阅读说明：本技术 一种液体静电分类控制方法 (Liquid electrostatic classification control method ) 是由 孙立富 刘全桢 李义鹏 宫宏 孟鹤 李亮亮 于 2018-06-06 设计创作，主要内容包括：本发明公开了一种液体静电分类控制方法,属于石油化工安全领域,包括如下步骤：根据闪点、电导率、工况将可燃液体分为本质静电危险类、外部静电危险类和特殊工况静电危险类三类；对本质静电危险类,实施常规静电放电控制措施；对外部静电危险类,实施外部静电放电控制措施；对特殊工况静电危险类,实施综合静电放电控制措施。本发明是根据液体的分类参数闪点、电导率以及生产储运工况确定应采取的静电危险性控制措施,可以用于液体生产、储运过程静电燃爆危险性控制措施的评估、设计以及现场应用。(the invention discloses a liquid static classification control method, which belongs to the field of petrochemical engineering safety and comprises the following steps: combustible liquid is divided into three types of intrinsic static hazard, external static hazard and special working condition static hazard according to flash point, conductivity and working condition; implementing conventional electrostatic discharge control measures for intrinsic electrostatic hazards; implementing external electrostatic discharge control measures for external electrostatic hazards; and implementing comprehensive electrostatic discharge control measures for electrostatic hazard types under special working conditions. The method determines the electrostatic risk control measures to be taken according to the classification parameters of the liquid, such as flash point, conductivity and production, storage and transportation working conditions, and can be used for evaluation, design and field application of the electrostatic explosion risk control measures in the liquid production and storage and transportation processes.)

1. a liquid electrostatic classification control method is characterized in that: the method comprises the following steps:

step 1: combustible liquid is divided into three types of intrinsic static hazard, external static hazard and special working condition static hazard according to flash point, conductivity and working condition;

step 2: implementing conventional electrostatic discharge control measures for intrinsic electrostatic hazards; the method specifically comprises the following steps: liquid level discharge and equipment accessory discharge caused by electrostatic electrification of liquid under a dynamic condition are controlled through grounding, flow rate control, isolated conductor prevention and external electrostatic discharge control measures;

And step 3: implementing external electrostatic discharge control measures for external electrostatic hazards; the method specifically comprises the following steps: the static discharge of the human body, the discharge caused by the electrification of the scale, the sampling tool and the foreign object are controlled by grounding, eliminating the static electricity of the human body, adopting an anti-static tool and preventing the entry of the foreign charged object;

and 4, step 4: implementing comprehensive electrostatic discharge control measures for electrostatic hazard types under special working conditions; the method specifically comprises the following steps: the comprehensive electrostatic discharge is controlled by adopting an electrostatic eliminator, a moderator, an electrostatic on-line monitor and a conventional electrostatic discharge control measure.

2. the liquid electrostatic classification control method according to claim 1, characterized in that: combustible liquid with the conductivity lower than 1000pS/m and the flash point lower than 60 ℃ is an essential static hazard class; combustible liquid with conductivity higher than or equal to 1000pS/m and flash point lower than 60 ℃ is an external static hazard class; combustible liquid with the conductivity higher than or equal to 1000pS/m and the flash point higher than or equal to 60 ℃ is a special working condition electrostatic hazard class.

3. The liquid electrostatic classification control method according to claim 1, characterized in that: the electrostatic hazard class under special working conditions comprises four conditions of fog formation, component change, steam aggregation and hydrogen-containing light hydrocarbon.

Technical Field

The invention belongs to the field of petrochemical engineering safety, and particularly relates to a liquid electrostatic classification control method.

Background

the electrostatic discharge is an important reason for the explosion during the production, storage and transportation of combustible liquid, and the standards and specifications at home and abroad have relatively comprehensive protective measures. However, due to the lack of the concept of classified protection, basically the same protection measures are taken for different liquids, so that the concept of design, construction and operation personnel is fuzzy in protection consciousness, the execution is not fixed, electrostatic explosion accidents happen occasionally, and the shortage or waste in the setting and management of protection instruments and equipment is caused sometimes.

therefore, it is very important to effectively avoid or reduce electrostatic explosion accidents by discussing the electrostatic hazard classification of the liquid and determining the control measures according to the classification.

The fire hazard, volatility, vapor pressure and conductivity are common liquid classification modes, and the main classification basis is the flash point or the conductivity of the liquid, so that the foundation is laid for electrostatic hazard classification. In fact, although there is no clear concept of electrostatic risk classification, foreign relevant standard documents such as international oil tanker and oil terminal safety guidelines, measures for preventing static electricity, lightning and stray current ignition (API RP2003) have proposed corresponding electrostatic protection measures based on two parameters of flash point and conductivity, and critical technology for preventing major explosion accidents in the oil tank field (2012BAK03B03) has also been studied.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides the liquid electrostatic classification control method which is reasonable in design, overcomes the defects of the prior art and has a good effect.

