JPH0226634Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a clean workbench that handles substances such as harmful bacteria that must not leak to the outside.

[Conventional technology]

The air pumped by the blower is purified by a filter and discharged into the work space, and the air in the work space is sucked in by the blower to maintain the work space at a negative pressure compared to the outside. Clean workbenches were used more frequently than before. This type of clean workbench is configured to adjust the amount of air blown into the work space by installing an exhaust duct equipped with a filter and adjusting the exhaust volume. When the blower is stopped and air pressure flows back into the exhaust duct, the collected harmful substances may separate from the filter, ride the airflow, and leak outside through the blower. It was hot.

[Problem that the invention attempts to solve]

In a clean workbench with an exhaust duct equipped with a filter, when the blower is not operating, if external pressure increases, this pressure will cause air to flow from the exhaust duct into the interior of the main body case in the opposite direction to the exhaust direction. The harmful substances collected in the exhaust filter are separated from the filter by the air flowing in from the exhaust duct, float inside the main body casing on the air flow, pass through the blower, etc. There were cases where it leaked out of the casing. Therefore, when the blower is stopped and airflow occurs in the opposite direction from the exhaust direction from the exhaust duct due to increased external pressure, this is immediately sensed, the backflow of air is blocked, and the exhaust filter is installed. The object of the present invention is to prevent the harmful substances collected by the casing from being separated by the backflowing airflow and leaking out of the main casing.

[Means for Solving the Problems] In order to solve the problems of the prior art as described above, the present invention aims to solve the problems of the prior art as described above. The internal pressure is increased to eliminate the so-called air backflow phenomenon.The inside of the main body case is divided into a work space and a ventilation space by a partition wall, and the air outside the main case and the work space is sucked into the ventilation space. An air blower is installed to forcefully send the air into the air blowing space, an opening is provided in the partition wall to communicate the work space and the air blowing space, and a filter is installed in the opening to filter the air forced into the air blowing space. In addition, an exhaust duct equipped with a second filter is provided in the main body case, and the pressure on the rear side is lower than the pressure on the front side of the second filter. A pressure gauge switch is provided that activates the blower when the pressure increases, and when the pressure in the ventilation space inside the main body case becomes lower than the outside, external air flows into the main case from the exhaust duct. If this occurs, immediately start the blower to increase the pressure in the air space.
It is designed to eliminate air backflow.

[Effect]

When the air pressure in the workroom in which the clean workbench is installed increases with the blower stopped, the air in the room flows into the main body case. If the air pressure flowing into the exhaust duct at this time becomes higher than the pressure on the air blowing space side of the main body case of the second filter provided in this duct, the pressure gauge switch detects this condition and the electric circuit of the blower is activated. Connect and operate. The operation of this blower increases the pressure in the ventilation space, which increases the pressure on the ventilation space side of the second filter provided in the exhaust duct, and the air flowing into the exhaust duct passes through the second filter to the main body case. Prevent it from flowing inside. This reliably prevents the harmful substances collected in the second filter from being separated by the airflow flowing in from the outside and scattering into the main body case, and leaking into the work room etc. Prevent accidents.

〔Example〕

An example of implementation of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a main body case in the form of a vertically elongated box, the interior of which is divided by a partition wall 2 into a work space 3 and a ventilation space 4. The work space 3 has an opening at the front to form an entrance 5 and a work table 6.
Several through holes 7, 7 are provided on the front side and the rear side. Reference numeral 8 denotes an elevating door that opens and closes the entrance 5 of the work space. Reference numeral 9 denotes an opening provided in the partition wall 2. A high-performance filter 10 is attached to this opening 9, and the working space 3 and the ventilation space 4 are connected through this filter.
It is in communication with. 11 is a blower, and a discharge port 12
is attached to the partition wall 2, with the air intake port 13 located in an air intake chamber 14 surrounded by the work table 6, the partition wall 2, and the main body case 1. 1
5 is an exhaust duct provided to cover an opening 16 provided in the ceiling of the main body case 1;
is covered with a second filter 17. 18 is a pressure gauge switch connected to the electric circuit of the blower 11, and the two pressure detection parts 19,
20 connects the first pressure detection unit 19 to the air blowing space 4
Inside, the second pressure detection section 20 is connected to the exhaust duct 15.
When the air pressure detected by the second pressure detection section 20 is higher than the air pressure detected by the first pressure detection section 19, the electric circuit of the blower 11 is connected to operate the blower 11. It is set as.

Now, to handle harmful bacteria, turn on a switch on an operation panel (not shown) to operate the blower 11.
The air in the intake chamber 14 and the work space 3 is sucked into the intake port 13 of the blower 11 and is forced into the ventilation space 4 through the discharge port 12. The air forced into the ventilation space 4 flows into the work space from the filter 10 as the pressure increases. At this time, the air is purified by the filter, clean air is sent to the work space 3, and the suction force of the blower 11 causes the work space 3 to have a negative pressure compared to the outside.
Also, a part of the air in the ventilation space 4 is passed through the second filter 1
7, and is discharged to the outside through an exhaust duct 15. When working in this state, some of the harmful bacteria handled on the workbench 6 are sucked into the ventilation space 4 by the air circulating inside the main body case 1, and are collected in the filter 10 and the second filter 17. be done.
When the work is completed and the blower 11 is stopped, the pressure within the main body case 1 eventually becomes equal to the room pressure, and when the room pressure becomes high in this state, the indoor air flows into the main body case 1. When the air entering from the exhaust duct 15 increases the pressure inside the duct 15,
The value detected by the second pressure detection part 20 located in the exhaust duct 15 is higher than the first pressure detection part 19 located in the ventilation space 4, and when such a state is detected, the pressure gauge switch is activated. 18 is on,
Operate the blower 11. As a result, the ventilation space 4
The internal pressure increases, preventing the air that entered the exhaust duct 15 from flowing into the ventilation space through the second filter 17, and the harmful substances collected in the second filter 17 are separated. This prevents the liquid from floating inside the main body case 1 and leaking into the work room.

[Effect of idea]

The cleaning workbench of the present invention is equipped with a pressure gauge switch by locating a detection section before and after the filter in an exhaust duct equipped with a filter, and connects the pressure gauge switch to the electric circuit of the blower. When the pressure inside the exhaust duct becomes higher than the pressure inside the case, the blower is activated immediately to increase the pressure inside the main case, so harmful bacteria collected in the filter can be removed. It is possible to reliably prevent the particles from being peeled off by the air flowing into the exhaust duct, completely eliminate contamination of the work room and danger to workers, and provide an extremely safe and clean workbench. It is something.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional side view schematically showing an example of the implementation of the cleaning workbench of the present invention. 1... Main body case, 2... Partition wall, 3... Work space, 4... Ventilation space, 10... Filter, 11...
Blower, 15... Exhaust duct, 17... Second filter, 18... Pressure gauge switch, 19... First
pressure sensing section, 20... second pressure sensing section.

Claims (1)

[Scope of utility model registration request] The inside of the main body case is divided into a work space, an intake room, and a ventilation space, and a blower is installed in the intake room to form a circulation path that connects the intake room, ventilation space, work space, and intake room, and an exhaust duct is installed in the ventilation space. A first filter is provided between the work space and the ventilation space, a second filter is provided between the ventilation space and the exhaust duct, and a surface is provided in the work space of the second filter. The cleaning workbench is equipped with a pressure gauge switch that detects the pressure difference between the front side facing the inside of the exhaust duct and the rear side facing the inside of the exhaust duct, and operates the blower when the pressure on the rear side increases.