust pipe 12 and the fastening elements of the screen 9 and the screen 11 to the rear wall 8 of the chamber 3, are made of plastic, which is selected taking into account its resistance in a particular aggressive working environment.

A fume hood operates as follows.

to work, the screen 9 is installed in one of three possible positions, allowing to optimize the operating conditions of the device depending on the specified parameter of harmful substances. The upper position of the screen 9, in which the gap between the countertop 2 and the screen 9 is maximum, and between the screen Ni screen 9 is minimal, is used when working with heavy harmful substances that are concentrated at the bottom of the working chamber 3. Accordingly, when working with light harmful harmful substances that are concentrated at the top camera 3, the screen 9 is set to the lower position, in which the gap between the screen 11 and the screen 9 is maximum, and between the countertop 2 and the screen 9 is minimal. When working with harmful substances, which are a mixture of substances with varying degrees of volatility (heavy and light), screen 9 is set to the middle position. In this particular example, in FIG. 1, the screen 9 is set to the upper position, and in FIG. 2 to the middle position.

Through a raised frame 5 with glass, harmful substances, for example chemical reagents, are placed on the countertop 2 of the working table 1. By connecting the exhaust pipe 12 to the ventilation system, air discharge is created in the working chamber 3, as a result of which the harmful substances enter the exhaust duct formed by the back the wall 8 of the chamber 3, the screen 9 and the screen 11, from where they are removed through the exhaust

pipe 12. Air flows have the following path: air enters the chamber through an opening in the front wall of the chamber 3 and is distributed into 2 ordered flows: the first flow passes through the working chamber 3 in front of the screen 9, through the gap between the screen 11 and the top of the chamber 3 and enters exhaust pipe 12 and a ventilation system; the second air stream passes through the working chamber 3 in front of the screen 9, through the gap between the screen 9 and the screen 11, through the chamber 3 behind the screen 9, through the gap between the screen 9 and the countertop 2, above the countertop 2 and the canopy 14 through the opening to the outside. When using the cabinet, condensation forms, which settles on the top of the screen 11 and on the back of the screen 9, this condensate flows down the back of the screen 9 into the recess 17 in the countertop 2 and is removed from the chamber 3 through the sink 15. The remaining reagents are also washed into the sink 15 with water supplied from the crane 16.

The side visors 7, the front visor 14 and the guiding 6, reliably protect the metal casing 4 on the sides and bottom from the penetration of harmful substances into it. In the region of the upper visor 7, the metal case 4 is protected from harmful substances by an air stream.

The proposed utility model eliminates the destruction of structural elements of the fume hood under the influence of an aggressive working environment, because the structural elements of the working chamber are made of plastic, selected taking into account its resistance to a specific aggressive

working environment, and metal parts of the case are protected from penetration of harmful substances into it.

In addition, the proposed technical solution allows you to create optimal working conditions for the fume hood taking into account the degree of volatility of harmful substances to be removed by changing the position of the screen relative to the table top and top of the working chamber.

The design of the proposed fume hood allows you to reduce the turbulence of air flows and create an orderly movement inside the chamber of the removed harmful substances: volatile substances through the exhaust pipe, and condensate through the hole in the countertop, thereby significantly increasing the efficiency of use of the cabinet.

These new properties of the claimed object provide increased durability and efficiency of the fume hood.

The proposed utility model can be implemented using conventional, well-known materials and devices, which, according to the applicant, indicates the compliance of the claimed object with the criterion of "industrial applicability.

Claims (3)

1. An exhaust hood including a work table with a worktop and a working chamber fixed on it, placed in the housing, the width of the worktop being greater than the depth of the working chamber, while an opening is made in the front wall of the working chamber, closed by a movable frame with a transparent insert, and located inside the chamber a screen mounted with a gap relative to the countertop and configured to change the size of this gap, and the upper part of the working chamber is made with a bevel from the back wall, characterized in that the inside of the chamber above the first screen has an additional screen located obliquely and with a gap relative to the first screen and the top of the working chamber, the lower edge of the additional screen being placed in the space between the first screen and the rear wall of the working chamber, while the lower edge of the opening is provided with a visor protruding beyond the front edge of the countertop. 2. A fume hood according to claim 1, characterized in that a recess is made in the countertop under the screen. 3. A fume hood according to claims 1 and 2, characterized in that a through hole is made in the countertop connected to the recess.