JPH04134027U - Tank water level detection piping - Google Patents

Abstract

(57) [Summary] [Purpose] This is related to water level detection piping for links that make up various plant systems. It can prevent hunting of detected water levels, and it is possible to inspect orifices and replace orifices from inside the tank. [Structure] A water level detector is installed between the upper nozzle and lower nozzle installed in the tank body, the piping connected to the lower nozzle is inserted inside the tank, and an orifice is screwed into the tip. Piping for detecting tank water level.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to water level detection piping for tanks that make up various plant systems. It is.

0002

[Conventional technology]

FIG. 3 shows a configuration diagram of a conventional tank water level detection piping. The water level detection piping is provided with nozzles at the top and bottom of the tank body 01, and the upper nozzle Piping 03a, 03b and water level detector 04 are connected between 02a and lower nozzle 02b. Generally, it consists of:

0003 The problem with this type of system is that when fluid enters the tank and hits the liquid level, Fluctuations in the liquid level may occur when the tank itself vibrates due to external vibrations. This causes a change in the hydrostatic head at the lower nozzle stub, causing damage to the tank and detection piping. Fluid flows in and out, causing fluctuations in the water level detected by the water level detector.

0004 Fluctuations in the detected water level correspond to noise when controlling the fluid inflow and outflow of the tank. (It has nothing to do with the amount of fluid stored in the tank) and has a large fluctuation range. Since this can lead to control malfunctions, it is desirable to suppress this as much as possible.

[0005] As one of the means, between the lower nozzle stub 02b of the detection piping and the water level detector 04 It is often practiced to provide orifice 05 in the It also reduces the flow of fluid in and out of the tank and detection piping, slowing down the response to detection water level fluctuations. It is. In this case, the hole diameter d' of orifice 05 suppresses the width of the fluctuation of the detected water level to 1/n. If you want to It is necessary to set the current length to be n times larger, which is required from fluid dynamics. be.

[0006] This is already in use and has a track record of suppressing fluctuations in the detected water level to 1/5 due to the control function. It is necessary to install one with a large diameter l'. Detection piping 03b40 ^A x S40 (inner diameter φ27.2mm) Install an orifice so that the equivalent length for pressure loss is 8m x 5 times = 40m. Orifice 05 hole diameter d' φ3.5mm Throttle length l' 8.8mm

[0007] In addition, the difference from the orifice installation method of the tank water level detection piping in this invention In order to clarify the detection Figure 5 shows a cross-sectional view of the orifice installation on the piping.

[0008] In the lower nozzle section 02b of the tank, the detection pipe 03b is connected to the outside of the tank body 01. are joined by welding. In addition, orifice 05 is installed with the above-mentioned proven product, and is suitable for the pipe diameter. A type with a fairly small hole diameter and a large aperture section is installed.

[0009]

[Problem that the idea aims to solve]

The conventional piping for detecting the water level of a tank has the following problems. Orifice installed to prevent detection water level hunting in water level detection piping It is necessary to install one with a fairly small hole diameter and a large aperture length, and it is difficult to use it for a long time. There is concern that water level detection functionality may be lost due to clogging caused by sludge, etc. be done. Therefore, periodically remove the sludge attached to the orifice or clean the orifice. Replacement must be carried out, which requires extra maintenance by cutting the detection pipe. I was forced to do some work.

0010

[Means to solve the problem]

This invention solves the above-mentioned conventional problems. In water level detection piping, which consists of a pipe and a water level detector connected between the pipe head and the Insert the pipe connected to the pipe holder into the tank, and screw the orifice onto its tip. Since the water level detection piping of the tank is Orifice to prevent hunting of detected water level, allowing maintenance work to be performed from inside the tank. can be installed.

[0011]

【Example】

An embodiment of the present invention is shown in FIGS. 1 and 2. Figure 1 shows the upper nozzle (not shown) and lower part installed in the tank body 1, similar to the conventional Figure 3. A water level detection arrangement in which a pipe 3b and a water level detector (not shown) are connected between the nozzle holder 2b. The pipe 3b is inserted into the tank body 1 and attached by welding. , a male thread 3c is formed at the tip of the insertion part, and an orifice 5 having a female thread 5a is formed therein. It is connected. The diameter of the orifice 5 is d, and the length of the aperture part is l.

0012 In this example, the hole diameter d is considerably small and the orifice length l is large relative to the pipe diameter. There is a concern that clogging may occur due to sludge adhesion in a relatively short period of time. It is something that will be done. However, checking for clogging of the orifice requires a person to enter the tank. This can be done by direct visual inspection, and if a blockage is found, the orifice 5 By rotating and removing the screw 5a that attaches the Fissures can be easily replaced.

[0013] The features of the orifice installation of the present invention and its effects are as follows: , as follows. (1) The orifice is installed inside the tank. You can easily enter the tank and check for clogging in the orifice hole. (2) The orifice is screw-mounted. Place for maintenance such as removing sludge from orifice holes and replacing orifices. In this case, only the orifice can be easily removed.

[0014]

[Effect of the idea]

Hunting can be prevented by applying this invention to water level detection piping in tanks. It is possible to prevent sludge from forming in the hole of the orifice installed for this purpose. You can easily check for clogging, and also perform maintenance such as removing sludge and replacing orifices. This can also be done extremely easily without cutting the detection piping. This makes it possible to obtain stable control in plant operation and prevent loss of control functions. Prevention can also contribute to improving reliability.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the installation of an orifice in a tank lower pipe stub of a water level detection piping according to the present invention.

FIG. 2 is a detailed view of the orifice of the present invention.

FIG. 3 is a configuration diagram of a conventional tank water level detection piping.

FIG. 4 is a sectional view of a tank lower nozzle stub of a water level detection piping according to the prior art.

FIG. 5 is a cross-sectional view of orifice installation in water level detection piping according to the prior art.

[Explanation of symbols]

1 Tank body 2b Lower nozzle 3b Piping 3c male thread 5 Orifice 5a Female thread

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Tatsuo Yashishi 2-1-1 Shinhama, Arai-cho, Takasago City, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Takasago Plant (72) Creator Kazumi Kitamura 2-1-1 Shinhama, Arai-cho, Takasago City, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Takasago Plant (72) Inventor: Shoji Onishi 2-1-1 Shinhama, Arai-cho, Takasago City, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Takasago Plant

Claims (1)

[Scope of utility model registration request] Claim 1: In water level detection piping in which a pipe and a water level detector are connected between an upper nozzle and a lower nozzle provided in a tank body, the piping is connected to the lower nozzle. A pipe for detecting water level in a tank, characterized in that the pipe is inserted into the tank, and an orifice is screwed to the tip of the pipe.