Safety issues to be aware of when installing chemical instrumentation automation equipment

Safety issues to be aware of when installing chemical instrumentation automation equipment

Fan Lei Shanxi Delixin Electronic Technology Co., Ltd.

Abstract: A brief description of the safety issues that should be noted when installing chemical instrumentation automation equipment. The key points are discussed from the three aspects of construction preparation stage, construction stage and commissioning handover stage. The safety of installing chemical instrument automation equipment can also be simply summarized as human safety, equipment safety, production safety and environmental safety. In order to ensure the continuity of chemical production and long-term safety, stability, high efficiency and low consumption operation, automatic design and installation is especially important.

Keywords: chemical instrumentation; automation equipment; safety; construction

The so-called instrument installation is to make the instrument body, pipeline, cable, auxiliary equipment, etc. into a loop or system according to the design requirements, to complete the acquisition of the state detection signal of the measured object or the adjustment task of the control signal to the adjusted object. That is to say, the instrument installation is based on the design requirements, between the instrument and the instrument, the instrument and process equipment, the instrument and process pipeline, the field instrument and the central control room, the field control room. This connection can be piped (such as measuring pipes, pneumatic pipes, heat pipes, etc.) or cable connections (including power and signal cables), which are usually a combination of these two connections.

The instrument installation is generally divided into three phases, namely the construction preparation phase, the construction phase, and the commissioning handover phase.

1 construction preparation stage

In the construction preparation stage, a special instrument automation installation project department is generally established. Specialized personnel are responsible for data preparation and material supply work, and organize installation personnel to learn drawings, installation techniques and installation safety knowledge. In addition, various tools, standard calibration instruments, and instrument calibration tables for installation must be prepared in advance. All kinds of installation materials should be prepared. The detailed scientific self-control professional construction plan should be prepared to ensure the safety and quality of the construction. In terms of material supply, all kinds of instruments and equipment should be carefully self-tested, and the self-inspection should be completed and filled out. Installation tools and consumables must be of sufficient quality and quantity.

2 construction stage

In addition to ensuring the quality of the installation and the progress of the project, safety work is a top priority. In order to ensure the personal health and safety of the installer and the safe application of the instrument automation equipment, the following principles must be observed:

(1) Installers should wear personal protective equipment when installing. Including insulated non-slip shoes, helmets, as well as climbing the seat belt and handling the corresponding ascending work permit, the climb operation generally chooses no wind or small wind during the day, and select the appropriate personnel to climb, with special supervision.

(2) The instrument installer should be familiar with the instrumentation and instrumentation and the safety knowledge of electrical and toxic liquids and gases.

The specific work of the instrument installation and construction phase is divided into the following steps:

(1) The overall installation requirements of the bridge are horizontal and vertical, neatly arranged, and there is room for operation between the buildings and the distance between the buildings. When the bridge frame is welded, the welding should be firm and the bridge frame should not be deformed. The installation work of the bridge frame should pay special attention to safety problems. When installing in high-altitude pipelines or places with inflammable and explosive objects, the safety rules for high-altitude operations should be observed. And regulations for inflammable and explosive places. The power tools used, electrical equipment, and the grounding of the casing should have strict insulation measures. Do not insert the wire directly into the socket without a plug.

Pay attention to electricity safety, prevent high altitude from falling during welding, prevent welding burns, and pay attention to protect workers' eyes.

(2) According to the process flow chart with control points, find the position of each instrument, open the welding on the equipment pipeline or connect with flange bolts, pay attention to the installation of instruments and accessories, the instrument can be equipped with various instrument pipelines, including pressure Pipe, gas source pipe, cable threading pipe, etc. The field instrument protection box, intermediate junction box, and power box can also be installed and piped at the same time. All of these should be installed in accordance with the construction drawings and in accordance with the requirements of the construction and acceptance specifications of the automated instrument installation engineering. At the same time of on-site installation, make various records, including adjustment records and installation records of various instruments. It is not allowed to install, inspect, inspect and debug the instrument cabinet with electric power. If necessary, wear insulated shoes and gloves, and it must be operated by 2 people. It is not allowed to place equipment, lines and pipes that interfere with the sensitivity of the meter around the instrument (disk), and it is not allowed to store chemicals that generate corrosive gases. Keep the workplace clean and airy. The adjustment of the mercury-filled meter should be carried out away from the concentration of personnel. Do not blow or use direct mouth contact with mercury. The mercury surface must be covered with a layer of water. Dedicated equipment and tools used. Single tube, U-tube pressure gauge, etc., should be properly kept to prevent breakage, and the surface of mercury should be sealed with water or glycerin to prevent evaporation.

