月: 2022年12月

What Is a Turbine Flowmeter?

A turbine flowmeter measures the flow rate by the rotation of an impeller within a pipe, typically applied to liquids in industrial and process control settings. Known for high measurement accuracy, especially in moderate to high flow ranges, turbine flowmeters have wide flow range capabilities and are durable across various fluid types and conditions. However, they are not suitable for viscous fluids or those containing solids.

Uses of Turbine Flowmeters

Turbine flowmeters find applications across several industries:

1. Petroleum Industry

Used in oil and gas distribution, refining processes, and trade metering, turbine flowmeters provide precise measurements essential in these sectors.

2. Food and Beverage Industry

In food processing and beverage manufacturing, they are integral for controlling metering and mixing processes and dosing food additives.

3. Heating and Air Conditioning Industry

Turbine flowmeters in heating and cooling systems ensure proper heat exchange by measuring water or refrigerant flow rates, contributing to energy efficiency and comfort.

Principle of Turbine Flowmeters

The operating principle involves an impeller rotated by fluid force, with rotational speed correlating to the volumetric flow rate. Speed is detected by sensors or magnetic elements, with data converted to flow rate by computers or displayed on units for monitoring and control.

Types of Turbine Flowmeter

Turbine flowmeters are categorized based on impeller type:

1. Axial Impeller Type

Fluid flows axially through the turbine blades, offering a compact design, high accuracy, and responsiveness.

2. Tangential-Flow-Impeller Type

With impellers arranged in an arc, the fluid flows tangentially, transferring kinetic energy to generate rotation. These meters are robust, durable, and ideal for high flow ranges.

What Is a Frequency Discriminator?

A frequency discriminator is a circuit and device that cuts the noise portion of an electrical signal.

This device can also convert frequency variations into corresponding amplitude changes, which is a fundamental principle in FM radio broadcasting.

When plotted with input frequency on the horizontal axis and output voltage on the vertical axis, the characteristic curve of a frequency discriminator resembles an ‘S’ shape.

Each frequency discriminator value can be set from 0V to 10V in 0.01V increments. It can also be turned off if necessary.

Uses of Frequency Discriminators

A frequency discriminator is used to exclude noise from the actual measurement result, such as in detection systems for abnormalities in manufacturing and detection systems for samples with minute changes in research and development.

For example, in manufacturing, it is used in systems to detect standard arc welding in welding spatter. In biochemical research, flow cytometers use frequency discriminators to evaluate cells and bacteria, avoiding the output of unwanted cell fragment information.

Principles of Frequency Discriminators

The discriminator can be set to any voltage pulse. When the voltage of the set voltage pulse exceeds the exclusion threshold, the voltage pulse is captured by an analog-to-digital converter and converted into a numerical value. Typically, there are eight different voltage settings. If none of the set values exceed the exclusion criteria, it is judged as noise, and no data is captured.

When used in a flow cytometer, cells other than those to be evaluated may be present. To avoid detecting such cells, it is necessary to set voltage pulses specific to the substance to be measured.

In FM demodulation, the discriminator plays a crucial role by converting frequency variations of the radio wave into amplitude changes, which are then processed to retrieve the original audio signal.

What Is a Tensioner?

A tensioner is an adjustment device used to prevent slack in drive chains and belts.

Tensioners provide constant tension to the chain or belt, preventing it from falling off, damaging peripheral parts, or deteriorating transmission efficiency due to slack.

Tensioners are used in combination with sprockets and chain guides for chains, and with pulleys for belts, to prevent resistance to rotation. They are broadly classified into two types: those that adjust the tension on a case-by-case basis and those that automatically adjust the tension to an appropriate level.

Uses of Tensioners

Tensioners are mainly used to adjust the tension of automobile fan belts, air conditioner belts, and timing chains.

Since fan and air conditioner belts are made of rubber, they stretch during use. If left unchecked, this can result in high-frequency noise due to belt slippage, inadequate alternator power generation due to deteriorated transmission efficiency, and insufficient cooling of the air conditioner. Providing tension with a tensioner can solve these problems.

Also, by limiting the range of motion of the tensioner, it is possible to determine the limit of belt/chain elongation when slack occurs, even after adjusting the tensioner to its maximum value.

Principles of Tensioners

There are two main types of belt tensioners: manual and automatic, which use hydraulic pressure or spring tension.

In the case of manual tensioners, the pulleys and gears are adjusted up or down with bolts and nuts to set the belt to the desired tension, offering the advantage of being less expensive than automatic tensioners.

