JPH01224499A - Oil diffusion pump - Google Patents

Abstract

PURPOSE:To make an oil diffusion pump in the simple configuration and obtain high degree of vacuum in a short time to improve efficiency by forming a bulge portion at a steam conduit which is narrowest among the steam conduits composing a jet conduit and the upper face of the bulge portion in taper shape being parallel to a shade portion. CONSTITUTION:A container A is vacuumed out by operating an auxiliary pump P connected to an exhaust pipe 2. Oil O is heated to be evaporated by energizing a heater 17 of a boiler C. Steam jet generated by heating the oil O to be evaporated blowouts in the downward direction from a steam conduit B via shade portions 12 and 13. Bulge portions 6 and 7 are formed at the narrowest steam conduit among the steam conduits B. Upper faces of the bulge portions 6 and 7 are formed in taper shape being parallel to the shade portions respectively. Accordingly, An oil diffusion pump is made to be in the simple configuration and high degree of vacuum is obtained in a short time to improve efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an oil diffusion pump for obtaining high vacuum.

(Prior Art) Generally, what is called a steam injection pump is known.

This device heats vacuum pump oil with low vapor pressure to generate steam, jets the steam out at ultra-high speed into the low-pressure gas to be exhausted, and uses its kinetic energy to compress the suction mixture. This is to obtain a high vacuum.

Among these pumps, those that are efficient when the intake airflow is in the molecular region are called diffusion pumps.

Conventionally, oil diffusion pumps that use oil vapor have the 8th.
There are vertical types as shown in Figure 9, and horizontal types such as the Hickman type pump.

In Fig. 8, the jet tube main body (
Bo) is arranged and installed, and this jet tube body Bo
) is a three-layer steam conduit (Bl'> (B2°) (・83
′).

(Co) is the boiler section, which contains oil (0').

In addition, (31) is an intake pipe, (32) is an exhaust pipe connected to the auxiliary pump (P), (33) and (34) are water jackets, and (35) is a heater.

FIG. 9 shows the main part of a jet tube body (Bo) consisting of two layers of steam conduits (Blo) (B2°), and the other parts are the same as those in FIG.

First, an evacuated air body in a container (not shown) installed in front of the container (A') and the intake pipe (31) is evacuated to a certain extent by the auxiliary pump (P) connected to the exhaust pipe (32).

Next, the heater (35) of the boiler section (Co) is energized to heat and evaporate the oil (0°) in this container (Ao).

Then, this heated and evaporated steam jet flows into the container (Ao
) of the jet pipe body (B') installed in each steam conduit (
Bl') (B2°) (B3) [In the case of the one in Figure 9, each steam conduit (Bl'> (B2°) (the same applies hereinafter)] From the upper end of each of the umbrella parts (36), (37
), (38) [In the case of the one in Figure 9, the umbrella part (3
6), (37) (the same applies hereinafter)].

Then, the gas molecules of the evacuated object are carried to the exhaust pipe (32) along with the ejection, and a pumping action is performed.

(Problem to be Solved by the Invention) When heated in the boiler section (Co), the boiled and vaporized oil (O゛) flows through each steam conduit (Bl) of the jet tube main body (B'').
o) (B2°) (B3°), but on the way, liquefaction occurs on the inner wall of the pipe.

In conventional oil diffusion pumps, this liquefied oil (○°
) closes the inside of the narrowest steam pipe (Blo) and rises to the top of the pipe, causing liquid oil (0') to flow into the umbrella part (36
).

In addition, in order to obtain a higher vacuum, the umbrella parts (36), (3
7) and (38), it is necessary to reduce the upward movement of gas molecules in the container (Ao) as much as possible, but in conventional oil diffusion pumps, the umbrella part The disadvantage is that the steam jet ejected through the pipe spreads out in a wide-spread shape, and its shielding is not sufficient.

In the case shown in FIG. 9, this drawback is most noticeable in the steam jet ejected through the upper umbrella part (36).
It also appears in the steam jet ejected through the lower umbrella (36).