Safety precautions to be taken after the instrument is installed in place:

(1) Fasten the foundation bolts to prevent tipping.

(2) When multiple dashboards are in parallel. Fingers must not be placed at the joint.

(3) It is strictly forbidden to place tools and other objects on the top of the plate and on the meter.

(4) When opening a hole with a hole saw, no one should come close behind the plate.

(5) When installing the orifice plate at high altitude, it is necessary to set up the shelf, and it is not allowed to sit on the pipe to open the hole and the saw pipe.

(6) It is forbidden to open holes in the medium and the pressurized pipe.

(7) The AC and DC power supply and voltage level used for the calibration instrument shall be clearly marked.

(8) When using hydraulic equipment, the automatic temperature regulator should be normal and reliable, and the heating temperature must not exceed the ignition point of the oil used. Do not open the top cover when heating to prevent burns.

When the field instrument and bridge, various pipelines and instrument panels are installed in place, the cable is laid and calibrated, and the cable connection between the instrument and the control room and the field control cabinet is completed. When laying cables on the bridge, the "safety regulations for high work" should be observed. The climbing brackets should be stable, the rotation should be flexible, the bars should be prevented from falling off and dumped, and the nails on the wooden shaft cylinders should be bent or unplugged. When turning, stand on the outside to prevent crushing. Cable laying generally requires no intermediate joints. If it is unavoidable, it should be wired in the connection box or the threading box. Cables and cables must be inspected for cable laying and must be well insulated. Do not allow moisture and excessive temperature around the wires. After passing the test, mark it and wire it as shown. The cable should be attached to the control room.

3 test car handover stage

The test consists of three stages: single test, combined test and chemical test.

Before the unit test, it is generally necessary to carry out the test of each test point. After the completion of the test, the unit test is started. When the process equipment is installed, the process pipeline is pressure tested and purged, and the project enters the monomer test phase. The main work of the unit test phase is to test the drive equipment test operation equipment, only some test instruments are applied, and most of them are local indication instruments, such as pump outlet pressure indication, bearing temperature indication, etc. When the large-scale operation equipment is tested, the instrument is more complicated. In addition to the local indication instrument, the signal, alarm and interlock system must also be put into operation, and it is also controlled by the local instrument panel or smart meter and strong program controller. Important compressors are also subject to anti-surge and shaft displacement control. In the monomer test process, the focus is to prevent the instrument from exceeding the limit measurement damage to the instrument. The safety threats of the test crew are mainly caused by high-altitude falling objects, bruises, electric shock or mechanical damage caused by multiple types of work. When testing the interlock system, care should be taken to prevent personnel safety and equipment safety problems caused by interlocking. The linkage test is carried out on the basis of the success of the single test, and the moving equipment, static equipment and pipeline of the whole device are connected. At this stage, in principle all automatic control systems must be put into operation. The local display meter is fully invested, and the control room instrument (or DCS) is also mostly invested. The automatic control system is manual, and when the system is balanced, it is transferred to automatic. Except for the individual liquid level system, all flow systems, liquid level systems, pressure systems and temperature systems are put into operation. During the joint commissioning phase, pay attention to the key equipment equipped with professional instrumentation, keep the test communication unblocked, and formulate detailed test plan to prevent unnecessary damage to the test personnel safety and equipment and instruments. Since the construction site has not yet been fully put into operation, some construction sites are inevitably not fully installed, such as guardrails. At this time, the test crew should pay attention to their personal safety.

Feeding is the key to commissioning. Instrumentation should be fully coordinated. The instrumentation of the construction unit has taken over the instrumentation of the construction unit and entered the site. With the progress of the chemical test, the automatic control system is put into operation one by one until all the instruments are put into normal operation. After the feeding, the construction unit instrumentation only participates in the chemical test run as a bodyguard, and the specific operation and elimination of possible failures are all completed by the instrumentation of the construction unit. Feeding should be taken to prevent the capacity and pressure of the equipment from being within the safe range.

In general, the installation of chemical instrumentation automatic instrumentation equipment requires both the construction quality and the construction schedule to be compatible with the construction progress of the general project. The priority of the re-ordering is safe work, including human safety, equipment safety, installation and after commissioning. The entire system is safe and reliable. The focus of human safety is to prevent electric shock, fall from high altitude, prevent poisoning, and prevent mechanical damage from electric equipment.

Construction Industry Roll Forming Line

Steel Rolling Machine,Construction Roll Forming Machine,Construction Industry Roll Forming Machine,Construction Industry Roll Forming Line

Xinxiang Tianfeng Machinery Manufacture Co., Ltd. , http://www.tfrollforming.com

Posted on