JPH0828479A - Screw refrigerator - Google Patents

Abstract

PURPOSE:To achieve improvement of oil recovery efficiency and efficiency of maintenance work as well as to improve muffling performance. CONSTITUTION:In a screw cooling machine 1 built up with rotors 9, 9 for sucking and compressing gas from a suction port 6, a rotor casing 3 provided with a discharge port 7 for discharging gas compressed by the rotors 9, 9, and a discharge chamber 4 for rotatably supporting the rotors 9, 9 by bearings 12, a muffling container 5 provided with an inner space A for covering the discharge port 7 is provided on the rotor casing 3 or the discharge chamber 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw refrigerator in which lubricating oil is introduced into a gas compression space.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand from users for noise reduction of screw refrigerators to improve the working environment. At the same time, there is an increasing demand for machines with easy maintenance.

Therefore, as a sound deadening structure of a conventional screw refrigerator, a sound deadening device having a member having at least one throttle portion described in JP-A-54-54309 is attached to a suction port or a discharge port. JP-A-56-549
No. 87 disclosed in Japanese Patent Laid-Open No. 4-132891 with a flat muffler forming a muffling chamber in the gas passage in the high pressure chamber following the discharge port, and a vibration absorber following the discharge port described in Japanese Patent Laid-Open No. 4-132891. , Those in which an oil recovery device having an oil separation element inside is connected have been proposed.

[0004]

In any of the devices of the prior art, the pressure pulsation at the discharge port is quite large, reaching a sound pressure level of up to about 180 dB, and in order to reduce the pressure pulsation, a silencer is provided at the discharge port. The current situation is to install.

However, although vibration due to pressure pulsation on the outlet side of the silencer can be reduced, the plate thickness of the silencer outer wall is considerably smaller than the wall thickness of the rotor casing having the rotor, and the silencer outer wall has a rotor casing or the like. Therefore, there is a problem that sound pressure is excited by solid propagating vibration and pressure pulsation to propagate the vibration, and the radiated sound becomes loud to generate noise.

Further, in the conventional apparatus, the compressed gas is separated by a flat muffler or an oil collector for the purpose of recovering the oil injected for the rotation of the rotor, but the oil recovery effect is not sufficient, and these flat gas are not recovered. There was a problem that maintenance work on mufflers and oil recovery units could not be facilitated.

The present invention has been made in order to solve such a problem, and provides a screw refrigerating machine capable of improving the sound deadening performance, improving the oil recovery efficiency, and improving the efficiency of maintenance work. The purpose is to

[0008]

In order to solve the above problems, in the screw refrigerator of the present invention, in claim 1, the rotor for sucking and compressing the gas from the suction port and the gas compressed by this rotor are discharged. A screw refrigerating machine comprising a rotor casing having a discharge port and a discharge chamber having a bearing for rotatably rotatably supporting the rotor, wherein the rotor casing or the discharge chamber has an internal space covering the discharge port. It is provided with a container.

According to a second aspect of the present invention, in the screw refrigerator according to the first aspect, the sound deadening container is formed integrally with either the rotor casing or the discharge chamber.

According to a third aspect of the present invention, in the screw refrigerator according to the first or second aspect, an outlet opening to the internal space is formed in the lower portion of the muffler container.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a sound absorbing member is detachably attached from the one end opening of the sound deadening container into the internal space of the sound deadening container, and the one end opening is removable. It is closed by a possible lid.

According to a fifth aspect, in the fourth aspect, the sound absorbing member is arranged at a position facing at least the discharge port of the rotor casing.

[0013]

In the screw refrigerator of the present invention, since the sound deadening container is provided in the rotor casing or the discharge chamber so as to cover the discharge port of the rotor casing, it is possible to prevent noise from being emitted to the screw refrigerator, and also the rotor casing. Alternatively, it is possible to increase the mass of the discharge chamber, and to reduce the vibration propagated by solid propagating vibration or pressure pulsation from the rotor casing or the like.

