Description

APPARATUS FOR PREVENTING EXPLOSION OF INSTRUMENT USING ORGANIC SOLVENT

Technical Field

[1] The present invention relates to an apparatus for preventing explosion of an instrument using an organic solvent. Background Art

[2] A dry cleaning machine is an instrument using an organic solvent commonly found around us. The dry cleaning machine is an instrument for removing soil and stains from clothing or textiles using a volatile organic solvent. The use of organic solvent provides good removal efficiency of oil stains. Because the dry cleaning is superior in removing oil stains and hardly damages the laundry in contrast to washing using water and detergent, expensive cleaning items are cleaned in general by dry cleaning.

[3] But, when released into the atmosphere withoutprocessing, the volatile organic solvent may contribute to severe air pollution, including photochemical smog, when it chemically reacts with nitrogen oxides. Therefore, (as the regulations on air pollution and public health become stricter) most of the dry cleaning machines manufactured these days are equipped with means for preventing discharge of organic solvent.

[4] Although the means for preventing discharge of organic solvent can reduce the discharge of the organic solvent to some extent, there is a risk that overheating of the dry cleaning machine or explosion may occur while recovering the organic solvent, for example, when the saturated oil vapor is exposed to electric spark or static electricity. Various means for preventing explosion have been applied to solve this problem, but they have complicated structure and are difficult to use. Disclosure of Invention Technical Problem

[5] The present invention has been made in order to solve the aforesaid problem. An object of the present invention is to provide an apparatus for preventing explosion of an instrument using an organic solvent which is safe because the temperature and pressure inside the instrument using an organic solvent are monitored in real time and maintained using a controller and sensors, and is capable of preventing explosion by immediately reducing pressure and temperature through the controller when the temperature or pressure is increased above an allowed level for some abnormal reason and promptly spraying fire-extinguishing fluid in the event of a fire. Technical Solution

[6] In order to attain the aforesaid object, in an embodiment, an apparatus for preventing

explosion of an instrument using an organic solvent comprising a casing which provides an isolated internal space and an operation unit which is installed inside the casing and performs a certain task using an organic solvent according to an embodiment of the present invention comprises: a plurality of temperature sensors and a pressure sensor which are installed inside the casing and detect the temperature and pressure inside the casing a controller which is connected with the temperature sensors and the pressure sensor and monitors the temperature and pressure inside the casing a decompressor which is installed at the casing and reduces the pressure inside the casing in response to a control signal from the controller when the pressure inside the casing increases above an allowed level and a cooler which is controlled by the controller, along with the decompressor, and reduces the temperature inside the casing when the temperature inside the casing increases above an allowed level.

[7] In another embodiment, the apparatus for preventing explosion further comprises a fire extinguisher comprising: a fire-extinguishing fluid tank which is installed outside the casing and stores a fire-extinguishing fluid; a plurality of injection nozzles which are connected to the fire-extinguishing fluid tank via a pipe and installed inside the casing; and a valve which is installed at the pipe, is opened and/or closed by the controller, and allows the fire-extinguishing fluid to be sprayed inside the casing through the injection nozzles when it is open.

[8] In another embodiment, the decompressorcomprises a decompression valve which is opened and/or closed by the controller, and reduces the pressure inside the casing by allowing the inside and outside of the casing to communicate with each other when it is open.

[9] In another embodiment, the coolersprays cooling water inside the overheated casing, and comprises: a water supply pipe the end of which is fixed inside the casing and which guides water from the outside into the casing; a water spraying nozzle which is installed at the end of the water supply pipe; and a water supply valve which is installed at the water supply pipe, is opened and/or closed by the controller, and allows water from the outside to be sprayed through the water supply pipe and the water spraying nozzle when it is open.

[10] In another embodiment, at the outside of the instrument using an organic solvent, a power circuit breaker is equipped, which connects the instrument with an outside power source and the connection and/or disconnection of which is controlled by the controller.

