JPH07246349A - Separation plate type centrifuge - Google Patents

Abstract

PURPOSE:To efficiently operate this centrifuge and to make the grade of a light liquid thus separated and purified constant by using a relatively inexpensive flow detector or pressure detector to detect the interface of a heavy liquid accumulated inside the separation plate type centrifuge. CONSTITUTION:On a heavy liquid pipe line 22 arranged from a raw liquid feeding pipe 9 to a sludge discharge hole 10 holded on the outer periphery of a rotary drum in the radial direction, a relatively inexpensive flow detector or pressure detector 14 is provided. Based on the detected value of the detector 14, a control part 15 controls a valve opening operating water control valve 23 and also a heavy liquid impeller diameter D4 is made almost the same as a heavy liquid free surface diameter D3. When a sudden decrease in the flow rate or pressure of the heavy liquid is detected by the detector 14 on the heavy liquid pipe line 22, a signal is given to the controller 15, which opens the control valve 23 to introduce valve opening operating water to an auxiliary valve 7. In this way, an auxiliary valve 7 is slid in the inward radial direction, and the operating water in a main valve water chamber 11 is discharged through the auxiliary valve 7, and a main valve 5 is opened by internal pressure of a separation chamber 16 to discharge solid matter and the heavy liquid in a rotary drum 1 from a discharge hole 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation plate type centrifuge.

[0002]

2. Description of the Related Art A control plate type separation plate type centrifuge has been conventionally used for cleaning lubricating oil, fuel oil, etc. containing solid matter and water. An annular outlet weir (hereinafter referred to as an adjustment plate) is provided at the outlet of the heavy liquid passage so that the interface with oil (hereinafter referred to as light liquid) is stably maintained on a predetermined radius of the separation plate.

However, in this type of centrifuge,
If the specific gravity of the treated oil (hereinafter referred to as the undiluted solution) changes, the adjusting plate with the optimum diameter should be positioned accordingly so that the adjusting plate can be positioned on a predetermined radius according to the fluctuation of the interface between the heavy liquid and the light liquid. It is cumbersome to handle as it has to be changed. Therefore, the applicant of the present invention has previously disclosed a means for detecting the water content in the light liquid discharged from the centrifuge and controlling the discharge of the heavy liquid as an alternative to the adjusting plate method in JP-A-61-78451. Proposed.

That is, when a capacitance-type moisture detector is provided in the light liquid discharge line and a predetermined amount or more of water is separated and accumulated in the separation chamber in the rotary drum, the water carries over to the light liquid side. When the water content of the light liquid is detected by the same water detector, the accumulated water is discharged to the outside by opening and closing the main valve for sludge discharge of the rotating drum (hereinafter referred to as the main valve) via the controller. Is the way to do it.

[0005]

However, since the capacitance type moisture detector is expensive and requires labor for maintenance, it is desired to develop a moisture detecting means which is relatively low in cost and easy to maintain. Has been done. The present invention has been proposed in view of the above circumstances, and an object thereof is to provide an economical separation plate type centrifugal separator having a high separation performance and a relatively low cost.

[0006]

Therefore, the invention of the apparatus of claim 1 is to provide a main valve for sludge discharge provided in a rotary cylinder, a light liquid impeller provided in a light liquid discharge passage, and a heavy liquid. In a separation plate type centrifuge having a heavy liquid impeller provided in a discharge flow path, one end is connected to the heavy liquid discharge flow path and the other end is inserted into a heavy liquid flow path connected to a stock solution supply flow path. It is equipped with a flow detector or pressure detector and a controller that opens and closes the control valve of the working water for opening and closing the main valve in response to the output of the flow detector or pressure detector. It is characterized in that the diameter is almost the same as the liquid free surface diameter.

[0007]

The operation of the separation plate type centrifuge of the present invention, in particular, the progress of separation of heavy and light liquid components in the rotary cylinder will be described with reference to FIG. 2 which is a principle view of the present invention. (1) Start the introduction of the stock solution. (2) At the beginning, the light liquid flows out from the light liquid impeller and the light liquid also flows out from the heavy liquid impeller. (3) Heavy liquid gradually accumulates on the inner surface of the rotating drum. (4) The state of (2) continues until the heavy / light liquid interface D ₂ reaches the tip D _{1 of the} partition plate. (5) When the heavy / light liquid interface D ₂ reaches the inward radial direction from the tip of the partition plate as shown in FIG. 2, the light liquid stops flowing toward the heavy liquid impeller. This is because the flow path that makes a U-turn at the lower end of the partition plate is blocked by the heavy liquid, the separation of the heavy liquid proceeds, and the interface D ₂ between the heavy and light liquids moves inward in the radial direction.