Further, a sound absorbing member is removably attached to the internal space of the sound deadening container through the opening at one end of the sound deadening container, and the opening at the one end is supposed to be closed by the removable lid body. The oil mixed in the gas discharged from the outlet into the sound deadening container can be separated by this sound absorbing member, and the sound absorbing member can be easily incorporated into and removed from the internal space by removing the lid. .

Further, by disposing the sound absorbing member at a position facing the discharge port, the oil component mixed with the gas can be separated more efficiently. Further, the separated oil can be discharged into the internal space by the outlet formed in the lower portion of the sound deadening container.

[0016]

【Example】

Example 1 Hereinafter, Example 1 of the screw refrigerator according to the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view of the screw refrigerator in the first embodiment, and FIG. 2 is a horizontal sectional view of the screw refrigerator in the first embodiment.

In FIG. 1 or 2, 1 is a screw refrigerator, and 2 is a compression body of the screw refrigerator. Compression body 2
Is composed of a rotor casing 3, a discharge chamber 4, and a sound deadening container 5.
Has a thickness equal to or greater than that of the casing 3.

Inside the rotor casing 3, the rotor chambers 8 and 8 are opened at one end to the suction port 6 and at the other end to the discharge port 7.
have. In the rotor chambers 8 and 8, screw rotors 9 and 9 are provided with rotary shafts 10 and 10 extending in the axial direction.
The rotor casing 3 is rotatably supported by through holes 11, 11 formed in the discharge chamber 4.

The discharge chamber 4 is provided with a bearing 12 fitted in the through hole 11 and the rotary shaft 1 of the screw roll 9, 9.
By externally fitting it to 0, the roll rolls 9 and 9 can be rotated via the bearing 12, and the rotor casing 3
And are installed continuously.

A muffling container 5 is integrally formed on the upper side of the discharge chamber 4 by a method such as casting. An internal space A having a predetermined volume V, which is open at both ends, is formed in the sound deadening container 5, and the discharge port 7 of the rotor casing 3 communicates with the internal space A. The open end surface of the sound deadening container 5 (open end on the rotor casing 3 side) is in contact with the flange portion 15 protruding outward from the rotor casing 3 and is covered with this flange portion 15.

Here, the volume V of the internal space A of the sound deadening container 5
Is the number of revolutions n of the screw rotor 9, the number of teeth Z, the speed of sound C
(M / s) and the wavelength λ are calculated as follows. When the length in the compressed gas direction flowing in the internal space A is a (the axial direction of the screw roll 9) and the width and height are c and d, respectively,

V = a × b × c (1) and the values of a, b, and c are as follows. .

A> λ / 4 ... (2)

B or c> λ / 10 (3)

Here, λ is obtained by λ = (60 × C) / (n × Z) ... (4), and the volume V of the internal space A is Is the formula (2)-
It is obtained by obtaining each value in (4) and substituting it in the equation (1).

A sound absorbing member 20 is detachably attached to the interior space A of the sound deadening container 5. The sound absorbing member 20 is composed of a porous plate 21 and a porous sound absorbing material 22 such as stainless wool. The sound absorbing member 20 projects from both side surfaces 5A, 5A of the sound deadening container 5 into the internal space A and extends to both open ends. The porous plate 21 and the porous sound absorbing material 22 are inserted in this order between the protrusions 23, 23 and the upper surface 5B of the sound deadening container 5, and are placed on the protrusions 23, 23. Further, in the sound deadening container 5, the flange portion 1 is provided on the side surface 5A on the bottom surface 5C side.
An outlet 30 that opens to the internal space A is formed in the vicinity of the opening end on the opposite side that is covered by 5. This exit 30
Is connected via a pipe to an oil separation and recovery machine having an oil separation element (not shown).

Reference numeral 35 denotes a lid member, which covers the opening end and the through hole 11 of the discharge chamber 4 from the opposite opening end side covered with the flange portion 15 of the sound deadening container 5, and the sound deadening container 5 with a bolt 36. And attached to the discharge chamber 4. As a result, the sound deadening container 5 is closed at both ends.

As described above, the screw refrigerator according to the first embodiment is configured as described above.
The operation of the screw refrigerator will be described.