In addition, in cases where the upper part of the container (Ao) is formed with a removable lid (Do), the lid (Do) is crimped using bolt nuts (39), etc. Although a ring or the like is used, there is a problem that it cannot withstand high vacuum and leaks from this part, and furthermore, there is a problem that strong mechanical tightening is required to deal with gas leakage.

All of these impede pump efficiency, resulting in the disadvantage that the time required to obtain the desired high vacuum value becomes extremely long, or the desired high vacuum value itself cannot be obtained. .

The present invention aims to solve the above problems and provide an efficient oil diffusion pump, as well as various improvements to the oil diffusion pump.

(Means for Solving the Problems) In order to solve the above problems, the present invention first uses an auxiliary pump connected to the exhaust pipe to prevent the liquefied oil from clogging the inside of the steam pipe. Oil, etc. is heated and evaporated in a vacuumed container, and the heated and evaporated steam jet is jetted downward from the upper end of the steam conduit constituting the jet tube body disposed in the container through an umbrella part to cover the The oil diffusion pump is configured such that an ampulla is formed in the thinnest steam conduit among the steam conduits constituting the jet tube body, in a device that performs a pumping action by transporting gas molecules of a vacuum air body to the exhaust pipe. .

In order to sufficiently shield the steam jet inside the container, the upper end of the steam conduit constituting the jet tube body is arranged to extend diagonally downward.

In addition, in cases where the upper part of the container is formed with a removable lid, a male or female tapered surface is formed on the lid, and a female or male tapered surface that is in close contact with the lid is formed on the lid. It was formed on the upper part and was configured to be sealed by rubbing both sides together.

In addition, in cases where a boiler section for heating oil, etc. is formed at the bottom of the container, an insertion tube is installed that enters the boiler section from the outer wall of the container, and the oil temperature can be measured with a temperature sensor inserted into this insertion tube. It was configured as follows.

(Function) In the oil diffusion pump of the present invention configured as described above, the oil liquefied in the narrowest steam conduit constituting the jet pipe body is temporarily collected in the bulk part, and a certain amount of the oil is temporarily collected in the bulk part. If it accumulates in the water, it will flow smoothly down the pipe wall due to its own weight.

In addition, in the case where the upper end of the steam conduit extends diagonally downward, the steam jet is ejected from the gap with the umbrella part, so that the steam jet becomes strong and layered.

In addition, in cases where the upper part of the container is formed of a removable lid, the male or female tapered surface formed on the lid is brought into close contact with the female or male tapered surface formed on the container, It will be sealed at room temperature using a vacuum heat welding agent or the like.

Furthermore, in cases where a boiler section for heating oil, etc. is formed at the bottom of the container, a temperature sensor can be inserted into the insertion tube that enters the boiler section from the outer wall of the container to measure and control the oil temperature. .

(Example) The present invention will be explained in detail below.

In Fig. 1, (A) is a container, (B) is a jet pipe body disposed inside this container (A), and (C) is a boiler section formed at the bottom of the container (A). , contains oil (0) used for an oil diffusion pump (Lion S (trade name) is used as oil (0) in the example).

(D) is a lid that is removable from the top of the container (A), and the female tapered surface (DI) formed on the lid (D) and the top of the container (A) The tapered surface (A1) of the formed male mold is rubbed together with a vacuum hot adhesive applied in the form of a film to seal the container (A). Note that this vacuum heat welding agent can be easily softened by heating it to about 60 to 70°C using a dryer or the like.

Reference numeral (1) denotes an intake pipe, from which molecules of the air to be evacuated in a container (not shown) installed in front of the pipe enter into the container (A).

(2) is an exhaust pipe connected to the auxiliary pump (P),
It is connected slightly diagonally upward to the container (A).

(3) is a water jacket that cools the inner wall of the container (A>), (4) is its water supply port, and (5) is its drain port.

