Pneumatic one-way throttle valve, installed in the branch and installed in the main road, why is the effect different? (If the explanation is easy to understand, I will get extra points.)

I don't know what kind of air compressor you are talking about. Below I will provide you with some matters about the installation and operation of the screw machine for your reference!

General knowledge of air compressor pipeline installation

Use carbon steel pipe with sufficient size, so that the pressure loss on the whole gas pipe does not exceed 0.02 1MPA, and the pressure loss/loss of the compressed air pipeline system is kept at 10% (from the compressor to the farthest end). The diameter of the exhaust pipe should be at least as large as the compressor exhaust port.

1. If adjustment and control are needed, install a bypass pipe on the exhaust pipe. The bypass pipe can also be used to connect the standby air compressor.

2. Several manometers can be installed on the whole system for monitoring. Install bypass channel. The bypass passage can also be used to connect the standby air compressor.

3. Several manometers can be installed on the whole system for monitoring. Installation locations include gas storage tanks, gas distribution packages, pneumatic tools, production settings and piping systems.

4. Use elbow with radius (R & gt3~5D), and adopt ball valve or butterfly valve. To reduce the pressure drop on the pipeline.

5. The compressed air pipeline should have an inclination of 6.35MM every 0.3M, and a water valve for discharging condensed water should be installed in the middle.

6. The ideal compressed air system is annular design, with air supply and two-way airflow supply. Dendritic pipeline can also be used.

7. Annular pipeline: stable pressure at each point, small pressure difference, low flow rate, long pipeline and high energy efficiency.

8. Dendritic pipeline: the pressure at each point is relatively stable, depending on the gas consumption of the branch pipe. The pipeline is relatively short and the investment is low.

9, from the main trachea with trachea, should be as close as possible to the gas equipment. The branch pipe should be taken out from above the main pipe.

10, compressed air pipes usually use carbon steel pipes as exhaust pipes, and black iron, galvanized, copper or stainless steel pipes can also be used. But plastic pipes must never be used.

1 1, p > in the connecting pipe; 0.7MPA, preferably with flange connection.

12. Air leakage and plant expansion should be considered to eliminate the obsolescence of compressed air system.

13. The main gas pipe should be designed according to the maximum gas supply, including full-load production and factory expansion plan.

General requirements and precautions for compressor pipeline installation

1. When the total length of the workshop main pipeline is more than 200M, the internal diameter of the pipeline shall be no less than 3IN( 1IN=25.4MM) to ensure the pressure balance of compressed air and sufficient air flow.

2. The compressed air freeze-drying equipment shall be designed with standby pipelines for equipment maintenance and equipped with compressed air check ball valves.

3. When installing the annular closed main pipeline, it is recommended that the air inlet end be inclined to the farthest end of the pipeline 1 ~ 2, and the automatic or manual oil-water discharge device and oil-water collection container should be installed at the lowest end of the main pipeline.

4. The main compressed air pipeline should try to avoid sharp turns (the internal angle is less than 90); If the main pipeline needs to be fixed on the ceiling, it should avoid beams or various pipelines; When the air pipeline is U-shaped, it is suggested to install a drainage device at the bottom of the U-shaped pipeline to prevent condensed water in compressed air from accumulating at the bottom of the U-shaped pipeline.

5. When the compressed air branch pipeline is a branch of the main pipeline, a "gooseneck" connection mode should be adopted to prevent the condensed water in the main pipeline from directly entering the branch pipeline.

6. It is suggested to install an oil-water separator with enough compressed air filtration flow on each branch pipeline connected with pneumatic tools (such as SATA 0/424 oil-water separator for pneumatic tools/pneumatic equipment) to ensure the normal operation of pneumatic tools and equipment and prolong their service life.

7. In order to ensure the spraying quality, it is suggested to install a professional oil-water separator (such as SATA 0/444 standard or SATA 0/244 economical oil-water separator) with high filtering accuracy of compressed air (filtering accuracy reaches 0.0 1 micron) and large air volume (air volume reaches 3600L/MIN) in the painting room.

