DE4402541A1 - Laboratory ventilation system - Google Patents

Abstract

The system has air consumers (1,3) which are all provided with a built-in air extraction regulator (2,6) and are adjusted to more or less the same pressure drop. The air consumers are connected to a single common air extraction channel (12) which forms the air extraction facility. A ventilation controller (8), to which are communicated the actual values of air extraction mix of the consumers, forms from them a regulated quantity for controlling the inlet air regulator (17) of the inlet air gallery (16).

Description

The invention relates to a laboratory ventilation system for a laboratory that has multiple air consumers the generic term of claim 1.

There is usually a large number of air users in use, who are sometimes deductions delt that in different widths and depths as well as in different which designs, in particular for special applications in schools, for digestion, biochemical and isotope work ten are manufactured. It is therefore a multitude of different ones  Fume cupboards available on the market whose suction air volume is from 300-2000 m³ per hour range, the pressure losses between 20 and 1000 Pascals fluctuate. In addition to the deductions are called air consumer open suction eating, source suction as well as Aufbe currency cabinets with suction devices for all chemicals Kind used. There are also ventilated under-floor extraction systems Substructures and ventilated cupboards. Finally, in one In addition, laboratories also use floor suction systems or ceilings suction used, some of these suction constantly others are switched on as required.

The supply air required for room ventilation must be draft can be freely supplied, also the room air conditioning and keeping the room temperature constant have to. Especially in summer, buildings with large glass due to the devices installed in the laboratories as well as a high cooling load from the sun. If only a few deductions are provided to determine these cooling loads in the Summer the necessary supply air volume, while in the colder Mona the necessary supply air volumes were determined more by the fume cupboards become.

The laboratory aeration and ventilation previously used in practice systems are complex systems that in particular in laboratories with elaborate equipment it can hardly be overlooked are.

In Fig. 2 of the accompanying drawing, a conventional laboratory ventilation system is shown, which is provided with an exhaust air duct 31 for extracting ventilated cupboards 32 , an exhaust air duct 33 for extracting fume cupboards 34 and an exhaust air duct 35 for other extractors. The supply air is supplied via a supply air line 36 from adjacent rooms and room 37 air is added, since there must always be a negative pressure in the laboratory.

In the example of a conventional laboratory ventilation system shown in FIG. 2, three different exhaust air lines 31 , 33 , 35 and one supply air line 36 are thus present in the room.

Given the wide spread of pressure drops, it happens moreover, that deductions with two different Ab air systems must be driven, because with large fume cupboards Line pressures are not sufficient. This is then complicated Pipe guides necessary, which in turn increase the room heights and therefore increase the cubature of the building and the investment costs drive up.

The object underlying the invention is therefore therein, a laboratory ventilation system according to the genus Concept of claim 1 to create the simple structure is and in which the exhaust air and supply air lines in a central Exhaust and supply air systems are integrated. By the invention Training should be investment, space and Be drive costs can be reduced.

This object is achieved according to the invention through training solved, which is specified in the characterizing part of patent claim 1.

In the training according to the invention is therefore only a single exhaust duct is provided, which works with all consumers is connected, and supply air and exhaust air are controlled via a central Ventilation controller regulated, on which all exhaust air volume values of Ver need lying and accordingly the manipulated variable for the Supply air control device delivers. Such a laboratory ventilation The system is simple and flexible to set up, both at Retrofits as well as conversions and rescheduling.

Particularly preferred refinements and developments the laboratory ventilation system according to the invention are Ge subject matter of claims 2 to 6.

If especially the main consumers, namely the deductions automatically when not in use in a state of minimal energy energy consumption or minimum exhaust air volume is switched it is possible for the entire exhaust air and supply air system to 50% of the  to design the necessary peak capacity by using the Ventilation controller also reduces the incoming air becomes. This contributes significantly to a reduction in investment need for space and operating costs.

Furthermore, it is when using the invention Laboratory ventilation system possible, the previously necessary Floor height of, for example, 4 m, for example 3.5 m be reduced since only a single air duct can be provided got to.

