JPH1114249A - Explosionproof freezing/refrigerating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an explosionproof structure with excellent explosionproofing performance while allowing use of a commercial non-explosionproof structured apparatus by a method wherein a seal type bearing is interposed between a rotating shaft of a motor and a through hole of a container and a dimension is set to avoide running of fire through a clearance at a lead-in part of metal pipes. SOLUTION: A container 3 is made up of a cast product made of an aluminum alloy which comprises a box-shaped body 3a with an upper part opened and a lid body 3b for closing the upper opening thereof. Rotating shafts 4b and 5b of motors 4a and 5a of blowers 4 and 5 and a plurality of through holes 3c for insertion of a wire 11 or the like are formed in a side wall and a bottom wall of the container 3. At this point, a seal bearing 12 is interposed between the rotating shaft 4b and 5b and the through holes 3c to block the run away of fire. The dimension is so set to avoide the run of the fire at a clearance of a lead-in part of the wire 11 and metal pipes 13b, 14b and 15c to the container 3 thereby enabling the building of the container 3 in an explosionproof structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called ceiling-type explosion-proof refrigeration / refrigeration apparatus in which a refrigerator unit is installed on the ceiling of a refrigerator / refrigerator. Used in a gas (or flammable gas) atmosphere, or used to store volatile organic solvents that may generate explosive or flammable gas. Various devices such as switches, terminals, relays, and motors that generate electric sparks and arcs are housed in a single explosion-proof container to reduce the size and explosion-proof of the refrigerator unit. Regardless of the size of the refrigerator, the refrigerator unit can be installed on the ceiling of the refrigerator / refrigerator, and explosions caused by various devices such as motors or explosions generated inside the devices are ignition sources. Explosion around It relates explosion refrigerated apparatus which can completely prevent causing Yubaku atmosphere.

[0002]

2. Description of the Related Art Generally, a compressor, a control panel, a blower for a condenser, a blower for a cooler, a temperature detector, and a pressure detector (gas leak detector) are required to make a refrigeration / refrigeration apparatus a complete flameproof structure. It is necessary to use explosion-proof construction for all devices such as the compressor and the blower and control panel.
It is assembled by installing it on the lower or upper part of the refrigerator and connecting them with an explosion-proof electric wire or the like.

[0003]

However, since most of the various devices having a pressure-resistant explosion-proof structure are non-mass-produced products, the manufacturing cost is extremely high. As a result, there has been a problem that the refrigeration / refrigeration apparatus using them significantly increases the production cost.

[0004] Commercially available non-explosion-proof compressors and blowers are modified to have a structure close to the explosion-proof structure, and these are used to enhance the explosion-proof performance of the refrigeration / refrigeration equipment. No explosion-proof countermeasures could be taken unless significant modifications were made to non-explosion-proof compressors and blowers, and in this case, it was difficult to significantly reduce the production cost of explosion-proof refrigeration / refrigeration equipment. .

[0005] Further, when manufacturing a ceiling-type explosion-proof refrigeration / refrigeration apparatus using various equipment having a flameproof structure, each equipment must be independently installed on the ceiling of the refrigerator / refrigerator. Requires a fairly large installation space. However, in the case of small refrigerators / refrigerators, it is practically impossible to manufacture a small ceiling-type explosion-proof freezer / refrigerator because a sufficient installation area cannot be provided on the ceiling.

In addition, in the conventional explosion-proof refrigeration / refrigeration equipment,
Since a temperature sensor having a structure for transmitting an electric signal is provided inside the refrigerator, it is usually necessary to take the temperature signal out of the refrigerator using a barrier device.
It was necessary to perform seed grounding work. However, in order to secure the first-class grounding (1 / 100Ω or less), considerable cost is required for the grounding work, and it is difficult to secure the first-class grounding in some places. There is a problem in that it is limited in terms of ground resistance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in a conventional overhead explosion-proof refrigeration / refrigeration apparatus, and has as its object the refrigerating machine regardless of the size of the freezing / refrigerator. The unit can be installed on the ceiling of a refrigerator or refrigerator, and it is possible to completely prevent explosions and explosions caused by the equipment while using commercially available non-explosion-proof equipment.
An object of the present invention is to provide a ceiling-type explosion-proof refrigeration / refrigeration apparatus which is inexpensive and has a low manufacturing cost so that the first-class grounding becomes unnecessary. More specifically, explosion grades 1 to
2, explosion-proof freezer and having a proof performance Ignitability G ₁ ~G ₄
Refrigeration equipment is provided.

[0008]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 of the present invention provides a box-shaped freezing / refrigerator having a storage room which can be opened and closed by an opening / closing door, and a freezing / refrigerator. And a refrigerator unit installed on the ceiling of
The refrigerator unit, a refrigerant circuit including a fully-sealed compressor, a condenser and a cooler installed respectively on the ceiling of the refrigerator / refrigerator, and a container having a pressure-resistant explosion-proof structure installed on the ceiling upper surface, A motor is housed in a container, and a blower for the condenser whose rotation axis passes through a part of the container, and a motor is housed in the container, and the rotation axis passes through a part of the container and the ceiling of the refrigerator / refrigerator. Cooler blower and housed in a container,
A refrigerant circulation path, a control mechanism for controlling a condenser blower and a cooler blower, wherein a seal-type bearing is interposed between the rotation shaft of each of the motors and the through hole of the container, It is characterized in that all the gaps in the lead-in portion of the electric wire and the metal tube forming a part of the control mechanism into the container are dimensioned to avoid flame escape.

