JPH0214998B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a new dryer device for a multi-stage compressor, and particularly to a dryer device using an adsorption cylinder.
By heating and regenerating the adsorption cylinder that has reached a moisture absorption saturation state using the heat held in the pressure discharged from the compressor, and by controlling the temperature of the pressure air introduced from the previous stage compression section into the final stage compression section, the final The present invention relates to a dryer device for a multi-stage compressor that can control the dew point to below a certain value while maintaining the temperature of the discharge pressure air discharged from the compression section of the stages above a certain value.

[Technical background of the invention and its problems] Generally, a plurality of adsorption cylinders are arranged in parallel on the discharge pipe of a compressor, and some of the adsorption cylinders are used for the moisture absorption process, and some of the adsorption cylinders are used for the moisture absorption process. There is a known compressor dryer device in which a saturated adsorption cylinder is placed in a regeneration process for heating and regeneration, and upon completion of the heating regeneration process, the adsorption cylinder in the moisture absorption process is replaced with the regenerated adsorption cylinder. .

In conventional dryer apparatuses, the adsorption cylinder that has reached moisture absorption saturation is heated and regenerated by a heating means such as a heat transfer heater, and it is necessary to provide this heating equipment and a heat source.

By the way, the pressure air discharged from the compressor is approximately 110
The pressure air is at a high temperature of ~170℃, and in conventional equipment, the pressurized air at such a high temperature was cooled to about 40℃ using an aftercooler, and the drain was removed using a drain separator before being introduced into the adsorption cylinder. .

Therefore, the heat held in the pressurized air discharged from the compressor is released without any effective use, which is not preferable from the viewpoint of energy saving.

In addition, in this type of compressor, the actual application
No. 181143 proposes a "rotary compressor dryer." This proposal uses the heat of the pressurized air discharged from the air discharge line connected to the inlet side of the compressor to increase the regeneration heating efficiency of the adsorption tower. It is not possible to supply high-temperature and high-pressure air to the adsorption tower. Also, Jitsugan 54
-No. 181144 proposes a "compression dryer" that heats the pressurized air discharged from a compressor using a separate heating device, but this proposal requires a separate heating means and may consume a lot of power. .

[Object of the Invention] Therefore, the present invention has been devised to effectively solve the problems in the conventional devices described above.

An object of the present invention is to enable the adsorption column that has reached hygroscopic saturation to be heated and regenerated by the heat possessed by the pressure air discharged from a multi-stage compressor, so that the pressure air introduced from the previous stage compression section into the final stage compression section is kept at a predetermined level. To provide a dryer device for a compressor, which can maintain a temperature above a certain value, thereby controlling the dew point below a certain value, and preventing the occurrence of dew condensation.

[Embodiment of the Invention] Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in the figure, 1 is a two-stage multi-stage compressor,
Between the first stage compression section 1a and the second stage (final stage) compression section 1n, there is a discharge port 2 of the previous stage compression section 1a.
An intercooler 5 is provided in a conduit 4 that connects the inlet 3 of the compression section 1n and the inlet 3 of the compression section 1n at the subsequent stage.

A discharge pipe line 6 is connected to a discharge port of the compression section 1n at the final stage of the compression section 1. Branch pipes 7, 7 are connected to this discharge pipe line 6 so as to be branched into two. The above-mentioned discharge pipe line 6 is connected to each branch pipe 7, 7.
Adsorption cylinders 8 and 9 are interposed so as to be connected in parallel to the cylinders. In addition, the discharge pipe line 6 and the branch pipes 7, 7
A first switching valve 10 is provided at the branch point between the two adsorption cylinders 8 and 9, and this switching valve 10 allows high-temperature pressure air from the compressor 1 to be introduced into one of the adsorption cylinders 8 or 9 at the same time. As will be described later, it has the function of extracting dry pressurized air to demand load equipment outside the system, and is constituted by a four-way valve having at least two valve parts.

At the outlet 11 of the adsorption cylinder 8 or 9 which is being heated and regenerated by the introduction of high-temperature pressure air from the compressor 1, there is a drain separation device that cools the pressure air that has passed through the adsorption cylinder and removes condensate from the cooled pressure air. 12 is connected via a second switching valve 13.

This drain separator 12 mainly includes a cooler 14 that cools the pressure air that has passed through the adsorption column, and a cooler 14 that cools the pressure air that has passed through the adsorption column.
A cyclone 15 removes condensate from the pressurized air cooled by the cyclone 4.

