JPH0343150Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field of the invention The invention relates to tanks lined with fluororesin, and more specifically, the fluororesin liner rises from the inner surface of the tank even when used under negative pressure conditions. Concerning tanks lined with fluororesin.

Technical background of the idea and its problems Tanks made of metal or general-purpose synthetic resin cannot be used for corrosive fluids because they have poor chemical resistance, and scale etc. adhere to the tank walls. Therefore, fluoroplastic-lined tanks are used in which a fluoroplastic liner is provided on the inner peripheral surface of the tank.

By the way, tanks are generally divided into open types and sealed types. Of these, to explain the open type as an example, the open type tanks 1 have an upper body ( In particular, it consists of an upper lid body (2) and a lower body (3). The upper lid body 2 has a flange portion 4 and a fluororesin first liner 5 on its inner peripheral surface. A flared portion 6 is formed along. Also, lower body 3
Similarly, it has a flange portion 7 and a fluororesin second liner 8 on its inner peripheral surface, and the flange portion 7 of the lower body 3 is attached to the tip of the fluororesin second liner 8. Flare section 9 along
is formed. The upper body 2 and lower body 3 are joined by tightening the flanges 4 and 7 of each other.

Note that the upper body 2 and lower body 3 of tanks have openings A and B, respectively, as necessary.

Tanks lined with such fluororesin can withstand quite high pressure if the pressure of the fluid stored inside is positive pressure, which is higher than normal pressure, but conversely, if the pressure inside the tank is constant If the negative pressure is lower than the normal pressure, the fluororesin liner 8 will float up from the inner peripheral surface of the tank 3, as shown in FIG. There was a problem that this could occur.

Purpose of the invention The present invention is an attempt to solve the problems associated with the conventional technology as described above. The aim is to provide tanks lined with fluororesin that has excellent properties.

Summary of the invention Tanks lined with fluororesin according to the present invention are tanks whose inner circumferential surface is covered with a fluororesin liner, and are reinforced internally on the fluororesin liner. It is characterized by an annular body made of fluorine resin embedded in the body.

In the tanks lined with fluororesin according to the present invention, an annular body made of fluororesin with a reinforcing body embedded inside is embedded on the fluororesin liner provided on the inner peripheral surface of the tank. Therefore, the fluororesin liner does not lift up from the inner peripheral surface of the tank, and therefore, the tanks according to the present invention have sufficient durability even under negative pressure conditions.

Specific Description of the Invention The present invention will be described below based on embodiments shown in the drawings. In the following description, the same members as those shown in FIG. 1 are given the same reference numerals.

The present invention will be explained using an open type tank as an example. The tank 1 is composed of an upper body (particularly an upper lid body) 2 and a lower body 3 as described above. The upper lid body 2 has a flange portion 4 and a fluororesin first liner 5 on its inner peripheral surface. A flared portion 6 is formed along. Similarly, the lower body 3 has a flange portion 7 and a fluororesin second liner 8 on its inner peripheral surface. A flared portion 9 is formed along the flange portion.
The upper lid body 2 and the lower body 3 are joined by tightening the flanges 4 and 7 of each other.

Note that the upper lid body 2 and lower body 3 of tanks can have openings A and B, respectively, as necessary.

The fluororesin that forms the liner is
PTFE, vinylidene fluoride (PVDF) or a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, PFA, a copolymer of tetrafluoroethylene and hexafluoropropylene
FEP, ETFE, a copolymer of tetrafluoroethylene and ethylene, etc. are used. Among these, PTFE is most preferred because of its high reliability as a liner.

Any method may be used to manufacture the fluororesin liners 5 and 8 shaped to follow the inner circumferential surfaces of the upper lid 2 and lower body 3 of tanks. For example, if the fluororesin is a non-thermofusible fluororesin such as PTFE, a flexible diaphragm approximately similar in shape to the inner circumference is wrapped along the inner circumference of the upper or lower body. After filling the gap between the diaphragm and the inner circumferential surface with PTFE powder, liquid such as water is injected into the upper lid or lower body through the core to inflate the diaphragm and fill the inner circumferential surface. A so-called hydropressure forming method is employed, in which a PTFE liner is preformed by pressure contact, and the obtained preformed liner is placed in a heating furnace and fired to a temperature equal to or higher than the melting point of PTFE.

In addition, in order to manufacture the fluororesin liners 5 and 8, fluororesin sheets are joined in advance to complete a liner having the same shape as the inner circumferential surface of the upper lid or lower body of the tank. A pull-in lining method (tentative name) will also be adopted, in which a liner is glued to the inner circumferential surface of the tank after it is drawn into the tank.

The present invention is characterized in that, as shown in FIG. 2, an annular body 11 made of fluororesin and having a reinforcing body 10 embedded therein is inserted onto the inner peripheral surface of the fluororesin liner. be.

The fluororesin forming this annular body 11 may be PTFE, PVDF, PFA, FEP or ETFE.
Among these, PTFE,
PFA is particularly preferred.

It is preferable to weld the ends of the annular body 11 to the fluororesin liner so that the annular body 11 does not slip off the inner peripheral surface of the fluororesin liner. For example, if both the liner and the annulus
If it is made of PTFE, the end of the annular body and the liner can be welded via a heat-melting fluororesin 12 such as PFA.

The reinforcing body 10 buried inside the annular body 11 is
It is preferably made of metal, and a ring-shaped metal or a spring-shaped metal band as shown in FIG. 3 is used. When a spring-like metal band is used as the reinforcing body 10,
An annular body 11 whose end is open as shown in FIG. 4 due to the expanding force of the spring-like metal band.
is obtained.

The annular body 11 is inserted at appropriate intervals on the inner circumferential surface of the fluororesin second liner 8 provided mainly on the inner circumferential surface of the lower body 3, but on the inner circumferential surface of the upper lid body 2. It can also be provided on the fluororesin first liner 5 provided on.

In the above description, the present invention has been described with respect to open tanks, but the present invention can also be applied to closed tanks.

Effects of the invention In tanks lined with fluororesin according to the present invention, an annular body made of fluororesin with a reinforcing body embedded inside is placed on the fluororesin liner provided on the inner peripheral surface of the tank. Since the fluororesin liner is buried, the fluororesin liner does not rise from the inner peripheral surface of the tank, and therefore the tanks according to the present invention have sufficient durability even under negative pressure conditions.

[Brief explanation of drawings]

Figure 1 is a sectional view of open tanks, and Figure 2 is a cross-sectional view of open tanks.
The figure is an explanatory diagram of the annular body inserted into the tanks shown in Figure 1, Figure 3 is an explanatory diagram of the reinforcing body embedded in the annular body, and Figure 4 is an explanatory diagram of the reinforcement body shown in Figure 3. It is an explanatory view of the annular body in which the reinforcing body is buried,
The figure is an explanatory diagram showing a state in which the fluororesin liner is lifted up from the inner circumferential surface of the tank. DESCRIPTION OF SYMBOLS 1... Tanks, 2... Upper lid body, 3... Lower body, 4... First flange part, 5... First liner, 6... First flare part, 7... Second flange part, 8 ... Second liner, 9 ... Second flare part, 10 ... Reinforcement body, 11 ... Annular body.

Claims (1)

[Scope of utility model registration request] In tanks whose inner peripheral surfaces are covered with a fluororesin liner, an annular body made of fluororesin with a reinforcing body embedded inside is inserted onto the fluororesin liner. Characterized by
Tanks lined with fluorocarbon resin.