JPH108902A - Compressor and polypropylene production plant provided with same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To spread lubricating oil uniformly over a compressing chamber whole inner wall while also preventing deposition of foreign matter in a compressing chamber, with a simple structure. SOLUTION: A compressor 1 is constituted such that, by driving a piston in a cylinder chamber 9a, after compressing gas sucked into the cylinder chamber 9a through a suction pipe 37, the gas is delivered from a delivery pipe. Here, in the suction pipe 37, a lubricating oil supply pipe 44 supplying lubricating oil is connected, lubricating oil is supplied into the suction pipe 37 through the lubricating oil supply pipe 44 from a lubricating oil supplier, and it is set so as to flow in the cylinder chamber 9a with gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor used in, for example, a polypropylene manufacturing plant.

[0002]

2. Description of the Related Art Conventionally, as a compressor of this kind, a piston is reciprocated to suck gas from a suction pipe into a cylinder chamber through a suction side valve, compress the gas to a predetermined pressure, and then set a discharge side valve. In some cases, the liquid is discharged from a discharge pipe through a discharge pipe.

[0003] There are two types of such compressors: a lubricating type and a non-lubricating type. In the case of the lubricating type, an oil path is formed in a cylinder block, and a cylinder inner wall on which a piston slides and a portion on which a cylinder rod slides are formed. We refuel and lubricate.

[0004] In the non-lubricating type, the material and shape of each sliding portion are devised to ensure durability.

[0005]

However, in such a conventional lubricating type, it is difficult to form an oil passage in a cylinder block, and at the same time, the lubricating oil is supplied to an oil supply point. Because it is a part corresponding to the road,
It becomes local, and it is difficult to spread it over the entire cylinder chamber wall.

[0006] In the case of a non-lubricating type, when a small foreign matter is mixed in the gas sucked into the cylinder chamber, the fine foreign matter is deposited on the cylinder head or the like, so that
When hit by the piston, problems such as damage to the piston and vibration of the crank mechanism may occur.

[0007] Further, regardless of the oil supply type or the oil-free type, foreign substances contained in gas adhere to and accumulate on each suction-side valve and discharge-side valve. Function may be impaired.

Accordingly, an object of the present invention is to provide a compressor which can distribute lubricating oil evenly over the entire inner wall of a cylinder with a simple structure and can prevent accumulation of foreign matter in the cylinder chamber. And

Another object is to prevent the accumulation of foreign matter on each suction / discharge side valve.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, after the gas sucked into the compression chamber is compressed by driving the driving body in the compression chamber,
The discharge compressor is characterized in that the gas and the lubricating oil are mixed and flow into the compression chamber.

According to a second aspect of the present invention, there is provided a compressor for compressing a gas sucked into a compression chamber through a suction pipe by driving a driving body in the compression chamber, and then discharging the compressed gas from a discharge pipe. A lubricating oil supply pipe for supplying lubricating oil, and supplying lubricating oil from the lubricating oil supply device into the suction pipe via the lubricating oil supply pipe so that the lubricating oil flows into the compression chamber together with gas. It is characterized in that it is a compressor that is.

According to a third aspect of the present invention, a driving member in a compression chamber is driven to compress gas sucked through the suction pipe into the compression chamber through the suction pipe and then discharged through the discharge side valve. In the compressor discharging from the pipe, a lubricating oil supply pipe for supplying lubricating oil is connected to the suction pipe upstream of the suction side valve, and the lubricating oil supply pipe and the suction side valve are connected from the lubricating oil supply device. The compressor is configured so that lubricating oil is supplied into the suction pipe through the suction pipe and flows into the compression chamber together with gas.

The invention described in claim 4 is the invention according to claim 2 or 3.
In addition to the above configuration, the lubricating oil is set so as to be atomized and flow into the suction pipe.

[0014] The invention according to claim 5 provides the invention according to claims 1 to 4.
In addition to the configuration according to any one of the above, the lubricating oil supply device,
It is characterized in that it is set so that it can be arbitrarily controlled between a supply state and a stop state.

[0015] The invention according to claim 6 is the invention according to claims 1 to 5.
After the compressor according to any of the above is disposed downstream of the polymerization machine, unreacted propylene not polymerized by the polymerization machine is compressed by the compressor, and the compressed gas is cooled to be a liquid. And a polypropylene production plant equipped with a compressor that is recirculated to the polymerization machine.