In the case of automatic tensioners, the tension is continuously adjusted to an appropriate level by hydraulic pressure or spring tension. This saves maintenance time and is particularly useful for parts like timing chains that are not exposed and difficult to adjust manually.

Additionally, tensioners that incorporate a hydraulic anti-return mechanism minimize tension fluctuations caused by hydraulic pulsations.

Manual adjustment of tensioners requires careful attention to avoid noise from insufficient tension or belt breakage due to over-tensioning. In contrast, auto tensioners avoid these issues, though they are more expensive. When replacing a tensioner, often other parts like chain guides and pulleys must also be replaced. If a tensioner with an anti-return mechanism is removed during belt or chain replacement, it cannot be reused as it is stretched to the limit and will not return.

What Is a Torque Tester?

Torque testers are testing devices that measure torque (unit: Nm in SI units), which is the force in the twisting direction.

There are general-purpose torque testers that measure the torque generated by installing a workpiece on a table and specialized torque wrench testers that inspect and calibrate torque wrenches used as tools.

Some companies can inspect and calibrate torque wrenches on your behalf and issue the various necessary documents in about one week.

Some general-purpose torque testers are manual testers in which the workpiece is fixed to a base, and the torque generated is measured by rotating the workpiece by hand.

Uses of Torque Testers

Torque testers are used primarily for the inspection and calibration of torque wrenches, for measuring the torque generated in laboratories, and when the torque of a product is an important quality parameter for manufacturers. We also have experience delivering torque testers to electric power companies, where strict control is required.

For example, purchasing a testing machine can be expensive when inspecting and calibrating torque wrenches. Still, if an agent performs the testing, the cost is several thousand yen to several tens of thousands of yen, with all necessary documentation, and can be done in a few days (3 to 10 days).

Principles of Torque Testers

A general-purpose torque tester has a torque sensor installed on a pedestal, and wiring and a touch panel are arranged so the sensor can output to a specified PC or other devices.

Torque testers can organize the output from the sensor (torque meter) section over time. For example, a graph that displays torque on the vertical axis and time on the horizontal axis can be created.

It is also possible to organize the hysteresis of the hydraulic torque. For example, a graph can be created displaying pressure on the vertical axis and torque at the output on the horizontal axis. The difference between multiple hydraulic operations and the theoretical value can be displayed to determine whether hydraulic pressure needs to be inspected or calibrated.

Torque testers dedicated to torque wrenches are more specialized, and some are automated from measurement to calibration by simply placing the torque wrench in the designated mounting area.

Torque testers dedicated to torque wrenches need to confirm the vendor’s torque tester specifications when the agent performs calibration. There are limitations depending on the equipment and operating systems, such as the corresponding torque measurement range and accuracy and the number of torque points to be measured.

What Is a Sodium Lamp?

Sodium lamps are lamps that emit light through an arc discharge in sodium vapor, which has a high vapor pressure.

Arc discharge is a phenomenon in which plasma is generated and electricity flows in a non-conductive gas. Sodium lamps are characterized by their warm orange light and boast higher luminous efficacy than mercury lamps.

They are also sometimes used for road lighting due to their long life and excellent transmittance performance. However, with the advent of LED lighting, which consumes less power and has a longer life, demand for sodium lamps is declining.

Uses of Sodium Lamps

Figure 1. Sodium lamps and visibility

Sodium lamps are often used in roadway, industrial, and commercial lighting applications to save energy. The most famous example is tunnels. Since visibility in tunnels is impaired by exhaust gases and dust, orange-colored sodium lamps, which are less susceptible to these effects, have been used since around the 1960s.

The demand for sodium lamps has been on the decline as regulations on automobile exhaust emissions have been tightened, visibility in tunnels is no longer reduced, and LED lighting has become more widely used. However, because the light from sodium lamps does not easily attract insects due to their nature, they are in high demand as lighting in industries where insect infestation can be a serious problem, such as the food and manufacturing industries.

Principle of Sodium Lamps

Sodium lamps are classified into three types according to their vapor pressure: low-pressure, high-pressure, and high-pressure sodium lamps with high color rendering.

1. Low-Pressure Sodium Lamps

Figure 2. Structure of a low-pressure sodium lamp

The pressure of the enclosed sodium vapor is very low, around 0.5 Pa, and contains trace amounts of neon and argon as light emitting aids. It has the longest history among sodium lamps, and its luminous efficiency is up to 180 lm/W, which is higher than LEDs.

However, they also have drawbacks, such as a monochromatic orange light that makes red objects appear black and a short life span.

