JPH0118187Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a compressed air dehumidifying device attached to an oil-cooled compressor.More specifically, the present invention relates to a compressed air dehumidifying device attached to an oil-cooled compressor. The purpose is to supply air that is sufficiently dry to the extent that no condensation occurs.

[Prior art and problems]

Conventionally, this type of compressed air dehumidification device is configured to cool the discharged air with an aftercooler installed on the discharge side of the compressor, and after separating the drain, dust and oil mist are separated and sent to a dryer. , a primary heat exchanger, and a secondary heat exchanger (refrigeration machine). In the secondary heat exchanger, the compressed gas is heat exchanged with low-temperature refrigerant gas to become a low-temperature dehumidified saturated compressed gas, and then the primary heat exchange is performed again. introduced into the vessel. In this primary heat exchanger, the high temperature compressed gas introduced into the dryer is precooled by heat exchange between the high temperature compressed gas introduced into the dryer and the low temperature compressed gas cooled by the secondary heat exchanger consisting of the above-mentioned refrigerator. The purpose is to reduce the load on the refrigerator and heat the saturated compressed gas to obtain dry compressed gas with low relative humidity. As mentioned above, such conventional equipment requires a secondary heat exchanger consisting of an aftercooler, a drain separator, and a refrigerator, and a dryer having a primary heat exchanger, etc. It is complex and large, and is necessarily expensive and requires complicated maintenance and management, and running costs are also high. Further, it has the disadvantage that the entire device cannot be made compact. Furthermore, the compressed air to be used should be heated to its usable limit and its relative humidity should be lowered, but the heat medium in the above-mentioned primary heat exchanger is the cooled discharge air after passing through the aftercooler. Inevitably, the temperature was low, and a sufficient dehumidification effect by heating could not be obtained. Therefore, a method has been proposed in which the primary heat exchanger in the dryer is provided on the discharge side of the compressor, and the discharged air is cooled by the secondary heat exchanger consisting of a refrigerator in the dryer, and then reheated by the primary heat exchanger. It was done, but
According to this, it is possible to reheat at a high temperature in the primary heat exchanger, but since a dryer with a secondary heat exchanger consisting of a refrigerator is essential, equipment costs, maintenance, and running costs are high. However, the problem of installation space was not solved, and the burden on the refrigerator was increased. Conventionally, a cooler is installed in the oil reservoir of the receiver tank, and the cooled discharge air that has passed through the aftercooler is passed through the cooler to lower the oil temperature and increase the temperature of the discharge air after it has passed through the aftercooler. Although drying devices have been proposed,
This device has the disadvantage that the temperature of the discharge air in the receiver tank decreases as the oil temperature decreases, so the moisture contained in the discharge air condenses in the receiver tank, which causes the lubricating oil in the receiver tank to emulsify. It was hot. This invention was made to eliminate the above-mentioned conventional drawbacks, and has a compact configuration that uses an afterwarmer to heat the service air for the consumption side.
After drying, the compressed air is reheated by a heater, so it is sufficient even when heating the compressed air only by after-heating, such as when it is cold or when the engine is operating with a light load, cannot obtain the desired heated dry air. It is an object of the present invention to provide a dehumidifying device that can heat and dry compressed air and prevent overheating of the compressed air even in warm weather.

[Means to solve the problem]

In order to achieve the above-mentioned purpose in this invention,
An engine-driven compressor, a receiver tank communicating with a discharge port of the compressor, and an aftercooler communicating with a compressed air discharge port of the receiver tank, the compressor and receiver tank being communicated via an oil cooler for lubrication. In a compressed air dehumidifier attached to an oil-fed compressor that is installed to circulate and supply oil to the compressor, a pipe line for collecting cooling water after cooling the engine into a radiator is branched, and a pipe line for collecting cooling water after cooling the engine is branched, and A temperature detection means and a heater are provided in an air supply conduit that communicates with the inlet, communicates the aftercooler with the secondary flow path of the afterwarmer, and connects with the outlet of the secondary flow path of the afterwarmer; The present invention is characterized in that the temperature detecting means is connected to a power battery via a relay that is closed in response to a set temperature detection signal of the temperature detecting means, and the temperature detecting means is connected to the power battery via an engine key switch.