According to a second aspect of the present invention, the control mechanism detects a temperature at a refrigerant discharge port side of the compressor, a metal pipe connected to the temperature sensor and penetrating the container, A temperature switch comprising a temperature sensor connected to the pipe, and an operating portion which is operated by expansion and contraction of the temperature-sensitive liquid sealed in the metal pipe; Constructed of a metal tube, the gap between the container and the metal tube was set to 0.2 mm or less, and the compressor was stopped when the temperature of the refrigerant discharge port side of the compressor became a certain temperature or more. There is a feature.

The invention according to claim 3 of the present invention is characterized in that the control mechanism detects a temperature at the refrigerant outlet side of the condenser, a metal pipe connected to the temperature sensor and penetrating the container, A temperature switch comprising a temperature sensor connected to the pipe, and an operating portion which is operated by expansion and contraction of the temperature-sensitive liquid sealed in the metal pipe; Constructed of a metal tube, the gap between the container and the metal tube is set to 0.2 mm or less, and the compressor is stopped when the temperature of the refrigerant discharge port side of the condenser exceeds a certain temperature. There is a feature.

According to a fourth aspect of the present invention, the control mechanism includes a temperature sensor for detecting a temperature in the storage room, and a metal tube connected to the temperature sensor and penetrating the ceiling and the container of the refrigerator / fridge. A working part connected to the metal pipe and operated by expansion and contraction of the temperature sensor and the temperature-sensitive liquid sealed in the metal pipe, and connected to the working part and installed on the ceiling of the freezer / refrigerator outside the container, A temperature controller comprising a digital display type temperature controller main body capable of adjusting a set temperature, wherein the metal tube is constituted by a flexible metal tube having an inner diameter of 0.3 mm or less, and a ceiling of a refrigerator / refrigerator. It is characterized in that the gap between the metal tube and the section and the container is set to 0.2 mm or less, and the compressor is started and stopped so that the temperature in the storage room becomes constant.

The invention according to claim 5 of the present invention is characterized in that a connection portion between a motor and an electric wire of a completely hermetic compressor is enclosed and sealed with a resin material.

According to a sixth aspect of the present invention, in the first aspect, the control mechanism 6 uses the low-pressure refrigerant introduced through a low-pressure refrigerant pressure detection pipe 10a branched from a refrigerant pipe 10 connected to a refrigerant inlet side of the compressor 7. When the refrigerant pressure introduced through the low-pressure refrigerant pressure detection pipe 10a is out of the range of the set pressure value, the pressure switch 26 is activated.
6, the operation of the compressor 7 is stopped.

According to a seventh aspect of the present invention, the low pressure refrigerant pressure detecting tube 10a is a flexible metal tube having an inner diameter of 0.8 mm or more.
The portion through which a penetrates the wall surface of the container 3 is hermetically inserted into a through hole 3c formed in the wall surface of the container 3, and low-pressure refrigerant pressure detection tubes 10a are connected to the both side walls in communication with the internal space. A hollow sheath 27 having a predetermined length L is inserted into the inner space of the sheath 27 and forms a refrigerant passage gap Go of 0.2 mm or less between the sheath and the inner wall surface of the sheath 27. It is constituted by a cylindrical body 28.

According to an eighth aspect of the present invention, in the seventh aspect, the length of the cylindrical body 28 is set to 25 mm or more, and the cross-sectional area of the refrigerant passage gap Go is the same as the cross-sectional area of the low-pressure refrigerant pressure detecting tube 10a. Or more than that.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the explosion-proof refrigeration / refrigeration apparatus according to this embodiment has a unit structure that is mounted on a base 17 independently of the refrigerator / freezer 1 on a ceiling 1a of the refrigerator / freezer 1. It is formed by fixedly installing the refrigerator unit 2.

As shown in FIG. 1, the refrigerator / fridge 1
The storage room 1b can be freely opened and closed by an opening / closing door 1c, and the peripheral wall of the storage room 1b and the opening / closing door 1c are formed of a normal steel plate, a heat insulating material or the like. As will be described later, all members that may emit electric sparks or the like are housed in the pressure-resistant container, and even if a fire or explosion occurs in the pressure-resistant container, the flame or the like leaks to the outside. Since the refrigerator / refrigerator 1 has no adverse effect on the external atmosphere at all, the refrigerator / refrigerator 1 is formed as a heat insulating structure composed of ordinary structural members.

On the other hand, the refrigerator unit 2 is shown in FIGS.
As shown in the figure, a container 3 having a flameproof structure, a blower 4 for a condenser, a blower 5 for a cooler, a control mechanism 6, a compressor 7, a condenser 8, a cooler 9, temperature switches 13, 14, and temperature sensors 13a, 14a, Temperature controller 15 and temperature sensor 1
5a and the like, all of which are incorporated on a base 17 forming the ceiling 1a of the refrigerator / freezer 1. That is, the base 1 on which the refrigerator unit 2 is separately assembled.
The assembly and formation of the refrigerator / refrigerator 1 is completed by inserting and fixing the refrigerator / fridge 7 to the ceiling 1a of the refrigerator / refrigerator 1.