[0016]

Embodiments of the present invention will be described below.

FIGS. 1 to 9 show an embodiment of the present invention.

First, the structure will be described.
1 shows a flow sheet of a polypropylene production plant usually called a slurry method, in which a compressor 1 is provided.

In this polypropylene production plant, the purified propylene is polymerized in the polymerization machine 2 in the presence of a catalyst and a solvent to produce a polymer. The produced polymer is suspended in a solvent to form a slurry. Next, in the flash tank 3, the slurry composed of the catalyst, polymer and solvent is separated into gaseous unreacted propylene and gaseous solvent, and the slurry is led to the surge drum 4 and the gaseous unreacted propylene is separated. The gaseous solvent is led to a solvent recovery unit 6 via a condenser 5. In the solvent recovery device 6, unreacted propylene and the solvent are separated,
Unreacted propylene is guided to the compressor 1 and compressed and cooled, then collected in the propylene recovery unit 7, and is returned to the polymerization machine 2 as recovered propylene. The description of other configurations of this plant is omitted.

As shown in FIG. 1, the compressor 1 has a three-stage compression function. The first stage is composed of two large-diameter cylinders 9, 9 and pistons 10, and the second stage is composed of two cylinders. One cylinder 11 and piston 1 of smaller diameter
According to 2, the third stage further compresses the gas sequentially from the first stage to the third stage by one cylinder 13 / piston 14 having a smaller diameter than the second stage.

More specifically, each of the pistons 10, 12, and 14 as a "drive" is provided with a piston rod 15, 1
6 and 17 are connected, and these piston rods 1
5, 16, 17 are inserted through the packings 18, 19, 20 and these packings 18, 19, 20 cause the "compression chamber".
The inside of the cylinder chambers 9a, 11a, 13a is sealed. In addition, the packing 18, 1
Below the pistons 9, 20, the piston rods 15, 16, 17
Are inserted into a guide bearing 52 supported by a frame 53, and lower ends of these piston rods 15, 16, 17 are connected to a crank mechanism (not shown).

The cylinder heads 9b, 11b, 13b of the cylinders 9, 11, 13 are provided with cooling pipes 21.
Are connected, and cooling water is circulated through the cooling pipe 21.

The cylinders 9, 11, 13
As shown in FIG. 2, a pair of suction side valves 22 are respectively disposed above and below, and a pair of discharge side valves 23 are disposed at positions opposed to the suction side valves 22.

As shown in FIGS. 3 and 4, the suction side valve 22 is provided with a valve seat 25 having a plurality of slits 25a formed in a casing 24.
Plate 26, buffer plate 27 and valve retainer 2 so that
8 are provided. These valve plate 26, buffer plate 27 and valve retainer 28 are provided with slits 26 at corresponding positions.
a, 27a and 28a are formed, and these slits 26a, 27a and 28a and the slit 2 of the valve seat 25 are formed.
The valve plate 26 is formed at a position different from that of the valve plate 5a. When the valve plate 26 is urged by a plurality of springs 29, the slit 25a of the valve seat 25 is closed by the valve plate 26. . When a predetermined pressure acts on the valve plate 26 in the direction of the arrow in FIG. 4 and the valve plate 26 is moved rightward in FIG. Is opened, and the valve plate 26 is opened.
Gas flows into the cylinder chambers 9a, 11a, 13a through the slits 26a, 27a, 28a. Actually, as shown by arrows in FIGS. 2 and 3, a side wall opening 24a formed in the side wall of the casing 24 is formed.
Gas flows into the suction side valve 22 through the
5a... Flows into the cylinder chambers 9a. Of course, the suction side valve 22 is connected to the cylinder chamber 9.
The check valve is a check valve that blocks the flow of gas in the direction opposite to the arrow so that the gas in a, 11a, and 13a does not escape.