[Effect]

The key switch starts the compressor and connects the temperature detection means to the power supply. As the compressor operates, the compressed air is fed to the aftercooler, where it is cooled and dehumidified. In the afterheater, it is mixed with the heated cooling water after cooling the engine. It is heat exchanged, heated and dried, and sent into the air supply pipe. Then, when the temperature of the compressed air in the pipe is lower than the set detection temperature of the temperature detection means, a relay between the heater and the power source is closed, and the heater is energized to reheat the compressed air. Further, when the temperature of the compressed air exceeds the set temperature of the temperature detection means, the heater is de-energized.

【Example】

The details of the present invention will be explained below based on the embodiments shown in FIGS. 1 and 2. In addition, in the figure
indicates air piping, 〓 indicates lubricating oil piping, 〓 indicates cooling water piping, 〓 indicates engine exhaust piping and flow direction. Reference numeral 1 denotes an oil-cooled compressor, which is directly connected to and driven by a water-cooled engine 2. This engine 2 is equipped with a radiator 8, sucks compressed air from an intake port through an air cleaner 11, and supplies compressed air to a receiver tank 3 communicating with a discharge port. is discharged together with lubricating oil. A filter 12 is built into the receiver tank 3, and the filter 12 separates lubricating oil contained in the compressed air. The bottom of the receiver tank 3 communicates with an oil cooler 7 via a pipe, and the lubricating oil cooled here is supplied again into the compressor 1 for lubrication, sealing, and cooling. The oil cooler 7 is installed in parallel with the radiator 8, and the oil cooler 7 has
An air-cooled aftercooler 4 is arranged in parallel, which communicates with the compressed gas outlet of the receiver tank 3 via a conduit. Like the radiator 8, the oil cooler 7 and the aftercooler 4 are air-cooled by a fan 9. The filter 12 of the receiver tank 3 opens into a pipe line leading to an aftercooler 4 that cools compressed air, and the compressed air cooled here is passed through a pipe line 25.
It is introduced into the aphtauoma 6 via. In addition,
A drain trap 5' is provided to branch the pipe 25 between the inlets of the secondary flow paths of the aftercooler 4 and the afterwarmer 6, and condensed moisture in the compressed air after passing through the aftercooler 4 is separated. The pipes leading to the engine 2 and the radiator 8 are branched, one branched pipe is returned to the radiator 8, and the other pipe is a flow path for passing waste heat after cooling the engine 2, that is, heated cooling water. The pipe 25 communicates with the aftercooler 4, which is a primary flow path, and is connected to the aftercooler 4 at the entrance of the secondary flow path of the afterheater 6. Therefore, the compressed air cooled by the aftercooler 4 is introduced into the secondary flow path of the afterheater 6 via the pipe line 25. The outlet of the primary flow path joins the cooling water supply pipe leading from the radiator 8 to the engine 2 via a pipe, and the outlet of the secondary flow path leads to an air tool etc. via the air supply pipe 15. Connected to piping and serves as an outlet for service air. Further, a heater 16 is installed near the air supply pipe 15.
are arranged in parallel, and temperature sensors 17 and 18 are attached to the air supply pipe 15 near both ends of the heater 16 as temperature detection means. As will be described in detail later, the sensor 17 installed on the supply side of the temperature sensors operates to detect the temperature of the compressed air supplied as service air and prevent the heater 16 from being energized. Prevent overheating. On the other hand, the temperature sensor 18 operates to prevent the supply of electricity to the heater when the heating by the after-heater 6 is sufficient (such as during high temperatures in summer). That is, two types of temperature sensors are arranged to detect the temperature of the compressed air before and after heating by the heater 16. FIG. 2 shows a circuit diagram of the above embodiment. An engine key switch 30 is connected in series to a power battery 32 via a main switch 31, and this main switch circuit is connected in parallel to a battery relay 33 and a generator 34 attached to the engine. On the other hand, the heater 16 is connected to a relay 35 for energizing the heater.
The heater energizing relay 35 is connected to the main switch circuit via the temperature sensor 1 installed near both ends of the heater 16 of the air supply pipe 15.
