JPH02253067A - Improved ball valve, and charging device of foaming synthetic resin particle into prefoaming machine using the same - Google Patents

Abstract

PURPOSE:To prevent the adhesion of a fluid near a valve seat in a ball valve consisting of a valve box and a ball received in the valve box through the valve seat by mounting an inlet port for introducing compressed gas in a space part partitioned by a valve box and the valve seat. CONSTITUTION:The constitution is such that two valve seats 2 are provided in a valve box 1 to receive a ball 3 through the valve seats 2, and the ball is rotated at 90 deg. by a handle mounted on a valve bar 4 to open and close the flow of a fluid. Further, in the valve box 1, a compressed gas inlet port 5 for introducing compressed gas into a space part partitioned through the valve box 1, the ball 3, and the two valve seats 2 is provided. When the ball 3 is rotated from open to close or reversely, a minute gap is formed between the ball 3 and the valve seats 2. As the fluid tries to enter into this gap, then, the compressed gas is injected from the compressed gas inlet port 5 to prevent the adhesion of the fluid near the valve seats 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improved ball valve and a device using the same for introducing foamable synthetic resin particles into a pre-foaming machine. This invention relates to a ball valve that prevents clogging, and a device for introducing foamable synthetic resin particles using the ball valve.

[Conventional technology and problems]

Ball valves, which are widely used for various gases, air, oil, water, powder, granules, etc., are shown in Figures 4 (A) and (B).
A ball (3) is housed in a valve box (1) through two valve seats (2), and the ball (3) is inserted through a handle (not shown) attached to a valve stem (4). The structure is such that the flow can be opened and closed by rotating it 90 degrees.

FIG. 4(A) shows the "closed" state, and FIG. 4(B) shows the "open" state.

The ball valve with the above structure is sealed by the valve seat (2) in the open or closed state, but the ball valve (3) changes from open to closed or from closed to open. When the ball valve rotates, a slight gap is created between the ball (3) and the valve seat (2), and fluid enters this gap and adheres there, making it impossible to operate the ball valve. There is a problem with making it.

For example, in a batch-type pre-foaming machine for foamable synthetic resin particles, the particles are metered and then introduced into the pre-foaming machine through a butterfly valve or a ball valve, but in a pressurized pre-foaming machine, a ball valve is used because internal pressure is applied. has been done. However, as mentioned above, the particles adhere to the sealing part, and the adhered particles foam and solidify during pre-foaming, making it impossible to operate the ball valve and, as a result, making pre-foaming impossible. .

[Means for solving problems]

In view of the above circumstances, the present inventors have conducted extensive research and have now provided a ball valve that solves the above-mentioned problems, and a device for introducing foamable synthetic resin particles using the ball valve.

That is, the first aspect of the present invention is, in a ball valve consisting of a valve box and a ball accommodated in the valve box via a valve seat, a space defined by the valve box, the ball, and the valve seat. The second aspect of the present invention is an improved POL valve characterized in that it is equipped with a compressed gas inlet for introducing compressed gas into the valve. A device using a ball valve, characterized in that a compressed gas inlet for introducing compressed gas into a space defined by a valve box, a ball, and a valve seat of the ball valve is provided. Each of these includes a device for charging synthetic resin particles into a pre-foaming machine.

An explanation will be given based on drawings showing embodiments of the present invention. In FIG. 1, the ball valve of the present invention has a ball (3) housed in a valve box (1) via two valve seats (2). , a compressed gas inlet (5) for introducing compressed gas into the space defined by the valve box (1), the ball (3), and the two valve seats (2) is connected to the valve box (1). ). (4) is the valve stem. The compressed gas used in the present invention is one that is inert to the fluid, such as nitrogen and air, with air being particularly preferred.

FIG. 2 is a schematic view of the ball valve used as a feeder for foamable synthetic resin particles in a pressurized pre-foaming machine, and FIG. 3 is an enlarged cross-sectional view of the main parts.

In FIGS. 2 and 3, the pre-foaming device (11) is equipped with a perforated plate (12) having small holes (not shown) that allow steam and air to pass through but prevent the foamable resin particles from passing through. It is divided into a foaming chamber (13) and a lower steam chamber (14). (18) and a baffle bar (19) to aid the stirring effect. Furthermore, a pre-foaming chamber (13
) is provided with a charging device for the resin particles, which is composed of a hopper (20) and a ball valve (21), and further includes a pressure gauge with a contact (22L, which controls the amount of steam displacement when pressurized). Throttle valve (23), exhaust valve (2
A 4L safety valve (25) is provided, and a level meter (26) is installed on the side wall to detect the position of the pre-expanded particles.
In addition, there is an outlet in the lower part for taking out the pre-expanded particles (
27) and a cylinder (28), there is provided an outlet cover (29) which is movable forward and backward. On the other hand, the tea room (14) is provided with a steam supply line (30) and a cooling air supply line (31).