As shown in FIGS. 5 and 6, the discharge side valve 23 has a structure similar to that of the suction side valve 22, and a casing 30 having a valve seat 31 having a plurality of slits 31a attached thereto. A valve plate 32, a buffer plate 33, and a valve presser 34 are disposed so as to sequentially overlap the valve seat 31. These valve plate 32, buffer plate 33 and valve retainer 34
The slits 32a, 33a, 34
a are formed, these slits 32a, 33
a, 34a and the slit 31a of the valve seat 31 are formed at different positions. When the valve plate 32 is urged by a plurality of springs 35, the valve seat 3
One slit 31a is closed. Then, a predetermined pressure acts in the direction of the arrow in FIG.
Is moved to the right in FIG. 6 against the urging force of the spring 35, the slit 31a of the valve seat 31 is opened, and the gas in the cylinder chambers 9a, 11a, 13a is released from the valve plate 3.
2, and is discharged through a side wall opening 30a formed in the side wall of the casing 30 (see arrows in FIGS. 2, 5, and 6). Of course, the discharge-side valve 23 is connected to the cylinder chamber 9a,
The check valve is a check valve that prevents gas flow in the direction opposite to the arrow so that gas does not flow into 11a and 13a.

On the other hand, as shown in FIG. 7, the first-stage suction pipe 3 corresponding to the cylinder chamber 9a is provided in the cylinder block 8.
7 and the first-stage discharge pipe 38 correspond to the cylinder chamber 11a, and the second-stage suction pipe 40 and the third-stage discharge pipe 40 correspond to the cylinder chamber 13a. Discharge pipes 42 are connected to each other.

The first-stage, second-stage and third-stage suction pipes 3
7, 39, 41 are respectively connected to the side walls of the cylinder block 8, and the suction-side valves 22, 22, 2 are formed through suction communication passages 8a, 8c, 8e formed in the cylinder block 8.
The first-stage, second-stage and third-stage discharge pipes 38, 40, and 42 are respectively connected to the discharge communication passages 8b, 8d, and 8 formed in the cylinder block 8 while communicating with the second side wall opening 24a.
f, the side wall opening 30a of the discharge side valve 23, 23, 23
Is to be communicated with. In FIG. 2, for convenience, each suction communication passage 8a, 8c, 8e or each discharge communication passage 8
Although b, 8d, and 8f point to the same position, each of the communication passages 8a... is, in fact, an independent passage defined.

The first-stage suction pipe 37 is connected to the separator 6, the first-stage discharge pipe 38 is connected to the second-stage suction pipe 39, and the second-stage discharge pipe 40 is connected to the third-stage suction pipe. 41, and the third-stage discharge pipe 42 is connected to the propylene re-separation tower 6.
0 (see FIGS. 7 and 9).

The first-stage suction pipe 37 is provided with the components shown in FIGS.
As shown in FIGS. 7 and 8, a lubricating oil supply pipe 44 is connected. As shown in FIG. 8, the lubricating oil supply pipe 44 extends from a lubricating oil supply device 46 driven by a geared motor 45, and lubricating oil from an oil tank 47 is supplied by the lubricating oil supply device 46 to the first stage. Suction pipe 3
7 is supplied. This lubricating oil supply pipe 4
4 is provided with a check valve 48 and a stopper valve 49 at the connection portion of the first-stage suction pipe 37. In addition, a relief valve 50 is provided for returning the lubricating oil in the lubricating oil supply pipe 44 to the oil tank 47 when the pressure in the lubricating oil supply pipe 44 rises above a certain value. Further, a strainer 51 is provided between the oil tank 47 and the lubricating oil supply device 46.

The geared motor 45 can be driven or stopped arbitrarily by a control device (not shown).

Next, the operation will be described taking a polypropylene production plant by the slurry method as an example.

In this polypropylene production plant, the purified propylene is polymerized in the polymerization machine 2 in the presence of a catalyst, a solvent and the like to produce a polymer. The produced polymer is suspended in a solvent to form a slurry. Next, in the flash tank 3, the slurry composed of the catalyst, polymer and solvent is separated into gaseous unreacted propylene and gaseous solvent, and the slurry is led to the surge drum 4 and the gaseous unreacted propylene is separated. The gaseous solvent is led to a solvent recovery unit 6 via a condenser 5. In the solvent recovery device 6, unreacted propylene and the solvent are separated,
The unreacted propylene is guided to the compressor 1 to be compressed and cooled, then collected in the propylene recovery unit 7, and returned to the polymerization machine 2 as recovered propylene. The description of other operations of this plant is omitted.

In the compressor 1, unreacted propylene gas flows from the first-stage suction pipe 37 into the first-stage cylinder chamber 9 a via the suction-side valve 22. It is compressed to a predetermined pressure, and is guided to the first-stage discharge pipe 38 via the discharge-side valve 23. Then, this gas is further sucked into the second-stage cylinder chamber 11 a by the second-stage suction pipe 39, compressed to a pressure higher than the first-stage cylinder chamber, and then guided to the second-stage discharge pipe 40. Next, the gas is sucked into the third-stage cylinder chamber 13 a by the third-stage suction pipe 41 and is compressed to a pressure higher than the second-stage cylinder chamber 13. Will be led to.

