月: 2023年9月

What Is a Positive Pressure Damper?

A positive pressure damper is a device for regulating the internal pressure of a clean room or similar.

It is sometimes also called a differential pressure damper or relief damper. Positive pressure dampers are used to maintain positive pressure in clean rooms.

The installation of a positive pressure damper adjusts the differential pressure between the clean room and the outside and maintains a constant positive pressure inside the clean room.

Uses of Positive Pressure Dampers

Positive pressure dampers are used in clean rooms. This is because the room must be kept at a positive pressure to prevent dust and dirt from entering from the outside. Air has the property of flowing from higher to lower atmospheric pressure. Dust and dirt in the air also diffuse with the air flow.

Therefore, in clean rooms, the air pressure in the room is increased compared to the air pressure outside the room, thereby creating an air flow from inside to outside the room. This prevents dust and dirt from entering the clean room.

However, if the pressure in the room is too high compared to the outside of the room, adverse effects can occur, such as difficulty in opening and closing doors when entering and leaving the room. In addition, in clean rooms used for semi-conductor manufacturing, the load is so heavy on the workers that they are said to be carrying 2-3 kg on their backs at any one time.

Therefore, by opening and closing the positive pressure damper from time to time in accordance with the pressure difference with the air outside the room, it is possible to keep the air inside a clean room at a constant positive pressure. Depending on the installation method, it may also be possible to make the room negative pressure in the opposite direction.

Principle of Positive Pressure Dampers

A positive pressure damper consists of a damper body, a control unit and an actuator. The control unit sends control signals to the actuator based on information from the pressure sensor. The actuator controls the opening of the damper based on this control signal.

The pressure sensor then detects the difference in air pressure between the inside and outside of the clean room and controls the opening of the valve in the damper body so that the pressure difference is kept to a certain degree. In other words, when the air pressure is higher than the specified value, the damper is opened to discharge air outside the room, and when the air pressure is lower, the damper is closed to keep the air pressure constant.

Types of positive pressure damper?
The main types of positive pressure damper used in clean rooms are:

1. Shutter Dampers.

This type of positive pressure damper controls the passage of airflow by opening and closing. They are generally installed horizontally and adjust the damper opening by opening and closing. Shutter dampers can be opened and closed at high speeds and can therefore cope with sudden changes in air pressure.

2. Damper Unit

These are specialised damper units built into the walls and ceilings of clean rooms. The damper unit has controllable openings to control air supply and exhaust air. Damper units are used in combination with damper boxes and controls.

3. Operating Theatre Dampers.

This system combines several damper units. The system is used to regulate the air pressure in different areas of the cleanroom. Each area can be independently controlled and different cleanliness levels can be maintained.

4. Regulatory Dampers.

In addition to controlling air pressure, these dampers can also control air speed and air volume. This allows the movement of air in the cleanroom to be regulated in more detail. Regulatory dampers are particularly suitable for clean rooms where a high degree of control is required.

5. Dampers With Fire Shutters.

This type of damper automatically closes the opening blades when a thermal fuse blows above a specific temperature. Air flow can be blocked, preventing the spread of fire and the filling of toxic gases.

What Is a Conveyance Device?

A conveyance device is a device for moving parts or products in conveyance or manufacturing processes.

Conveyance devices can move even heavy objects safely and at low cost. They are therefore used in various locations, from large factories to small workpieces in semiconductor manufacturing. The use of conveyance devices increases productivity and reduces human error.

There are various types of conveyance devices, including conveyor-type conveyors, unmanned vehicles, lifting devices and robots, which are commonly used in manufacturing processes. The style of conveyance device is selected according to the workpiece to be applied.

Uses of Conveyance Devices

Conveyance devices are available in a variety of conveyance systems and are mainly used for conveying between manufacturing processes. Most heavy items such as steel materials and vehicles are manufactured using conveyance devices. In addition, in the food industry, conveyance devices are often used in factory production to maintain product cleanliness, moving products between processes without human intervention.