When the screw refrigerator 1 is operated, the suction port 6
The gas flowing into the rotor chambers 8, 8 from the compressor is compressed by the rotation of the screw rotors 9, 9 and is discharged from the discharge port 7 together with the lubricating oil injected into the rotor chambers 8, 8 for the purpose of freezing or the like. Is discharged to the inner space A where both ends are closed, the noise is reduced by the sound emitted from the screw rotors 9 and 9 due to the constant volume V obtained by the above-mentioned formulas (1) to (4), and the discharge chamber 4 and the noise are eliminated. Along with an increase in the transmission loss due to the increase in mass due to the integral formation with the container 5, the rigidity of the structure is increased, and the vibration of the compression body 2 is reduced, so that the radiation sound from the outer wall of the compression body 2 is reduced.

At this time, the compressed compressed gas mixed with the lubricating oil discharged from the discharge port 7 into the internal space A directly collides with the perforated plate 21 of the sound absorbing member 20 mounted on the upper side of the sound deadening container 5, and Since a part of the perforated plate 21 penetrates into the porous sound absorbing material 22 through the holes 21A, the lubricating oil mixed with the compressed gas is dropped on the bottom surface 5C of the sound deadening container 5 to separate the lubricating oil from the compressed gas.

The compressed gas from which the lubricating oil has been separated is
Together with the separated lubricating oil, the lubricating oil is discharged from the outlet 30 to the outside of the screw refrigerator 1 and is sent to the oil separation and recovery machine through a pipe, and the lubricating oil is further separated by the oil separation element.

When the function of the sound absorbing member 20 mounted in the sound deadening container 5 is deteriorated and maintenance (replacement) is performed, the bolt 36 is loosened and the lid member 35 is compressed.
After the removal, the perforated plate 21 and the porous sound absorbing material 22 can be pulled out for easy maintenance or replacement work.

FIG. 3 shows an actual measurement value obtained by conducting an experiment on the effect of reducing pressure pulsation. The screw refrigerator 1 having the sound deadening container 5 having the structure of the first embodiment, and the first embodiment.
5 is a graph comparing the sound deadening effect with a screw refrigerator having no sound deadening container 5.

In FIG. 3, the vertical axis represents the sound pressure level (dB
A) is the center frequency (Hz) of 1/3 octave on the horizontal axis. As is clear from this graph, the pulsation pressure of about 15 (dB) is about 15 (dB) by using the structure of the first embodiment. It has become possible to have a reduction effect.

Embodiment 2 Hereinafter, Embodiment 2 of the screw refrigerator according to the present invention will be described with reference to the drawings.

FIG. 4 is a vertical sectional view of the screw refrigerator in the second embodiment, and FIG. 5 is a horizontal sectional view of the screw refrigerator in the second embodiment. 4 and 5, the same reference numerals as those in FIG. 1 or 2 in the first embodiment denote the same parts, and detailed description thereof will be omitted.

In FIG. 4 or 5, the sound deadening container 5 is integrally formed on the upper side of the rotor casing 3 by casting or the like. The silencer container 5 has an internal space A formed at one end (on the opposite side 9 from which the discharge chamber 4 projects) and having a predetermined volume V determined by the above formulas (1) to (4). The discharge port 7 of the rotor casing 3 is opened in this internal space A. Further, the outlet 30 is a bottom surface 5C of the sound deadening container 5.
The side surface 5A of the above is located near this opening and opens into the internal space A. The lid member 35 covers the open end of the sound deadening container 5 and is attached to the sound deadening container 5 with bolts 36.

As described above, also in the screw refrigerator according to the second embodiment, the same operation as in the first embodiment is performed to reduce the noise and the sound emitted from the outer wall of the compression main body 2.
The lubricating oil of the compressed gas mixed with the lubricating oil discharged from the discharge port 7 into the internal space A can be separated from the compressed gas.

Then, the function of the sound absorbing member 20 deteriorates,
When performing maintenance (replacement) or the like, after loosening the bolt 36 and removing the lid member 35 from the compression main body 2, the porous plate 21 and the porous sound absorbing material 22 can be pulled out to easily perform maintenance or replacement work. .

