JPH08135008A - Preventive device against back flow of vacuum car - Google Patents

Abstract

PURPOSE: To prevent the back flow of froth to a pump, by providing a guide cylinder having a vent hole, a blow-change guide a bar float, etc., in a manhole of a tank and changing downward the air flow when the tank is fully filled, to eliminate the froth. CONSTITUTION: When the level of raw sewage or the like in the tank 1 of a vacuum car rises gradually and reaches the top level, a bar float 12 is pushed up due to the buoyant force and a ball 3 is pushed up and a valve 6 is closed before a guide cylinder 5 is submerged in the raw sewage to prevent the back flow to the vacuum pump. In this case, the froth generated from the raw sewage is transferred together with air flow before the valve is closed but the air conducted to flow in from an air vent 4 of the guide cylinder is forced to downward change the flowing direction by a blow change guide 13 and air continuously flows in from the lower end opening of the guide cylinder 5. Accordingly, the air conducted to flow in from the air vent 4 of the guide cylinder 5 collides with the air conducted to flow in from the lower end opening of the guide cylinder 5 and the forth is eliminated And hence, the froth to the vacuum pump can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum suction car such as a suction cleaning car for sucking and collecting an object to be treated such as human waste together with an air flow into a tank, and to a pressure supply source such as a vacuum pump. The present invention relates to a device for preventing backflow of an object to be processed.

[0002]

2. Description of the Related Art Generally, for example, a suction cleaning vehicle for collecting and processing an object to be processed such as human waste has a tank for containing the object to be processed,
A vacuum pump, which is a pressure supply source for generating an air flow for sucking an object to be processed, is provided in this tank, and this tank and the vacuum pump are connected via an air pipe, and suction is applied to the lower end of the tank. A suction nozzle is attached via a hose, and an air flow is generated in the tank and the suction nozzle by exhausting the air in the tank through an air pipe with a vacuum pump. The workpiece is sucked, the sucked workpiece is gravity-separated or collision-separated in the tank to gradually store it, and the air flow separated from the workpiece is led to a vacuum pump through an air pipe. I have to.

In the suction cleaning vehicle, when suction is continued even if the tank is filled with the object to be treated, the object to be treated enters the air pipe and the air pipe is corroded by the object to be treated. Alternatively, there is a problem that the vacuum pump is clogged, and if the object to be processed enters the vacuum pump, the vacuum pump may be damaged.

Therefore, in such a suction cleaning vehicle, a backflow preventing device for preventing backflow of the object to be processed into the air pipe and the vacuum pump at the same time as the object to be processed is full is built in the manhole of the tank.

Conventionally, this type of backflow prevention device has a ball (3) loosely fitted inside a manhole (2) of a tank (1) and at several upper ends, as shown in FIG. 2, for example. A guide cylinder (5) having a vent hole (4) is fitted and inserted, and an opening / closing valve (6) which can be moved up and down by a ball (3) is rotatably supported at an upper end opening of the guide cylinder (5), and an appropriate number of the valves. Open hole (7)
The bearing member (8) having the
A vacuum pump (not shown), which is a pressure supply source on the upper end
And a discharge pipe (9) connected to each other via an air pipe (not shown), and a manhole cover (11) having a valve port (10) at the inner end of the discharge pipe (9). When the level of the object to be processed in the tank (1) gradually rises and reaches near the top plate of the tank (1), the balls (3) are pushed up by the buoyancy from the object to be processed. Therefore, the on-off valve (6) also gradually rises along with it, and when the tank (1) becomes full, the on-off valve (6) closes the valve port (10) and the objects to be processed to the air pipe and the vacuum pump are closed. Prevent backflow.