In the semiconductor industry, conveyor systems are also commonly used in order to prevent contamination of semiconductors during processing, while maintaining a high level of cleanliness.

Principle of Conveyance Devices

1. Conveyor System

Conveyance devices use multiple rollers, belts and suspension chains to convey. Parts or products are conveyed by placing them on a rotating roller or belt conveyance device. There are also pneumatic levitation conveyors, where the belt is supported by air to eliminate vibration.

2. Elevating-Type

Elevating conveyance devices perform vertical loading and unloading. These include simple lifts, lifts and elevators. As they are basically conveyance devices, most of them do not allow people to get on board. Depending on the device, it may be necessary to check the Building Standards Act, Occupational Health and Safety Act, etc. for installation.

3. Unmanned Transport Vehicles

An unmanned conveyance device is a device in which magnetic tape or magnetic rods are installed on the floor so that a trolley carrying a load is guided by the magnetism emitted from the magnetic tape, etc., and can proceed unmanned. They can also carry heavy objects such as moulds. Unmanned transport vehicles, also known as AGVs, are also used in factories, hospitals and logistics sensors operating 24 hours a day.

Types of Conveyance Devices

Conveyance devices in the manufacturing industry can be broadly classified into conveyance devices for transport processes, such as conveyors, elevators and AGVs, and conveyance devices that are integrated into manufacturing processes, such as the transport and retrieval of workpieces on production lines.

1. Classification by Transport Process

In the conveyance process, conveyance devices such as overhead suspension conveyors, roller and belt conveyors, screw conveyors, elevators and automatic guided vehicles are used to convey workpieces. Depending on the item, vacuum or electromagnetic suction may be used in the suspension method.

The drive for conveyors and other travel is chain-driven or pneumatically or hydraulically driven. Heavy loads can also be moved using pneumatic or electromagnetic levitation.

2. Classification by Manufacturing Process

In manufacturing processes, conveyance devices such as robot conveyors and actuators are used in addition to the usual conveyor systems. Gantry loaders and autoloaders are used for loading workpieces into machine tools and removing them after machining.

Conveyance devices are also used in press processing. Conveyance devices are incorporated between press machines to transport the workpiece to the next process. For the manufacture of semiconductors and other components, conveyance devices are available for conveying wafers of different thicknesses and for very thin wafers.

Other Information on Conveyance Devices

1. Advantages of Conveyance Devices

Improved Efficiency and Productivity of Transfer Operations

Conveyance devices enable workpieces of various shapes and weights to be conveyed reliably, quickly and accurately, without manual handling. This has a significant effect on work efficiency and productivity.

It is essential to shift to highly productive operations, freeing valuable human resources from simple tasks such as workpiece transfer.

Improved Quality
The workpieces and components to be conveyed are diverse, including those that are difficult to pick and those that are delicate and easily damaged. Some items are also unsuitable for human transport, such as wafers in semi-conductor manufacturing.

Conveyance devices reduce the risk of workpieces falling or being damaged during transport, make it easier to carry out reliable processing operations and improve quality.

A Step Towards Automation
Conveyance devices are the first step towards automation and manpower-saving in production lines. Furthermore, the use of factory equipment, including conveyance devices, and the IoT (Internet of Things) can lead to the realisation of so-called smart factories.

2. Examples of Conveyance Devices

Small-Radius Swivel Trolleys

Small radius swivel trolleys are used for transport in narrow factories. The minimum radius is around 750 mm.

Refuse Container Transfer/Storage Equipment
Refuse container transfer/storage equipment is a conveyance device for transferring and storing containers at refuse collection centres.

Substrate Transfer Conveyors
In worker conveyors, substrates are paused on the conveyor and visually checked by the operator. In cooling conveyors, cooling fans are used to cool the substrates.

What Is an Automated Pipetting System?

Automated pipetting systems are devices that perform pipetting automatically.