As described above, in the polypropylene production plant, unreacted propylene is compressed by the compressor 1. However, since the gaseous unreacted propylene contains fine particles of polypropylene, the unreacted propylene is compressed. Conventionally, the fine particles adhere to and accumulate on the valve plate 26 of the suction-side valve 22 of the compressor 1, the inner wall of the cylinder chamber 9a, and the like.

However, according to the compressor 1 of the present invention, such accumulation is prevented. That is, as shown in FIG.
The lubricating oil is sent from the lubricating oil supply device 46 through the lubricating oil supply pipe 44 and is discharged to the vicinity of the upstream side of the suction side valve 22 of the first-stage suction pipe 37. Then, the lubricating oil flows into the cylinder chamber 9a via the suction side valve 22 together with the above-mentioned gas. At this time, since the gas is sucked into the cylinder chamber 9a at a high flow rate, the lubricating oil is atomized and is sucked into the cylinder chamber 9a together with the gas. In particular, in the suction side valve 22, the gas passes through the slits 25a, etc., and has a narrow passage area. As a result, the suction side valve 22 is washed by the lubricating oil to prevent foreign matter from adhering, and is always kept clean. Next, even in the cylinder chamber 9a, the upper and lower rings of the piston 10 and the surrounding rings and the top and bottom of the cylinder chamber 9a are also washed with the mist-like lubricating oil to prevent foreign matter from adhering. In this case, adhesion to the suction side valve 22, the cylinder head 9b, etc. is prevented beforehand, and the suction side valve 22
Of the engine and the vibration of the crank mechanism can be prevented. Needless to say, foreign substances are also prevented from being adhered to the second and third stage cylinder chambers 11a and 13a and the suction side valve 22 and the discharge side valve 23.

Since the compressor 1 is used at a position where fine particles are mixed in such a manner, the compressor 1 of the present invention is used in a plant in which the problem of foreign matter adhesion becomes remarkable, especially in a polypropylene manufacturing plant. Therefore, it is very effective to apply the compressor 1 of the present invention to a polypropylene manufacturing plant.

On the other hand, since the lubricating oil is sucked into the cylinder chambers 9a with the gas, the lubricating oil uniformly adheres to the entire inner wall of the cylinder chamber 9a, and compared with the conventional locally supplied lubricating oil, the cylinders 9 ... The sliding resistance between the pistons 10 and the piston rods 15 can be reduced, and the sealing performance of the packings 18 can be improved. Further, if the lubricating oil is atomized from the lubricating oil supply pipe 44 and injected into the first-stage suction pipe 37, the sealing performance can be further improved.

Further, a part of the lubricating oil is
5. Also lubricate the packing 18 of the guide bearing 5
The droplets are dropped on the second frame 53 and collected separately by a collecting device (not shown), which effectively works to prevent the packings 18 from being worn.

Since the lubricating oil is supplied from the first-stage suction pipe 38, it is not necessary to form an oil passage in the cylinders 9 as compared with the conventional oil supply type lubricating oil type. Easy to do.

Further, by supplying the lubricating oil periodically or at an arbitrary time, it is also possible to remove foreign substances adhering during use without lubrication. In this way, a compressor having the above advantages can be used under conditions of use in which lubricating oil must not be mixed, such as in the case of food products, that is, even in places where conventionally only oilless compressors can be used. Can be used.

The gas thus compressed contains trace amounts of foreign matter and lubricating oil, and is contained in the condensed liquid by intermediate cooling after compression. Has been proven to have no effect.

Although the above embodiment has a three-stage compression function, it goes without saying that only one stage may be used. The compressor 1 of the above embodiment is of a type that compresses gas by reciprocating motion of the pistons 10. However, the present invention is not limited to this, and may be of a type that compresses gas by rotating motion of an impeller or a rotor. The present invention can also be applied to the present invention.

[0043]

According to the invention described in claim 1 or 2,
Since the lubricating oil is allowed to flow into the compression chamber together with the gas, it adheres evenly to the entire inner wall of the compression chamber, and the driving body and the inner wall of the compression chamber are compared with the conventional one that supplies the lubricating oil locally. Can be further reduced.