8. It is suggested to install a drainage device (automatic drainage valve or ball valve) at the end of the branch pipe about 90 ~ 120 cm away from the oil-water separator, so as to discharge the oil-water condensate in the pipeline at any time. This can also improve the filtration accuracy and service life of the oil-water separator.

9. In order to improve the filtration efficiency of the oil-water separator, when installing the oil-water separator, it should be as far away from the air compressor as possible, and the pipeline distance should not be less than 30M, so that the compressed air can have enough cooling time.

10. If water-based paint is sprayed, an air filtering device with activated carbon filter (such as SATA0/484 triple oil-saving water separator with activated carbon filter) must be installed, which can not only filter oil, water and particles in compressed air, but also absorb oil and water vapor in compressed air at the same time to avoid the defects of water-based paint coating.

General principles of compressed air pipeline design

Design standard of compressed air pipeline;

The pipeline system of compressed air meets the user's requirements for compressed air flow, pressure and quality, and should also be comprehensively determined from the aspects of reliable gas supply, energy saving, reduced investment and convenient maintenance. Specifically, there are the following principles:

1. Considering the pressure requirements:

When the compressed air system has two or more pressure requirements, the following can be considered:

A) The pipeline system is designed according to the highest gas supply pressure, and the pressure reducing device installed on the pipeline can meet the partial pressure gas supply.

B) According to the user's gas pressure and the layout of the workshop or equipment, several pressure levels are divided, and the gas is supplied by pipeline systems with different pressures.

2. Considering the air quality requirements:

A) With untreated compressed air pipeline system, it is necessary to purify some high-quality gases by adding post-treatment equipment on the pipeline.

B) Two sets of piping systems are designed for the whole plant. One is a general gas system and the other is an air purification system.

3. Considering the characteristics of gas consumption:

The instantaneous maximum gas consumption of some gas equipment is quite different from the average gas consumption (such as air hammer and shot blasting). ). In order not to affect the gas consumption of other equipment, a special pipeline is generally used to supply gas or an air storage tank is added near the gas consumption to buffer the load.

4. Consider energy saving:

A) When the factory uses several kinds of compressed air with different pressures at the same time, using several kinds of air compressors with different pressure grades to form pipelines with different pressure grades can effectively save energy, but it will increase the capital investment. The specific gas supply scheme should be decided after economic comparison.

B) According to the investigation, the air leakage of compressed air pipes in some factories can reach 20%, so when compressed air is only used in a few workshops and factories at a certain stage, it can be considered to supply air separately on the spot to reduce the air leakage of long pipes.

5. Consider investment and maintenance:

A) Sharing the branch piping system is beneficial to saving investment.

B) The primary radiation pipeline system centered on the air compressor station or the secondary radiation pipeline system of the intermediate gas distribution station is beneficial to the management and maintenance of the compression system and equipment.

6. Considering the reliability of gas supply:

A) The annular pipeline system can reliably supply gas and ensure the stability of each gas supply pressure. The maintenance of one pipeline will not affect the gas supply of other pipelines.

B) When it is necessary to ensure uninterrupted gas supply to all gas consumption points, a double-branch pipe system can also be used, but the investment of this system is twice that of a single-branch pipe system, so only gas can be stopped.

Installing compressed air pipeline

5. 1 General provisions

5. 1. 1 In mines, factories and construction industries, compressed air is widely used, which can be used to drive pneumatic machines and tools such as pneumatic drills, shovels, pneumatic grinding wheels, sandblasting, painting, solution mixing, powder conveying, etc. It can also be used to control automatic instruments and conduct leakage tests on pressure vessels, pipelines and valves. Compressed air has the characteristics of rising temperature, high water content, oil and dust, and can expand to do work.

5. 1.2 This chapter is applicable to the installation of compressed air pipeline in industrial pipeline engineering.