Dispensing refers to the process of measuring and dispensing liquids, such as samples or chemicals, in fixed quantities. This operation can be carried out automatically, e.g. by a robot, to ensure efficient and accurate operation.

Automatic dispensing equipment is also referred to as liquid automatic dispensing system, automation pipetting system, and dispensing workstation.

Uses of Automated Pipetting Systems

Automated pipetting systems are used to save time and effort and avoid human error in simple tasks such as taking out the required amount of liquid or powder sample and dispensing it into the desired container. They are used in a wide range of fields, including research, food, clinical (medical and laboratory) and drug discovery.

1. Medical and Pharmaceutical Sciences

Automated pipetting systems play an important role in the fields of medicine and pharmacy. The dispensing of medicines and reagents requires the rapid delivery of accurate quantities. Due to their high accuracy and stability, automated pipetting systems are indispensable in pharmaceutical production and research.

2. Chemistry and Biochemistry

Automated pipetting systems are also widely used in chemistry and biochemistry research. The accurate dispensing of minute quantities of reagents ensures that the results of reactions and analyses are reliable. The high working efficiency also enables researchers to process more samples and conduct more effective experiments.

3. Food and Beverages

The food and beverage production process also sees a lot of action. They are used for accurate dispensing and blending operations of specific ingredients, which can produce products of consistent quality. In addition, productivity is increased by speeding up production lines and automating tasks.

4. Environmental Analysis

Environmental analysis requires the accurate dispensing of minute quantities of samples, for example, for testing water quality and air pollutants. The high accuracy and reproducibility of automated pipetting systems ensure accurate analysis results.

5. Medical Testing and Diagnosis

Automated pipetting systems are also indispensable in medical testing and diagnosis. In the dispensing of biological samples such as blood and urine, accurate quantities must be supplied quickly. As in environmental analysis, accurate operation eliminates human error and wasted time.

Principles of Automated Pipetting Systems

Automated pipetting systems operate through a combination of mechanisms and control systems. Broadly speaking, automated pipetting systems consist of three components: a container for holding the sample, supply components such as syringes and tubes for dispensing, and a computer that controls these movements.

A control system is built into the device, which processes the dispensing based on pre-set parameters. The control system works in conjunction with a high-precision measuring mechanism to accurately measure and control the sample volume.

The motors, pumps and other mechanisms in the device are activated by the dispensing feed components to aspirate the required amount of sample and dispense it into the desired vessel. Valves and sensors are also utilised in this process to control sample velocity, flow rate, etc. This ensures that the dispensing operation is carried out with a very high degree of accuracy and has an outstanding effect on efficiency.

Furthermore, automated pipetting systems can process several samples and several vessels simultaneously. The instrument is equipped with several channels, each of which has the ability to dispense samples individually. This significantly increases work efficiency by processing several samples at the same time.

How to Choose Automated Pipetting Systems

There are various types of automated pipetting systems, depending on their performance and features. It is therefore ideal to select the appropriate device for your application.

The three main points to consider are the dispensing volume range, the characteristics of the sample to be used and the accuracy and reproducibility. Define how much needs to be dispensed and check the range that the instrument can handle.

It is also essential to determine whether the equipment can handle the sample properly, taking into account its viscosity, corrosiveness, temperature and other characteristics, as the suitable equipment depends on the characteristics of the sample to be used. As a result, the performance of the equipment is checked by referring to the manufacturer’s specifications and evaluation values to ensure that the equipment is accurate and that the dispensing results are consistently reproduced.

What Is a Centrifugal Concentrator?

Centrifugal Concentrators are devices that apply centrifugal force to a sample in solution under reduced pressure to evaporate the solvent and concentrate the sample.

It generally consists of a centrifugal chamber, a cooling chamber and a decompression unit.

