1.The top of the tank exhaust gas does not mix with the sewage tank exhaust treatment

When combustible gases or liquid vapors and air (or oxygen) in a certain range of uniform mixing, will explode when encountering an ignition source, the concentration range that is its explosion limit. Maximum permissible oxygen content is when given enough ignition energy can make a concentration of combustible gases or liquids vapors just do not occur combustion explosion of the critical maximum oxygen concentration, i.e., for the explosion and non-explosion of the critical point, in the entire range of the explosion limit, the upper and lower limits of the explosion and the maximum permissible oxygen content of the maximum value, the minimum value of the one-to-one correspondence; the minimum value of its maximum permissible oxygen content is numerically equal to be in the lower limit concentration of combustibles just fully react to the critical oxygen content required.

Volatile material storage tanks are generally protected by nitrogen seals and breathing valves. The storage tank exhaust components are mainly VOCs and nitrogen in the tank and do not contain oxygen, while the cesspool exhaust is mainly air and also contains a small amount (a certain amount) of volatile gases. When the tank emissions and sewage pond exhaust gas mixed, it is possible to reach the explosive range of VOCs and the range of oxygen content requirements, in a certain energy or temperature will explode. Therefore, these two types of gases should not be mixed directly for disposal. However, we can consider the tank area exhaust gas to do some pretreatment and buffer after access to the system to achieve mg level standard, do a good job of safety chain protection.

2.Concentration detector and exhaust gas shut-off valve distance

At present, the RTO device online exhaust gas detector are generally set up 2, to realize 2 to choose 1, and in the online exhaust gas concentration detector after a certain distance to set the exhaust gas shut-off valve. When the high concentration of gas through the online exhaust gas concentration detector, the exhaust gas shut-off valve should be in the high concentration of gas before the arrival of the completion of the closure, i.e., online exhaust gas concentration detector to the shut-off valve distance should be greater than the online exhaust gas concentration detection response time and the exhaust gas shut-off valve closure time sum of the length of the pipeline through which the gas flows. Generally speaking, according to the LEL and valve response time combined, combined with the overflow wind speed, generally need to be spaced 100-120 meters.

3.Fresh air dilution and fan control

In order to reduce the risk of explosion, the RTO device should increase the corresponding logic control, when a high concentration of gas is detected, the RTO device triggers an interlocked stop, i.e., the emergency exhaust gas discharge valve opens, the exhaust gas shut-off valve closes, the fresh air valve opens, and the main fan reduces the air volume to ensure that the furnace has been into a lower concentration of gas.

4.Flame arrestor and rupture disc

Flame arrestor is a very important safety accessories, flame arrestors must be identified through the safety to determine whether it meets the requirements, unqualified flame arrestor will not be able to effectively isolate the spread of energy, resulting in flash events. If the rupture disc bursting pressure and bursting area is not appropriate, can not effectively release the energy, resulting in equipment explosion damage and other consequences of the accident. Lower burst pressure and exhaust gas piping on the multiple rupture discs on the energy release site, can effectively prevent equipment and pipeline damage, reduce the occurrence of accidents.

5.Operating pressure selection

Considering that some exhaust gases are toxic gases, in order to prevent personal injury to the site personnel under positive pressure gas leakage, the operating pressure of the RTO is recommended to use micro-negative pressure operation. At the same time should be set according to the location of the leakage dew point of the corresponding toxic gas detector, the leakage point should also be installed rupture disc.

6.The breathing valve of the storage tank is connected with the outlet exhaust gas transportation pipeline by non-contact oxygen mask.

In order to reduce the risk of safe operation of the storage tank, the tank breathing valve and the exit of the exhaust gas pipeline is recommended to be connected with a gas mask, the back end of the gas mask with a non-return valve and flame arrester, which can prevent the gas from flowing back, tempering, isolating the transfer of energy, to a certain extent, to prevent the expansion of the state of affairs in case of accidents.

7.Fan material selection

Due to the need for corrosion prevention, some fan impeller material selection for non-metal, easy to generate static electricity, resulting in accidents, it is recommended to select metal material, but need to consider anti-corrosion measures.

RTO device emergency management measures

Enterprises should establish and improve the RTO device emergency response system, clear RTO device emergency rescue duties of each position, equipped with a full range of emergency rescue equipment to ensure that the RTO device emergency, emergency response system to operate effectively.

1.The preparation of RTO device special plans, on-site emergency disposal program. Regularly carry out various types of emergency plan training and drills, assess the effectiveness of the plan and improve the plan in a timely manner.

2.Improve emergency response capability. Enterprises should establish RTO device emergency response system, clear RTO device at all levels of personnel emergency rescue responsibilities, after the occurrence of emergencies, emergency response personnel should arrive at their respective positions within a specified time, in accordance with the requirements of the emergency plan for disposal.

3.For the hazardous factors existing during the production and operation of RTO device, the enterprise should at least be equipped with emergency rescue equipments such as chemical-proof suit, heat-insulating suit, gas mask, positive-pressure air respirator, explosion-proof emergency lighting, hand-held combustible and toxic gas detector, and other emergency rescue equipments.

(Source: North Star Ecology and Environment, VOCs Classroom, VOCs Emission Reduction Work , please contact to delete if any infringement