5.2 Construction preparation

5.2. 1 technical preparation

5.2. 1. 1 Be familiar with and review the design drawings and related materials;

5.2. 1.2 Investigation and analysis of original construction data;

5.2. 1.3 Prepare the construction organization design or construction scheme, clearly put forward the construction scope and quality standards, formulate a reasonable construction period, and implement the power supply such as water and electricity;

5.2. 1.4 Prepare the construction drawing budget and construction budget.

Material preparation

5.2.2. 1 Materials and equipment are confirmed to be qualified, ready and transported to the site.

When all materials from 5.2.2.2 enter the site, their varieties, specifications and appearance shall be inspected. The packaging shall be intact, and the surface of the material shall be free of scratches and external impact damage. Unqualified materials shall not be put into storage, and qualified materials shall be classified, listed and piled up.

The materials, specifications, models and quality of pipeline components and pipeline supports in 5.2.2.3 shall comply with the provisions of design documents, and shall be visually inspected according to the current national standards. Unqualified persons shall not be used.

The main instruments and equipment in 5.2.2.4 must have complete installation instructions. During transportation, storage and construction, effective measures should be taken to prevent damage or corrosion.

5.2.2.5 pipeline components and pipeline supports shall be properly kept during construction, and shall not be confused or damaged, and their color codes or signs shall be obvious and clear. Pipe components and pipe supports made of stainless steel and non-ferrous metals shall not come into contact with carbon steel during storage. For pipelines that cannot be installed temporarily, the nozzle should be closed.

Main tools

5.2.3. 1 machinery: threading machine, bench drill, electric welding machine, cutting machine, bending machine, beveling machine, grooving machine, pressure testing pump, etc.

5.2.3.2 tools: workbench, pipe wrench, hacksaw bow, pipe cutter, electric drill, electric hammer, hot-melt connecting tool, pipe wrench, hand hammer, adjustable wrench, socket wrench, ring wrench, chain pliers, elbow spring, pipe cutter, ring expander, chisel, electrode holder, oxyacetylene bottle, pressure reducer, hose, cutting torch, chain hoist and wire rope.

5.2.3.3 measuring tools: level, level, steel tape, steel ruler, angle ruler, welding inspection ruler, wire pendant, pressure gauge, etc.

Operating conditions

5.2.4. 1 Design drawings and other technical documents are complete, and the construction conditions are confirmed.

5.2.4.2 organization design or construction scheme has been approved, and after necessary technical training, technical disclosure and safety disclosure have been completed.

5.2.4.3 arranged the workshop and warehouse according to the construction plan.

The civil works related to pipeline installation in 5.2.4.4 have passed the inspection and met the installation requirements, and the handover procedures have been completed.

5.2.4.5's materials, equipment, confirmed qualified, ready, sent to the scene.

The equipment connected with the pipeline in 5.2.4.6 has been leveled, aligned, qualified and fixed in place.

Procedures that 5.2.4.7 must complete before pipeline installation, such as cleaning, degreasing, internal corrosion protection and lining, have been completed and accepted.

5.2.4.8's pipelines, fittings, instruments and valves have been checked and qualified, and relevant technical documents are available to confirm that they meet the design requirements.

5.2.4.9 pipeline, fittings, valves, etc. The interior has been cleaned and there are no sundries. The quality of pipelines with special requirements has met the requirements of design documents.

5.2.4. 10 Construction machinery related to pipeline installation has been arranged and implemented, which can meet the technical and progress requirements of construction.

5.3 Key points of material quality control

5.3. 1 Generally, welded steel pipes or seamless steel pipes are used for compressed air pipelines. When DN > 200 mm, steel plate coils are used. The pipeline valve is cut off.

Check valve, DN = 15 ~ 40mm adopts J 1 1T- 16 internal thread stop valve, and DN≥50mm adopts J4 1T- 16 flange to stop.