FIGS. 3 and 4 show the arrangement of the equipment around the refrigerator unit 2 of the refrigerator / refrigerator 1 according to the present invention and the circulation system diagram of the refrigerant. FIG. FIG. 4 shows a case of using as a freezer. 3 and 4, reference numeral 7 denotes a compressor, 8 denotes a condenser, 9 denotes a cooler, and 18 denotes a refrigerant flow having an appropriate length for preventing freezing around the opening / closing door 1c of the freezer / refrigerator 1. Tube, 19 dryer, 20 capillary tube, 1
3a and 14a are temperature sensors for detecting the temperature of the refrigerant liquid,
15a is a temperature sensor for the inside of the storage (inside the storage room 1b), 4c
Is a condenser fan, and 5c is a cooler fan. or,
4 is an expansion valve, 22 is an explosion-proof solenoid valve, and when used as a freezer, as shown by a dotted line in FIG.
The explosion-proof solenoid valve 22 is installed as a single unit on the side of the container 3.

That is, as shown in FIGS. 1 to 4, the circulation path of the refrigerant is a base 1 fixed to the ceiling 1a of the refrigerator / freezer 1.
7, a compressor 7 and a condenser 8, a refrigerant flow pipe 18, a dryer 19, and a storage room 1 b of the freezer / refrigerator 1.
And a refrigerant pipe 10 connecting these components to each other. The refrigerant (for example, Freon gas) in the compressor 7 is supplied to the condenser 8, the dryer 19, the capillary tube 20 (or The refrigerant is circulated to the compressor 7 through the expansion valve 21) and the cooler 9 (evaporator) in order, and the cool air generated by the low-temperature evaporation of the refrigerant in the cooler 9 is circulated in the storage room 1b, whereby the storage room The inside of 1b is kept in a cold gas phase atmosphere in which the stored material can be frozen and cooled.

The compressor 7 includes a motor (not shown).
The control mechanism 6 described later
Start / stop control. The circulation path of the refrigerant including the compressor 7 of the completely hermetic type is a closed container including the refrigerant pipe 10, and has an internal pressure explosion-proof structure. Further, in the refrigerant flow tube 18, the refrigerant tube 10 drawn from the middle part of the condenser 8 is buried in the periphery of the opening of the storage room 1b, and is stored with the high-temperature refrigerant drawn from the condenser 8 (normally about 30 ° C.). The peripheral portion of the opening of the chamber 1b is heated, so that the refrigeration
Condensation and the like in the opening and closing part of the refrigerator 1 are prevented as much as possible.

The container 3 installed on the base 17 is an airtight container 3 having a pressure-resistant explosion-proof structure made of a high-strength member.
It houses the blower 4 for the condenser, the motors 4a and 5a of the blower 5 for the cooler, the control mechanism 6, the temperature controller 15 and the like which generate electric sparks and arcs which cause ignition. In this example, the container 3 is a box-shaped main body 3a having an open top.
And a lid 3b for closing the upper opening of the main body 3a, and is formed of a casting made of an aluminum alloy.
In the side wall and the bottom wall of the container 3, a plurality of through holes 3c through which the rotating shafts 4b and 5b of the motors 4a and 5a of the blowers 4 and 5 and the electric wire 11 (cable) are inserted.

The condenser blower 4 sends cooling air to the condenser 8 to cool a high-temperature refrigerant.
As shown in FIG. 1, the rotating shaft 4b is fixedly accommodated in the container 3.
Comprises a motor 4a projecting from the through hole 3c, and a fan 4c attached to the rotating shaft 4b of the motor 4a and facing the condenser 8. A seal type bearing 12 is interposed between the rotating shaft 4b and the through hole 3c so that the flame does not escape between them. This seal type bearing 12
Is a device in which the space between the inner ring and the outer ring is sealed with an annular seal plate made of metal. That is, the gap between the rotary shaft 4b and the through hole 3c is adjusted to 0.2 mm or less (preferably 0.1 mm), so that even if a flame is generated inside or outside the container 3, the Does not escape through the gap G.

The cooler blower 5 blows air to the cooler 9 to circulate the low-temperature cold air generated by the cooler 9 in the storage room 1b, and is accommodated in the container 3 as shown in FIG. The motor 5a is fixed and the rotating shaft 5b penetrates the ceiling 1a of the refrigerator / freezer 1 from the through hole 3c of the container 3 and protrudes into the storage room 1b, and is attached to the rotating shaft of the motor 5a to the cooler 9. And a fan 5c for sending wind. A seal type bearing 12 is interposed between the rotating shaft 5b and the through hole 3c so that the flame does not escape between them.
In this seal type bearing 12, a space between an inner ring and an outer ring is sealed with a metal annular seal plate. That is, the gap between the rotating shaft 4b and the through hole 3c is 0.2
mm (preferably 0.1 mm)
The flame does not escape through the gap G.

The control mechanism 6 includes a compressor 7, a condenser 8,
It controls the refrigerant circulation path including the cooler 9 and the like, the blower 4 for the condenser, and the blower 5 for the cooler, respectively, and includes a start relay circuit (not shown) for starting the motor of the compressor 7, and a motor of the compressor 7. Overload relay circuit (not shown) for preventing overheating, control circuit (not shown) for blower 4 for condenser, and control circuit (not shown) for blower 5 for cooler
A temperature switch 13 for stopping the motor of the compressor 7 when the temperature of the refrigerant outlet of the compressor 7 becomes higher than a certain temperature, and the temperature of the refrigerant outlet of the condenser 8 becomes higher than a certain temperature. A temperature switch 14 for stopping the motor of the compressor 7 when the compressor 7 is turned on, and a temperature controller 15 for starting and stopping the motor of the compressor 7 in accordance with the temperature in the storage room 1b. The control mechanism 6 is housed in the explosion-proof container 3 and has a motor of the compressor 7 and a motor 4 a of the blower 4 for the condenser.
And, it is connected to the motor 5a of the blower 5 for the cooler via the electric wire 11, respectively.

