Restaurant service counter and a method for using same

The invention relates to a restaurant service counter, such as a bar counter. The invention also relates to a method in connection with a restaurant service counter.

For a long time, attempts have been made to restrict smoking in restaurant facilities by means of legislation by referring e.g. to the exposure of the staff in the restaurant to tobacco smoke. For example in Finland, the law on tobacco nowadays forbids smoking at bar counters.

Solutions for solving the problems caused by tobacco smoke in restaurant facilities are disclosed for example in the US patent 5441279, in which a casino table contains a filter which filters the air sucked from the customers' side and blows it up on the worker's side. Similar type of circulation is disclosed in the GB application publication 2180054, in which on the customer's side of the counter an air curtain is blown upwards with the purpose of isolating tobacco smoke from the person working behind the table, and the air that is blown upwards is collected and filtered to be blown again. A problem in the latter solution is the unpleasant feeling of draught on the customer's side, in addition to which a common problem occurring in the circulation of air is that despite of the filter, smoke-laden air may be released in the air blast (e.g. if the filter functions in reduced capacity/is out of order), and problems are, at any rate, caused by the need for maintenance resulting from the heavy loading.

It is an aim of the invention to eliminate the aforementioned drawbacks. To attain this purpose, the invention is set out in independent claim 1.

In this invention an air nozzle is arranged on the staff's side of the counter in particular, wherein the customer does not experience a feeling of draught. Fresh air that will be blown upwards is taken from the free smokeless air space of the restaurant, for example under the counter. An exhaust duct is connected to the air-discharge system of the restaurant. The blast air is capable of taking along secondary air both from the staff's side and from the customers' side.

The air nozzle is directed diagonally above the counter. Thus, the air blast takes place in an area where it cannot be noticed easily.

The method according to the invention, in turn, is primarily characterized in what will be presented in the characterizing part of the appended claim 8. An air curtain of is blown upwards from the rear edge of the counter, directed diagonally forward, and it is extracted by means of local exhaust ventilation as exhaust air. When the clean air of the room is used as fresh blast air and the air blown upwards is extracted with the exhaust air of the room, problems of closed circulation of air do not occur. When the blast exits from the rear edge of the counter, the above-described advantages are attained.

In the following, the invention will be described in more detail with reference to the appended drawing, in which

• Fig. 1 shows a side-view of the apparatus,
• Fig. 2 shows a rear view of the apparatus, and
• Fig. 3 shows the nozzle on a larger scale.

On the rear edge of a restaurant service counter 1, such as a bar counter, an air duct is arranged in parallel with the edge, one side of the air duct being equipped with a horizontal air nozzle 2 by means of adjacent nozzle openings. The nozzle structure can also be composed of a continuous longitudinal nozzle opening (nozzle slot) or adjacent slots. The nozzle structure is attained by perforating the wall of the pipe forming the air duct with a suitable spacing in such a manner that when the holes are formed, collars extending outwards are produced therein. The air nozzle 2 (openings) are directed in such a manner that air is directed diagonally upwards towards the front edge (arrow P). Thus, the air current is primarily directed to an area not attended, and the customers and workers do not experience the feeling of draught. The air duct is partly built in below the table level so that only the wall containing the nozzle is visible therefrom, and thus it can be made to look like an elevated rear edge of the counter. In Fig. 1 the wall of the air duct in which the nozzle is located is arranged in an inclined position rising from the plane of the counter 1. The air duct in the wall of which the opening/openings are located, is a pipe-like structure located against the rear edge of the table top of the restaurant service counter and shown in cross-section on a larger scale in Fig. 3.

The produced air curtain is directed towards the upper bracket, i.e. a shelf 4, located above the table level of the counter 1, and the air current and the smoke entrained therein, coming from the customer's side with the secondary air (arrow S1) ends up in a horizontal exhaust duct 3 extending on top of the shelf 4 and located closer to the customer's side, i.e. the front side, when seen from the rear edge of the counter. The exhaust duct 3 can contain a sufficient amount of discharge openings, i.e. the discharge openings form a local exhaust ventilation area substantially parallel to the air curtain. The exhaust duct 3 is connected to the air discharge system of the restaurant, i.e. it can lead to the exhaust air unit belonging to the general ventilation of the restaurant. Behind the counter 1, above the working area there is also an inlet 5 of the supply air ducting bringing fresh supply air, i.e. a diffuser of supply air, and secondary air (arrow S2), entrained by the air curtain from the fresh supply air coming from said inlet, enters the exhaust duct 3. When the supply air is brought to the staff's side, it is at the same time possible to ensure the flow of air therefrom to the customers' side, which prevents the access of tobacco smoke to the other direction. Similarly, the air intake point of the air nozzle 2 is located behind the front panel of the counter, i.e. it is isolated from the customer premises and at the same time located on the inlet side of fresh air. Thus, the air intake of the nozzle and the air exhaust of the nozzle are connected to the general ventilation system of the restaurant room, the air intake to the supply air of this general ventilation and the exhaust to the exhaust air of the general ventilation, and a closed circulation is not necessary. The blast air intake point for the nozzle is also clearly separated from the area (customers' side) in which the emission (especially tobacco smoke) is produced that is to be isolated and extracted by the air curtain P.

Fig. 1 also shows the alternative that the exhaust duct 3 is brought to the blasting area of the nozzle from the ceiling, for example as a pipe branching from an exhaust air duct belonging to the general ventilation of the room and located on the ceiling. The air intake point is located in the blasting area of the nozzle, towards the customers' side from the rear edge of the counter. Thus, the air coming from the air nozzle 2 and the secondary air entrained therein are discharged as local exhaust ventilation in this alternative as well. In this alternative, there may also be several intake points distributed over the width of the counter, as in the horizontal exhaust duct extending parallel to the counter.

Fig. 2 shows the location and air intake of the air nozzle 2 when seen from behind the counter. In the middle of the horizontal air duct located at the rear edge of the counter, an inlet duct 6 of blast air is coupled, said inlet duct containing a control damper 7 and possibly a filter in its intake end. The inlet duct 6 contains a blower 8 (for example with a thyristor control) and on both sides of the same silencers, i.e. sound traps 9. The intake end can also be located elsewhere than underneath the counter and behind the front panel of the same, in such a point, however, that it is connected to the fresh air coming from the general ventilation of the room.

Hereinabove, the concept of air curtain refers either to a curtain extending continuously in the lateral direction of the counter, or to several adjacent air cones (coming from separate nozzle openings) together producing an isolating and secondary air guiding effect similar to that produced by an air curtain.