5.3.2 Pipe components and pipe supports must have the manufacturer's quality certificate, and their quality shall not be lower than the current national standards. 5.3.3 All materials shall be inspected for variety, specification and appearance when entering the site. The packaging shall be intact, and the surface of the material shall be free of scratches and external impact damage.

Unqualified materials shall not be stored in the warehouse, and qualified materials shall be classified, listed and stacked.

5.3.4 The materials, specifications, models and quality of pipeline components and pipeline supports shall comply with the design documents and the current national conditions.

Standard for appearance inspection, unqualified shall not be used.

5.3.5 Main instruments and equipment must have complete installation instructions. Effective measures should be taken during transportation, storage and construction.

Prevent damage or corrosion.

5.3.6 Before installing the valve, check the packing and gland bolts for adjustment allowance; And should be based on design documents, according to the media to check its model.

The flow direction determines its installation direction.

5.3.7 Valves must have the factory certificate and the nameplate of the manufacturer, and the nameplate shall indicate the nominal pressure, nominal diameter, working temperature and working time.

As a medium, etc.

5.3.8 The number of safety valve opening and closing tests shall be no less than 3 times, and the test process shall be supervised and confirmed by users and relevant departments on site.

After the test is qualified, lead seal shall be carried out, and the constant pressure record of safety valve shall be filled in.

5.3.9 Pipeline components and pipeline supports shall be properly kept during construction, and shall not be confused or damaged, and their color codes or signs shall be obvious and clear. Pipe components and pipe supports made of stainless steel and non-ferrous metals shall not come into contact with carbon steel during storage. For pipelines that cannot be installed temporarily, the nozzle should be closed.

5.4 Installation of compressed air pipeline

5.4. 1 compressed air pipeline classification

According to the classification of working pressure, it can be divided into three categories: high pressure pipeline, medium working pressure10.0 MPa; ;

Medium pressure pipeline, the working pressure of medium is1.0 ~1.0 MPa;

The working pressure of low-pressure pipeline and medium is 0.2 ~ 65438±0.0 MPa.

5.4.2 Installation requirements of compressed air pipeline

5.4.2. 1 should be laid underground, but it can also be laid on the pillar of overhead heating or gas pipeline. When laid underground, it should be laid in the same ditch as the heating pipeline as far as possible. Directly buried laying should be buried below the freezing line, and the external surface of the pipeline should be provided with anti-corrosion insulation layer, and the number of layers of insulation layer should be determined according to the corrosiveness of the soil layer. Directly buried pipelines should pass through steel or cement casing when crossing railways and important highways, and both ends of the casing should extend out of the road side1m. The gap between the pipeline and the casing should be at least 20mm, and both ends of the casing should be filled with hemp strips soaked with asphalt.

There should be more than two entrances and exits in 5.4.2.2, and the equipment and accessories at the entrances and exits should be installed in a position convenient for operation and management. The pipeline can be laid underground or overhead,

Under the premise of meeting the safety requirements, it shall be laid together with other pipelines as far as possible. The control valve shall be set at the beginning of the main pipe laid along each column.

The branch pipe is connected to one side of 5.4.2.3. For the convenience of construction, the angles of branch pipe and main pipe can generally be 90, 60, 30 and15. Water collectors should be arranged at the end and bottom of the pipeline. When the pipeline passes through the wall or floor, a casing shall be set.

5.4.2.4 pipeline connection

1 Welded steel pipe: DN≤50mm, threaded connection. The filler is white lead oil hemp or ptef; When Dn > 50 mm, welding connection should be adopted.

2 Seamless steel pipe: DN≤50mm, connected by oxygen-acetylene welding; Dn > 50 mm, electric welding connection: the steel coil is connected by electric welding.

5.4.2.5 Slope:

I = I = 0.002 ~ 0.003 downstream slope.

5.4.2.6 quality requirements:

Pipe support should be installed firmly, in the right position, without skew movement. Verticality of riser: when the length is more than 4m, the allowable deviation is 12mm, and when the length is less than 4m, the allowable deviation is 4mm. The slope deviation of horizontal pipeline shall not exceed 0.0005.