The temperature controller 15 included in the control mechanism 6
Is provided with a temperature setting push button, a dial 15b, and the like. The push button 15b and the like are exposed to the outside from the front side wall of the container 3 as shown in FIG. The temperature is set by operating the push button 15b or the like from the outside of the refrigerator 1. or,
The push button 15b and the like provided outside the container 3
It is formed in a so-called explosion-proof structure, so that, of course, the hermeticity and explosion-proof property of the container 3 are not deteriorated.

The temperature switch 13 for stopping the motor of the compressor 7 in accordance with the temperature of the refrigerant discharge port of the compressor 7 is provided so that the temperature of the refrigerant discharge port of the compressor 7 is equal to or higher than a predetermined temperature (room temperature + 70 ° C.).
C.), the motor of the compressor 7 is stopped, and the temperature switch 13 is of a liquid expansion type. That is, the temperature switch 13 is connected to the compressor 7.
A temperature sensor 13a responsive to the temperature of the refrigerant, a flexible metal tube 13b (capillary tube) connected to the temperature sensor 13a and penetrating the container 3, and a temperature sensor 13a. And metal tube 13
a diaphragm (not shown) and a switch mechanism (not shown) operated by expansion and contraction of the temperature-sensitive liquid enclosed in b
(Not shown).
Thus, according to the temperature switch 13, the temperature sensor 13a senses the temperature at the refrigerant discharge port side of the compressor 7, and the change in the temperature causes the temperature-sensitive liquid to expand and contract to operate the operating portion. The temperature of the refrigerant outlet side of the compressor 7 is room temperature + 70 ° C.
At this time, the switch of the operating section is turned off, and the operation of the compressor 7 is stopped.

The temperature switch 14 for stopping the motor of the compressor 7 in accordance with the temperature of the refrigerant discharge port of the condenser 8 is provided when the temperature of the refrigerant discharge port of the condenser 8 is equal to or higher than a predetermined temperature (40 ° C. to 5 ° C.).
0 ° C.), the motor of the compressor 7 is stopped, and the temperature switch 14 is of a liquid expansion type. That is, the temperature switch 14 is provided in contact with the refrigerant discharge port side of the condenser 8, and a temperature sensor 14 a that responds to the temperature of the refrigerant, and a flexible metal tube connected to the temperature sensor 14 a and penetrating the container 3. 14b (capillary tube), temperature sensor 14a and metal tube 1
4b is provided with a diaphragm section (not shown) which is operated by expansion and contraction of the temperature-sensitive liquid enclosed in 4b, and an operation section (not shown) comprising a switch mechanism (not shown). Thus, according to the temperature switch 14, the condenser 8
The temperature sensor 14a senses the temperature of the refrigerant discharge port of the condenser 8 and the temperature-sensitive liquid expands and contracts due to a change in the temperature to operate the operating part.
When the temperature reaches ５０50 ° C. or higher, the switch of the operating unit is turned off, and the operation of the compressor 7 is stopped.

The temperature controller 15 starts the motor of the compressor 7 in accordance with the temperature in the storage room 1b so that the temperature in the storage room 1b of the refrigerator / freezer 1 is maintained at a preset temperature. A liquid expansion type temperature sensor 15
a, a flexible metal tube 15c, a digital temperature controller main body 15d, a temperature switch 15e, and the like. That is, the temperature switch 15e is connected to the temperature sensor 15a protruding into the storage room 1b, the temperature sensor 15a, and the flexible metal tube 15c penetrating through the base 17 and the container 3 of the ceiling 1a of the refrigerator / freezer 1. (Capillary tube) and an operating unit (not shown) including a diaphragm (not shown) and a switch mechanism (not shown) that are operated by expansion and contraction of the temperature-sensitive liquid sealed in the temperature sensor 15a and the metal tube 15c. It is provided.

The temperature controller body 15d is provided with an MCU (microcontroller unit) in a metal box.
And alarm means (alarm lamps and alarms) and the like, which are disposed in the container 3. On the front side of the box, a digital display (not shown) and a push button 15 are provided.
b, etc. are provided, and these display portions and push buttons 15b, etc., penetrate the side wall surface of the container 3 and protrude to the outside, so that the display portion can be seen from the outside of the freezing / refrigerator 1, The set temperature and the like can be adjusted by operating the push button 15b. The temperature controller body 1
For 5d, a digital temperature controller (NEW ZERO SERIES) manufactured by Rika Kogyo Co., Ltd. is used.

Thus, according to the temperature controller 15, the temperature sensor 15a senses the temperature in the storage room 1b, and the temperature-sensitive liquid expands and contracts due to the change in the temperature, thereby operating the operating section. As a result, the switch of the operating section is turned on and off to start and stop the motor of the compressor 7, so that the inside of the storage room 1b can be maintained at a preset temperature. The set temperature can be arbitrarily adjusted or changed by manually operating the push button 15b or the like of the temperature controller main body 15d that is exposed to the outside of the container 3. During operation of the refrigerator unit 2, the storage room 1
b is a set temperature (for example, 10 hours or more)
° C) or more, an alarm is issued by an alarm means (alarm lamp or alarm).

In the refrigerator unit 2 described above, the electric wires 11 and the metal pipes 13b, 14b, and 16b forming a part of the control mechanism 6 are drawn into the explosion-proof structure of the container 3. Thorough explosion-proof measures are taken by making all the gaps dimensionable to avoid flame escape, and sealing and sealing the connection between the motor of the compressor 7 and the electric wire 11 with the resin material 23.

That is, electric wires 11 (cables) connecting the motor of the compressor 7 and the control mechanism 6, the respective temperature switches 13,
As shown in FIGS. 5 and 6, the gap G between the electric wire 11 and the through-hole 3 c of the container 3 is provided at a portion where the metal tubes 13 b and 14 b of FIG. 14 and the metal tube 15 c of the temperature controller 15 are drawn into the container 3. In addition, the gap G between each of the metal tubes 13b, 14b, 15c and the through hole 3c of the container 3 is set to a size capable of avoiding flame escape. It is generally said that this flame escape does not occur if the gap is 0.2 mm or less.
If the size of the gap at the lead-in portion of the electric wire 11 and each of the metal tubes 13b, 14b, and 15c is set to 0.2 mm or less, it is considered that flame escape in the gap can be avoided. Therefore, in this example, the gap between the electric wire 11 and the through hole 3 c of the container 3, and the metal pipes 1 of the temperature switches 13 and 14 are provided.
The gap between 3b, 14b and the through hole 3c of the container 3 and the gap between the metal tube 15c of the temperature controller 15 and the ceiling 1a of the refrigerator / freezer 1 and the through hole 3c of the container 3 are each set to 0.2 mm or less. I have.

FIG. 7 shows a state in which a Pt 100Ω type temperature sensor 15a used in the present invention is mounted in a refrigerator (in a storage room 1b). A through-hole 3c is formed in a sealed container 3 fixed on a base 17. The protection tube 15f of the temperature sensor 15a is inserted therein, and the flange portion is fixed to the bottom wall surface of the container 3. In FIG. 7, G is a gap between the container 3 and the temperature sensor 15a, and is 0.2 m.
m or less. 16 is silica for filling, 1
7a is a steel plate, 17b is a heat insulating material, and 15c is a flexible metal tube. Further, since the temperature sensor 15a of the present invention does not transmit an electric signal for detecting the temperature from the inside of the refrigerator as before, the first-type grounding is unnecessary, and the third-type grounding is usually sufficient.

Each of the temperature switches 13, 14, 15e is a liquid expansion type, and each of the temperature switches 13, 14, 15
Since the metal tubes 13b, 14b, and 15c of 15e are drawn into the container 3, the metal tubes 13b, 14b, and 15c are damaged when the metal tubes 13b, 14b, and 15c are damaged by an explosion in the storage room 1b or the container 3. There is a possibility that the passages in 13b, 14b, and 15c may become flame escape gaps. By the way, since it is generally said that flame escape does not occur if the gap is 0.2 mm or less, if the inner diameter of the metal tubes 13b, 14b, and 15c is 0.2 mm or less, the metal tubes 13b, 1
It is considered that flame escape in 4b and 15c can be avoided. However, when the inner diameter of the metal tubes 13b, 14b, and 15c is 0.2 mm or less, the temperature switch 1
3, 14, and 15e may malfunction. The inventor of the present invention has conducted various experiments to obtain conditions under which no flame escape occurs through the passages in the metal tubes 13b, 14b, and 15c. As a result, the metal tubes 13b, 14b, and 15c were obtained.
It was confirmed that if the inner diameter of c was 0.3 mm or less, flame escape could be avoided reliably.

From these, each of the temperature switches 13,
The inner diameter of the metal tubes 13b, 14b, 15c of 14 and 15e is 0.3 mm or less in order to avoid flame runaway, and is a dimension (generally, a size that can sufficiently function as the temperature switches 13, 14, 15e). Is preferably at least 0.2 mm). In this example, each metal tube 13b,
The inner diameter of 14b, 15c is set to the flame escape limit value of 0.3.
mm. In addition, each metal tube 13b, 14b, 15c
Is preferably 3 m or less in consideration of the functions as the temperature switches 13, 14, and 15e.

Further, as shown in FIGS. 8 and 9, the motor of the compressor 7 and the control mechanism 6 in the container 3 connect the electric wire 11 (cable) to each electrode 7b of the hermetic terminal 7a exposed on the outer surface of the compressor 7. ) Pin jack 11 at each wire end
The connection portion is connected by pressing a. The connection portion is surrounded and sealed by an appropriate non-conductive resin material 23 such as a silicone resin as shown in FIGS. In this example, a metal box 25 surrounding the connection portion is attached to a mounting bracket 24 brazed to the container peripheral wall of the compressor 7, and a silicone resin 23 is injected into the metal box 25, and a metal box including the connection portion is provided. 25 is filled with a silicone resin 23. The injection of the silicon resin 23 is performed by removing a part of the metal box 25.

The refrigerant pipe 1 extending from the condenser 8 to the cooler 9
Since the refrigerant pipe 10 extending from the cooler 9 to the compressor 7 penetrates the base 17 attached to the ceiling 1a of the refrigerator / refrigerator 1, the gap in this penetrating portion can also avoid flame escape. At the same time, it is necessary to exclude the cold air in the storage room 1b from leaking outside. In this example, the escape of the flame and the leakage of the cool air are prevented by hard brazing the refrigerant pipe 10 to the base 17.