[11] In another embodiment, the controller is connected with a warning means which informs the operation of the decompressor and the cooler.

[12] In another embodiment, the instrument using an organic solvent is a dry cleaner or a dryer.

Advantageous Effects

[13] The apparatus for preventing explosion of an instrument using an organic solvent according to the present invention is safe because the temperature and pressure inside the instrument using an organic solvent are monitored in real time and maintained using a controller andsensors, and is capable of preventing explosion by immediately reducing pressure and temperature through the controller when the temperature or pressure is increased above an allowed level for some abnormal reason and promptly spraying fire-extinguishing fluid in the event of a fire. Brief Description of the Drawings

[14] Fig. 1 and Fig. 2 illustrate the overall construction of an apparatus for preventing explosion of an instrument using an organic solvent according to an embodiment of the present invention.

[15] Fig. 3 illustrates the relationship between the temperature sensors and the controller of Fig. 1.

[16] Fig. 4 illustrates the relationship between the pressure sensor and the controller of

Fig. 1.

[17] Fig. 5 illustrates the operation of a controller of an apparatus for preventing explosion according to an embodiment of the present invention.

[18] Fig. 6 is a block diagram illustrating the operation mechanism of an apparatus for preventing explosion according to an embodiment of the present invention. Best Mode for Carrying Out the Invention

[19] Hereinafter reference will be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below.

[20] Fig. 1 and Fig. 2 illustrate the overallconstruction of an apparatus for preventing explosion of an instrument using an organic solvent according to an embodiment of the present invention.

[21] Fig. 1 illustrates a dry cleaner 10, and Fig. 2 illustrates a dryer 40 as examples of the instrument using an organic solvent. The dryer 40is an instrument for removing the organic solvent from the cleaning item cleaned using the dry cleaner 10. Since the organic solvent is released from the cleaning item in liquid or gas state, the dryer 40 is exposed to the risk of explosion as much as the dry cleaner 10.

[22] Referring to Fig. 1, the apparatus for preventing explosion according to this embodiment comprises a plurality of temperature sensors 26 and a pressure sensor 28 installed inside a casing 12 of the dry cleaner 10. The temperature sensors 26 and the pressure sensor 28 are previously known ones and are respectively connected with a controller 34 outside the casing 12 via signal transfer cables (not drawn). The number

and position of the temperature sensors 26 and the pressure sensor 28 may be varied as occasion demands.

[23] The controller 34 is connected to the temperature sensors 26 and the pressure sensor

28, and performs real-time monitoring based on the detection by the temperature sensors 26 and the pressure sensor 28. If required, it controls a decompressor, a cooler, a fire extinguisher, a power circuit breaker, or the like, as will be described later.

[24] Reference numeral 14 is an operation unit (cleaning drum) which holds the laundry along with an organic solvent, additives, and the like and performs cleaning as it rotates.

[25] The dry cleaner 10 operates by the power supplied from an outside power source 32.

It is to be noted that the supplied power passes through a power circuit breaker 30. The connection and/or disconnection of the power circuit breaker 30 is controlled by the controller 34. When the power circuit breaker 30 is disconnected, power supply is stopped and the dry cleaner 10 stops operating.

[26] The apparatus for preventing explosion according to the embodiment further comprises a decompressor and a cooler for preventing explosion of the dry cleaner 10 and a fire extinguisher which operates in the event of a fire.

[27] The decompressor is equipped with a decompression valve 16 which allows the inside and outsideof the casing 12 to communicate with each other. The decompression valve 16 is a solenoid valve remotely controlled by the controller 34 and is closed to isolate the space inside the casing 12 at normal times. When the pressure inside the casing 12 detected by the pressure sensor 28 is above an allowed level, the controller 34 transmits an electrical signal to the decompression valve 16 and opens the decompression valve 16. When the decompression valve 16 is opened, the pressure inside the casing 12 decreases quickly and a stable state is attained.