5.4.3 Installation of process piping in compressed air station

Chapter IV Installation Knowledge of Air Compressor

Installation standards and requirements

A. Installation environment layout requirements

1. In order to meet the needs of development, the overall layout of the computer room should have room for expansion.

2. The air compressor sucks air directly from the atmosphere. In order to reduce the possibility of abrasion, corrosion and explosion of the unit, the machine room must have a certain distance from the place where harmful substances such as explosive, corrosive, toxic gas and dust are emitted. Due to the large heat dissipation of the compressor, especially the high temperature inside the compressor in summer, the orientation of the machine room should make the machine room well ventilated and minimize the sunlight exposure.

3. Although the compressor has a box, it is forbidden to get wet, so the compressor should not be installed in the open air.

4. The compressor room is an independent building.

5. The compressor room must be equipped with fixed carbon dioxide fire extinguishing equipment, and its manual switch must be set outside the danger zone. And can be touched at any time. Fire extinguishing equipment Carbon dioxide fire extinguisher or dry powder fire extinguisher should be placed near the protected target, but outside the danger zone.

B. Installation requirements of computer room

1. The floor should be smooth cement floor, and the inner surface of the wall should be painted. The compressor base should be placed on the concrete floor, and the levelness of the plane should not be greater than 0.5/ 1000(mm). There is a groove about 200mm away from the unit, so that oil and water can flow out of the groove when the unit stops to change oil, overhaul or flush the ground. The size of the groove is determined by the user.

2. When the compressor unit is placed on the ground, ensure that the bottom of the box body is attached to the ground to prevent vibration and increase noise.

3. For qualified users, sound-absorbing boards can be attached to the wall of the computer room, which can further reduce the noise, but it is not advisable to decorate the wall with hard materials such as tiles.

4. Because the air-cooled compressor is greatly influenced by the ambient temperature, the ventilation of the machine room should be good and dry, and the heat exchange air can be led out of the room by air duct or exhaust fan, and the ambient temperature of the compressor should be controlled within the range of -5℃ ~ 40℃.

5. The machine room has less dust, clean air and no harmful gases and corrosive media such as sulfurous acid. According to the nature of the products processed by your company, the air inlet should be equipped with a primary filtering device. The effective area of window circulation should be greater than 3m2.

C. power supply and peripheral wiring requirements

1. The main power supply of compressor is AC (380V/50Hz) three-phase, and that of freeze-dryer is AC (220V/50HZ). Please confirm the power supply.

2. The voltage drop shall not exceed 5% of the rated voltage, and the voltage difference of each phase shall be within 3%.

3. The compressor power supply must be equipped with isolating switch to prevent short circuit and open-phase operation.

4. Check the secondary circuit fuse, and select the appropriate fuse-free safety switch according to the power of the compressor.

5. It is best to use a power system alone for the compressor to avoid parallel use with other different power systems. Especially when the compressor power is high, the compressor may be overloaded due to excessive pressure drop or unbalanced three-phase current, resulting in tripping of the protection device.

6, must be grounded to prevent leakage from causing danger, and shall not be connected to the air duct or cooling water pipe.

D, pipeline installation requirements

1. The air supply port of this unit has a threaded nozzle, which can be connected with your air supply pipeline. Please refer to the factory manual for installation dimensions.

2. In order to avoid affecting the operation of the whole station or other units during maintenance and reliably prevent compressed air from flowing back during maintenance, a cut-off valve must be installed between the unit and the gas storage tank.

3. In order to avoid affecting gas consumption during filter maintenance, spare pipes should be provided on each filter pipe.

4. The branch pipes must be connected from the top of the main pipe to prevent the condensed water in the pipe from flowing down to the compressor unit.

5. Pipes should be as short and straight as possible, and elbows and valves should be reduced to reduce pressure loss.

E. Connection and arrangement of air pipes

1, the main pipeline of compressed air pipeline is 4 inches, and the existing pipelines are used as far as possible for the branch pipelines.