Further, the second switching valve 13 transfers the pressurized air discharged from the adsorption column during heating and regeneration, in the illustrated example, the adsorption column 8, to the drain separator 12, and at the same time transfers the pressure air discharged from the drain separator 12, which has already been removed, to the drain separator 12. It is formed by a four-way valve having at least two valve parts configured to transfer pressurized air to another adsorption cylinder 9 that has been heated and regenerated. A dry pressurized air transfer path 16 is connected to the first switching valve 10 for transferring dry pressurized air from the adsorption cylinder 9 in the moisture absorption process to a demand load device outside the system. Therefore, the outlet of either the adsorption cylinder 9 or 8 during the moisture absorption step and the dry pressure air transfer path 16 are automatically connected via the first switching valve 10.

Next, a temperature detector 18 is provided in a conduit 17 that connects the discharge port 2 of the preceding stage compression section 1a to the inlet 3 of the final stage compression section 1n via the intercooler 5. On the other hand, the refrigerant passage 19 of the intercooler 5 is provided with a refrigerant supply amount adjusting means 20 for adjusting the refrigerant supply amount. This regulating means 20 is specifically a flow regulating valve, and its control input is made by the output signal of the temperature sensor 18. In particular, the temperature sensor 18 passes through the conduit 17 to the compression section 1 at the final stage.
The temperature of the pressurized air introduced into the inlet 3 of the refrigerant is detected, and the detected value and a preset set value are compared and calculated, and the temperature of the flow rate regulating valve, which is the refrigerant supply amount regulating means 20, is adjusted so that the temperature becomes higher than the set value. It is configured to variably adjust the amount of refrigerant supplied by adjusting the opening, thereby changing the cooling capacity of the cooler 5. Further, the temperature (discharge temperature) T of the discharge pipe 6 connected to the discharge port of the final stage compression section 1n is the temperature t of the pressure air introduced from the previous stage compression section 1a into the inlet 3 of the final stage compression section 1n.
The following relational expression holds true.

In the formula, P ₁ is the input pressure of the final stage compression section 1n, P ₂
is the outlet pressure (discharge pressure) of the final stage compression section 1n, k
is the specific heat ratio of air, ηad is the adiabatic efficiency of the compressor, and therefore Δt is determined approximately by the pressure ratio of the final stage compression section 1n, and if P ₂ /P ₁ is constant, it can be used as a substitute for controlling the temperature of T. By controlling the temperature of t as follows, the temperature of T can be controlled to be above a certain value.

In this case, when the switching valves 10 and 13 are switched downstream of the compression section 1n of the final stage, and when the compressed air passes through the adsorption cylinders 8 and 9, the pressure _P2 of the pressurized air may fluctuate. , Therefore, the discharge temperature T becomes unstable.

The operation of the present invention having the above configuration will be described. In the illustrated example, the adsorption cylinder 8 located on the left is currently in the heating regeneration process, and the adsorption cylinder 9 located on the right is in the moisture absorption process. In this case, the first switching valve 10 and the second switching valve 13 are set in the direction shown by the solid line. By setting the switching valves 10 and 13 in this way, high-temperature pressure air (110 to 170°C) from the compressor 1 is directly introduced into the adsorption cylinder 8 which is in a moisture absorption saturated state, and the adsorption cylinder 8 is heated and regenerated by the high-temperature pressure air. will be done. Pressurized air flowing out from the outlet 11 of the adsorption cylinder 8 during heating and regeneration is in a high temperature state containing moisture expelled from the adsorption cylinder 8. This hot and humid pressure air flows out to the drain separator 12 via the second switching valve 13. The pressurized air introduced into the separator 12 is first cooled by a cooler 14 and drained by a cyclone 15. cyclone 1
The pressure air flowing out from the adsorption cylinder 9 is transferred through the second switching valve 13 to the adsorption cylinder 9 which has already been heated and regenerated. The pressurized air transferred to the adsorption cylinder 9 absorbs moisture, flows through the first switching valve 10 to the dry pressure air transfer path 16, and is transferred to demand load equipment outside the system.

Further, when the adsorption cylinder 9 that is absorbing moisture approaches the moisture absorption saturation state and the other adsorption cylinder 8 approaches the completion of heating regeneration, the first switching valve 10 and the second switching valve 13 are simultaneously switched. It will be set as shown by the middle broken line. By setting in this manner, the flow of pressurized air from the compressor 1 is switched from the adsorption cylinder 9 to the adsorption cylinder 8 so that the regenerated adsorption cylinder 8 and the adsorption cylinder 9 which has become saturated with moisture absorption are replaced.