In the explosion-proof refrigeration / refrigeration apparatus configured as described above, the refrigerant circulation path including the hermetic compressor 7 having a built-in motor is intrinsically an internal pressure explosion-proof structure, The motors 4a and 5a and the control mechanism 6 of each of the blowers 4 and 5 that may cause the airtightness are accommodated in the container 3, and the gaps in the drawn portions of the electric wires 11 and the metal tubes 13b, 14b and 15c into the container 3 are provided. The container 3 is configured as a flameproof structure with dimensions that can avoid flame escape, and the connection portion of the electric wire 11 exposed to the outside (the connection portion between the hermetic terminal 7a and the electric wire 11) is surrounded by the resin material 23. Since it is hermetically sealed, it is possible to reliably prevent a flash explosion due to an arc or spark.

The use of liquid expansion type switches as the temperature switches 13, 14, 15e allows the metal tubes 13b, 14b, 1 of the temperature switches 13, 14, 16 to be used.
There is a possibility that the inside of 5c may be a flame escape gap to the container 3,
Such a risk can be reliably prevented by setting the inner diameters of the metal tubes 13b, 14b, and 15c to 0.3 mm or less (preferably 0.2 mm).

Further, the motors 4a, 5a of the blowers 4, 5
And the control mechanism 6 are housed in a single explosion-proof container 3 to form a unit, so that the refrigerator unit 2 itself can be reduced in size, and even if the outer diameter of the refrigerator / refrigerator 1 is small, the refrigerator The unit 2 can be installed on the ceiling 1a of the freezer / refrigerator 1, and a small overhead-type explosion-proof freezer / refrigerator can be manufactured.

In addition, the temperature of the refrigerant discharge port of the compressor 7 and the temperature of the refrigerant discharge port of the condenser 8 are detected by the temperature switches 13 and 14, and when these temperatures reach a certain temperature or higher, compression is performed. Because the machine 7 is stopped,
It is possible to prevent the refrigerant discharge port side of the compressor 7 from being abnormally heated to become a source of ignition, and to detect a cooling failure of the refrigerant in the condenser 8 and the like, so that the refrigerator unit 2 can be favorably operated.

As described above, the above explosion-proof refrigeration / refrigeration apparatus is extremely excellent in explosion-proof properties, and can be used safely even in an explosive (or flammable gas) atmosphere.
In addition, it is possible to safely freeze, cool and store an organic solvent or the like which easily generates explosive or flammable gas.
Even if an explosion is triggered inside b, etc., other containers 3
This ensures that fire escapes to equipment and equipment and minimizes damage from explosions.

In the first embodiment of the present invention shown in FIGS. 1 to 4, the operation of the compressor 7 is not controlled by the detected pressure value of the refrigerant liquid, but the refrigerant liquid outlet side of the compressor 7 and Temperature sensor 13 provided on the refrigerant liquid outlet side of condenser 8
and the temperature of the refrigerant liquid is detected by the temperature sensor 14a and the detected temperature of the refrigerant of the former (temperature sensor 13a) is equal to or higher than room temperature + 70 ° C, and the detected temperature of the refrigerant of the latter (temperature sensor 14a) is approximately 50 ° C or higher. Then, the operation of the compressor 7 is stopped by judging that an abnormality has occurred in the refrigerant system. However, instead of the operation control method of the compressor 7 by the two temperature detection sensors 13a and 14a, the refrigerant pressure is reduced. The operation of the compressor 7 may be controlled based on the detected value.

FIG. 10 is an explanatory diagram of the refrigerant circulation path and the operation control system of the compressor according to the second embodiment of the present invention, in which the refrigerant pipe 10 on the inlet side of the compressor 7 is connected to the low-pressure refrigerant pressure detection pipe 1.
Oa is branched, the low-pressure refrigerant pressure detection tube 10a is introduced into the container 3 through the through hole 3c of the pressure-resistant explosion-proof container 3, and the low-pressure refrigerant pressure is introduced into the pressure switch 26 provided in the container 3. It was made.

That is, when the refrigerant pressure applied to the pressure switch 26 through the low-pressure refrigerant pressure detecting pipe 10a becomes a pressure value outside the set range, the pressure switch 26 is operated. Thereby, it is determined that an abnormality has occurred in the refrigerant system, and the operation of the compressor 7 via the control mechanism 6 is stopped.

FIG. 11 shows the mounting state of the low-pressure refrigerant pressure detecting tube 10a in the through hole 3c of the container 3. In FIG. 11, reference numeral 3 denotes a container having an explosion-proof structure, 3c denotes a through hole, and 27 denotes a through hole. Sheath tube, sheath tube body 27a, sheath tube cover 27b, cylindrical body 28, mounting bolt 29, mounting hole for forming a refrigerant passage, L is the length of the refrigerant passage gap Go,
M is a weld.

As the low-pressure refrigerant pressure detecting tube 10a, a flexible metal tube having an inner diameter of 0.8 mmφ or more having a cross-sectional area larger than the operable area of the pressure switch 26 is used in order to ensure the stability of the operation of the pressure switch 26. in use. The hollow cylindrical sheath tube 25 is hermetically inserted into and fixed to a through hole 3c formed in the wall surface of the container 3, and low-pressure refrigerant pressure detecting tubes 10a are provided on both end side walls.
The sheath is welded in communication with the internal space of the tube 27. Further, a cylindrical body 28 for forming a gap Go serving as a refrigerant passage is inserted into the inner space of the sheath tube 27 as described later.

The size of the gap Go for the refrigerant passage is 0.2 mm or less from the viewpoint of preventing flame escape, and the length L of the gap Go is 25 mm or more (preferably 40 to 50 mm). In this embodiment, the gap Go = 0.2 mm and the length L =
It is set to 40 mm.

