1 General provisions
1.0.1 This specification is formulated to implement the SHJ 24 Design specification for environmental protection used in petrochemical enterprises and meet the needs of petrochemical enterprises to monitor high-level pollution sources.
1.0.2 This specification is applicable to the design of sampling port of exhaust stacks for combustion flue gas and process waste gas newly built in petrochemical enterprises. It can be referred by the existing exhaust stacks.
1.0.3 In addition to this specification, the relevant current standards and specifications shall also be met.
2 General requirements
2.0.1 The exhaust stacks that discharge combustion flue gas and toxic and harmful process waste gas into the atmosphere shall be provided with sampling ports.
2.0.2 Sampling ports shall be set on the inlet and outlet pipelines of waste gas purification facilities.
2.0.3 The depth of the sampler into the exhaust stack shall be determined according to the general principles of petrochemical waste gas sampling technology.
3 Classification, setting and quantity of sampling ports
3.0.1 Sampling ports can be divided into the following categories:
3.0.1.1 Category I: sampling port for monitoring gaseous pollutants and dust;
3.0.1.2 Category II: sampling port for monitoring gaseous pollutants.
3.0.2 The setting of sampling port shall meet the following requirements:
3.0.2.1 Determination of the position of Category I sampling port
(1) The sampling port shall be set where representative samples can be collected;
(2) It should be set in the exhaust stack where the airflow is stable, and far from elbows and parts with sharp changes in cross section;
(3) It shall be installed in a safe and convenient place;
(4) It shall be set on the straight pipe section. The length of the upstream section and downstream section should not be less than 4 times the inner diameter and should not be less than 1 time the inner diameter respectively. When it is impossible to meet above requirements, the length of the upstream straight pipe section shall not be less than twice the inner diameter, and the downstream straight pipe section shall not be less than 0.5 times the inner diameter. See Figure 3.0.2.
When the exhaust stack is rectangular, its equivalent inner diameter can be calculated using the following equation:
E=2LW/(L+W) (3.0.2)
where,
E——the equivalent inner diameter of rectangular exhaust stack (m);
L, W——the section side length of rectangular exhaust stack (m).
3.2.2 Category II sampling port shall be located in accordance with 3.0.2.1 (1) and 3.0.2.1 (3) in this specification.
1 General provisions
2 General requirements
3 Classification, setting and quantity of sampling ports
4 Sampling port connection structure
5 Setting of working platform of sampling ports
Annex A Explanation of wording in this specification