[0006]

By the way, during the recovery process of the object to be processed, the object to be processed is sucked into the tank (1) together with the air flow, so that the object to be processed is removed by the air flow in the tank (1). The mixture is agitated to easily generate bubbles, and since the pressure inside the tank (1) is reduced, the bubbles easily grow. Even if bubbles are generated from the object to be processed in the tank (1) and reach the backflow preventive device, the ball (3) does not rise because the buoyancy from the foam is small, and the valve mouth (10 ) Remains open. When the level of the object to be treated reaches the guide cylinder (5) in this state, the air flow passes from the ventilation hole (4) of the air cylinder (5) through the opening (7) of the bearing member (8) to the discharge pipe ( 9), which makes it easier for the foam to flow to the discharge pipe (9), causing the foam to flow back from the discharge pipe (9) to the air pipe, and eventually to the vacuum pump, which may have an adverse effect. was there. In particular, in recent years, the use of suction cleaning vehicles has become widespread, and it is often the case that wastes such as domestic sewage of animals such as pigs and cows, domestic wastewater containing detergents, etc., which collect foam easily, are collected, and a large amount of foam is generated. If the air flows back into the air pipe and is left for a long time, the inside of the air pipe will be corroded, and the inside of the air pipe must be frequently cleaned, which is very time-consuming. Further, although oil is used as a lubricant and a coolant in the vacuum pump, when the foam reaches the vacuum pump, it mixes with the oil and causes damage to the vacuum pump.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and provides a backflow prevention device for a vacuum suction wheel which prevents backflow of foam to a pressure supply source such as an air pipe and a vacuum pump. That is the purpose.

[0008]

In order to achieve the above object, the present invention has a guide tube having a ball loosely fitted therein and having vent holes at several upper ends thereof, which are fitted in a manhole of a tank. An opening / closing valve that can be moved up and down by the ball is mounted in the upper opening of the guide cylinder, and a bearing member having an appropriate number of openings is fitted on the upper opening of the guide cylinder. A backflow prevention device for a vacuum suction vehicle, in which a pump and a discharge pipe connected via an air pipe are integrally formed, and a manhole cover having a valve port is airtightly fitted to an inner end portion of the discharge pipe. , A rod-shaped float that moves up and down depending on the increase or decrease of the processing object in the tank is supported by a guide member that is mounted and fixed below the guide tube so that it can move vertically, and is fixed to the lower surface of the ball in a suspended manner. The guide tube above. Blow change guide cylindrical shape for redirecting the air stream flowing from the hole downwards,
The guide tube is vertically provided between the ventilation hole of the guide tube and the opening of the bearing member.

[0009]

According to the present invention, the rod-shaped float closes the valve opening before the guide cylinder is immersed in the object to be processed, and
Since the blow change guide changes the direction of the air flow flowing from the ventilation hole of the guide cylinder downward, the air flow flowing from the ventilation hole of the guide cylinder collides with the air flow flowing from the lower end opening of the guide cylinder and the bubbles disappear. This prevents backflow of foam to the air piping and vacuum pump.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a backflow prevention device for a vacuum suction wheel according to the present invention will be described below with reference to FIG. However, the same components as those of the conventional device shown in FIG.

As shown in FIG. 1, the apparatus of the present invention is provided with a rod-shaped float (12) on a ball (3) which moves up and down according to the increase and decrease of the object to be treated in the tank (1), and a guide tube (5).
Cylindrical blow change guide (13) for changing the direction of the air flow flowing from the ventilation hole (4) of the
Is provided between the ventilation hole (4) of the guide tube (5) and the opening (7) of the bearing member (8).

The rod-shaped float (12) is made of a hollow plastic pipe or the like with its lower end closed, and is supported by a guide member (14) fixed below the guide cylinder (5) so as to be vertically movable. At the same time, the ball (3) is attached and fixed to the lower surface of the ball (3) in a suspended manner, and the ball (3) is moved up and down by moving up and down depending on the increase and decrease of the object to be treated in the tank (1).

The blow change guide (13) has a vent hole (4) in the guide tube (5) and an opening (7) in the bearing member (8).
And the ventilation hole (4) of the guide tube (5).
It redirects the air flow coming in from downward.

A connecting member (15) is provided between the top plate of the tank (1) and the manhole (2),
Even if the tank (1) is filled with the object to be processed, the guide member (5) is prevented from being immersed in the object to be processed by the connecting member (15).

The device of the present invention has the above-mentioned structure. Next, the operation of the device of the present invention having the above-mentioned structure will be described.

