DE3321555A1 - Method for controlling the ventilation of rooms and buildings in which open radioactive and/or toxic substances are employed - Google Patents

Abstract

In the previous control methods for ventilating rooms and buildings in which open radioactive and/or toxic substances are employed, large quantities of air are required, which is energy-consuming and leads to large quantities of special waste due to the used filters which result. This is remedied by a reduced air volume flow, in that the actual values of the room temperature, radioactivity and concentration of harmful substances and of the differential pressure at the filter are compared with desired values and, if they deviate from the desired values, the supply-air and/or exhaust-air flow are set accordingly by actuating regulating elements.

Description

³ 83 105 KN

NUKEM GmbH 6450 Hanau 11

Procedure for regulating the loading and. Ventilation of rooms and buildings in which open radioactive and / or toxic substances are used

The invention relates to a method for regulating the Be-15

and ventilation of rooms and buildings in which unsealed radioactive and / or toxic substances are used, by supplying supply air and removing exhaust air with the interposition of one or more filters.

Rooms and buildings in which unsealed radioactive and / or toxic substances are handled must be kept under negative pressure in relation to the outside atmosphere in order to prevent the escape of radioactivity or other toxicity carriers to the environment. and ventilation systems are provided, with the help of which in most cases the room temperature can also be kept constant within certain limits. Since the emitted or extracted air is charged from ₀ g these spaces and buildings with pollutants, it must filter HEPA are routed through highly effective before it can be released into the environment.

Rooms and buildings in which work is carried out with unsealed radioactive and gg toxic substances have so far been subject to loading and unloading Ventilation systems have been fitted with which the to

Removal of pollutants maximum required amount of air, calculated on the maximum possible pollutant content, constant supply and discharge and the temperature is regulated by heating or cooling the supply air. The continuous operation of However, such systems are associated with high energy costs. In addition, because of the high gas velocities, the filters quickly impermeable by entrained dust particles and must be reached when a certain Limit differential pressure are exchanged, which also leads to increased costs. Those laden with pollutants Filters must also be treated as hazardous waste and stored or disposed of accordingly.

It was therefore an object of the present invention to provide a method for regulating the ventilation of rooms and To find buildings in which unsealed radioactive and / or toxic substances are handled by feeding

_nn of supply air and removal of exhaust air with the interposition of one or more filters, whereby this control method should contribute to the reduction of costs and the generation of hazardous waste and the absolute emission of pollutants to the environment should be kept as low as possible

2g maintaining a certain room temperature and one required negative pressure within the rooms or buildings.

This object was achieved according to the invention in that the actual values of the room temperature, the radioactivity and / or the pollutant concentration and the differential pressure Measured with probes in relation to the exhaust air volume flow at the filter, compared with target values and in the event of deviations the supply and / or exhaust air flow is adjusted accordingly from the setpoints by actuating control elements.

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The room temperature is regulated by means of a variable air volume flow, if one is adhered to

certain minimum volume flow to discharge the harmful 5

fabrics. This air volume flow, which is considerably reduced compared to the previous control methods, is surprising completely sufficient in order not to exceed the required concentrations of pollutants in the rooms simultaneous compliance with the required room temperatures and the required negative pressure.

It has proven to be particularly advantageous for comparing the actual and setpoint values and for actuating the , p-rule elements to use a computer, in particular a process computer. The control elements used are preferably fans and control dampers.

Apparatus and system parts in which higher activities are released, such as boxes, washing towers or ovens, one regulates air technology advantageously separately and does not burden the regulation of the other rooms.

The figure shows schematically in an exemplary embodiment the ventilation control of rooms according to the invention.

The outside air is supplied by an outside air treatment system (17) with the help of a supply air fan (1) via a supply pressure chamber (3), a pressure maintenance control housed in it (2) and a speed controller (20). The amount of the space to be ventilated (4) to be supplied The amount of outside air is about a against atmospheric pressure working vacuum control device (5) and the control flaps (6) regulated. The supply air can z. B. over

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Supply air outlets with automatic air jet control (7) be distributed in the rooms to be ventilated (4).

There are temperature sensors inside the rooms to be ventilated

(8) attached, which monitor the room temperature and give the measured value to a process computer (13). Also are in the rooms to be ventilated also pollutant con-. _ centering or explosion protection measuring devices (9) attached, whose measured values are also given to the process computer (13). This process computer (13) controls the .gesamte Room ventilation.

, c The controlled variable is the room temperature. This acts via the process computer (13) either on a speed controller (14) on the exhaust air fan (15) or the exhaust air volume flow control flap (18) and in this way ensures that the exhaust air volume flow from the ^{rooms to be} oiled is not greater than the required via the exhaust air filter ( 10), which are absolute filters, are extracted and discharged through the chimney (16). In addition to room temperature, the exhaust air volume flow, which is measured by a probe (12) and the differential pressure at the absolute filter (10), which is measured by a probe (11), are controlled and measured variables that are fed to the process computer (13). A vacuum holding device (19) is required when using control flaps (10).

The process computer (13) is programmed so that, depending on the filter resistance, the maximum permissible volume flow is not exceeded. At the same time, the volume flow does not fall below a minimum, which is just sufficient for the required number of air changes.
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If the maximum permissible differential pressure at the exhaust air filter (10) is exceeded at the minimum volume flow, an alarm signal sounds, when it sounds the filter must be replaced with a new one or a new one redundant filter bank is switched. In this way it is guaranteed that only the one to maintain the Required room air conditions, required volume flow, _. is driven and the expensive absolute filter is not stronger be acted upon as absolutely necessary, resulting in a substantial saving in operating costs and minimization resulting in secondary waste.

10.1.1983 Dr.Br-hm

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Claims (2)

83 105 KN NUKEM GmbH
6450 Hanau 11 Patent claims:
10 Process for regulating the ventilation of rooms and buildings in which open radioactive and / or toxic substances are used Procedure for regulating the ventilation of rooms and buildings in which with open radioactive and / or toxic substances are used, by supplying supply air and removing exhaust air with the interposition of one or more filters, characterized in that the actual values of the room temperature, the radioactivity and / or pollutant concentration and the differential pressure in relation to 25 the exhaust air volume flow at the filter measured with probes, compared with setpoints and, in the event of deviations from the setpoints, by actuating control elements the supply and / or exhaust air flow is adjusted accordingly. 2. A method for regulating the ventilation according to claim 1, characterized in that a computer is used for the comparison of the actual and setpoint values and the actuation of the control elements. / 2 Method for regulating ventilation according to Claims 1 and 2, characterized in that fans and regulating flaps are used as regulating elements. . ^: