JPS61428A - Air purification system - Google Patents

Abstract

PURPOSE:To perfectly remove fine particulate dust which can not removed by a filter, in an air purification method, by mounting both of the filter and a centrifugal separator. CONSTITUTION:Air pressurized by a blower 1 passes through an ultra-fine particle filter (HEPA filter) 2 and the greater part of dust with a particle size of 0.1mum or more is adhered to the filter 2. Dust with a particle size of 0.1mum or less remains in air pased through the HEPA filter but air is discharged to a centrifugal separator 3 from a nozzle 4 to form a high speed stream and dust is collected to the cylinder side of the centrifugal separator while purified air is taken out from an upper take-out part. The collected dust is periodically removed by stopping the centrifugal separator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] This invention relates to an air cleaning system used in a clean room at equal pressure.

[Prior art and its problems]

Conventionally, HE was used to remove minute dust in clean rooms.
Although an ultrafine particle filter called a PA filter is used, the dust particles that can be removed are 0.1 μm or larger, and dust with smaller particles cannot be removed. As wafer microfabrication progresses in the future, the width of the flaps will become smaller, and dust of 0.1 μm or less will cause defects in the semiconductor manufacturing process.

[Purpose of the invention]

An object of the present invention is to provide an air cleaning method that can remove dust of 0.1 μm or less that cannot be removed by a filter.

[Summary of the invention]

The present invention is an air cleaning method that uses a centrifuge to separate air and dust to obtain ultra-clean air.

〔Effect of the invention〕

According to the present invention, particulate dust that could not be removed by a HEPA filter can be completely removed, contributing to the improvement of VLSI manufacturing technology.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG.

The air to be purified is pressurized by the blower 1 and passed through the ultrafine particle filter (
(hereinafter referred to as HEPA filter) 2.

At this time, most of the dust of 0.1 μm or more adheres to the glass fibers of the filter, but the dust of 0.1 μm or less remains in the air that has passed through the HEPA filter. This air is squeezed and discharged through a nozzle 4 into a centrifuge 3.

The centrifugal separator 3 is rotated at high speed by an electric motor 5 in a vacuum container 6, and the air discharged from the nozzle 4 becomes a high-speed flow, and the dust in the air collects in the cylinder of the centrifuge 3, and the dust-free air is sent to the upper part. It is taken out from the outlet. This ultra-clean air is supplied to necessary semiconductor manufacturing equipment or clean rooms. Note that the centrifuge is periodically stopped to remove dust collected in the cylinder.

Further, a seal 8 is provided to maintain high speed rotation of the centrifuge.

In this example, one centrifugal separator is used, but if necessary, it can be connected in parallel or in series to obtain the required air volume.

Cleanliness can be achieved.

Also, although the example explains the case where the dust is heavier than air, there are cases where the dust is lighter than air, so in that case, it is better to place the air outlet in the cylinder because the dust will collect in the center of the centrifuge. .

Further, FIG. 2 shows a modification of the clean air outlet. This cleans 19"" from the center of the cylinder rotating at high speed!
, D firCDf &< lff1% [ilffa
Mt-? 'i'''A method is shown in which a stationary hollow tube 10 for air extraction is inserted, the pressure is raised, and the air is taken out.In this case, in order to prevent the agitation of the air in the rotating cylinder and to reduce mixing with the collected dust, the rotating cylinder is used. It is also effective to install the gate plate 9.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the invention, and FIG. 2 is a sectional view showing another embodiment of the invention. l...Blower, 2...HEPA filter, 3...
Centrifugal separator, 4... Air blowing nozzle, 5... Electric motor, 6... Vacuum container, 7... Clean air outlet, 8... Seal portion. Agent: Patent Attorney Noriyuki Chika (and 1 other person) No. 1
Figure 2

Claims (1)

[Claims] An air purification system characterized by comprising a filter that purifies the air and a centrifugal separator that centrifugally separates dust that cannot be removed by the filter.