Incidentally, in the first or second embodiment of the present invention, design changes and the like within the scope of the invention are included in the first or second embodiment of the present invention.

For example, as shown in FIG. 6, an outlet 30 formed on the side surface 5A of the sound deadening container 5 is provided so as to extend outward from the periphery of this opening and to be separated from the outer peripheral surface 4A of the discharge chamber 4 by a predetermined distance. The L-shaped member 40 and the outer peripheral surface 4A of the discharge chamber 4 may form the discharge passage 41.

Also, as shown in FIG.
The two may be connected.

Further, as shown in FIG. 8, the sound absorbing member 20
However, the perforated plate 21 is fitted and inserted into the groove 50 formed on both side surfaces 5A and 5A of the sound deadening container 5 in a concave shape in cross section and extending to both open ends. 22
May be inserted and attached between the perforated plate 21 and the upper surface 5B of the sound deadening container 5.

[0045]

As described above, according to the screw refrigerator of the present invention, since the sound deadening container is provided in the rotor casing or the discharge chamber so as to cover the discharge port of the rotor casing, noise is emitted to the outside of the screw refrigerator. Can be prevented
Since it is possible to increase the mass of the rotor casing or the discharge chamber, it is possible to reduce the vibration propagated from the rotor casing or the like by sound pressure applied by fixed propagation vibration or pressure pulsation.
Radiated sound from the discharge chamber or the like is reduced.

Further, a sound absorbing member is detachably attached from the one end opening of the sound deadening container into the inner space of the sound deadening container, and the one end opening is supposed to be closed by the removable lid body. The oil mixed in the gas discharged from the outlet into the sound deadening container can be separated by this sound absorbing member, and by removing the lid, the maintenance work of incorporating and removing this sound absorbing member into the internal space. Can be done easily.

Further, since the sound absorbing member is arranged at the position facing the discharge port, the oil component mixed with the gas is easily separated, and the oil recovery efficiency is improved.

Further, since the oil component separated in this internal space can be discharged by the outlet formed in the lower part of the sound deadening container, the oil does not stay in the sound deadening container and hinder the sound deadening property. .

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a screw refrigerator according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the screw refrigerator according to the first embodiment of the present invention.

FIG. 3 is a graph showing actually measured values of an experiment of the effect of reducing pressure pulsation in the screw refrigerator of Example 1 of the present invention.

FIG. 4 is a vertical sectional view of a screw refrigerator according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a screw refrigerator according to a second embodiment of the present invention.

FIG. 6 is a perspective view of essential parts showing a modified example of the outlet of the screw refrigerator in the first or second embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a modified example of the outlet of the screw refrigerator according to the first or second embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a modified example of the sound absorbing member of the screw refrigerator in the first or second embodiment of the present invention.

[Explanation of symbols]

 1 Screw Refrigerator 3 Rotor Casing 4 Discharge Casing 5 Noise Suppression Container 6 Suction Port 7 Discharge Port 9 Rotor 12 Bearing 20 Sound Absorbing Member 30 Outlet 35 Lid

Claims (5)

[Claims] 1. A rotor casing having a rotor for sucking and compressing gas from a suction port, a discharge port for discharging the gas compressed by the rotor, and a discharge chamber having a bearing for rotatably supporting the rotor. In the screw refrigerator configured, a screw refrigerator having a sound deadening container having an internal space covering the discharge port is provided in the rotor casing or the discharge chamber. 2. The screw refrigerator according to claim 1, wherein the sound deadening container is formed integrally with either the rotor casing or the discharge chamber. 3. The screw refrigerator according to claim 1 or 2, wherein an outlet opening to the internal space is formed in a lower portion of the muffler container. 4. A sound absorbing member is removably attached to an inner space of the sound deadening container from an opening of the sound deadening container, and the one end opening is closed by a removable lid. The screw refrigerator according to claim 1, claim 1 or claim 3, respectively. 5. The screw refrigerator according to claim 4, wherein the sound absorbing member is arranged at least at a position facing the discharge port of the rotor casing.