JPH0353091Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is an example of an LPG in which liquefied petroleum gas (hereinafter referred to as "LPG") stored in a storage tank can be taken out from both the gas phase and liquid phase lines. The present invention relates to a pressure control valve which is used in a supply device, and which is particularly attached to a gas phase line so that it can be shut off by its own pressure when the fluid pressure on the inlet and outlet sides exceeds a certain range.

[Conventional technology]

Conventional LPG supply equipment was limited to so-called liquid-phase line-driven systems because no pressure control valve had been developed to effectively shut off the drop in extraction pressure from the gas-phase line. .

[The problem that the idea aims to solve]

According to the above-mentioned conventional liquid phase line-driven LPG supply device, in order to extract vaporized gas from the liquid phase line, in addition to a separate pressure storage tank, a pressure control valve with a complicated structure is required for pressure reduction and pressure control. Not only does it require a large amount of electricity (for example, see Japanese Patent Application Laid-Open No. 51-2019), but most of it is covered by forced vaporization using an evaporator, which poses problems such as huge power consumption and high LPG supply costs. Ta.

Therefore, the present invention has developed a self-powered pressure control valve that immediately responds to pressure changes in the gas phase line, shuts off the fluid, and can switch to and from the liquid phase line using its own pressure. This makes it possible to use this as an LPG supply device.

[Means to solve the problem]

In order to achieve the above-mentioned purpose, the present invention provides a diaphragm valve on one side of the machine casing for setting the lower limit pressure that is operated by the fluid pressure flowing in from the inlet, and works in conjunction with the diaphragm valve to set the inflow pressure to the lower limit. A lower limit pressure cut-off mechanism is installed that closes the valve body when the pressure falls below the specified limit, while a diaphragm valve for setting the upper limit pressure is installed on the other side of the machine housing, which operates when the fluid pressure near the outlet exceeds the set upper limit. By using a method in which the valve seat tube of the upper limit pressure cutoff mechanism that can close the valve body is placed opposite to the valve seat tube of the lower limit pressure cutoff mechanism, only gas phase gas within a certain pressure range can be supplied to the main pipe. This means that it can be supplied to both sides.

[Effect]

The above-mentioned self-operated pressure control valve for main flow inlet and outlet flow is closed on the inlet side by LPG at a predetermined pressure or less by each diaphragm valve of the above-mentioned double pressure cutoff mechanism, and on the outlet side, it is closed by LPG near the outlet. It has the special effect of automatically adjusting the LPG in the gas phase line supplied to the main pipe to a predetermined pressure range by closing when the pressure exceeds a set value.

〔Example〕

Hereinafter, the configuration of the self-powered pressure control valve of the present invention will be described in more detail according to an example in which it is used in an LPG supply device shown in the drawings. 3 is a valve seat cylinder having a through hole 3a communicating with the inlet 2 and a valve seat 3b on the inner surface of the upper part; 4 is a valve seat cylinder that can normally come into contact with the valve seat 3b via a spring 4a; This is a diaphragm valve for setting a lower limit pressure, which has a valve body 4b and its lower part connected to a diaphragm 4d via an interlocking element 4c. LPG incorporated into and flowing into
When the pressure of
It contacts the valve seat 3b with the elastic force of a, and the flow from the inlet 2
It is configured with a lower limit pressure cutoff mechanism that prevents the inflow of LPG.

Further, 5 is a valve seat cylinder built into the housing so as to communicate with an outlet 6 opened on the upper side of the machine housing 1, that is, on the downstream side, via a through hole 5a, and 7 is a diaphragm valve for setting the upper limit pressure. The valve body 7a is joined to a diaphragm 7d which is pushed down via a spring 7c provided at the upper end of the valve body 7a, and under normal conditions, the spring 7b is elastically compressed to close the valve at the lower end of the valve seat cylinder. so that it opens from the seat 5b, and near the exit 6.
An upper limit pressure cutoff mechanism is configured to close the valve body 7a and prevent LPG from flowing to the main pipe 12 side when the pressure of the LPG discharge stream rises above a set value. In the figure, reference numeral 8 indicates a pressure setting screw for each of the diaphragm valves 4 and 7, and reference numeral 9 indicates a pressure gauge.

Next, we will discuss the operation of the LPG supply device when the self-powered pressure control valve of the present invention is attached to the gas phase line 13 of the LPG supply device to make it a gas phase line-driven type. When the phase pressure is (P ₁ ), the inlet side pressure of the evaporator 11 is (P ₂ ), and the supply pressure of the main pipe 12 is (P ₃ ), in order to guarantee the supply pressure (P ₃ ), it is necessary to ^The pressure (P ₂ ) on the inlet side of the vessel ¹¹ must be at ^least (P _{3 +} The minimum pressure required for P ₂ ) is the gas phase pressure (P ₁ ), which changes depending on the outside temperature and LPG composition.
In general, it is expressed as P ₂ ≧{(P ₃ +X)+α}=(1,7+α)Kg/cm ² .