The jet tube body (B) has two steam conduits (B1) (B
2), and these steam conduits (B1) (B2)
Enlarged portions (6) and (7) are formed at the upper ends of the respective upper ends. Incidentally, it is also possible that the jet tube main body is composed of three steam conduits, as in the conventional example shown in FIG.

The upper end of the steam conduit (B1) has a large number of circular holes (8) that allow steam to pass through.
The upper end of B2) is provided with an opening (9) through which steam can pass. Further, the steam conduit (B2) is provided with an ejection hole (10) directed toward the exhaust pipe (2). These steam conduits (B1) (B2) are integrated by several supporting members (11).

Above the steam pipe (Bl) (B2), there is an umbrella part (12
>(13) are provided, respectively, so as to direct the ejected steam of oil (0) downward, as will be described later.

The enlarged portions (6) and (7) have upper surfaces (6') and 7' formed in a tapered shape parallel to the umbrella portions (12 and 13), and in the embodiment, the apex angle is approximately 110°. It has a tapered shape.

The jet tube main body (B) as described above has its lower end locked in a step (14) formed in the container (A), and its upper end locked in a recess formed in the lid (D). (1
5) through a spring (16), thereby being elastically supported.

The boiler section (C) has a band heater (17) wrapped around the lower part of the container (A), and a suitable current is applied to the band heater (17) to heat the oil (0).

An insertion tube (18) is provided from the outer wall of the container (A) that enters into the boiler section (C), and a temperature sensor is inserted into this insertion tube (18) to measure the temperature of the oil (○). It is now possible to do so.

In addition, in the example, the container (A)', the jet tube body (B)
) and the boiler section (C) are all made of glass to facilitate visual observation from the outside and to prevent gas leaks.

Next, the operation of the oil diffusion pump of the present invention constructed as above will be explained.

First, the auxiliary pump (P) connected to the exhaust pipe (2) is operated to evacuate the air object to be evacuated in the container (A>) and the container (not shown) installed in front of the intake pipe (1) to a certain extent. .

Next, the heater (17) of the boiler section (C) is energized,
Oil (0) is heated and evaporated in this container (A).

Then, this heated and evaporated steam jet rises inside each steam conduit (Bl) (B2) of the jet tube main body (B), and reaches the cap section (12) (13) and the ampullae section (6) (7).
) and the upper surface part (6°) (7°), and ejects forcefully downward in a film layer, and at the same time, the ejection hole (10
) toward the exhaust pipe (2).

Then, the gas molecules of the evacuated air in a container (not shown) located in front of the intake pipe (1) are carried to the exhaust pipe (2) as they are ejected, and a pumping action is performed.

Oil (0
) is each steam conduit (Bl) (
B2), and on the way, a phenomenon occurs where the steam liquefies on the inner wall of the steam pipe.

In the narrowest steam conduit (B1) that constitutes the jet tube body (B), this liquefied oil (○) is temporarily collected in the ampullae (6) and accumulates in a certain amount. It flows smoothly down the steam pipe wall due to its own weight.

In addition, the steam jet of oil (0) spouted from the upper end of each steam conduit (Bl) (B2) flows through the water jacket (3).
), the liquid hits the inner wall of the container (A), is liquefied, and is returned to the boiler section (C) where it is heated and evaporated again.

The lid (D) has a tapered surface (Dl) and a tapered surface (AH) formed at the top of the container (A) that are in close contact with each other through a hot welding agent, so that the inside of the container (A) is tightly sealed. Ru.

The temperature of the oil (0) in the boiler section (C) is
8) It is constantly detected by a temperature sensor (not shown) inserted in
By controlling the voltage value applied to the band heater (17), the temperature can be maintained at an appropriate temperature. In addition, in the example, the temperature was 240 to 245°C according to the oil for the oil diffusion pump used.
was controlled.

Figure 7 shows the results of a comparative test between the oil diffusion pump of the present invention and a conventional product. This clearly shows that the final high vacuum degree value itself is also high.

In addition, in the example, the inner diameter of the container (A) is 56 mm, the upper inner diameter of the steam conduit (B1) is 11 mm, and the steam conduit (B2)
The inner diameter of the lj part (6) (7) and the umbrella part (12
) (13) with a distance of 5 mm, and the wall thickness of each is 2 mm.
mm.

