Spiral pumps of the vacuum type with internal compression are electromechanical devices that are widely used in the scientific field and industry. The scope of their use includes certain technological processes, as a result of which a deep vacuum is created. The average productivity of the devices is up to 35 m3 / h. Due to the presence of a completely dry environment, such a pump can also be used for pumping active gases. Consider the features and advantages of this equipment.
History of creation
The first attempts to create a spiral pump can be considered a measurement of atmospheric pressure readings, carried out by a physicist from Italy named Torricelli. Having studied the information received, he concluded that there was a vacuum, soon proving his hypothesis.
The classic design of the device in question was created at the beginning of the 18th century according to the project of the French engineer Leon Croix. The scientist has developed a mechanism based on a rotary device with two constant pitch spirals. In this case, one of the elements remains stably stationary, mounted on the housing. The second spiral slides in the inner part along the orbital path.
Serial production of spiral vacuum pumps has been established since 1980. The first models provided air exhaust and boost for motors and air conditioners. Now the scope of use of such compressors has expanded significantly, including economic activities, space engineering, industry. Spiral modifications are mainly operated in laboratories and in enterprises.
Features
Two spirals are located among themselves at an angle of 180 degrees. They create crescent-shaped compartments in which the movement of gas is provided by the pressure difference in them. An electric motor transmits torque to the shaft, after which the spirals make orbital motion, and the gas volume, gradually compressing, tends to the central part.
Such devices belong to the class of dry-type forevacuum scroll pumps with internal compression. The design does not provide for the use of oils to seal mating elements. The pumps in question can be operated under conditions of high probability of condensation.
pros
Main advantages of scroll pumps:
- The complete absence of oil vapor allows the use of devices to create chemically pure components in a vacuum.
- During operation, no abrasives accumulate in the internal part, which extends the life of mechanical parts, providing a high coefficient of stability.
- The absence of noise and a low degree of vibration makes it possible to use the device in rooms where people are located.
- Starting and starting the pump requires minimal effort.
- The device is light in weight, does not require a special frame or bed for transportation.
- Compactness. There are even desktop modifications.
- Reliability of mechanical components and electronics.
- Units are equipped with special systems for sealing bearings, shaft seals, removing dust and particulate matter.
- High efficiency (approximately 95%).
- Wide range of operating pressures and high precision pumping option.
- The heat generated is minimal, there is a complete atmospheric cooling system.
- Almost all models are equipped with a hours worked counter; they do not require complex and costly preventive maintenance.
Equipment
The design of the spiral pump depends on the specific manufacturer, however, any design includes basic elements, namely:
- Case made of forged cast iron with semi-compact spraying.
- Bed (the distance to the movable spiral is from 0.05 to 0.01 mm).
- Counterweight mechanism.
- The movable part making orbital rotation.
- Adaptation against jamming.
- Eccentric shaft (aggregates with electric drive).
- Bellows, which provides tight connections, preventing the introduction of oil vapor.
- Lubricant resistant rubber sealant.
How does it work?
The principle of operation of the spiral pump is to push gas from the peripheral part to the center using a movable element that creates two series of sickle-shaped volumes. Then the volume is pumped through the steam room and the hole in the middle of the end disk of the fixed bed.
The number of rotations of the full duty cycle with one portion of gas is identical to the number of turns of the spiral. For this, involute, Archimedes spiral, various arcs of circles and their variations are used.
The main difference between the operation of the unit under consideration is that suction, compression and injection are carried out synchronously, simultaneously in several cavities. Gas diffusion between the low and high pressure sectors is reduced due to the separation of volumes among themselves. This decision made it possible to completely abandon the use of discharge and suction valves.
Anest Iwata Spiral Pumps
These units are produced by a Japanese company since 1990. These pumps are used in various fields, including vacuum furnaces, laboratory equipment, ion processing, spraying systems. The device has a well-balanced mechanism, low ripple and noise, and is also reliably protected from oil or particles entering the vacuum chamber.
Brief characteristics on the example of the Anest Iwata ISP-90 modification:
- Type of cooling - air.
- Pumping speed - 90 l / min at 50 Hz.
- The maximum vacuum is 5 Pa.
- Power consumption - 0.15 kW.
- Noise level - 52 dB.
- Weight - 13 kg.
- Dimensions - 308/182/225 mm.
- The operating voltage is 220 V.
XDS35i Vacuum Spiral Oil-Free Pump
In the manufacture of this device uses the patented technology of the bellows input motion, which allows you to completely isolate the bearings from the working compartment. This design eliminates the ingress of chemically active and oil components. The logical interface port allows you to adjust the shaft speed.
Parameters:
- Productivity - 43 cubic meters / h.
- Pumping to the maximum - 35 cubic meters / h.
- The maximum outlet pressure is 1 bar.
- Motor power - 520 watts.
- Operating temperature conditions - 10-40 degrees.
- Weight - 48 kg.
- Noise - 57 dB.
Application
Spiral centrifugal pumps are successfully used in various fields. The following is a list of key areas:
- In medicine - for cleaning the components of various substances at almost complete vacuum (ventilation devices and artificial respiration).
- In pharmacy - for the disinfection of drugs (antibiotics) from the waste products of microorganisms.
- In industry - as a forevacuum device in the assembly of pumps of a turbomolecular or diffusion type.
- For conducting physical studies in the study of photosensitive polymers and rarefied gases.
- In tests - to simulate weightlessness and wave-like vacuum (when testing satellites, weather balloons, orbital modules, aircraft, rockets).
- In biological research - to study the effect of vacuum on different life forms.
- In microelectronics - for the manufacture of semiconductors under conditions of leveling the oxidizing effect.
- In the chemical industry, to create a constant flow of raw materials (splitting the material into fractions, for example, when creating ethers).
- In the food industry - packaging of goods in a plastic sleeve.
- In the manufacture of complex optical-mechanical devices (electron microscopes).
Finally
The above list is far from all areas where a vacuum scroll pump is used. Such equipment greatly facilitates a variety of activities. Especially the device is indispensable in cases where the creation of an oil-free vacuum is required. It should be noted that this direction is prevailing in the industry of development and production of pumping equipment. Due to the wide possibilities and design features, models of both industrial design and compact (desktop) versions are manufactured.