[28] The size, number of position of the decompression valve 16 may be varied depending on the size or model of the dry cleaner 10.

[29] The cooler serves to lower the temperature inside the casing 12 by spraying cold water into the space inside the casing 12 when the temperature is above an allowed level. The cooler comprises a water supply pipe 54 the end of which is fixed inside the casing 12 and which allows tap water from the outside to be sprayed into the casing 12 and a water supply valve 52 which is installed at the water supply pipe 54. Further, a water spraying nozzle 50 is equipped at the end of the water supply pipe 54.

[30] The water supply valve 52is also a remotely controlled by the controller 34. When the water supply valve 52 is opened by the controller 34, tap water from the outside is sprayedthrough the water supply valve 52 and the water spraying nozzle 50 into the casing 12 as if a sprinkler sprays water, thereby quickly lowering the temperature. Of course, the water supply valve 52 is closed at normal times. The position or number of

the water spraying nozzle 50 may be varied as required.

[31] The fire extinguisher operates, for example, when a fire breaks out inside the casing

12 and immediately extinguishes the fire. The fire extinguisher comprises a high- pressure fire-extinguishing fluid tank 20 which stores a fire-extinguishing fluid, a fire- extinguishing fluid pipe 24 which is connected with the fire-extinguishing fluid tank 20 and is inserted into the casing 12, and injection nozzles 18 which are equipped at the end of the fire-extinguishing fluid pipe 24.

[32] A compressed fire-extinguishing fluid is filled inside the fire-extinguishing fluid tank

20. The fire-extinguishing fluid tank 20 is the same as that of a generally used fire extinguisher. When a valve 22 is opened, the fire-extinguishing fluid filled in the fire- extinguishing fluid tank 20 is transferred into the casing 12 via the fire-extinguishing fluid pipe 24.

[33] The valve 22 is asolenoid valve controlled by the controller 34 and is closed at normal times. It is opened in response to a signal from the controller 34and allows the fire-extinguishing fluid to be sprayed into the casing 12. That is, when a fire breaks out inside the casing 12, it is opened in response to the control signal from the controller 34 and allows the fire-extinguishing fluid in the fire-extinguishing fluid tank 20 to be sprayed into the casing 12, thereby quickly extinguishing the fire.

[34] Reference numeral 48 is a warning means. The warning means 48 operates when the decompressor, the cooler and the fire extinguisher are operated by the controller. It informs the user of the dry cleaner 10 that the decompressor, the cooler and (occasionally) the fire extinguisher are operating for the user to take an adequate measure. For example, the warning means may be a blinker light, an alarm bell a buzzer, a speaker, or the like.

[35] Fig. 2 illustrates a dryer 40 as an example of the instrument using an organic solvent.

As described earlier, the dryer 40 is an instrument for removing the organic solvent from the cleaned laundry. Since the organic solvent is released in liquid or gas state, the dryer 40 is exposed to the risk of explosion as much as the dry cleaner 10.

[36] The dryer 40comprises a casing 42 which provides an isolated internal space and a drying drum 44, as operation unit, which holds the laundry to be dried and rotates inside the casing 42.

[37] In the drawing, the reference numerals the same as those in Fig. 1 refer to the same elements with the same functions. Therefore, detailed description thereof will be omitted.

[38] Fig. 3 illustrates the relationship between the temperature sensors and the controller of Fig. 1.

[39] As illustrated in the figure, the plurality of temperature sensors (a first temperature sensor and a second temperature sensor) 26 are connected to the controller 34 via a

signal converter 46. The signal converter 46 converts the analog temperature (voltage) signals from each of the temperature sensors 26 into signals with a period of 0.3 ms and transfers them to the controller 34. The controller 34 receives the signals from the signal converter 46 and determines the current temperature inside the casing 12, 42.

[40] Fig. 4 illustrates the relationship between the pressure sensor and the controller of

Fig. 1.