2. High Pressure Sodium Lamps

These lamps have improved the color rendering properties of low pressure sodium lamps and are filled with sodium vapor pressure of 0.1 atm. They contain a small amount of xenon as an auxiliary agent for luminescence, and a special alumina ceramic is used for the light-emitting tube to prevent damage even under high temperature and high pressure conditions. Not only is the color rendering property improved, but the luminous lifetime is also about three times longer.

3. High-Pressure Sodium Lamps With High Color Rendering

Compared to high pressure sodium lamps, the vapor pressure of these lamps has been raised to about five times that of high pressure sodium lamps. The color rendering property is greatly improved, resulting in warm lighting similar to that of incandescent lamps.

Although the luminous efficiency is lower than that of other sodium lamps, it is still more than three times more efficient than incandescent lamps.

Other Information About Sodium Lamps

1. Why Sodium Lamps Are Less Likely to Attract Insects

Figure 3. Emission wavelengths of sodium lamps

Insects are attracted to ultraviolet light. Sodium lamps emit light at a wavelength of only around 590 nm and emit a monochromatic yellow light. In other words, the light is imperceptible to insects, making it difficult for insects to be attracted to the lamps.

Because of their monochromatic emission, sodium lamps are not suitable for use in places where color information is required for visual inspections, but they are suitable for use on farm roads and other places where you do not want to attract insects. 

2. Points to Keep In Mind When Replacing Sodium Lamps

With the discontinuation of mercury lamps, which emit light based on the same principle as sodium lamps, sodium lamps are being replaced by LEDs. However, sodium lamps have several characteristics due to their emission color.

It is important to select lighting that is appropriate for the site where it will be used, rather than simply substituting white LEDs with a focus on energy savings alone. In recent years, LEDs that reproduce the color temperature of sodium lamps have been developed, so such LEDs should also be considered.

What Is Thread Grinding Machinery?

As the name implies, thread grinding machinery is a machine tool for grinding screws. Screws are produced by grinding a specified groove in a metal material called “threading.” Thread grinding machinery is used to perform this process. Therefore, it is an indispensable machine tool for manufacturing screws.

Uses of Thread Grinding Machinery

Thread grinding machinery is a machine tool used to perform a process called “threading,” which is necessary when manufacturing screws.

Threads are created by either “rolling” or “cutting.” Each method is introduced below.

• Thread Rolling: Thread rolling is a method developed for the mass production of screws. As the name implies, a groove is dug by rolling the material between dies. This method utilizes plastic deformation, meaning the material will not return to its original shape if a certain amount of force is applied.
• Cutting: Cutting is the method used in thread grinding machinery. This method also literally digs thread grooves by cutting away metal. It is highly accurate, and many screws are made using cutting. The disadvantage is that cutting scraps are produced due to the grinding process.

Principles of Thread Grinding Machinery

This section describes the production of screws by cutting. As mentioned above, cutting is a method of manufacturing screws by grinding metal. The most significant advantage of cutting is that it is highly accurate. Rolling is a plastic deformation method by pressing a die, so the accuracy depends on the temperature at the time and the durability of the die, which can make it difficult to achieve accuracy. With cutting, each piece can be machined to an accuracy of a few millimeters so that accuracy can be significantly achieved. For this reason, screw machining by cutting is used for small-lot production and prototyping that requires precision. However, it is unsuitable for mass production because it produces chips requiring more processing than thread rolling. Thread grinders are machine tools that can produce considerable accuracy by automatically grinding screws.

What Is a Valve Actuator?

A valve actuator is a device used to automatically open and close control valves as part of the automatic control systems in chemical plants, air conditioning equipment, and more, to regulate the flow of fluids.

Valves equipped with these actuators as their driving mechanism are often referred to as automatic valves, and when they are electrically operated, they are known as electric valves.

Valve actuators are available in pneumatic, electric, or hydraulic drive systems, but the pneumatic type is the most commonly used due to its simple structure and high output capacity.

Uses of Valve Actuators

Valve actuators find wide application in machinery requiring automated fluid control.

A typical example is the variable valve lift mechanism used in automotive engines, which adjusts the volume of air in the engine by opening and closing intake valves based on engine speed. This enhances ignition performance, mitigates excessive combustion, reduces environmental impact, and improves fuel efficiency.

Additionally, there are valves with straightforward on/off functions, such as those used in automated restroom faucets triggered by sensors.

