JPS5837416Y2 - Fire prevention equipment for air transport ducts for raw materials, etc. - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fire prevention device that detects sparks generated in the duct of a pneumatic transportation device that pneumatically transports raw materials such as fibers, grains, and pieces of wood, and controls equipment necessary for fire prevention.

To explain the fire prevention device of a conventional pneumatic conveyance device using FIG. 1 as an example in the case of a spinning factory, in normal times, fiber mass A is passed through a duct 1 by a conveying blower 2 that also serves as defibration to the next process device B. continue to be transported by air.

In addition, stone pieces or metal pieces are mixed in the fiber mass A,
For example, if a spark collides with the rotating part of the blower 2 and ignites the fibers, the radiation fire detector 4 installed in the duct 1
′ works.

This radiation type fire detector 4' consists of a solar cell or photomultiplier tube, an amplifier, and a switching circuit (Japanese Patent Publication No. 45-172
57, Utility Model Publication No. 4526750), and its operation enables a control panel 1 equipped with relays, bells, etc.
7 is activated and an alarm is issued.

Also, the blower 2 is stopped, the automatic valve 14 is opened, and the nozzle 15 is opened.
Fire extinguishing agent was released into duct 1.

However, in such a device, the blower 2 is stopped and extinguishing agent is discharged into the duct 1 every time a spark is generated, which is uneconomical because it takes time to restart the work.

In consideration of the above points, this invention provides a fire protection device for a pneumatic transportation device that is safe and does not cause interruption of work.

Hereinafter, an embodiment of this invention will be explained with reference to FIG. 1.
2 is a duct for air transportation; 2 is a conveying blower that pneumatically transports the fiber mass A sent from the primary side of the duct 1, that is, the upstream side, to the secondary side, that is, the next process equipment B; 3 and 4 are first and second radiation fire detectors that are installed at a predetermined interval on the secondary side of the blower 2 and detect sparks generated in the duct 1; It consists of a battery or photomultiplier tube, an amplifier, and a switching circuit that operates at a predetermined value.

5 is installed between the sensor 3 and the sensor 4, and when the sensor 3 operates, the duct 1 is shut off and the flow of fibers is instantaneously switched to the fire extinguishing chamber 6.
The fire extinguishing chamber 6 is composed of an inner wall 7 and an outer wall 8 having a large number of holes, and the chamber 6 includes:
A third fire detector 9 that detects a fire in the room 6 operates, for example, at a predetermined temperature, and a first fire extinguishing device 12 that is equipped with an automatic valve 10 and a nozzle 11 that operate in conjunction with this detector 9 are provided. .

Further, 13 is a second fire extinguishing device equipped with an automatic valve 14 and a nozzle 15 that discharge extinguishing agent into the duct 1, and 16 is a second damper that prevents the ignited fibers from flowing out into the next process equipment B. , these are configured to be activated by the operation of the first and second radiation type fire detectors 3 and 4.

Reference numeral 17 denotes a control panel that coordinately controls the above-mentioned devices, and the connection relationship will be explained with reference to the block diagram in FIG. , and the first damper 5 through the OR circuit G1 and the monostable multivibrator MM that operates for a predetermined time.
AND circuit G3 through the OR circuit G1 and the timer circuit T which outputs the output after a predetermined time delay.
are connected to each.

The output of the second radiation fire detector 4 is connected to the electric lock of the second damper 16 and the second fire extinguishing device 13 through the OR circuit G2 and the AND circuit G3, and the OR circuit G2
is connected to the blower 2 through an AND circuit G3, a NOT circuit (2), and an AND circuit G5, and the other input of the AND circuit G5 is connected to a push button switch PB for starting the blower 2.

Further, the output of the third fire detector 9 is connected to the automatic valve 10 of the first fire extinguishing system 12 through an OR circuit G4.

Next, the operation of this device will be explained.

Push button switch PB for starting the blower in Figure 3
When is pressed, the output of the AND circuit G5 becomes high level, the blower 2 is operated, and the fiber mass A is air-transported through the duct 1 to the next process equipment B while being defibrated by the blower 2.

In addition, if stone pieces or metal pieces are mixed in the fiber mass A, for example, if they collide with the rotating part of the blower 2, sparks are generated and the fibers are ignited.
The light activates the radiation type fire detector 3 and the OR circuit G1
The output becomes high level, the alarm circuit is activated, an alarm is issued, and the monostable multivibrator MM is operated for a predetermined short time.