In addition, for cleaning the container (A), replenishing/replacing the oil (0), etc., heat and melt the hot adhesive applied between the tapered surface (A1) and the tapered surface (Dl) with a hair dryer, etc. This can be done by removing the lid (D).
), it is convenient to prepare various types according to the target degree of vacuum.

FIG. 4 shows an air-cooled lid (D).

Figure 5 shows the water-cooled lid (D), (21
) is a cooling water supply port, and (22) is its drain port. Moreover, the cooling water of the water jacket (3) can also be used.

Figure 6 shows a recess (D) in which the cooling means can be filled.
23), and liquid nitrogen or the like can be used as the cooling means.

(Effects of the Invention) In any case, according to the oil diffusion pump of the present invention, the oil liquefied in the narrowest steam conduit constituting the jet pipe body is temporarily collected in the bulk part, and a certain amount of oil is temporarily collected in the bulk part. When it accumulates in the steam pipe, it smoothly flows down the pipe wall due to its own weight, so there is no problem of liquefied oil clogging the inside of the steam pipe or blowing out from the upper end, as in the past.

In addition, in the case where the upper end of the steam conduit extends diagonally downward, the steam jet is ejected from the gap with the umbrella part, and the steam jet becomes strong and layered, unlike the conventional method. This prevents the vapor jet from spreading into a wide-opening shape, and the upward movement of gas molecules within the container is significantly reduced, making it possible to obtain a higher vacuum.

Furthermore, the inside of the container is strongly sealed by rubbing the tapered surfaces formed on the lid and the container, so there is no problem of leakage due to the inability to withstand high vacuum as in the conventional case.

We also inserted a temperature sensor into the insertion tube that enters the boiler from the outer wall of the container to accurately detect the oil temperature.
By always controlling the temperature to an appropriate level, the pump can operate stably.

Therefore, the present invention has the feature of providing an efficient oil diffusion pump that has a simple structure and can obtain a high degree of vacuum in a shorter time than before, and can also obtain a higher degree of vacuum.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the oil diffusion pump of the present invention, Fig. 2 is a longitudinal sectional view of the container, Fig. 3 is a longitudinal sectional view of the jet tube body, and Fig. 4 is a longitudinal sectional view of the oil diffusion pump of the present invention.
Figures 6 to 6 are vertical sectional views of air-cooled and water-cooled lids and lids that can be filled with cooling means, Figure 7 is a graph showing the results of a comparison test between the oil diffusion pump of the present invention and a conventional product, and Figure 8 is a graph showing the results of a comparison test between the oil diffusion pump of the present invention and a conventional product. FIG. 9 is a vertical cross-sectional view of an oil diffusion pump according to the prior art, and FIG. 9 is a cross-sectional view of essential parts thereof. (A>... Container (B)... Jet tube body (B1)... Steam conduit (B2)... Steam conduit (C)... Boiler part (D)... Lid body (0 )...Oil (P)...Auxiliary pump (1)...Intake pipe (2)...Exhaust pipe (3)...Water jacket (4) (21)
... Water supply port (5) (22) ... Drain port (6) (7) ... Ampulla (8) ... Circular hole (9) ... Opening (9) (10) ... Ejection hole (11) ... Support member (12) (13) ... Umbrella section (14) ... Step section (15) ... Recess (16) ... Spring (17) ... ... Band heater (18) ... Plug tube (23) ... Four parts Applicant: Yoshio Kinoshita Figure 1 Figure 3 Figure 5 Figure 4 Figure 6 Figure 8 Figure 9 Procedure Xinbo (1 original) April 6, 1986 Director General of the Patent Office Kunio Ogawa 1, Indication of the case Shinagi 1986
3rd year patent application No. 50366 2, name of the invention oil diffusion pump 3, relationship with the case of the person making the amendment Patent applicant address 2-9-14 Mukaigaoka, Bunkyo-ku, Tokyo Name Thurs.
Yoshio Shimo (1 other person) 4, Agent 〒102