It is opened and closed by an overheating prevention relay 36 that opens and closes depending on the set temperature of 7 and 18. Further, the temperature sensors 17 and 18 are connected to the ACC contact of the engine key switch 30 via a heater switch 37 and a battery relay 33. To explain the operation of the above embodiment, when the main switch 31 is turned ON and the starter motor (not shown) is energized by connecting the B-C terminals of the engine key switch 30 and the engine 2 is started, the key switch 30 automatically turns B-C. Connects between ACC terminals. When the engine 2 is started, the air cleaner 11 is
The compressed air sucked in through the compressed air is sent from the discharge port to the receiver tank 3 while still containing lubricating oil, and the oil is separated by a filter 12 in the receiver tank 3. The lubricating oil in the receiver tank 3 is in a high temperature state together with the compressed air due to compression by the compressor 1, and this high temperature lubricating oil is sent to the oil cooler 7 via a pipe line. After being cooled by the oil cooler 7, the lubricating oil is injected and supplied into the compressor 1 again through the pipe line. The compressed air is introduced into the aftercooler 4, where it is cooled, and moisture in the compressed air condenses to become saturated. Next, the saturated compressed air is fed to the secondary flow path of the after-heater 6 after condensed water is separated by the drain trap 5'. On the other hand, since heated cooling water after cooling the engine 2 is introduced into the primary flow path of the after-heater 6, the heated cooling water in the primary flow path of the after-heater 6 is supplied to the secondary flow path. Since the compressed air exchanges heat with the compressed air, the compressed air is heated and dried, becomes dry compressed air with low relative humidity, and is supplied to the air supply pipe 15 from the outlet of the secondary flow path. At the same time, as will be described later, a relay is closed according to the set temperatures of temperature sensors 17 and 18, and the air is heated and dried again by a heater and is discharged from the outlet of the secondary flow path as service air. On the other hand, the cooling water after passing through the after-heater 6 heats the compressed air and then flows from the radiator 8 to the engine 2.
It merges with the cooling water supply pipe leading to engine 2 again.
Supplied and circulated for cooling. On the other hand, B- of the engine key switch 30 mentioned above
Due to the connection between the ACC terminals and the rotation of the generator 34 attached to the engine, the contact point of the battery relay 33 is turned on, and the temperature sensors 17 and 1 are turned on.
8 is connected to the power source via the ACC terminal of the engine key switch 30. When the air temperature in the air supply pipe 15 is lower than the set temperature,
Current flows through the coils of the overheating prevention relay 36 and the heater energization relay 35 based on the set temperature detection signals of the temperature sensors 17 and 18, and their respective contacts also close.
It becomes ON. Therefore, the heater 16 is connected to the power battery 32 and heats the compressed air in the air supply line. Further, when the outlet temperature of the compressed air becomes abnormally high and exceeds the set temperature of the temperature sensor, the relays 35 and 36 mentioned above are turned off and the power to the heater is cut off. The above operation occurs especially when the engine cooling water temperature is relatively low, such as when it is cold or when the engine is operating at a light load.
This is particularly effective in cases where sufficiently dry compressed air at a predetermined temperature cannot be obtained by heat exchange alone using the waste heat of the cooling water, and reheating with this heater allows the desired temperature to be reached according to the purpose of the work. Dry compressed air is obtained. Furthermore, when there is no need to energize the heater 16, such as during high temperatures in summer, reheating by the heater 16 is stopped by turning off the heater switch 37. Furthermore, the battery relay 33 mentioned above can be used to erroneously switch B-C when the engine does not start even though the main switch 31 is ON and the B-C terminals of the engine key switch 30 are connected.
This is provided to prevent the battery 32 from discharging when the heater 16 is energized when the ACC terminals are connected, and the coil of the battery relay 33 is turned off except when the generator 34 is energized. Connected so that it is not energized. After being cooled by the oil cooler 7, the lubricating oil is injected and supplied into the compressor 1 again through the pipe line.