[41] Referring to the figure, the pressure sensor 28is connected to the controller 34 via a signal converter 46. The signal converter 46 converts the analog pressure (voltage) signals from each of the temperature sensors 26 into signals with a period of 0.3 ms and transfers them to the controller 34. The controller 34 receives the signals from the signal converter 46 and determines the pressure inside the casing 12, 42 based on the signals.

[42] Fig. 5 illustratesthe operation of a controller of an apparatus for preventing explosion according to an embodiment of the present invention.

[43] Basically, all the operations of the apparatus for preventing explosion according to this embodiment are controlled by the controller 34.

[44] That is, as described above, all of the temperature sensors 26, the pressure sensor 28, the power circuit breaker 30, the decompression valve 16, the warning means 48 and the fire extinguisher operation valve 22 are connected to the controller 34. These elements operate their functions under the control of the controller 34.

[45] In particular, the ranges of allowed temperature and pressure inside the casing 12, 42 may be input in the controller 34 in advance.

[46] In this case, when the current temperature inside the casing 12, 42 informed to the controller 34 by the temperature sensors 26 is outside the allowed temperature range preset in the controller 34, the controller 34 opens the water supply valve 52 and the fire extinguisher operation valve 22.

[47] Similarly, when the current pressure inside the casing 12, 42 informed to the controller 34 by the pressure sensor 28 is abovethe allowed pressure upper limit preset in the controller 34, the controller 34 operates the decompression valve 16 to reduce pressure inside the casing 12, 42.

[48] The controller 34 also controls the power circuit breaker 30. When the temperature or pressure inside the casing 12, 42 is outside the allowed range, it operates the power circuit breaker 30 to disconnect power supply to the dry cleaner 10 or the dryer 40. The power circuit breaker 30 is previously known in the related art.

[49] Further, the warning means 48 is connected to the controller 34. When the water supply valve 52, the decompression valve 16, the power circuit breaker 30 or the fire extinguisher operation valve 22 is operated by the controller 34, the warning means 48 informs the emergency condition to the user so that he/she may take necessary

measures.

[50] Fig. 6 is a block diagram illustrating the operation mechanism of an apparatus for preventing explosion according to an embodiment of the present invention.

[51] When the instrument using an organic solvent comprising the apparatus for preventing explosion according to the embodiment of the present invention is operated, the controller 34sends electrical signals to the temperature sensors 26 and the pressure sensor 28to check if the temperature sensors 26 and the pressure sensor 28 operate normally. The technique of checking the operation condition of the sensor by sending a signal to the sensor is previously known in the related art.

[52] If it is determined that the sensors 26, 28 are operating normally, the temperature and pressure inside the casing 12, 42 are continuously monitored in real time (as long as the instrument using an organic solvent is operated) through the sensors 26, 28.

[53] If the current temperature inside the casing 12, 42 is below the temperature range preset in the controller 34 as a result of the monitoring, the pressure inside the casing 12, 42 is checked using the pressure sensor 28. If the current pressure inside the casing 12, 42 is below the pressure range preset in the controller 34 as a result of the monitoring, the monitoring of temperature and pressure is repeated.

[54] When the temperature inside the casing 12, 42 is above the preset temperature, the controller 34 disconnects power supply to the instrument by sending a signal to the power circuit breaker 30. If the temperature is not decreased apparently, the fire extinguisher is operated to spray the fire-extinguishing fluid into the casing 12, 42. However, if the temperature is decreased after the power disconnection and it is determined that there is no risk of firing, the fire extinguisher is not operated and only the fact that the temperature was above the preset temperature is informed through the warning means 48.

[55] When it is checked that the pressure inside the casing 12, 42 is above the pressure preset in the controller 34, the controller 34 disconnects power supply and reduce the pressure inside the casing 12, 42 by operating the power circuit breaker 30 and the decompression valve 16. If the pressure is not decreased apparently in spite of such measure, the fire extinguisher is operated as above. If it is determined that the risk of firing is not so high, only the warning is provided through the warning means 48.

[56] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.