Principle of Valve Actuators

Pneumatic valve actuators employ compressed air to pressurize and drive a piston inside the actuator. This converts the piston’s motion into rotational or vertical movement of the drive shaft, thereby controlling the opening and closing of the valve and regulating fluid flow. Removal of pressure causes the piston to return to its initial position, moving the valve in the opposite direction. A device known as a positioner is used to adjust air pressure.

This type of actuator features a simple structure with few control components and is suitable for repetitive use. However, it may not provide precise control, and it requires high-pressure air for operation.

Electric valve actuators operate by converting electrical energy into rotational and vertical movement of the actuator. Unlike pneumatic actuators, electric actuators offer precise control as they directly govern valve opening and closing. They require only an electrical power source for operation.

What Is a Palletizer?

A palletizer is a machine used to arrange products on pallets for shipping and storage.

Products manufactured for commercial use in factories are either stored in-house or shipped to customers. Storing large quantities of products efficiently in a limited space often involves stacking them vertically. However, manual stacking is labor-intensive and time-consuming, requiring items to be removed from the top to access those at the bottom.

Palletizers solve this problem by enabling the vertical stacking of products in smaller units, facilitating efficient logistics.

Uses of Palletizers

Palletizers are employed to load various types of cargo onto pallets. Common examples include corrugated cardboard boxes filled with various products, as well as bags of fertilizers, flour, one-ton cans, cylindrical cans, and items of various shapes and sizes.

For production lines that manufacture large quantities of a single product type, simple mechanical palletizers are utilized due to their high-speed capabilities. In contrast, for lines producing small quantities of diverse products, robotic palletizers are favored for their ability to stack items of various shapes.

Features of Palletizers

Different types of palletizers exhibit distinct features and mechanisms.

Mechanical palletizers, as mentioned earlier, excel at stacking a limited variety of products at high speeds. These machines repetitively perform the same operation, resulting in neatly arranged pallets even at high speeds. However, their layout flexibility is inferior compared to robotic palletizers. To minimize arm mobility while maintaining safety, mechanical palletizers often employ crank arms. These arms come in two main types: the suction type and the low-floor drop-in type. The suction type palletizes products by gripping them at one or two points, while low-floor drop-in type palletizers can load products without the risk of them falling.

On the other hand, robotic palletizers, as previously mentioned, can be programmed to stack items based on their shape. While arm movements are restricted through programming, similar to human range of motion, they are confined to fixed paths. In many cases, safety fencing is installed around the robotic arm to ensure safe operation even if the arm moves outside the designated area.

What Is a Hand Grinder?

A hand grinder is a tool used for grinding, employing a high-speed rotating grinding wheel. It typically features a motor and a speed controller to adjust the rotational speed, enhancing grinding precision. Various grinding wheels and abrasives can be chosen based on the desired sharpness and finish.

Hand grinders are utilized for resharpening blades and tools, smoothing welding surfaces, and finishing metal cuts. Electric hand grinders require a power source.

Uses of Hand Grinders

1. Sharpening Blades and Tools

Hand grinders are used to sharpen knives, scissors, drill bits, and other tools, as well as to polish surfaces of metal, plastic, glass, and ceramics.

2. Deburring and Finishing

They are also used for deburring and finishing welded and cut surfaces of steel, aluminum, stainless steel, and other metals.

3. Rust Removal

Additionally, hand grinders are effective for removing rust from metal parts and preparing surfaces for painting.

How to Use Hand Grinders

Using a hand grinder involves the following steps:

1. Preparation

Prepare and, if necessary, secure the material. Choose and attach the appropriate grinding wheel for the task to the hand grinder.

2. Start the Grinding Process

Begin the grinding process by contacting the material with the rotating hand grinder. Adjust the grinding direction based on the material’s strength and shape.

3. Continue Grinding

Adjust grinding conditions as needed, moving the grinder along the material. Ensure to cut perpendicularly to the surface with uniform pressure.

4. Finishing

Finish the surface after grinding. The finish and surface roughness depends on the grinding wheel and abrasive particle size used.

5. Dust and Debris Disposal

Dispose of the dust and debris generated during grinding. Remove any remaining debris from the material.

Features of Hand Grinders

Advantages

Electric hand grinders, with their high-speed rotating wheels, offer faster, more efficient grinding than manual methods. The constant rotation speed results in precise grinding and superior finish quality. Additionally, their ease of operation makes them accessible to beginners, and the ability to change grinding wheels allows for versatile grinding tasks. Their compact, lightweight design facilitates easy transportation, storage, and use.

