Before operation, the confined space shall be safely isolated:

Pipes communicating with confined spaces that may endanger safe operation shall be isolated by inserting blind plates or removing a section of pipes.

Holes that may endanger safe operation and those communicating with confined spaces shall be tightly closed;

The electrical equipment in the confined space should stop running, cut off the power supply, lock the power switch and hang warning signs.

2, cleaning or replacement

Before operation, the confined space should be cleaned or replaced according to the characteristics of the articles contained in the confined space, and the gas in the confined space should be detected. Test contents and requirements are as follows:

The oxygen content is 19.5% ~ 2 1%, which should not be greater than 23.5% in oxygen-enriched environment;

The allowable concentration of toxic substances shall comply with the provisions of GBZ 2. 1;

The concentration of combustible gas and steam shall not be greater than 10%LEL.

3. Good ventilation

Natural ventilation in facilities connected with the atmosphere; If necessary, adopt mechanical forced ventilation or pipe air supply.

4. Gas detection

Within 30 minutes before operation, gas analysis must be carried out in the confined space, and the confined space can only be entered after the analysis is qualified.

Monitoring points should be representative;

The analytical instrument shall be within the validity period of calibration and shall be in normal working condition before use;

When monitoring personnel enter or explore a confined space, they should ensure personal protective measures;

Inspection should also be carried out during operation. If the situation is abnormal, the operation should be stopped immediately, the personnel should be evacuated, and the site should be treated. Only after the analysis is qualified can the operation be resumed.

When coating with volatile solvents, forced ventilation measures should be taken;

When the interruption time exceeds 60 minutes, it should be reanalyzed.

5. Personal protection

Operators entering the confined space should dress in accordance with the regulations and correctly wear corresponding personal protective equipment, such as respiratory protective equipment, lifeline, anti-static work clothes, acid-base protective clothing, etc. In addition, necessary communication equipment should be equipped according to the site conditions.

6, electricity safety

The lighting voltage should be less than or equal to 36V, and the working voltage in wet containers and narrow containers should be less than or equal to12V; ;

In a wet container, the operator should stand on the insulation board and ensure that the metal container is reliably grounded.

7, job monitoring

There must be a guardian for confined space operation, and the guardian cannot leave during the operation.

The operation supervisor should be familiar with the environment and technological conditions in the operation area, have the ability to judge and handle abnormal situations, and master the knowledge of first aid;

When working in a high-risk confined space, additional monitoring personnel should be added.

8. Others

Set up safety warning signs and provide emergency equipment and materials;

The entrance and exit remain open;

Don't carry things unrelated to homework;

Wear and use protective equipment correctly;

It is difficult, labor-intensive, long-time, high-temperature confined space operation should adopt rotation operation mode;

After the operation, the unit where the confined space is located and the operation unit * * * shall check the inside and outside of the confined space and close the confined space only after it is confirmed that there is no problem;

The longest working time shall not exceed 24 hours; If it exceeds the time limit, it shall go through the formalities for business extension;

Unprotected rescue is strictly prohibited when there are abnormal situations in the operation.

Present situation of gas detection in confined space;

1. Working in a confined space, due to the limitation of the environment, the traditional portable gas detector carried by workers will not be able to transmit dangerous signals to external personnel at the first time.

2. It is difficult for supervisors outside the confined space to know the real-time status of workers in the confined space, which may easily lead to missing the best rescue time after the accident.

From a technical point of view, it is difficult to spread dangerous information in a confined space because we have witnessed too many cases. Because the change information of gas environment in confined space can not be transmitted to external monitors in time, they often miss the best rescue time. For example: reaction tanks, storage tanks or containers, sewers or other underground pipelines, underground facilities, agricultural closed granaries, railway tankers, ship cargo holds, tunnels and other workplaces.

Before people enter, they should first detect the gas in the confined space. Through the interconnected mobile gas detection and early warning instrument with sampling function, different parts of the confined space (upper, middle and lower) can be detected. For example, in general, the specific gravity of combustible gas is light, and most of it is distributed above the confined space. The specific gravity of carbon monoxide is similar to that of air, which is generally distributed in the middle of a confined space, while heavier gases such as hydrogen sulfide exist in the lower part of the confined space.

We can send the suction hose of the interconnected mobile gas detection and early warning instrument into the confined space. This equipment will continuously extract the gas in the closed space for real-time detection. When the internal gas environment changes and reaches the alarm value, the equipment will send out audible and visual alarm signals and wireless alarm signals. External safety officers and managers can get accurate alarm information at the first time, and can take corresponding rescue measures for the workers in the confined space in time to reduce unnecessary casualties.