Further, since the lubricating oil is caused to flow into the compression chamber together with the gas, there is no need to form an oil passage in the cylinder as compared with the conventional oil supply type, so that the structure can be extremely simplified. .

Further, the lubricating oil can prevent foreign matters from accumulating on the inner wall of the compression chamber, and can prevent damage to the driving body and vibration of the crank mechanism.

According to the third aspect of the present invention, a first aspect is provided.
Or, in addition to the effect described in 2 above, since lubricating oil is supplied to the upstream side of the suction side valve, accumulation of foreign matter on the suction side valve can be prevented.

According to the invention set forth in claim 4, according to claim 2,
Or, in addition to the effect described in 3, the lubricating oil is atomized and flows into the suction pipe, so that the lubricating property and the foreign matter accumulation preventing function can be further improved.

According to the fifth aspect of the present invention, the first aspect is provided.
In addition to the effects described in any one of (1) to (4), by setting the lubricating oil supply device to the supply state or the stop state, the supply of the lubrication oil can be performed periodically or at any time, and the lubrication oil is used in an unlubricated state. After removing the foreign matter adhering during the cleaning, it can be used again without lubrication. In this way, a compressor having the above advantages can be used under conditions of use in which lubricating oil must not be mixed, such as in the case of food products, that is, even in places where conventionally only oilless compressors can be used. Can be used.

According to the sixth aspect of the invention, in the polypropylene manufacturing plant, the problem of adhesion of foreign matters becomes remarkable because the compressor is used at a position where fine particles of polypropylene are mixed. The use of the compressor described in any one of 1 to 4 can prevent this, and it is extremely effective to apply this compressor to a polypropylene manufacturing plant.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a compressor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view in a direction orthogonal to FIG. 1 according to the embodiment.

FIG. 3 is a sectional view of a suction-side valve according to the embodiment.

FIG. 4 is an exploded perspective view of the suction side valve according to the embodiment.

FIG. 5 is a sectional view of a discharge-side valve according to the embodiment.

FIG. 6 is a sectional view of a discharge-side valve according to the embodiment.

FIG. 7 is a plan view of the compressor according to the embodiment.

FIG. 8 is a schematic diagram showing a lubricating oil supply path according to the embodiment.

FIG. 9 is a schematic diagram showing a polypropylene production plant according to the same embodiment.

[Explanation of symbols]

 1 Compressor 9a, 11a, 13a Cylinder chamber (compression chamber) 10,12,14 Piston (drive) 22 Suction side valve 23 Discharge side valve 37,39,41 Suction pipe 38,40,42 Discharge pipe 44 Lubricating oil supply Pipe 46 Lubricating oil supply unit

Claims (6)

[Claims] 1. A compressor that discharges a gas sucked into a compression chamber by driving a driving body in the compression chamber and then mixes the gas and lubricating oil to flow into the compression chamber. A compressor characterized by setting. 2. A compressor that compresses a gas sucked into a compression chamber via a suction pipe by driving a driving body in the compression chamber, and then supplies lubricating oil to the suction pipe in a compressor that discharges from a discharge pipe. A lubricating oil supply pipe is connected, lubricating oil is supplied from the lubricating oil supply device into the suction pipe via the lubricating oil supply pipe, and the lubricating oil is supplied into the compression chamber together with gas. Machine. 3. A compressor that compresses gas sucked through a suction pipe through a suction pipe into the compression chamber by driving a driving body in the compression chamber, and then discharges the gas from the discharge pipe through a discharge side valve. A lubricating oil supply pipe for supplying lubricating oil is connected to an upstream side of the suction side valve of the suction pipe, and lubrication is performed from the lubricating oil supply device into the suction pipe via the lubricating oil supply pipe and the suction side valve. A compressor which supplies oil and is set so as to flow into the compression chamber together with gas. 4. The compressor according to claim 2, wherein the lubricating oil is set to be in the form of mist and flow into the suction pipe. 5. The compressor according to claim 1, wherein the lubricating oil supply device is set so as to be arbitrarily controllable between a supply state and a stop state. 6. The compressor according to claim 1, which is disposed downstream of the polymerization machine, and the unreacted propylene not polymerized by the polymerization machine is compressed by the compressor. A polypropylene production plant equipped with a compressor, wherein the compressed gas is cooled to be a liquid, and then recirculated to the polymerization machine.