The ball valve (21) below the hopper (20) has its flange (21f) connected to the hopper (20) and the flanges (32) and (33) of the pre-foaming device (11) via bolts (34). installed. (21a) is the valve box, (2l b) is the valve seat, (21c) is the ball, (21
d) is a valve stem, and (21e) is a compressed gas inlet.

In the above device, a fixed amount of resin particles (35) are metered and introduced into the pre-foaming chamber (13) via the hopper (20) or Lahore valve (21), stirred by the stirring blade (1B), and supplied with steam. Pre-foaming chamber (13) from line (30)
) is pre-foamed to a predetermined foaming ratio by the steam blown into the chamber, and when the pre-foaming is completed, the exhaust valve (23) is opened to reduce the pressure inside the pre-foaming chamber (13) to atmospheric pressure. Cooling air is introduced from the cooling air supply line (31) to lower the temperature in the pre-foaming chamber (13) and stop foaming, at the same time drying the pre-foamed particles. When cooling and drying are completed, the pre-expanded particles are taken out of the apparatus through the outlet (27).

〔Example〕

The present invention will be described below based on Examples, but the present invention is not limited thereto in any way.

EXAMPLE Expandable polystyrene particles (containing 6.7% butane) were pre-foamed using an apparatus such as that shown in FIG.

The ball valve used was an improved ball valve with a compressed gas inlet pipe of 10 mm in diameter attached to the valve box of an air-operated ball valve with a diameter of 80 nm. Air (0.5kg/c
nl) was introduced by injection.

After the preliminary foaming was completed, the ball valve was disassembled and examined.
No adhesion of raw material particles or pre-expanded particles was observed.

For comparison, when pre-foaming was carried out in the same manner using a normal ball valve, adhesion of raw material particles and pre-foamed particles was observed near the valve seat.

[Action/Effect]

As described in Soft Earth, the present invention prevents fluid from adhering to the vicinity of the valve seat of the ball valve, allowing stable use over a long period of time. For example, when applied to a feeding device for raw resin particles of a pre-foaming device, adhesion of raw resin particles and pre-foamed particles is prevented, and the operating rate of the pre-foaming device is greatly increased.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts showing an embodiment of the ball valve of the present invention;
Fig. 2 is a schematic diagram of the ball valve of the present invention applied to a feeding device for raw resin particles in a pre-foaming device, Fig. 3 is an enlarged sectional view of the main part, and Fig. 4 shows a conventional ball valve. FIG. 4(A) is a sectional view showing the closed state, and FIG. 4(B) is a sectional view showing the open state. 1...Valve box, 2...Valve seat 3...Ball, 4...Valve stem 5...Compressed gas inlet,
11... Pre-foaming device 12... Perforated plate, 1
3... Pre-foaming chamber 14... Steam chamber, 15.
...Motor 16...Reducer, 17...Stirring shaft 18...Stirring blade, 19...Baffle bar 20
...Homper 21...Ball valve 22...
Pressure gauge with contacts, 23...throttle valve 24...exhaust valve,
25...Safety valve 26...Level meter,
27... Outlet 2B... Cylinder 29...
・Outlet cover 30...Steam supply line 31...Cooling air supply line 32.33...Flange part, 34...Bolt 3
5...Resin particles Figure 1 Patent applicant Kanebuchi Chemical Industry Co., Ltd. Figure 11-2 <22 Figure 3

Claims (1)

[Claims] 1. In a ball valve consisting of a valve box and a ball accommodated in the valve box via a valve seat, a space defined by the valve box, the ball, and the valve seat is An improved ball valve characterized by being equipped with a compressed gas inlet for introducing compressed gas. 2. The ball valve according to claim 1, wherein the compressed gas is compressed air. 3. In a device using a ball valve for introducing thermoplastic synthetic resin into a pre-foaming machine for foamable synthetic resin particles,
A pre-expanding machine for foamable synthetic resin particles, characterized in that a compressed gas inlet is provided for introducing compressed gas into the space defined by the valve box, ball, and valve seat of the ball valve. feeding device. 4. The charging device according to claim 3, wherein the compressed gas is compressed air.