月: 2023年12月

What Are Chest Freezers?

Chest freezers are top-opening freezers designed to store and preserve frozen food at temperatures below -20°C.

As the name implies, these freezers resemble a chest or box with a lid on top. The top-opening design minimizes the escape of cold air, maintaining a consistently low temperature. Advantages include a wide opening for easy access to all corners of the compartment, convenient cleaning, straightforward storage of large items, and efficient utilization of space.

Available in various sizes from small to large, chest freezers offer more diverse options than front-opening or sliding door freezers. They are used not only in commercial settings like restaurants but also as secondary freezers in households.

What Are Turnstiles?

Turnstiles are machines used at railway stations and similar locations to verify the validity of tickets and collect them.

In large urban stations, automatic turnstiles are often installed. These turnstiles read ticket information, confirm their validity, and can interact with contactless IC cards to record boarding sections and deduct fares.

Automatic turnstiles have internal mechanisms such as rollers, punch machines, and magnetic processing units. When a ticket is inserted, the roller transports it to the magnetic processing unit, which reads the magnetic information on the back of the ticket. If the ticket is valid, the turnstile punches a hole in it, returns it, and opens the gate.

What Are Power Strips?

Power strips are tools designed to supply power to multiple electrical devices from a single power outlet.

Typically equipped with multiple outlets, power strips are used to increase the number of electrical devices that can be used simultaneously. They come in various shapes, including corner taps or triple taps that distribute power in multiple directions, and models with extension cords. Some feature three-pronged outlets.

Additionally, there are power strips with switches to control the power to the entire strip or each individual outlet. Some power strips also have built-in varistors to absorb lightning surges from the power and ground lines, providing convenient functionalities to users.

What Are Thermocouples?

Thermocouples are temperature sensors composed of two different metal conductors.

They have metal conductor wires at the tip. By bringing the ends of these wires into contact to create a closed circuit, thermocouples measure temperature based on the voltage generated by the Seebeck effect.

The Seebeck effect is a phenomenon where a temperature difference applied to a conductor generates a voltage, known as the Seebeck coefficient, proportional to the temperature difference. The voltage produced depends on the types of metals used and the temperature difference between them.

Thermocouples offer rapid responsiveness and the capability to measure temperatures over a wide range. They come in two types: noble metal thermocouples, which use high-melting-point precious metals, and base metal thermocouples, which do not use precious metals. The choice of metal conductors determines the temperature range for measurement.

What Are Roasters?

Roasters are cooking tools used for broiling or roasting foods such as meat or fish.

While ovens utilize convection heat transfer to apply heat evenly through the temperature difference between a solid and the surrounding fluid, roasters employ radiant heat transfer. They emit infrared rays that generate heat upon striking an object. This method is distinct from the convection heat transfer of ovens.

Many roasters are designed to prevent fats and moisture from dripping onto the heating element, producing minimal smoke. In food factories, large-scale roasters often feature conveyor belts to transport items from input to output. Some models allow adjustment of internal temperature and oxygen concentration, which can shorten cooking times and contribute to improved texture in the finished products.

What Is a Paper Cutter?

A paper cutter is a cutting machine designed specifically for paper.

The most common type is the rotary paper cutter, which secures the paper on a metal base and cuts it by sliding the blade, which can be replaced with a perforation blade. Due to its relatively low cost, this type of cutter is widely used in offices and similar settings.

Guillotine-style paper cutters, which use a spring-loaded blade to cut the paper, can handle more sheets at once compared to rotary cutters, but they have higher maintenance costs as blade replacement can be challenging.

Typically, a standard paper cutter can cut around 10 to 50 sheets at a time. For larger volumes of cutting, electric cutting machines are often preferred.

What Is a Hydrogen Refueling Station?

A hydrogen refueling station is a facility where hydrogen, the fuel for fuel cell vehicles, is supplied.

These stations are equipped with a compressor, storage tank, and pre-cooler. There are on-site types that produce hydrogen on-site using raw materials like city gas and water, and off-site types that transport hydrogen from an external source. The hydrogen, either produced on-site or transported to the station, is compressed using a compressor. It is stored under pressure in a storage tank and cooled to -40°C by a pre-cooler before being filled into the vehicle’s tank to prevent the tank temperature from rising.

Hydrogen refueling stations can be installed at fixed locations similar to gas stations, and there are also mobile stations mounted on large trailers. Additionally, integrated stations combine the functions of a hydrogen station and a conventional gas station.

What Is a Gasoline Pump?

A gasoline pump is a device used to supply gasoline.

They are primarily employed at gas stations to refuel vehicles, where a motor moves a piston to pressurize gasoline from the tank. Equipped with a fuel nozzle, the pump allows manual fueling by pulling a lever.

The nozzle is fitted with a sensor that automatically stops fueling when the tank is full. When the nozzle’s tip is submerged in liquid, the internal pipe of the nozzle enters a vacuum state, triggering the sensor to stop the fuel supply.

There are also smaller electric pumps designed for refueling from drums, some of which are portable. However, pumps without explosion-proof structures should not be used for gasoline due to safety concerns.

What Is a Gas Pump?

A gas pump refers to a device used for injecting or discharging air or gas.

Gas pumps are found in a wide range of applications, including medical, industrial, and aeration processes. In aeration, they provide oxygen to activate aerobic microorganisms by sending air into the drainage process or a septic tank. Some gas pumps are capable of both pressurizing and depressurizing. Devices that allow significant pressure changes are also referred to as compressors or vacuum pumps.

Common types include diaphragm and piston pumps. Piston pumps are known for their large single-stroke capacity and long lifespan, whereas diaphragm pumps use a motor-driven diaphragm for movement. Although diaphragm pumps have a smaller single-stroke capacity than piston pumps, they are preferred in situations requiring precise and constant gas injection or discharge due to their high accuracy.

What Is a Gas Dryer?

A gas dryer is a device designed to remove moisture from gases, primarily used for compressed gases like helium, natural gas, and hydrogen.

Gas dryers can be categorized into three main types:

1. Adsorption: Removes moisture by adsorbing it onto an adsorbent material, and includes a heater for regenerating this material.
2. Cooling: Lowers the temperature to condense moisture, which is then discharged.
3. Membrane: A power-free gas dryer using a high molecular weight membrane, where moisture passes through hollow fibers and is expelled externally.

While cooling and membrane types are mainly used for compressed air, the adsorption type is commonly employed for other gases.