JPS59138794A - Circulating pump of high temperature liquid tank - Google Patents

Abstract

PURPOSE:To decrease the overhung length of a pump shaft so as to omit an underwater bearing and enable a pump to be suitably operated, by forming a suction flow path in a position higher than that of an impeller suction port from a pump suction port so that liquid, after flowing in an impeller and being pressurized, is allowed to flow toward a delivery port. CONSTITUTION:Liquid in the inside of a tank 1, flowing upward from a suction port 10 in a suction passage 15 formed by an inner barrel 13 and an outer barrel 14 and changing its flow into the direction at a right angle with an axis by a baffle plate 16, is allowed to flow in a suction guide part 17 through an impeller 18 as a downward flow and reach a pump delivery port 11 through a guide vane 19. While an overflow nozzle 20, being provided in the upper part of the baffle plate 16, sets a free liquid level H.W.L. By such constitution, a circulating pump, whose weight and size can be decreased, enables an underwater bearing of troublesome maintenance to be omitted further its operation to be stably performed by reducing the overhung length of a pump shaft.

Description

[Detailed description of the invention]

The present invention relates to a high temperature liquid tank circulation pump. In order to efficiently carry out reactions in the chemical reaction tank, a part of the internal liquid is taken out of the tank and an ash J circulation channel is installed in the tank. External circulation devices equipped with pumps are widely used. Figure 1 is a basic circulation system diagram of such external circulation devices, in which a pump P is installed outside the reaction tank T (J, circulation flow path L
1, 1. , 2. Various circulation routes and pump types are used depending on the function, shape, type of internal liquid, and physical and chemical properties of the reaction tank. To avoid circulating a large amount of high-temperature liquid, we provide an external circulation pump that has excellent functionality for installation, operation, and maintenance. Figure 2 (, of the conventionally used tank circulation system)
This is a notification map showing r. The highest liquid level (1-1/W-1) in tank 1 is determined by the partition plate inside the tank, and the free surface does not change.When the tank is full of liquid, the suction port 2 and discharge port of the circulation pump 3, the liquid level in the pump increases to 1, and overflows from A-Buff 1''-Nozzle 4. The liquid level inside the pump is covered with an inert gas injected from the cover gas injection pipe 5, and
It is sealed by. The impeller 7 of the circulation pump is located below the suction D 2 and is rotated by an electric motor 9 via a joint 8 to cause the liquid to flow from the top to the bottom of the impeller 7 and circulate under pressure. In this type of pump, the distance S between the mechanical seal 6 and the impeller 7 is inevitably long, and in order to ensure stable pump operation, the strength of the shaft and bearing structure must be carefully considered when manufacturing. For example, as shown in FIG. However, since the submerged bearing 8, which can be used in high-temperature chemical liquids, cannot use lubricant, it must be lubricated with white liquid, and no failure will occur.
AA)'4 Due to structural limitations, it is difficult to design a bearing with a human-friendly load capacity.As a result, the bearing must be replaced more frequently during maintenance. A structure as shown in Fig. 4 that does not use the bearing 8 can be considered.In order to increase the strength of the J5 shaft, make it as thick as possible, and then install two strong bearings Oa and 9b on top of the J-nical seal 6. Tokoro nQ LJ, impeller 7
completely set the submerged bearing as A-bahang ≧11 type 4-
There is no J. In the case of the mouth, the distance (span) Sl between the two bearings requires one stroke corresponding to the distance 1llIt (overhang) 82 from the lower bearing to the impeller, and the bearing device becomes quite large. For that purpose, the driving electric motor 9
If the position of the pump is high, it becomes difficult to suspend and support the entire pump just by connecting the suction port to the tank nozzle as a pump that handles high-temperature liquids. Furthermore, when replacing the mechanical seal, the manual bearing device must be removed, which is a disadvantage. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a high-temperature liquid tank circulation pump that can shorten the length of the overhang and can operate suitably without installing a large bearing device. According to the book, the circulation pump body forms a part of the circulation path, and the suction port of the circulation pump is connected to the suction pipe protruding from the tank, and the whole pump is suspended outside the vertical tank. In type circulation pumps, an overflow nozzle is installed on the pump body so that the liquid level inside the pump can be maintained at a position higher than the highest liquid level in the tank.