【effect】

As described above, the present invention includes an engine-driven compressor,
a receiver tank communicating with the discharge port of the compressor;
Attached to an oil-cooled compressor, the oil-cooled compressor is provided with an aftercooler that communicates with a compressed air discharge port of the receiver tank, and that connects the compressor and the receiver tank via an oil cooler to circulately supply lubricating oil to the compressor. In the compressed air dehumidification device, a pipe line for collecting cooling water after cooling the engine into a radiator is branched and communicated with an inlet of a primary flow passage of an after-heater,
Further, a temperature detecting means and a heater are provided in an air supply conduit that communicates the aftercooler with the secondary flow path of the after-warmer and is connected to an outlet of the secondary flow path of the after-warmer, and the heater is connected to the temperature detecting means. It has a compact configuration in which the temperature detection means is connected to the power battery via a relay that closes in response to a set temperature detection signal, and the temperature detection means is connected to the power battery via an engine key switch. The compressed air that has passed through the aftercooler is heated and dried by the aftercooler, and the compressed air is heated and dried. Depending on the temperature of the service air and needs, the heater is used to heat and dry the compressor while the compressor is operating after the engine has started. Since the compressed air is reheated afterwards, the compressed air can be sufficiently heated even when heating the compressed air by after-heater alone is insufficient, such as when it is cold or when the engine is operating at a light load. It is possible to always supply dry compressed air at a temperature suitable for the usage conditions to the consumer side without causing any problems. Therefore, the work results are particularly susceptible to the temperature conditions of the work site, etc.
(AIR SAND) construction method is suitable.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram thereof, and FIG. 2 is an electric circuit diagram of the same embodiment. 1: Compressor, 2: Engine, 3: Receiver tank, 4: Aftercooler, 5: Drain separator,
6: After-warmer, 7: Oil cooler, 8: Radiator, 9: Fan, 11: Air cleaner, 1
2: Filter, 15: Air supply pipe line, 16: Heater, 17, 18: Temperature sensor, 25: Pipe line,
30: Engine key switch, 31: Main switch, 32: Power battery, 33: Battery relay, 34: Engine attached generator, 3
5: Heater energization relay, 37: Heater switch.

Claims (1)

[Claims for Utility Model Registration] (1) An aftercooler consisting of an engine-driven compressor, a receiver tank communicating with the discharge port of the compressor, and an air-cooled heat exchanger communicating with the compressed air discharge port of the receiver tank. In a compressed air dehumidifying device attached to an oil-cooled compressor, the compressor and a receiver tank are connected through an oil cooler and lubricating oil is circulated and supplied to the compressor. A pipe line for recovering water to a radiator is branched and communicates with an inlet of a primary flow path of the after-heater, and the after-cooler is communicated with an inlet of a secondary flow path of the after-heater. A temperature detection means and a heater are provided in the air supply pipe connected to the outlet, the heater is connected to a power battery via a relay that is closed by a set temperature detection signal of the temperature detection means, and the temperature detection means is connected to the engine key. A compressed air dehumidifier characterized by being connected to a power battery via a switch. (2) The compressed air dehumidifying device according to claim 1, wherein a relay that closes when electricity is generated in the generator is interposed in the circuit between the temperature detecting means and the engine key switch. (3) The compressed air dehumidifying device according to claim 1, wherein the temperature detecting means is provided to detect the temperature of the compressed air after being heated and dried before and/or after being reheated by the heater. .