2. In general, the slope of the pipeline should be greater than 2/ 1000, and the low end should be provided with a drain valve (plug). The pipeline should be less bent and the short straight valve should be minimized.

3. When the underground pipeline passes through the main pavement, the buried depth of the pipe top shall not be less than 0.7m, and the secondary pavement shall not be less than 0.4m.. ..

4. The installation position and surface size of pressure and flowmeter should enable the operator to clearly see the indicated pressure, and the scale range of pressure grade should make the working pressure at the position of 1/2 ~ 2/3 of the dial.

5. After the system is installed, air pressure strength and air tightness test shall be conducted, and water pressure test shall not be conducted. The pressure of the same gas is 1.2 ~ 1.5 times, and no leakage is qualified.

F, air pipeline anticorrosion

After the installation is completed and the pressure test is qualified, remove the dust, dirt, rust spots, welding slag and other things on the surface and use paint for anti-corrosion treatment. Pipeline painting has the functions of anti-corrosion, prolonging the service life of pipeline, being easy to identify and beautiful. Generally, antirust paint is applied to the surface first, and then the specified ready mixed paint is applied.

G, lightning protection of air pipeline

Once lightning-induced high-voltage electricity is introduced into the pipeline system and gas equipment in the workshop, it will cause personal safety accidents of the equipment. Therefore, the pipeline should be grounded before entering the workshop.

E, pipeline pressure loss

When gas flows in the pipeline, friction resistance is generated in the straight pipe section; Local resistance is generated at the valve, tee, elbow and reducer, resulting in gas pressure loss.

Description:

The total pressure drop of the pipeline part should also add the pressure loss caused by elbows, reducers, tees and valves. These values can be found in the relevant manuals.

H. Ventilation of air compression system of compressor

Whether users use oil-free machine or oiler, whether users use air-cooled compressor or water-cooled compressor, they must solve the ventilation problem of air compressor room. According to our past experience, more than 50% of air compressor failures are due to negligence or misunderstanding in this respect.

In the process of air compression, a lot of heat will be emitted. If the heat cannot be discharged from the air compressor room in time, the room temperature of the air compressor room will gradually increase, so that the temperature of the air inlet of the air compressor will be higher and higher. This vicious cycle will cause the exhaust temperature of the air compressor to be high and alarm, and at the same time reduce the gas production because of the low density of high temperature air. For the water-cooled compressor, most of the heat is transferred to the cooling water through the heat exchanger, and the cooling water takes away the heat. At this time, only a small ventilator is needed to take away a small part of the heat generated by the main motor. For an air-cooled compressor, a large amount of fresh air is needed to exchange the heat generated in the compression process, so it is necessary to consider the inlet of fresh air, which should be close to the cooling air inlet of the air compressor (the air inlet of the compression part should also be close to the fresh air inlet). If necessary, a separate air duct can be set to introduce fresh air to avoid the hot air in the air compressor room from affecting the refrigeration process. Of course, it depends on the structure of the air compressor room and the customer's situation. Generally speaking, it is necessary to set an air duct to guide the hot air after heat exchange out of the air compression chamber, and if necessary, set a fan or fan at the outlet to enhance the export effect of hot air. The fresh air inlet mentioned above should be set at the low position of the air compressor room, and the hot air outlet (including the corresponding fan or blower) should be set at the high position. Because of the low density of hot air, it usually stays at the high position, which is beneficial to the hot air outlet and prevents the discharged hot air from entering the air inlet again and causing short circuit of air flow. In addition, it should be noted that the fresh air inlet and hot air outlet are preferably arranged on two opposite walls, which is also to prevent the exhausted hot air from entering the air inlet again and causing short circuit of air flow. It is best to set up a dustproof net at the entrance of fresh air to prevent more dust or catkins from entering the air compressor room, and it is best to set up a rain cover at the exit of hot air to prevent rainwater from flowing into the exhaust duct. Whether it is the air duct at the air inlet or the air duct at the air outlet, it is necessary to avoid large diameter reduction or elbow, because this will cause greater ventilation resistance and affect the ventilation effect. Because the air in the air compressor room is constantly used for compression and cooling, and the supplement of fresh air is generally passive, it is normal to maintain a certain negative pressure in the air compressor room. However, if the negative pressure value exceeds the allowable value, it means that the size of the air inlet or the air intake volume needs to be increased, because too large negative pressure value will lead to poor cooling effect and reduced exhaust volume. Although the above content is relatively simple, it is very important. If we can do a good job in this area with users, we will rule out the possibility of 50% failure, so it is very worthwhile for us and users to spend more energy in this area.