First, when the level of the object to be treated in the tank (1) gradually rises and reaches the vicinity of the top plate of the tank (1), the rod-shaped float (12) is pushed up by the buoyancy force from the object to be treated and the ball (3) can also be pushed up,
The on-off valve (6) also gradually rises along with these, and the on-off valve (6) closes the valve port (10) before the guide cylinder (5) is immersed in the object to be processed, and the air pipe and the vacuum pump are closed. Prevent backflow of the object. In this case, the foam generated from the object to be processed is conveyed together with the airflow until the valve port (10) is closed, but the airflow flowing from the ventilation hole (4) of the guide cylinder (5) is changed by the blow change guide ( The direction is changed downward by 13), and since the guide tube (5) is not immersed in the object to be processed and the air flow continues to flow from the lower end opening of the guide tube (5), the vent hole ( The airflow flowing from 4) collides with the airflow flowing from the lower end opening of the guide cylinder (5), and the collision of this airflow eliminates the bubbles and prevents the backflow of the bubbles to the air piping and the vacuum pump. It

According to the device of the present invention, the rod-shaped float (12)
Closes the valve port (10) before the guide cylinder (5) is immersed in the object to be processed, and the blow change guide (13) lowers the air flow flowing from the ventilation hole (4) of the guide cylinder (5). Since the air flow flowing from the ventilation hole (4) of the guide cylinder (5) and the air flow flowing from the lower end opening of the guide cylinder (5) collide with each other to eliminate bubbles, the air pipe and the vacuum pump are changed. Prevents backflow of foam to the.

It should be noted that the above describes one embodiment of the present invention, and the present invention is not limited to this embodiment. For example, in the above embodiment, the rod-like float (12) is made of a hollow body such as a plastic pipe whose lower end is closed. However, if it is a material having a lower specific gravity than the object to be processed, it should be made of a solid body. Is also possible. Further, in the above-mentioned embodiment, even if the object to be processed is filled in the tank (1), the guide tube (5) is prevented from being immersed in the object to be processed.
Although the additional member (15) is separately provided between the top plate of the tank and the manhole (2), the additional member (15) may be integrally formed with the top plate of the tank (1) or the manhole (2). It is possible.

[0019]

According to the present invention, even when a large amount of foam is generated from the object to be processed during the work of recovering the object, the foam disappears due to the collision of the air flow, and the foam to the air pipe and the vacuum pump is prevented. It is possible to prevent backflow. Therefore, unlike the conventional case, a large amount of foam does not flow back into the air pipe to corrode the inside of the air pipe, and it is not necessary to remove the air pipe for frequent cleaning, which greatly saves labor. Further, since the oil is not mixed in the oil inside the vacuum pump, the cause of the failure of the vacuum pump due to the backflow of the foam can be eliminated and the reliability thereof is improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a backflow prevention device according to the present invention.

FIG. 2 is a vertical cross-sectional view of a conventional backflow prevention device.

[Explanation of symbols]

 1 Tank 2 Manhole 3 Ball 4 Vent hole 5 Guide tube 6 Open / close valve 7 Opening hole 8 Bearing member 9 Discharge pipe 10 Valve port 11 Manhole cover 12 Rod float 13 Blow change guide 14 Guide member 15 Joint member

Claims (1)

[Claims] 1. A guide cylinder having a ball loosely fitted therein and having vent holes at several upper ends is inserted into a manhole of a tank, and the ball is vertically moved by an upper end opening of the guide cylinder. A bearing member supporting the on-off valve and fitted with a bearing member having an appropriate number of openings, on which a vacuum pump as a pressure supply source and a discharge pipe connected via an air pipe are integrated at the upper end And a backflow prevention device for a vacuum suction car, in which a manhole cover having a valve opening is airtightly fitted to the inner end of the discharge pipe is moved up and down by increasing or decreasing the object to be processed in the tank. The rod-like float is vertically movably supported by a guide member attached and fixed to the lower part of the guide cylinder, is attached and fixed to the lower surface of the ball in a suspended manner, and the air flow flowing from the ventilation hole of the guide cylinder is fixed. To change direction downwards A backflow prevention device for a vacuum suction vehicle, wherein a cylindrical blow change guide is vertically provided between a ventilation hole of the guide cylinder and an opening of the bearing member.