Therefore, the upper limit pressure cutoff mechanism of the proposed self-powered pressure control valve installed in the gas phase line 13 is set to 0.7 Kg/cm ² , which is the same as the above supply pressure (P ₃ ), and the pressure regulator 15 on the liquid phase line 14 side is set to 0.7 Kg/cm 2 . , and 0.65 Kg/cm ² which are slightly lower than those, LPG in the storage tank 10 is preferentially supplied to the main pipe 12 side from the gas phase line 13. In this case, the gas phase pressure (P ₁ ) in the storage tank is the required minimum pressure (1,7+α) Kg/cm ² for (P ₂ ).
When the pressure drops below the lower limit pressure, the above-mentioned lower limit pressure cutoff mechanism automatically closes, and the pressure of the diaphragm valve 4 for setting the lower limit pressure is set by the screw 8 in advance so that the pressure required for LPG supplied to the evaporator 11 can be secured. Set it accordingly. In other words, as LPG is consumed, storage tank 1
When the gas phase pressure (P ₁ ) at 0 falls below (P ₂ ),
The LPG flow path from the gas phase line 13 is closed,
Since the new supply of LPG in this line is stopped, the supply pressure (P ₃ ) to the main pipe 12 side used subsequently decreases gradually, and this decreases to 0.65Kg/cm ²
At the point when the pressure is reached, the pressure regulator 15 of the liquid phase line 14 opens, and the LPG vaporized by the evaporator 11 is supplied to the main pipe 12 instead of to the gas phase line 13.

Incidentally, while LPG is being supplied from the liquid phase line 14, natural vaporization of LPG in the storage tank 10 is promoted,
When the pressure (P ₁ ) exceeds (P ₂ ), the lower limit pressure cutoff mechanism operates in the opposite manner to the one described above and opens the valve, allowing LPG from the gas phase line 13 to flow once again to the main pipe 12.
is supplied to the side, and the pressure (P ₃ ) at that part is 0,
70 Kg/cm ² , so during that time, the pressure regulator 15 works to stop the supply of LPG from the liquid phase line 14.

On the other hand, in the upper limit pressure cutoff mechanism on the outlet 6 side, the valve body 7a is normally in an open state, but when the consumption amount of LPG decreases or stops, the fluid pressure near the outlet 6 becomes sufficient. When the pressure increases and exceeds the set upper limit, the diaphragm valve 7 for setting the upper limit pressure operates to seat the valve body 7a on the valve seat 5b.
This blocks the flow of LPG to the exit side. Therefore, by providing the self-powered pressure control valve of the present invention in the gas phase line, it is possible to stably supply gas phase LPG within a pressure range with upper and lower limits set in advance.

[Effects of the invention] As described above, according to the self-powered pressure control valve of the present invention, the two upper and lower pressure cut-off mechanisms built into the machine casing operate on their own when receiving the pressure of LPG near the inlet 2 and outlet 6. Since it operates in the gas phase, auxiliary devices such as pilot valves can be omitted, and the structure of the valve itself can be significantly simplified and downsized. In addition, the entire supply device using this can be sufficiently downsized, and the gas phase By prioritizing the gas supply from the liquid phase to the liquid phase,
Since the evaporator's operating opportunities are reduced, the electricity cost required for operation is reduced, making it highly economical, making it particularly effective as a control valve in gas-phase line-driven LPG supply systems.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the central part of the pressure control valve of the present invention, and FIG. 2 is a layout diagram of a gas phase line-driven LPG supply device. In addition, in the figure 1... Machine casing, 2... Entrance, 3, 5...
Valve seat cylinder, 4, 7...Diaphragm valve, 6...Outlet.

Claims (1)

[Scope of utility model registration request] A lower limit pressure cut-off mechanism is provided on the upstream side of the machine casing 1, which operates a diaphragm valve 4 for setting a lower limit pressure by fluid pressure flowing in from the inlet 2 of the machine casing 1, so that the valve seat 3b can be opened and closed. The valve body 7a of the valve seat cylinder 5, which is provided on the downstream side facing the valve seat 3b of the valve seat cylinder of the lower limit pressure cutoff mechanism, is operated by the fluid pressure near the outlet 6 leading to the main pipe 12 side. A self-powered pressure control valve for a gas phase line of a liquefied petroleum gas supply device, etc., which incorporates an upper limit pressure cutoff mechanism in which the valve body can be opened and closed via a diaphragm valve 7 for setting the upper limit pressure.