The following is based on the associated drawing particularly preferred embodiment of the invention closer described. Show it

Fig. 1 is a schematic representation of the game Ausführungsbei the laboratory ventilation and ventilation system according to the invention and

Fig. 2 is a schematic representation of a conventional laboratory ventilation system.

In the laboratory ventilation system shown in Fig. 1, all exhaust air extraction points are connected to a common exhaust system. The suction points, which work continuously, such as the cupboards 1 for storing chemicals or the base cupboards, medication cupboards, drying cupboards and the like have mechanically fixed air volume flow regulators or flaps 2 , which are firmly regulated. These are devices that use a spring construction to keep the volume flow constant regardless of the form.

The deductions 3 as larger consumers are equipped with a control system 5 , 6 , which is installed in the deductions, and also designed in the following manner. A motion detector is provided on each fume cupboard so that the sliding window of the fume cupboard automatically moves down and provides a minimum volume flow required for this operation if no one is working on the fume cupboard for a certain period of time.

Via a data line 7 are used by all controllers 6, the current consumed flow rates, the exhaust air-ie actual values to a central ventilation controller namely a room controller 8 applies ge. On the room controller 8 are still all the values, for example, on the flaps 2 of the cabinets 1 constant set volume flows. The room controller 8 forms a manipulated variable from the applied values, which is via a data line 9 as a control signal to the building management system, which controls a flap 17 in the supply air line 16 so that the laboratory space is kept in the supply air / exhaust air balance. The room controller 8 can also operate the flap 17 directly.

The room is operated at a constant negative pressure, 50 that a volume flow 18 flows into the laboratory from the adjacent rooms.

If, in addition, room suction devices 20 of the ceiling or floor suction devices 21 are provided and connected, then these are regulated via fixed volume flow controllers 19 and 22 , which can be locked and are controlled by the sliding window controller 6 of the deductions. The setting values of these consumers are also on the room controller 8 .

All consumers are connected to a single exhaust air line 12 , which is possible in that they are all set to about the same pressure loss.

The laboratory ventilation system shown in FIG. 1 works in the following way:

The underlying data via the data line 7 at the room controller 8 via the consumers 1, 3 fixed or varia bel regulated exhaust air amounts in a corresponding manipulated variable for adjusting the flap 17 of the Zuluftstrang 16 umgewan punched such that for the required exhaust air volumes appropriate air supply is ensured.

If a user wants to work on the trigger 3 , then he can raise the sliding window of the trigger, which means that the controller 6 of the trigger increases the volume flow of the trigger and thereby enables safe work on the trigger. The corresponding data for the changed exhaust air quantities are on the room controller 8 . When the user leaves the trigger, this is registered by a motion detector 4 on trigger 3 , whereupon the sliding window closes automatically. After the sliding window has been closed, the controller 6 regulates the volume flow back to the minimum via the control flap 5 .

At room controller 8 are thus the air values of all fixed extraction systems and additionally via bus or analog lines by all regulators currently consumed flow rates, that is, the actual values of the exhaust air volumes. The controller 8 adds these values and passes a corresponding bus or analog signal to the room control center. This regulates the supply air line 16 in such a way that the room supply air is adapted to the required exhaust air quantity via the flap 17 . There remains a small amount of residual air 18 which is sucked in through doors from corridors in order to maintain a negative pressure in the laboratory.

All fume cupboards and suction devices are so constructed that a maximum pressure drop of 150 Pascal does not exceed is stepped so that this as a constant value for the construction side exhaust air can be prescribed. Deductions with increased Volume flow, for example through filters, receives a boost fan to ensure the uniformity of the exhaust system Afford. By consistently closing the sliding window of the Deductions if not used are all deductions that are not in Operation are kept at the minimum air volume value. Thereby can have a maximum of 50% simultaneity the peak demand are assumed, so for this reason all supply and exhaust air lines are reduced by a factor of 50% can.