As mentioned above, the water vapor pressure, ie, the dew point P ₀ of the pressurized air taken in to the outside of the system via the dry pressure air transfer path 16 is determined by the following equation P ₀ =P _S1 ×P ₃ /P _S2 (3). However, P _S1 is the saturated water vapor pressure at the discharge port temperature of the compressor, P _S3 is the saturated water vapor pressure at the regeneration temperature of the adsorption cylinder in the regeneration process, and P ₃ is the water vapor pressure of the pressurized air taken into the adsorption cylinder in the regeneration process. It is.

On the other hand, the discharge port temperature of the compressor 1 is determined by the inlet temperature of the final stage (second stage in the above example) if the pressure ratio and efficiency of the compressor do not change. This inlet temperature is mainly determined by the flow rate of the refrigerant supplied to the intercooler 5.

When the cooling capacity of the refrigerant increases, the discharge port temperature of the compressor 1 is also lowered accordingly. Since the regeneration heating capacity of the adsorption column during the regeneration process decreases,
As is clear from the above equation (3), the dew point of the pressure air taken into the discharge pipe 2 also increases.

Therefore, when the cooling capacity of the intercooler 5 increases and the discharge port temperature of the compressor 1 falls below a preset value, the temperature detector 18 detects that the final stage compression section 1
The refrigerant supply amount adjusting means 20 detects the inlet temperature of n.
The valve opening degree of the flow rate control valve is reduced to reduce the cooling capacity of the cooler 5. As a result, the inlet temperature of the final stage compression section 1n rises above the set value, and thereby the temperature of the discharged pressurized air can rise above the specified value.

Moreover, since the pressure air temperature on the inlet side of the compression section 1n is detected, stable temperature detection can be performed regardless of pressure fluctuations occurring on the downstream side of the compressor 2 and fluctuations in the discharge pressure.

Therefore, due to changes in the load conditions of the compressor 1,
If the cooling capacity of the intercooler 5 tends to increase, this can be detected in advance and the pressure from the compressor 1 can be maintained at a desired set value or higher. Thereby, the pressure air to the outside of the system to the pressure air demand equipment can be automatically controlled to be below the preset dew point value.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) The adsorption cylinder can be heated and regenerated using the heat possessed by the pressure air discharged from the compressor, which is extremely effective as an energy saving measure.

(2) Can be used in compressors equipped with intercoolers such as multi-stage compressors.

(3) Dried pressurized air below a preset dew point value can be continuously supplied to pressurized air-demanding equipment.

(4) Since the pressure air temperature on the inlet side of the compression section is detected,
Stable temperature detection is possible regardless of fluctuations in discharge pressure.

[Brief explanation of drawings]

The drawings are diagrams showing an embodiment of the device of the present invention. In the figure, 1 is a multistage compressor, 1a is a first stage (first stage) compression section, 1n is a second stage (last stage) compression section,
3 is an inlet of the final stage compression section 1n, 5 is an intercooler, 6 is a discharge pipe connected to the final stage compression section, 8 and 9 are adsorption cylinders, 10 is a first switching valve, 12
13 is a drain separator, 13 is a second switching valve, 17 is a pipe that introduces pressurized air from the compression section in the previous stage to the compression section in the final stage via the intercooler, 18 is a temperature detector, and 20 is a refrigerant supply amount adjustment. It is a means.

Claims (1)

[Claims] 1. In a multi-stage compressor dryer device in which compression sections are connected in multiple stages, an adsorption cylinder that has reached moisture absorption saturation is heated and regenerated by the pressure air discharged from the final stage compression section, and the pressure air used for heating regeneration is cooled. A drain separator that removes condensate, a heated and regenerated adsorption cylinder that dries the pressure air from which condensate was removed by the drain separator, a temperature detector provided on the inlet side of the compression section of the final stage, and a final stage. and a refrigerant supply amount adjusting means for adjusting the amount of refrigerant supplied to the intercooler provided between the compression section and the compression section at the preceding stage,
The temperature detector detects the temperature of the pressurized air introduced from the previous stage compression section to the inlet of the final stage compression section,
A dryer device for a multi-stage compressor, characterized in that the cooling capacity of the intercooler is adjusted by the refrigerant supply amount adjusting means based on this detected value, and the pressure air discharged from the compressor is controlled to be above a certain value. .