As described above, the cylindrical body 26 is provided to secure a clearance cross-sectional area for the refrigerant passage larger than the operable area of the pressure switch 26. In the present embodiment, the cylindrical body 26 is used. The outer diameter of the body 28 is set to 1.25 mm, the inner diameter of the sheath tube body 27a is set to 1.65 mm, and the cross-sectional area of the refrigerant passage at the gap Go is set to 0.91 mm ² .

In the explosion-proof refrigeration / refrigeration apparatus according to the second embodiment of the present invention shown in FIGS.
As in the case of the embodiment, not only excellent explosion-proof properties can be obtained, but also safe use in an explosive (or flammable gas) atmosphere. Further, an organic solvent or the like which easily generates explosive or flammable gas can be safely frozen, cooled and stored, and even if an explosion is induced in the storage room 1b or the like, the other Flame escape to the container 3 and the equipment can be reliably prevented, and damage due to the explosion can be minimized.

It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention.

[0053]

As will be easily understood from the above description, the explosion-proof refrigeration / refrigeration apparatus of the present invention has excellent explosion-proof properties and has a pressure-resistant explosion-proof structure. That, Industrial Safety Technology Institute defined explode grades 1-2, are those having explosion-proof performance of the ignition of G ₁ ~G _4, upon which can also be safely used in a combustible gas atmosphere, explosive, flammable It is possible to safely freeze, cool, and store the reactive gas itself, the organic solvent that generates these gases, and the like. In addition, the explosion-proof refrigeration
Refrigeration equipment can be used without modification, such as commercially available compressors and blowers that do not take explosion-proof measures, and does not require significant remodeling of such commercial equipment. Is not very expensive to manufacture and is very practical in terms of manufacturing economy. Further, since the motor and control mechanism of each blower are housed in a single explosion-proof structure container to form a unit, the size of the refrigerator unit itself can be reduced. Therefore, even when the outer diameter of the refrigerator / refrigerator changes,
Freeze the refrigerator unit regardless of the outside diameter of the refrigerator.
It is possible to reliably and satisfactorily install the apparatus on the ceiling of the refrigerator, and it is possible to manufacture a ceiling-type freezing / refrigeration apparatus of any size. In addition, since the temperature sensor installed in the refrigerator is not an electric signal transmission type sensor, it does not require first-class grounding work as before, and there is no restriction on the installation of explosion-proof refrigerators and refrigerators from this aspect. Become.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing a main part of an explosion-proof refrigeration / refrigeration apparatus according to the present invention.

FIG. 2 is a plan view of the explosion-proof refrigeration / refrigeration apparatus.

FIG. 3 is an explanatory diagram showing a refrigerant circulation path when the present invention is used as a refrigerator.

FIG. 4 is an explanatory diagram showing a circulation path of a refrigerant when the present invention is used as a freezer.

FIG. 5 is a cross-sectional view showing a drawing part of an electric wire into a container having a flameproof structure.

FIG. 6 is a cross-sectional view showing a drawn portion of a metal tube into a container having a flameproof structure.

FIG. 7 is a longitudinal sectional view showing a state where a temperature sensor is inserted into a refrigerator.

FIG. 8 is a front view of the fully hermetic compressor, with a portion cut away.

FIG. 9 is an enlarged sectional view taken along line AA of FIG. 5;

FIG. 10 is an explanatory diagram showing a relationship between a refrigerant circulation path (for a refrigerator) and an operation control system of a compressor in an explosion-proof refrigeration / refrigeration apparatus according to a second embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view of a low-pressure refrigerant pressure detection pipe through a container wall portion;

[Explanation of symbols]

1 is a refrigerator-freezer, 1a is a ceiling, 1b is a storage room, 1c is an opening / closing door, 2 is a refrigerator unit, 3 is a container, 3c is a through hole, 4 is a condenser blower, 4a is a motor, 4b is a rotating shaft, 5 is a blower for a cooler, 5a is a motor, 5b is a rotating shaft, 6 is a control mechanism, 7 is a compressor, 8 is a condenser, 9 is a cooler, 10 is a refrigerant pipe, 11 is an electric wire, 12 is a seal type bearing, 13 is a temperature switch, 13a is a temperature sensor, 1
3b is a metal tube, 14 is a temperature switch, 14a is a temperature sensor, 14b is a metal tube, 15 is a temperature controller, 15a is a temperature sensor, 15b is a push button, 15c is a metal tube,
5d is a temperature controller body, 15e is a temperature switch, 17 is a base, 18 is a refrigerant flow tube, 19 is a dryer, 20 is a capillary tube, 21 is an expansion valve, 22 is an explosion-proof solenoid valve, 23 is a resin material, and 26 is a resin material. Pressure switch, 27 is a sheath tube, 27a is a sheath tube body, 27b is a sheath tube lid, 28 is a columnar body, 29 is a mounting bolt, Go is a coolant passage gap, L is the length of the coolant passage gap Go, M is welding Department.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02K 5/08 H02K 5/08 A 5/136 5/136 5/22 5/22

Claims (8)