If no building management system is provided, which is the case, for example, if there is no laboratory air conditioning, the room controller 8 can directly control the flap 17 via analog output signals.

If the signal formed as the volume flow values of the consumers on the room controller 8 for controlling the flap 17 in the supply air line 16 assumes a value which is below the value for the smallest prescribed supply air quantity, then the flap 17 is set so that this smallest prescribed supply air quantity is ensured is. This value, which is usually the case with an eightfold change of room air, is thus never undercut when controlling the flap 17 .

If the laboratory is equipped with an air conditioning system, there are various temperature and air quality sensors for air conditioning technology in the room of the laboratory. It can happen that when using many devices in the laboratory, the amount of exhaust air, especially when the sliding window of the fume cupboards 3 is no longer sufficient to ensure safe cooling. If the air conditioning system determines that the extracted and the supplied air quantities are too small, it can give the room controller 8 a higher ren setpoint via a line 10 . The room controller 8 can then in turn influence the subordinate controllers, for example the controller 6 of the fume hood 3 , in such a way that the air volume flows are increased even when the sliding window is closed, so that consequently more fresh air is also supplied to the room. It is also possible to open the sliding window accordingly, so that the controller 6 automatically increases the amount of exhaust air. A separate room exhaust air for the air conditioning system with its own room exhaust air controller and its own room exhaust air flap is therefore unnecessary, since these functions can be fulfilled by the controllers integrated in the fume cupboards.

The signal transmission between the room controller 8 and the connected units can take place with analog signals up to 10 V or 4 to 20 mA signals. However, it is also possible to use a bus technology, for example a two-wire or three-wire bus technology. In this case, the number of interfaces is considerably reduced and it is ensured that the building management system can be informed about the operating states by the room controller 8 at any time.

The laboratory ventilation system described above has the intent part of a simple ventilation system, with all measuring and ring elements are basically integrated into the laboratory equipment. These include all deductions, all other suction systems, all ventilated cupboards and, if necessary, the necessary ceiling and floor air outlets. These components are required on site only a predetermined minimum pressure and regulate their air volume flows automatically after fluctuations. The furnishing tion manufacturer therefore only needs a single connection point for the total indoor air per line.

Preferably, the training is such that in vertical Shafts the exhaust pipes run through the building, whereby the central fans sit in the roof or in the basement. This makes it possible to control the entire exhaust air flow in the laboratory to standardize. Standardized ones are therefore sufficient Ventilation ducts that go across the entire width of the laboratory. These can be prefabricated in the factory, are sent to the consumer attached and attached to the on-site through line closed. Also on the supply air side can be done in the same way be moved. Walk in another part of the room if vertical supply line through the room. This too Supply lines can have prefabricated supply air systems be closed. It is only necessary to put a flap between the supply lines and the room line, which controls the volume flow. Especially when it comes to the supply air, le of supply air ducts, also brick walls or lightweight concrete walls serve as supply air lines.

With such a design, there is an almost cross  tongue-free operation of exhaust and supply air lines. The structure, which is a lot with the previously used laboratory ventilation systems number of different pipelines had to be there reduced and clear in height and cubature become cheaper. This is made possible by the fact that everyone Components as well as the self-regulating consumers who make it possible to insert measuring and actuating elements in the tightest of spaces set, have uniform pressure drops.

In a specific embodiment of the above laboratory ventilation system, vertical passage lines for the exhaust air are arranged in a vertical duct through the corresponding shaft, which is integrated in a wall between the hallway and the laboratory. Laboratory branch lines branch off in front of this shaft and lead to the individual consumers, for example to two fume cupboards. However, other extraction systems can also be connected. On the other side of the room is the supply duct for the supply air. This can be installed inside the room but also outside of the building. From this supply air duct branch supply lines for the room, which are controlled by the valve 17 shown in FIG. 1 Darge. The actual room air outlets are attached to these supply lines. They can run separately, but can also be integrated in the duct. Due to the intersection-free operation of supply air and extract air and due to the simple piping, a room height of approx. 3.20 m is sufficient, which leads to a floor height of 3.40 m. Standard laboratories have so far been planned and built approx. 1 m higher, so that this results in considerable cost savings. In the above example, the location and location of the inlet and outlet lines can be replaced at any time, so that the exhaust air lines can also run outside the building, while the supply air lines run in the building.