Disadvantages

The high-speed rotation of hand grinders can cause noise and vibration. They also produce dust and debris, potentially containing hazardous substances, necessitating appropriate safety measures. Manual operation may lead to uneven pressure application and variability in finish quality, limiting cutting accuracy for fine or precision tasks.

Other Information on Hand Grinders

1. Classification by Power

Hand grinders are classified into electric-powered and manual types. Electric grinders offer higher efficiency and accuracy but may generate noise and vibration. Manual grinders, operating at lower speeds, are suited for detailed work. Electric models require a power source and are typically used indoors or where power is available. Battery-powered options offer cordless convenience for outdoor use or where no power supply is available.

2. Types of Grinding Wheels

Grinding wheels for hand grinders include silicon carbide, alumina, and diamond types, each selected based on the material and intended task.

3. Types of Abrasives

Abrasives for hand grinders also vary, including diamond, silicon carbide, and alumina options, chosen according to the material and specific job requirements.

What Is a Pump Piston?

A pump piston is a device that supplies and transfers liquids and gases through the reciprocating motion of a piston.

The pump piston moves liquid or gas by utilizing the volume change that occurs when the cylindrical piston moves in a linear reciprocating motion inside the cylinder of the pump housing. The simplest pump piston, a combination of a piston and two valves, has long been used for wells and other applications. Due to their high discharge pressure characteristics, they are also widely used in industrial fields.

Pump pistons are considered positive displacement pumps. This category includes gear, vane, screw, scroll, plunger, and diaphragm pumps.

Uses of Pump Pistons

Pump pistons are relatively simple in construction and easy to handle. They have long been used for tasks such as manual well pumps and kerosene pumps. Some specific uses of pump pistons include:

• Drainage systems in industrial production lines, transfer systems for highly viscous liquids, water, sewage lines, high-pressure gas lines, etc.
• Transfer and precise filling of food oils and materials, cosmetics, medicines, reagents, electrolytes, shampoos, conditioners, additives, fragrances, etc.
• Hydraulic pumps for construction vehicles, steel, shipbuilding, machine tools, industrial machinery, etc.
• Conveying sewage dehydration cake, sewage dehydration sludge containing foreign matter, coal slurry, etc.

Principles of Pump Pistons

The basic operating principle remains consistent for all pumps: liquids or gases are transferred through repeated suction and discharge actions. Pump pistons incorporate valves at the inlet  and discharge ports to prevent backflow and apply pressure.

The capacity of a pump piston is determined by three factors: piston diameter, stroke, and the number of pistons. The flow rate is determined by the number of revolutions. Pump characteristics are represented in a chart with flow rate on the horizontal axis and pressure on the vertical axis. Pump pistons designed for liquid applications exhibit minimal pressure variation concerning flow rate.

Among pump pistons, axial and radial types offer continuous capacity adjustment. Even when the required capacity changes, it can be adjusted without altering the rotation speed, simplifying control and conserving energy.

Features of Pump Pistons

1. Capable of Handling High Pressure

Pump pistons exhibit superior pressure resistance compared to other pumps and can withstand pressures of up to 50 MPa. They also demonstrate high efficiency.

1. Adaptability to Variable Displacement

Axial and radial pump pistons can be easily adapted for use in variable displacement pumps.

1. Use as a Motor

Axial and radial pistons can function as motors because their design is fundamentally similar to that of pumps. These pistons and motors can be connected to transmit power.

Types of Pump Pistons

Pump pistons are broadly categorized into axial, radial, and reciprocating types.

1. Axial Type

Pistons in axial pumps are arranged close to the drive shaft. They are divided into two types: axial and swash plate, based on the method of piston reciprocation. This structure can also be employed in motors, making it the most commonly used positive displacement pump.

Axial pump pistons can be converted into variable displacement pumps by adjusting the swash shaft or swash plate angle, thereby varying the piston’s displacement from zero to maximum continuously.

1. Radial Type

In radial pumps, multiple pistons are arranged radially around the drive shaft. Eccentric cam rings or cams drive the pistons. In eccentric radial pumps that use an eccentric cam ring, the pistons reciprocate, and the entire cylinder block rotates. This type can also be used as a motor.

Eccentric radial pumps can be adjusted for variable displacement by altering the eccentricity of the cam ring, providing excellent responsiveness.

1. Reciprocating Type

Reciprocating pistons are driven by a crankshaft or cam. There are various configurations, including single, double, and multiple pistons. Valves at the inlet and discharge ports make them unsuitable for motor applications. Despite their larger size and weight, they can handle relatively high pressures compared to other methods.