Selection of installation site

1, the choice of the installation site of air compressor is the most neglected by the staff. Often, the air compressor will find a place at will after purchase, and then it will be used immediately after piping. There is no plan before. I don't know that such a hasty result will lead to air compressor failure, difficult maintenance and poor air quality in the future, so a suitable installation site is a prerequisite for the correct use of air compressor system:

(1) Choose a wide and well-lit place to facilitate the space and lighting required for operation, maintenance and repair.

(2) Choose a place with low air humidity, less dust, fresh air and good ventilation to avoid water mist, acid mist, oil mist, dusty and multi-fiber environment.

(3) According to the requirements of GB50029-2003 Code for Design of Compressed Air Stations, the heating temperature between machines in the compressed air station should not be lower than 15℃, and the temperature between machines during non-working hours should not be lower than 5℃.

(4) When the air inlet of the air compressor or the cooling air outlet of the unit is set indoors, the indoor ambient temperature should not be greater than 40℃.

(5) If the factory environment is poor and there is much dust, pre-filtration equipment must be installed to ensure the service life of air compressor system components.

(6) When the displacement of a single compressed air station is equal to or greater than 20m3/min and the total installed capacity is equal to or greater than 60 m3/min, lifting equipment for maintenance shall be provided, and its lifting capacity shall be determined according to the heaviest component of the air compressor unit.

(7) reserved access and maintenance space. According to GB50029-2003 Code for Design of Compressed Air Stations, the channel width between the air compressor unit and the wall is 0.8 ~ 1.5m according to the displacement.

2. Matters needing attention in compressed air pipeline and piping

(1) When piping the main pipeline, the pipeline must have an inclination of 1 ~ 2 to facilitate the discharge of condensed water in the pipeline, as shown in Figure 1 and Figure 2.

(2) The pressure drop of the piping line shall not exceed 5% of the service pressure of the air compressor, so it is best to choose the pipeline greater than the design value when piping, and its calculation formula is as follows:

Diameter calculation d = mm = mm

Q pressure-the flow of compressed air in the pipeline, m3/min.

V-velocity of compressed air in the pipeline, m/s.

Q scalar m3/min on nameplate of self-contained air compressor

P Exhaust-Air compressor exhaust absolute pressure bar (equal to air compressor exhaust pressure plus 1 atmospheric pressure)

(3) The branch pipes must be connected from the top of the main pipe to prevent the condensed water in the main pipe from flowing down to the working machine or back to the air compressor.

(4) Don't shrink or expand the pipeline at will, and use a reducer for the pipeline, as shown in Figure 2. If the reducer is not used, turbulence will occur at the joint, which will lead to a large pressure drop and adversely affect the service life of the pipeline.

(5) After the air compressor, if there are purification buffer devices such as air storage tanks and dryers, the ideal piping sequence should be air compressor+air storage tanks+dryers. The gas storage tank can filter out part of condensed water and also reduce the gas temperature. Re-introducing compressed air with lower temperature and less water content into the dryer can reduce the load of the dryer.

(6) If the gas consumption is large and the time is short, it is best to install an air storage tank as a buffer, which can reduce the loading and unloading times of the air compressor and is of great benefit to the service life of the air compressor.

(7) Minimize the use of elbows and various valves in the pipeline.