In order to achieve the purpose, the invention adopts the following technical scheme:

A liquid electrostatic classification control method comprises the following steps:

Step 1: combustible liquid is divided into three types of intrinsic static hazard, external static hazard and special working condition static hazard according to flash point, conductivity and working condition;

step 2: implementing conventional electrostatic discharge control measures for intrinsic electrostatic hazards; the method specifically comprises the following steps: liquid level discharge and equipment accessory discharge caused by electrostatic electrification of liquid under a dynamic condition are controlled through grounding, flow rate control, isolated conductor prevention and external electrostatic discharge control measures;

and step 3: implementing external electrostatic discharge control measures for external electrostatic hazards; the method specifically comprises the following steps: the static discharge of the human body, the discharge caused by the electrification of the scale, the sampling tool and the foreign object are controlled by grounding, eliminating the static electricity of the human body, adopting an anti-static tool and preventing the entry of the foreign charged object;

And 4, step 4: implementing comprehensive electrostatic discharge control measures for electrostatic hazard types under special working conditions; the method specifically comprises the following steps: the comprehensive electrostatic discharge is controlled by adopting an electrostatic eliminator, a moderator, an electrostatic on-line monitor and a conventional electrostatic discharge control measure.

Preferably, combustible liquids with conductivity below 1000pS/m and flash point below 60 ℃ are intrinsically static hazard; combustible liquid with conductivity higher than or equal to 1000pS/m and flash point lower than 60 ℃ is an external static hazard class; combustible liquid with the conductivity higher than or equal to 1000pS/m and the flash point higher than or equal to 60 ℃ is a special working condition electrostatic hazard class.

Preferably, the static hazard class under special working conditions comprises four conditions of fog formation, composition change, steam accumulation and hydrogen-containing light hydrocarbon.

The invention has the following beneficial technical effects:

The invention provides a liquid electrostatic classification control method aiming at the electrostatic safety problem in the liquid production, storage and transportation processes at present, and according to the existing liquid classification method, the method determines the electrostatic danger control measures to be taken according to the classification parameters flash point, conductivity and production, storage and transportation working conditions of the liquid, and can be used for evaluation, design and field application of the electrostatic explosion danger control measures in the liquid production, storage and transportation processes.

Drawings

FIG. 1 is a flow chart of a liquid electrostatic classification control method according to the present invention.

Detailed Description

The invention is described in further detail below with reference to the following figures and detailed description:

A liquid electrostatic classification control method, the flow of which is shown in fig. 1, comprising the following steps:

Step 1: combustible liquid is divided into three types of intrinsic static hazard, external static hazard and special working condition static hazard according to flash point, conductivity and working condition; combustible liquid with the conductivity lower than 1000pS/m and the flash point lower than 60 ℃ is an essential static hazard class; combustible liquid with conductivity higher than or equal to 1000pS/m and flash point lower than 60 ℃ is an external static hazard class; combustible liquid with the conductivity higher than or equal to 1000pS/m and the flash point higher than or equal to 60 ℃ is a special working condition electrostatic hazard class.

The electrostatic hazard class under special working conditions comprises four conditions of fog formation, component change, steam aggregation and hydrogen-containing light hydrocarbon.

step 2: implementing conventional electrostatic discharge control measures for intrinsic electrostatic hazards; the method specifically comprises the following steps: liquid level discharge and equipment accessory discharge caused by electrostatic electrification of liquid under a dynamic condition are controlled through grounding, flow rate control, isolated conductor prevention and external electrostatic discharge control measures;

and step 3: implementing external electrostatic discharge control measures for external electrostatic hazards; the method specifically comprises the following steps: the static discharge of the human body, the discharge caused by the electrification of the scale, the sampling tool and the foreign object are controlled by grounding, eliminating the static electricity of the human body, adopting an anti-static tool and preventing the entry of the foreign charged object;

And 4, step 4: implementing comprehensive electrostatic discharge control measures for electrostatic hazard types under special working conditions; the method specifically comprises the following steps: the comprehensive electrostatic discharge is controlled by adopting an electrostatic eliminator, a moderator, an electrostatic on-line monitor and a conventional electrostatic discharge control measure.

the classification parameters of the liquid, such as flash point and conductivity, are obtained by inquiring relevant standards, technical data or field and laboratory tests. The working conditions refer to the processes, equipment and formed states in the processes of liquid production, storage and transportation, and can be divided into four conditions: firstly, the liquid is formed into mist, and the liquid is split into tiny droplets to form oil mist which can be charged, and the oil mist is easy to generate in top loading, splash loading and the initial loading period; second, composition changes, changes in water and other contaminants or compositions; thirdly, steam is gathered, and high-concentration flammable liquid steam is gathered in the container when the flammable liquid is loaded, which can happen in the process of converting the loading; and fourthly, hydrogen-containing light hydrocarbon, combustible liquid, particularly hydrotreated material, if dissolved hydrogen or other light hydrocarbon brought in during the treatment process is released in the oil tank, combustible steam-air mixture can be generated in the gas phase space of the fixed-top oil storage tank.

The ethanol gasoline for the vehicle is a combustible liquid, the flash point of the ethanol gasoline is not more than-37 ℃ after being inquired about relevant data, and the multiple-test value of the conductivity is more than 2000 pS/m. The production, storage and transportation processes of the ethanol gasoline for the automobile are integrated, the working condition is complex, 10% of deformed fuel ethanol and 90% of component oil are mixed in an oil depot through a pipeline, and then the ethanol gasoline is directly filled into an automobile tank car and is transported to a gas station for use. The composition change in the oil depot belongs to the special working condition electrostatic dangerous liquid, should adopt comprehensive electrostatic discharge control measure, in addition to adopting conventional electrostatic discharge control measure in the practical application, still designed antistatic mixer (one kind of mitigator). There is no special working condition in the gas station, it belongs to the external static dangerous liquid, it can adopt the external static discharge control measure, it is the important thing to prevent the human static discharge.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.