Uses of Centrifugal Concentrators

Centrifugal Concentrators are characterised by lowering the boiling point of the solvent in the sample during concentration and by applying centrifugal force to the sample to prevent solvent ejection, foaming, etc. This means that sample loss due to heating or boiling can be reduced, making it suitable for the concentration of samples for microanalysis where very small quantities of sample are used.

They are used to concentrate DNA, RNA and peptides, and to prepare other applications requiring concentration and drying. They are also used in many areas for the concentration of solvent and water mixtures, residue analysis, toxicological investigations and forensics, combinatorial chemistry, food analysis and environmental analysis.

Principle of Centrifugal Concentrators

Centrifugal Concentrators used for microanalysis and other applications are characterised by the use of the ‘three states of matter’ to concentrate samples. Specifically, the solvent in the sample is evaporated under reduced pressure at a lower temperature than under atmospheric conditions, vaporised and collected, and the sample is concentrated by reducing the amount of solvent in the sample. Therefore, the minimum configuration required for a Centrifugal Concentrator is a centrifugal chamber, a cooling chamber and a pressure reducing device such as a vacuum pump.

In Centrifugal Concentrators, the centrifugal chamber is depressurised using decompression device while the liquid sample is inside the centrifugal chamber. The reduced pressure lowers the boiling point of the substance, and consequently, the boiling point of the solvent within the sample placed in the centrifugal chamber is also reduced. Solvent evaporation is therefore possible at lower temperatures than under atmospheric conditions.

The evaporated solvent moves to the cooling chamber, where it is cooled and collected. At this point, the sample is heated, which promotes solvent evaporation and prevents the solvent freezing that occurs during depressurisation. The pressure at the sample surface in the centrifuge chamber is the same as in the depressurised centrifuge chamber. At this time, the Centrifugal Concentrator applies centrifugal force to the sample, which causes a pressure gradient inside the sample where the pressure is higher the deeper it goes.

Therefore, when the pressure within the centrifugal chamber is carefully controlled, only the surface layer of the sample experiences a lower boiling point due to the reduced pressure. This results in surface boiling without affecting the interior of the sample, effectively preventing eutectic boiling, which occurs when the interior of the sample undergoes boiling.

Other Information on Centrifugal Concentrators

1. Sludge Concentration by Centrifugal Concentrator

Centrifugal Concentrators are mainly used in fields such as microanalysis, but in recent years they have also been used in sewage sludge treatment. Among sewage sludge, sludge from the first settling basin settles easily and can be easily thickened by gravity settling.

However, sludge in the final sedimentation basin (especially excess sludge) does not settle easily, making it difficult to concentrate the sludge by gravity settling. Centrifugal Concentrators are therefore used as a type of mechanical sludge thickening method (mechanical thickening method). Mechanical thickening methods also include atmospheric pressure floating thickeners and belt-type filtration thickeners.

2. Structure and Operation of Centrifugal Concentrator for Sludge Concentration

Centrifugal Concentrators for sludge concentration concentrate excess sludge by centrifugal force. At this time, no depressurisation is carried out. Centrifugal Concentrators for sludge thickening have a structure in which the outer body and the inner body with screw rotate around the sludge feed pipe while maintaining a certain difference in rotation between them.

This rotational difference is set to be, for example, three to eight revolutions, with the inner cylinder with the screw rotating slightly slower. The sludge is first fed into the outer cylinder through the sludge feed pipe of the Centrifugal Concentrator. Before the sludge is fed to the Centrifugal Concentrator, flocculants or other agents are generally added.

The outer cylinder rotates at high speed and the sludge is subjected to centrifugal force, causing sedimentation and separation due to the difference in specific gravity between water and solids, resulting in the accumulation of thickened sludge in the outer cylinder. At this point, there is a difference in rotation between the inner and outer cylinders, with the inner cylinder rotating slightly slower, so the deposited concentrated sludge is scraped off and pushed out by a screw attached to the inner cylinder and discharged.

Such Centrifugal Concentrators can, for example, be used to concentrate sludge with a concentration of 1% or less into a concentrated sludge of 4-6%.