(8) The ideal piping is that the main pipeline surrounds the whole plant, so that compressed air in two directions can be obtained at any position. If the gas consumption of a branch line suddenly increases greatly, the pressure drop can be reduced. In addition, the annular main pipeline should be provided with a suitable valve group for cutting off during maintenance.

(9) When the air output pipes of multiple air compressors are connected in parallel, there is no need to install a check valve at the output end of the air compressors.

3. Foundation of air compressor

The foundation of air compressor should be built on hard soil, and the foundation elevation should be leveled before installation to avoid vibration. If it is installed upstairs, anti-vibration measures must be taken, otherwise the vibration will spread to the downstairs or produce * * * vibration phenomenon, which will easily cause harm to the air compressor and buildings. Generally, the vibration speed of screw air compressor is below 1 1.2mm/s (belt drive) and 7. 1 mm/s (coupling drive), so it is unnecessary to make a special foundation. It is suggested to build a platform foundation with a height of about 120mm and a length and width slightly larger than the bottom area of the air compressor to facilitate sewage discharge.

4. Cooling system

The water quality standard of cooling water of water-cooled air compressor shall comply with the provisions of GB50050 Code for Design of Industrial Circulating Cooling Water Treatment. When the enterprise has softened water available and the system is economical and reasonable, softened water can be used as circulating water in the system. Mainly to prevent calcium and magnesium plasma in water from reacting chemically in the cooler due to high temperature, and finally form scale in the cooler, thus affecting the cooling efficiency of the cooler. The water pressure of cooling water is generally between 0. 15 ~ 0.4 MPa, and the outlet temperature of cooling water should be kept between 6 ~ 10℃ higher than the inlet temperature. The cooling water inlet pipe should be equipped with a filter screen, and the inlet and outlet pipes should be equipped with a pressure gauge, a thermometer and a stop valve respectively.

Air-cooled air compressor should pay attention to its ventilation environment, and should not be placed near high-temperature machinery or in a closed space with poor ventilation to avoid shutdown due to high exhaust temperature. If it is placed in a confined space, it must be equipped with air intake and exhaust equipment. The air inlet is located at the lower part of the machine room, and the air outlet is located at the upper part of the machine room, which is convenient for cold air circulation. Generally speaking, its intake and exhaust air volume must be greater than the cooling exhaust air volume of the air compressor.

5. Power system

When the air compressor distributes power, it must ensure the correctness of the power supply voltage.

According to the power of the air compressor used, choose the correct power cord diameter, and don't use a small power cord, otherwise the power cord will be burned due to heavy load and high temperature. The power cord should be multi-stranded copper core cable, and one of the three-phase four-wire systems should be ground wire.

It is best to use a power system alone for air compressors, especially to avoid using it in parallel with other power systems, otherwise the main motor of air compressors may be overloaded and shut down due to excessive voltage drop or unbalanced three-phase current, especially for high-power air compressors. And the power supply network load should be uniform, the voltage fluctuation should be within 5%, and the three-phase voltage imbalance should be allowed within 65438 0%. There can be no connection point in the middle of the power supply cable from the distribution cabinet to the air compressor.

According to the power of the air compressor, the appropriate air switch is selected to maintain the safety and maintenance of the power system.

The grounding wire of the power system shall be erected, and the grounding wire shall not be directly connected with the compressed air delivery pipe or the cooling water pipe.

6. Appendix

1kW is equivalent to 2 amps rated current, and 1mm2 copper wire can pass 4 ~ 6 amps current.

Specification of ordinary wire (rubber copper wire) (number of cores × section mm2+ number of cores × section mm2)

3× 10+ 1×6、3× 16+ 1× 10、3×25+ 1× 10、3×35+ 1× 10

3×50+ 1× 16、3×70+ 1×25、3×95+ 1×35

The supporting capacity of low-voltage 380V transformer is 3 times of the rated capacity of motor, and that of high-voltage 6000V transformer is 2 times of the rated capacity of motor.