(6) As the amount of heavy liquid accumulated in the rotary drum gradually increases, the light liquid in the heavy liquid passage is replaced by the heavy liquid. (7) This state further progresses, and as shown in FIG. 2, a level difference δ occurs between the heavy liquid surface and the light liquid surface in the rotating drum due to the difference in specific gravity between the heavy and light liquids. (8) If the state of (7) is further advanced, the outflow of the heavy liquid from the heavy liquid impeller is stopped. This is the heavy
This is because as the light liquid interface moves inward in the radial direction, the heavy liquid surface D ₃ of the heavy liquid impeller chamber moves in the outward radial direction and becomes the same as the heavy liquid impeller diameter D ₄ (this is It is also clear from the formula below). (9) It is detected that the heavy liquid has accumulated in the rotating drum due to a sudden decrease in the detection value of the flow rate detector or pressure detector provided in the heavy liquid discharge pipe line, and the discharge signal causes the main valve to open and accumulate the heavy liquid. The liquid is discharged to the outside through the discharge hole. (10) Continue the operation and return to (1).

Between the heavy liquid free surface diameter D ₃ , the light liquid free surface diameter D ₀ , the heavy / light liquid interface diameter D ₂ and the heavy liquid specific gravity γ ₁ and the light liquid specific gravity γ ₀ of the above heavy liquid chamber. The following well-known equation is established. γ ₀ / γ ₁ = (D ₂ ² −D ₃ ² ) / (D ₂ ² −D ₀ ² ) (Kamei Saburo, Theory and Calculation of Chemical Machines, Industrial Books, P428,1
970) From the above equation, when the interface diameter D ₂ moves inward in the radial direction within the range of D ₁ > D ₂ , the heavy liquid free surface diameter D ₃ may move outward in the radial direction because D ₀ is constant. I understand.

With the progress of the stock solution treatment, the amount of separated heavy liquid gradually increases, D ₂ moves inward in the radial direction, and eventually D ₂ <
At D ₁ , the upper part of the partition plate becomes heavy liquid, and further D ₃ > D ₀ , and if D ₃ according to the above formula becomes the same as the heavy liquid impeller diameter D ₄ (D ₃ = D ₄ ), heavy liquid becomes The outflow from the impeller stops. Therefore, it is possible to insert the flow detector or the pressure detector into the discharge line of the heavy liquid and to know the level of the boundary surface diameter D _{2 from} the detected value.

From the above, the heavy liquid free surface diameter D ₃ is calculated by the above equation so that the heavy / light liquid boundary surface diameter D ₂ becomes a suitable position between the outer diameter of the separation plate 4 and the partition plate diameter D _1. , If the diameter of the heavy liquid impeller D ₄ is the same as this, the diameter of the heavy / light liquid interface is
_It can be seen that the ₂ can be operated while being maintained at a suitable position.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described. FIG. 1 is an overall longitudinal sectional view thereof. In FIG. 1, 1
Is a rotary cylinder that rotates at high speed around a vertical axis by a driving means (not shown), and a rotary body lid 2 is fitted on the upper portion by a tightening ring. Reference numeral 3 denotes a light liquid chamber attached to the upper portion of the rotor lid 2, 4 a plurality of truncated cone-shaped separating plates laminated around the guide tube 6 with appropriate gaps, and 5 a lower inner peripheral portion of the rotary cylinder 1. A main valve that is slidably inserted in the vertical direction, 7 is a plurality of sub-valves that are respectively provided on the outer periphery of the rotary cylinder 1 so as to be slidable in the radial direction, and 25 is a valve that is provided below each sub-valve 7 and opens. A drain hole for discharging the working water to the outside of the machine, 8 is a light liquid impeller inserted in the upper opening of the rotor lid 2,
It is mounted in a stationary position regardless of the high-speed rotation of the rotary cylinder 1 and the rotary body lid 2 which are integrally performed.

Reference numeral 9 is a stock solution supply pipe inserted axially through the upper end opening of the rotor lid 2, and 10 is a plurality of sludge discharge holes radially formed on the outer periphery of the rotary drum 1 at appropriate intervals.
Reference numeral 15 is a controller that controls the valve opening operation water control valve 23 based on the detection value of the flow detector or the pressure detector 14.