Claims (1)

[Scope of Claims] (1) A jet that heats and evaporates oil, etc. in a container that has been evacuated to a certain extent by an auxiliary pump connected to an exhaust pipe, and emits the heated and evaporated steam jet in the container. The steam conduit constituting the jet tube main body is jetted downward from the upper end of the steam conduit constituting the jet tube body through an umbrella portion, and performs a pumping action by carrying gas molecules of the evacuated air to the exhaust pipe. An oil diffusion pump characterized by the formation of an ampulla in the thinnest steam conduit. (2) The oil diffusion pump according to claim (1), wherein the enlarged portion is formed at the upper end of the narrowest steam conduit. (3) The upper surface of the enlarged portion is formed in a tapered shape parallel to the umbrella portion.
The oil diffusion pump according to 1) or (2). (4) The oil diffusion pump according to claim (3), wherein the tapered shape has an apex angle of about 110°. (5) Steam constituting the jet tube body, in which oil, etc. is heated and evaporated in a container that is evacuated to a certain extent by an auxiliary pump connected to the exhaust pipe, and the heated and evaporated steam jet is placed in the container. In a device that performs a pumping action by jetting downward from the upper end of the conduit through an umbrella section and carrying the gas molecules of the air to be evacuated to the exhaust pipe, the upper end of the steam conduit constituting the jet pipe body is directed diagonally downward. An oil diffusion pump characterized by an extended installation. (6) The upper end portion of the steam conduit is formed in a tapered shape parallel to the umbrella portion.
5) Oil diffusion pump as described. (7) The oil diffusion pump according to claim (6), wherein the tapered shape has an apex angle of about 110°. (8) A jet tube main body is constructed by heating and evaporating oil, etc. in a container that is evacuated to a certain extent by an auxiliary pump connected to an exhaust pipe, and then distributing the heated and evaporated steam jet into the container. In the device which performs a pumping action by ejecting the vapor downward from the upper end of each of the above two or more steam conduits via an umbrella portion and carrying the gas molecules of the evacuated air object to the exhaust pipe, an enlarged portion is provided at the upper end of each of the two or more steam conduits. An oil diffusion pump characterized in that the enlarged part has a tapered upper surface parallel to the umbrella part. (9) The oil diffusion pump according to claim (8), wherein the tapered shape has an apex angle of about 110°. (10) Steam constituting the jet pipe body, in which oil, etc. is heated and evaporated in a container that is evacuated to a certain extent by an auxiliary pump connected to the exhaust pipe, and the heated and evaporated steam jet is disposed in the container. The container is ejected downward from the upper end of the conduit through an umbrella part to carry gas molecules of the air to be evacuated to the exhaust pipe to perform a pumping action, and the upper part of the container is formed of a removable lid. In the container, a male or female tapered surface is formed on the lid, and a male or male tapered surface that comes into close contact with the lid is formed on the top of the container, and the container is sealed by rubbing both surfaces together. An oil diffusion pump characterized by: (11) The oil diffusion pump according to claim (10), wherein the removable lid is air-cooled. (12) The oil diffusion pump according to claim 10, wherein the removable lid is water-cooled. (13) The oil diffusion pump according to claim 10, wherein the removable lid body has a recessed portion for filling the cooling means. (14) Steam constituting the jet pipe body, in which oil, etc. is heated and evaporated in a container that is evacuated to a certain extent by an auxiliary pump connected to the exhaust pipe, and the heated and evaporated steam jet is disposed in the container. The gas molecules of the air to be evacuated are ejected downward from the upper end of the conduit through the umbrella part to perform a pumping action, and a boiler part for heating the oil etc. is provided at the bottom of the container. 1. An oil diffusion pump characterized in that the oil diffusion pump is provided with an insertion tube that enters into the boiler section from the outer wall of the container, and the oil temperature can be measured with a temperature sensor inserted into the insertion tube.