Another reason for the lower design of the building  the is that the building is no longer for the top must be designed, but for a simultaneity of approx. 50% can be built. The previous laboratory ventilation systems operate continuously and are at 100% peak load designed. The reason for this is that experience has shown that even with sliding window controlled deductions Many sliding windows are open that the system is at maximum load must be built. In that in the manner described above the sliding windows when the fume cupboards are not used the system can dim in advance to 50% of the peak load be sioned. That means, for example, that in a laboratory torium with multiple deductions the basic load with all continuous consumers and all suits in a closed slide window position is set. If a sliding window is opened net, the deduction increases to 50% of the peak load. We then worked two deductions, so the system can briefly over the Supply line in the room can also reach peak load operation. However, it can be assumed that times are relevant are limited. The 50% peak load that is obtained relates all of the building management systems, which can be reduced by 50%. Can in a laboratory a peak load can be driven for a short time.

Claims (6)

1. Laboratory ventilation system for a laboratory, which has several air consumers, with a supply air line with supply air control devices for the amount of air to be supplied and an exhaust device that is connected to the air consumers, characterized in that all air consumers with a built-in exhaust air control device ( 2 , 6 ) and are set to approximately the same pressure losses, the air consumers ( 1 , 3 ) are connected to a single common exhaust air duct ( 12 ), which forms the exhaust air device, and a ventilation controller ( 8 ) is provided, on which the actual values of the exhaust air quantities of the air consumers ( 1 , 3 ) and which forms a manipulated variable for controlling the supply air control device ( 17 ) of the supply air line ( 16 ). 2. Laboratory ventilation system according to claim 1, characterized in that the ventilation controller ( 8 ) also has the value of a prescribed minimum exhaust air quantity and the ventilation controller ( 8 ) controls the supply air control device ( 17 ) so that the prescribed minimum exhaust air quantity is independent of the required one Exhaust air volume of the air consumers ( 1 , 3 ) is always ensured. 3. laboratory sector and -entlüftungsanlage according to claim 1 or 2 for a laboratory, which is provided with an air conditioning system, characterized in that the value of the air demand of the ACU location is located at the ventilation regulator (8) and the ventilation controller (8) if the control variable for the supply air control device ( 17 ) resulting from the exhaust air quantities of the air consumers ( 1 , 3 ) is below a value which ensures the air requirement of the air conditioning system, the supply air control device ( 17 ) is controlled primarily in accordance with the air requirement of the air conditioning system. 4. Laboratory ventilation system according to claim 3 for a laboratory in which at least one air consumer is a fume cupboard with a sliding window for opening and closing the work space, the amount of exhaust air is regulated according to the degree of opening of the sliding window, characterized in that then If a supply air quantity is required that is above the value that results from the exhaust air quantities of the air consumers ( 1 , 3 ) due to the manipulated variable of the ventilation controller ( 8 ), the sliding window of the fume cupboard ( 3 ) is opened, so that the Exhaust air volume increases, the actual value of which lies on the ventilation controller ( 8 ). 5. Laboratory ventilation system according to one of the preceding claims, characterized in that the fume cupboards are designed so that they are automatically operated in an operating state with the lowest amount of exhaust air, if no one is working before the fume cupboard, and the supply air and the exhaust air duct ( 12 , 16 ) are dimensioned to a maximum of 50% of the peak exhaust and supply air volume. 6. Laboratory ventilation system according to one of the preceding claims, characterized in that the manipulated variable for the supply air control device ( 17 ) from the ventilation controller ( 8 ) is located on a building management system, which in turn controls the supply air control device ( 17 ).