The operation of the multivibrator MM causes the motor of the first damper 5 to rotate, which switches the damper 5 as shown by the dotted line, instantaneously cuts off the duct 1, guides the ignited fibers to the fire extinguishing chamber 6, and stops energizing the motor. Then, it switches back to its original state due to its own weight and opens the duct 1.

By this restart, it is confirmed whether or not the fibers passing through the duct 1 are ignited by the second radiation fire detector 4. If the detector 4 does not operate, the fibers passing through the duct 1 are instantly stopped by the first damper 5. The fibers continue to be pneumatically transported to the next process equipment B just by being interrupted.

Further, the state of the ignited fibers bypassed to the fire extinguishing chamber 6 is monitored by the third fire detector 9, and when the fire becomes stronger and the temperature of the chamber 6 rises, the detector 9 is activated and the
The R circuit G4 becomes high level, fire extinguishing water is discharged from the nozzle 11 of the first fire extinguishing device 12, and safety is ensured.

On the other hand, even after the first damper 5 has been restored and transportation has resumed, if some ignited fibers still exist in the duct 1 and flow into the sensing area (shown by dotted lines) of the radiation fire detector 4, the light will cause The detector 4 operates and the output of the OR circuit G2 becomes high level, which is ANDed with the output of the first radiation fire detector 3 that operated first, which is sent through the timer circuit T.
The signal is input to circuit G3 and the output is set to high level.

This output operates the electric lock of the second damper 16 to release the latch, and the damper 16 descends under its own weight as shown by the dotted line to block the outflow of the fibers to the next process apparatus B.

Furthermore, the AND circuit G5 becomes low level due to the action of the NOT circuit I, so the blower 2 is stopped, and the second fire extinguishing device 14 is activated to emit carbon dioxide gas from the nozzle 15 to extinguish the fire in the duct 1.

The above embodiment was adapted to a pneumatic conveying device in a textile factory, but it is also applicable to a device that pneumatically conveys raw materials such as small pieces of wood, grains of medicine, or grains that can cause sparks and cause a fire when being pneumatically conveyed through a duct. The fire protection device of this invention can be implemented in a similar manner.

This device is configured and operates as described above, so if the distance between the first radiation fire detector and the second radiation fire detector and the position of the damper that switches to the fire extinguishing room are appropriately determined, a fire can be detected. Most of the raw materials can be led to the fire extinguishing room, and there is an effect of providing a fire protection device for pneumatic transport ducts that does not require long-term interruptions in transportation.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional air transport duct fire protection device.
FIG. 2 is a sectional view of an embodiment of the fire prevention device for air transport ducts of this invention, and FIG. 3 is a block circuit diagram of the device shown in FIG. 2. 1... Duct for air transportation, 2... Air blower for transportation, 3... First radiation fire detector, 4... Second Radiant fire detector, 5...
...First damper, 6... Fire extinguishing room, 7...
...Inner wall, 8...Outer wall, 9...Third fire detector, 12.13...Fire extinguishing system, 16.
...Second damper, A...Fiber mass, B.
...Next process equipment.

Claims (1)

[Scope of utility model registration request] 1. A first fire detector and a second fire detector that detect sparks generated in the duct are installed at a predetermined interval in a duct that pneumatically transports raw materials, etc., and between these detectors there is a A damper is provided to switch the flow to the fire extinguishing room for a short time, and the damper is controlled by a first fire detector installed on the upstream side of the duct, and a second fire detector installed on the downstream side of the duct.
A fire prevention device for a pneumatic transport duct for raw materials, characterized in that a fire detector detects the state of the duct after the damper is restored. 2. The second fire detector uses its output to stop a transporting blower and also to operate a duct-blocking damper and fire extinguishing device installed downstream of this detector. A fire protection device for a duct for pneumatic transport of raw materials, etc. as described in item 1. 3. The fire extinguishing room is composed of an inner wall with a large number of holes and an outer wall, and a third fire detector for detecting a fire in this room and a fire extinguishing device controlled by this detector are installed inside the room. A fire protection device for a duct for pneumatic transportation of raw materials, etc. as set forth in claim 1 of the registered utility model.