In such an apparatus, after the centrifuge reaches a constant speed rotation, the stock solution is fed from the stock solution supply pipe 9 to the guide tube 6.
When it is supplied via the above, the stock solution is centrifuged on the separation plate 4,
Due to the difference in specific gravity, the solid content, the heavy liquid H, and the light liquid L are layered in the separation chamber 16 in this order from the outer diameter side to the inner radial direction.

The heavy liquid H gradually accumulates in the separation chamber 16 in the rotary drum, and as the heavy / light liquid interface diameter D ₂ thereof exceeds the diameter D ₁ of the partition plate 17 and moves inward in the radial direction. , The heavy liquid enters the heavy liquid chamber 20 through the heavy liquid passage 18, and the heavy liquid impeller 19 passes through the heavy liquid conduit 22 to supply the raw liquid supply pipe 24.
Reflux to. The flow detector or the pressure detector 14 inserted in the heavy liquid pipe 22 detects that there is a sharp decrease in the flow rate or pressure of the heavy liquid, and sends the output signal to the controller 15, which then controls the control valve. 23 is opened and the valve opening working water is introduced into the sub valve 7.

As a result, the sub valve 7 slides inward in the radial direction, the working water in the main valve water chamber is discharged through the sub valve 7, the main valve 5 is opened by the internal pressure of the separation chamber 16, and the rotary cylinder 1 The solids and heavy liquid inside are discharged to the outside through the discharge holes 10. After the discharge, the supply of the valve-opening working water is stopped by the action of the timer, the working water in the sub-valve 7 is completely discharged from the drain hole 25, and the sub-valve 7 is slid outward in the radial direction by the centrifugal force to be closed. At the same time, since the valve-closing working water is constantly supplied to the main valve water chamber 11, the main valve 5 is pushed up by the water pressure and the rotor cover 2
The discharge hole 10 is closed by abutting on the packing attached to the lower end of the, and the discharge of the heavy liquid in the rotary cylinder is stopped.

Here, the 14 flow detectors or pressure detectors may be conventional ones. For example, as the flow detector, a flat plate (flapper) is swingably suspended at right angles to the liquid flow, As the flapper type that detects that the flat plate oscillates according to the flow velocity, as the pressure detector, an arc-shaped tube having an oval cross section, a Bourdon type that detects that the tube is deformed when internal pressure acts, etc. Are suitable. As shown in Figure 1,
The light liquid flowing out from the light liquid impeller 8 flows into a service tank or sump tank (not shown) as it is.
The light liquid or heavy liquid flowing out from the heavy liquid impeller 19 is
It merges with the stock solution and circulates circularly around the rotating drum.

[0018]

According to the present invention having the above-described configuration and operation, the relatively high-priced device is used instead of the expensive capacitance type moisture detector to deposit inside the separator plate type centrifuge. Since it is possible to detect the interface of the heavy liquid to be used, it is possible to efficiently operate the centrifuge and obtain the effect that the quality of the separated and purified light liquid (oil) can be made constant.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a principle diagram of the present invention.

[Explanation of symbols]

1; Rotating body, 2; Rotating body lid, 3; Light fluid chamber, 4;
Separation plate, 5; Main valve, 6; Guide cylinder, 7; Sub valve, 8; Light liquid impeller, 9; Stock liquid supply pipe, 10; Discharge hole, 11; Main valve water chamber, 13; Light liquid flow path, 14 Flow detector or pressure detector, 15; controller, 16; separation chamber, 17; partition plate, 1
8: heavy liquid flow path, 19; heavy liquid impeller, 20; heavy liquid chamber, 22; heavy liquid pipe, 23; control valve, 24; stock solution supply pipe, 25; drain hole, D ₀ ; light liquid free surface diameter , D ₁ ;
Partition plate diameter, D ₂ ; Boundary surface diameter, D ₃ ; Heavy liquid free surface diameter, D
₄ ; heavy fluid impeller diameter, H; heavy fluid, L ;: light fluid.

Claims (1)

[Claims] 1. A separation plate having a main valve for sludge discharge provided in a rotary cylinder, a light liquid impeller provided in a light liquid discharge passage, and a heavy liquid impeller provided in a heavy liquid discharge passage. Type centrifuge, one end is connected to the heavy liquid discharge flow path, the other end is connected to the stock solution supply line flow detector or pressure detector inserted in the heavy liquid line, and the flow detector or pressure It has a controller that opens and closes the control valve of the working water for opening and closing the main valve in response to the output of the detector, and its heavy liquid impeller diameter is almost the same as the heavy liquid free surface diameter. Separation plate type centrifuge.