GB/T 25749.9-2012Safety of machinery -- Evaluation of the emission of airborne-hazardous substances -- Part 9: Decontamination index (English PDF)

1 Scope

This part of GB/T 25749 specifies pollutant control systems (e.g. capture equipment including local exhaust ventilation, sprinkler systems, and, where appropriate, separation equipment installed on the machine) method of measurement of the purification index. This method uses actual pollutants (see GB/T 25749.1-4.2 in 2010), and can be performed in indoor or field environments.

2 Normative references

The following documents are essential for the application of this document. For dated references, only the dated version applies to this article pieces. For undated references, the latest edition (including all amendments) applies to this document.

ISO 12100 Safety of machinery design general risk assessment and risk reduction (Safety of machinery-General principlesfordesign-Riskassessmentandriskreduction)

3 Terms and Definitions

ISO 12100 and the following terms and definitions apply to this document.

4 Principles

The principle of this measurement method is to determine the decontamination index specified in 3.1 and the concentration measured at predetermined points around the machine under test, and the Explanation of the index value, taking into account its range of variation and influencing factors.

Measuring the purification index of a pollutant control system can be used to.

a) evaluation of the performance of the machine's pollutant control system;

b) evaluation of pollutant control system improvements;

c) comparisons between machine pollutant control systems of similar design;

d) Classification of pollutant control systems according to purification efficiency;

e) determine the air flow of the exhaust system to the specified level;

f) Determine the technical level of the machine pollutant control system according to the purification efficiency.

5 Determine the concentration measurement point

Measurement points should be determined by pre-testing to ensure that they are located within the measurable discharge area. The number and precise location of the measuring points should be Specified in Type C standards.

6 Test methods

7 Applications for specific machine groups

Taking into account a variety of different practical situations (eg. room type, machinery, working method, product variety, operating category, pollutant characteristics), It is not easy to define a completely fixed method that is not bound by the different factors mentioned above.

If the Type C standard gives additional information on specific conditions, the location of the air sampling point, the test, and the duration of sampling should be specified and the operating conditions of the machine.

8 Influencing factors

Many factors can affect the measurement results. Attempts should be made to identify these factors and, if possible, evaluate these factors. very The following points should be recorded.

---Relevant data of the inspected machine, type of working process, type of processed product, type of operation (continuous, batch, cyclic formula), the duration of the operation;

--- Relevant data of surrounding machines and other technological processes;

--- data related to the pollutant control system, especially the exhaust flow of the capture device;

--- Separation of system-related data, especially traffic;

--- the dimensions of the room;

--- data about the layout of the room (e.g. the location of the machine);

--- Relevant data on the overall ventilation system, especially the characteristics of air entry and exhaust equipment, including the rate of cross-interference airflow. same It is also very useful to record air temperature and humidity.

Some methodological difficulties may limit the application of this method in the field, such as.

--- If the spatial and/or temporal differences of pollutants are considered, a large number of measurements are required;

--- Special attention should be paid to minimize fluctuations in exhaust flow and airflow patterns, especially indoors, machines or ventilation devices connected to them Open or close period.

9 Representation of results

The purification index is calculated by formula (1).

The decontamination index was calculated for each measurement point and for each of the three measurements. Then calculate the average of the purification index of each measurement point value. The test result is the average value of the purification index of each measurement point.

Other conditions remain unchanged, the higher the purification index, the higher the efficiency of the pollutant control system.

Example: When IA=0, ie Ca=Cm, the purification system does not contribute to the improvement of air quality. However, when IA=1, that is, Cm=Cf, the purification system can Effectively make indoor air pollution reach the background concentration.

10 Test report

The test report should contain at least the following information.

b) Description of the machine under test and the air purification system for the pollutant control system under test (manufacturer, style, type, modification, design, size, Year of manufacture, serial number, etc.) - the machine itself and each additional piece of equipment;

c) operating data during the test, including the tools used by the machine, the material processed by the machine and the air flow;

d) description of the general ventilation system;

e) a description of the measurement procedure, in particular.

1) method;

2) the location and sampling point of the emission source;

3) the duration of the measurement;

f) the measuring instruments used and the time of the last calibration;

g) environmental data (temperature, humidity, atmospheric pressure);

h) a description of the procedures used for concentration and flow measurements (eg list of standards);

i) test results, including the mean value and 95% confidence interval of different measurement points;

j) a statement of deviation from any relevant standard;

k) laboratory;

l) The name of the person responsible for the test;

m) test data;

n) Other supplementary instructions.