[P, Suction L] Position the pump blade at a position tb higher than the overflow nozzle and lower than the overflow nozzle, open the impeller suction port upward, and pour the liquid from the pump suction port to a position higher than the impeller suction port. After the liquid passes through the pump impeller and is pressurized, the pump l! A flow path is formed through 1 il L and back to the tank. The present invention will be described in detail below with reference to FIGS. 5 and 6. FIG. 55 shows an embodiment of the present invention and is a 1)) j-side view. 10 is a pump suction port connected to the tank, 11
is a pump outlet connected to a tank via an expansion joint (not shown). The liquid inside the tank is sucked [2110
The flow flows upward through the suction flow path 15 formed by the inner shell 13 and the outer shell 11ii114, and the direction of the flow is changed by the baffle plate 16 in the direction perpendicular to the axis. 17, passes through the impeller 18 as a non-directional flow, passes through the guide vanes 19, and reaches the outlet 11 of the pump 111. Over 70-nozzle 20I is installed above the baffle plate 16, and the free liquid level 1'' W-L is set. Small chamber 2 between cover 〇 and mechanical seal 22
1, the sealing liquid leaking from the mechanical seal 22 is
It is thrown off by the drainer LM 23 that rotates together with the shaft 28, and is taken out from the drain 24 of the small chamber 21 without entering the inside of the pump. A subere 27 is interposed between the pump-side shaft joint 25 and the motor-side shaft joint 26 to facilitate mechanical seal replacement (the dimensions of the embodiment up to 111 are shown in Fig. 6. Pump shaft 28 and motor shaft 29 By rigidly assembling the joint 25.2G and the suberly 27 that connect the
The pump shaft 28 becomes one rigid shaft, and the rotary shaft can be rigidly supported by a bearing with a large load capacity of oil lubrication inherent in Tanabata. Since this is not necessary, replacing the mechanical seal becomes extremely simple. By using a circulation pump like the one shown in Figure 5, it is possible to make the circulation pump more compact, and by shortening the overhang length of the pump shaft, it is possible to omit submerged bearings, which require troublesome maintenance. , and for those who expect stable driving,
Mechanical seal replacement work can be significantly shortened.

[Brief explanation of drawings]

Figure 1 is a basic system diagram of an external circulation system, Figure 2 is a structural diagram showing an example of a conventionally used tank circulation system,
Figures 3 and 4 are sectional views showing an example of a conventional device, Figure 5 is a sectional view showing an embodiment of the present invention, and Figure 6 is a sectional view showing an application example using a subere. be. 10...Suction port 11...Discharge 1113...
Inner shell 14... Outer shell '16... Baffle plate 1
8... Impeller 19... Guide vane 20... Overflow nozzle 22... Nucanical seal
25.26...Shaft coupling Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (3)

[Claims] (1) The circulation pump itself forms part of the circulation path, and the circulation pump's suction port is connected to the suction pipe protruding from the tank, so that the entire circulation pump is suspended in the tank. In order to maintain the maximum liquid level in the pump at a position higher than the R high liquid level in the tank, an over degree 70-nozzle is installed on the pump body, and the position is higher than the suction port and lower than the large over flow nozzle. The pump impeller is positioned at , the suction port of the impeller is opened upward, and a suction flow path is formed so that the liquid is guided from the pump suction port 11 to a position higher than the impeller suction port. A high-temperature liquid tank circulation pump characterized by forming a flow path that returns to a tank through a pump discharge port after being pressurized through a pump impeller. (2) Claim 1, which includes a double mechanical seal car 1 to azalea, which seals a cover gas with a pressure higher than atmospheric pressure at the highest liquid level inside the pump and contains a sealing liquid to seal the cover gas. High temperature liquid tank circulation pump as described. (3) High-temperature liquid tank circulation according to claim 2, wherein a spacer is interposed between the motor-side shaft joint and the pump-side shaft joint so that the seal can be easily replaced without an opening for removing the mechanical seal. pump.