[Claims] 1. A box-shaped refrigerator / freezer (1) in which a storage room (1b) can be freely opened and closed by an opening / closing door (1c), and a refrigerator installed on a ceiling (1a) of the refrigerator / refrigerator (1). And a unit (2), wherein the refrigerator unit (2) is a hermetic compressor (7), a condenser (8), and a compressor (8) which are respectively installed on the ceiling (1a) of the refrigerator / refrigerator (1). Cooler (9)
, A container (3) of an explosion-proof structure installed on the upper surface of the ceiling (1a), and a motor (4a) are accommodated in the container (3), and a rotating shaft (4b) of the container (3) is 3)
And a motor (5)
a) is accommodated in the container (3), and the rotation axis (5b) of the container (3) is part of the container (3) and the ceiling (1) of the refrigerator / freezer (1).
a) a blower for a cooler penetrating through a), and a control mechanism (6) housed in the container (3) and controlling the refrigerant circulation path, the blower for the condenser (4) and the blower for the cooler (5). And the rotating shafts (4b) and (5b) of the motors (4a) and (5a) and the through holes (3) of the container (3).
c) with a sealed bearing (12) between
Also, the electric wire (11) and the control mechanism (6) into the container (3)
Metal tubes (13b), (14b), (1)
5c) An explosion-proof refrigeration / refrigeration apparatus characterized in that all gaps in the drawn-in portion are dimensioned to avoid flame escape. 2. A temperature sensor (13a) for detecting a temperature at a refrigerant discharge port side of the compressor (7) by the control mechanism (6);
A metal pipe (13b) connected to the temperature sensor (13a) and penetrating the container (3); and a thermosensitive liquid connected to the metal pipe (13b) and sealed in the temperature sensor (13a) and the metal pipe (13b). A temperature switch (13) comprising an operating part operated by expansion and contraction of the container, wherein the metal tube (13b) is formed of a flexible metal tube having an inner diameter of 0.3 mm or less, and the container (3) The gap between the metal pipe (13b) and the metal pipe (13b) is set to 0.2 mm or less, and the compressor (7) is stopped when the temperature of the refrigerant discharge port side of the compressor (7) becomes higher than a certain temperature. The explosion-proof refrigeration / refrigeration apparatus according to claim 1. 3. A temperature sensor (14a) for detecting a temperature at a refrigerant discharge port side of the condenser (8) by the control mechanism (6);
A metal pipe (14b) connected to the temperature sensor (14a) and penetrating the container (3); and a thermosensitive liquid connected to the metal pipe (14b) and sealed in the temperature sensor (14a) and the metal pipe (14b). A temperature switch (14) comprising an operating part operated by expansion and contraction of the metal pipe. The metal pipe (14b) is formed of a flexible metal pipe having an inner diameter of 0.3 mm or less, and a container (3) The gap between the pipe and the metal pipe (14b) is set to 0.2 mm or less, and the compressor (7) is stopped when the temperature on the refrigerant discharge port side of the condenser (8) becomes higher than a certain temperature. The explosion-proof refrigeration / refrigeration apparatus according to claim 1. 4. A control mechanism (6) for detecting a temperature in the storage room (1b), a temperature sensor (15a) connected to the temperature sensor (15a), and a ceiling (1a) of the refrigerator / fridge (1). ) And a metal pipe (15c) penetrating the container (3)
And a temperature sensor (15) connected to the metal pipe (15c).
a) and an operating part operated by expansion and contraction of the temperature-sensitive liquid sealed in the metal tube (15c), and a ceiling part (1a) of the refrigerator / refrigerator (1) connected to the operating part and outside the container (3). A temperature controller (15) comprising: a digital display type temperature controller main body (15d) which is installed in the apparatus and can adjust a set temperature.
And a metal tube (15c) having an inner diameter of 0.3
mm or less, and the ceiling (1a) and the container (3) of the freezer / refrigerator (1) and the metal tube (1).
5c) is not more than 0.2 mm, and the storage room (1
The explosion-proof refrigeration / refrigeration apparatus according to claim 1, wherein the compressor (7) is started and stopped so that the temperature in a) is constant. 5. The explosion-proof refrigeration / refrigeration as claimed in claim 1, wherein the connection between the motor of the compressor (7) and the electric wire (11) of the hermetically sealed type is sealed and surrounded by a resin material (23). apparatus. 6. A pressure switch operated by a low-pressure refrigerant introduced through a low-pressure refrigerant pressure detection pipe (10a) branched from a refrigerant pipe (10) connected to a refrigerant inlet side of a compressor (7). 26), when the refrigerant pressure introduced through the low-pressure refrigerant pressure detection pipe (10a) is out of the range of the set pressure value, the pressure switch (26) is operated to stop the operation of the compressor (7). The explosion-proof refrigeration / refrigeration apparatus according to claim 1. 7. A low-pressure refrigerant pressure detection pipe (10a) is a flexible metal pipe having an inner diameter of 0.8 mm or more, and a part where the low-pressure refrigerant pressure detection pipe (10a) penetrates a wall surface of the container (3) is provided. Is airtightly inserted into a through hole (3c) formed in the wall surface of the container (3), and the low-pressure refrigerant pressure detection pipe (1
0a) having a predetermined length (L), which is connected in communication with the internal space, a hollow sheath tube (27), and a sheath tube (2).
A cylindrical body (28) inserted into the internal space of (7) and forming a coolant passage gap (Go) of 0.2 mm or less between the inner wall surface of the sheath tube (27). An explosion-proof refrigeration / refrigeration apparatus according to claim 6. 8. The length of the cylindrical body (28) is set to 25 mm or more, and the cross-sectional area of the refrigerant passage gap (Go) is set to be equal to or larger than the cross-sectional area of the low-pressure refrigerant pressure detecting pipe (10a). The explosion-proof refrigeration / refrigeration apparatus according to claim 7.