JP3002089U - Vertical basket bottom discharge centrifuge - Google Patents

Abstract

(57) [Abstract] [Purpose] In a vertical basket bottom discharge centrifuge, high accuracy and stable liquid supply control by improving the detection accuracy of the slurry liquid level in the basket and the stability of the detector. To enable. [Structure] In a vertical basket bottom discharge type centrifuge equipped with a liquid supply pipe, a charge valve lifting device, and a liquid level detection device on the top plate of the casing, the liquid level detection device is placed on the top plate. It is composed of a sensor cover installed, an ultrasonic sensor head fixed in the sensor cover, and a nozzle that ejects compressed air toward the detection surface of the sensor head. It controls the opening and closing of the valve.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a vertical basket bottom discharge type centrifuge used for solid-liquid separation and dehydration treatment, and by improving the liquid level detection device constituting a liquid supply control device, it is highly accurate and stable. The present invention relates to a vertical basket bottom discharge type centrifugal separator capable of controlling liquid supply.

[0002]

[Prior art]

 Generally, when processing a slurry having a high concentration and a large particle size and good filterability, the basket of the centrifuge is stopped or rotated at a very low speed to supply the liquid into the basket. Because when the basket is rotated at high speed to supply liquid, the centrifugal force is too large and the slurry is instantaneously solid-liquid separated, and as a result, the thickness of the dehydrated cake stuck to the inner wall of the basket is uneven. This is because abnormal vibration occurs due to weight imbalance, which makes it difficult to continue smooth operation.

When the slurry is supplied to the basket, the operator usually visually determines the amount of the supplied liquid, that is, the height position of the liquid supply surface in the basket. However, the method of visual inspection by the operator requires a lot of trouble to discriminate, and depending on the model, there is a structure in which the visual inspection of the liquid supply surface is extremely difficult, which causes a problem that the liquid supply work efficiency is lowered.

On the other hand, in order to solve the above-mentioned problem of visually detecting the liquid supply surface, a detection rod is provided in the basket, and a change in the electrical characteristics of the detection rod when the slurry contacts the detection rod is detected. However, a liquid supply control system in which the liquid supply valve is opened / closed by the detection signal has been developed and put into practical use (Japanese Patent Publication No. 42-6148, etc.).

However, this method has no particular problem when the liquid is supplied while the basket is stopped, but when the liquid is supplied by rotating the basket at a very low speed, the tip of the detection rod becomes a slurry. There is a problem in that the contact movement causes abrasion or damage, and the degree of change in electrical characteristics varies depending on the type of slurry, resulting in lack of stability in liquid level detection. If the basket is rotated at high speed with the tip of the detection rod in contact with the slurry, the detection rod will be worn more severely.Therefore, it is necessary to pull the detection rod upward from the slurry surface before rotating the basket at high speed. There is a problem that a separate device for raising the detection rod is required.

[0006]

[Problems to be solved by the device]

 The present invention has the above-mentioned problems in the liquid supply control of the conventional vertical basket bottom discharge type centrifuge, that is, the method of detecting the liquid supply surface by the operator's eyes is troublesome and the discrimination accuracy is extremely poor. In addition, it is not possible to automate the liquid supply, and in the method using a detection rod, the detection rod is easily worn or damaged, requiring a lot of trouble for repairs, etc. This is intended to solve problems such as chipping, and it is possible to perform highly accurate and stable liquid supply control over a long period of time even when liquid is supplied by rotating the basket at a very low speed. The present invention provides a vertical basket bottom discharge type centrifugal separator.

[0007]

[Means for Solving the Problems]

 The invention of the present application is a highly accurate centrifuge in a vertical bottom basket discharge type by using an ultrasonic sensor for the liquid supply surface and constantly detecting the detection surface of the sensor head with compressed air. The basic principle is to perform stable liquid level detection at. That is, the present invention is a vertical basket provided with a liquid supply pipe on the top plate of a casing, a lifting device for a charge valve that opens and closes an opening at the bottom of the basket, and a liquid level detection device that detects the liquid supply surface in the basket. In a bottom-discharging centrifuge, the liquid level detection device is installed on the top plate of the sensor cover, the ultrasonic sensor head fixed inside the sensor cover, and the detection surface of the ultrasonic sensor head. And a nozzle that ejects compressed air toward the liquid level detector, and controls the opening and closing of the liquid supply valve provided in the liquid supply pipe by the detection signal from the liquid level detection device. Is.

[0008]

[Action]

 The ultrasonic waves (incident waves) emitted from the ultrasonic sensor head toward the liquid supply surface in the basket are reflected by the liquid supply surface, and then pass through the detection surface of the sensor head again and the receiving portion of the sensor head. Is incident on. In the receiving section of the ultrasonic sensor, the reflected wave is detected, exchanged and amplified into an electric signal, and then inputted to the amplifier unit provided in the liquid supply control panel. The time required from the emission of the incident wave to the reception of the reflected wave is detected by the amplifier unit, and the distance between the sensor head detection surface and the liquid supply surface is continuously calculated from the change in the required time. . When the calculated distance reaches a value indicating the preliminarily set liquid level height position, a valve control signal is transmitted from the liquid supply control panel and the liquid supply valve is closed. As a result, the liquid supply surface in the basket is automatically controlled to a predetermined height position, and the basket is continuously switched to high speed rotation, whereby the slurry is centrifugally separated.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 is a partially longitudinal front view of a vertical basket bottom discharge centrifuge according to the present invention, and FIG. 2 is a plan view thereof. 1 and 2, 1 is a basket, 1a is a basket barrel, 1b is a basket upper plate, 2 is a casing, 2a is a frame, 2b is an outer plate, 2c is a top plate, 3 is a spindle, 4 is a spindle nut. 5 is a gland, 6 and 7 is a bearing, 8 is a V belt, 9 is a motor, 9 is a drainage port, 11 is a drain port, 12 is a drain port receiver, 13 is a column, 14 is a scraper, and 15 is a scraper. Reference numeral 16 is a charge valve, 17 is a lifting device for raising and lowering the charge valve, 17a is a lifting cylinder, 18 is a liquid supply pipe, and 20 is a liquid level detection device.

The liquid level detection device 20 which constitutes the essential part of the present invention is arranged and fixed on a top plate 2c forming a casing 2 as shown in FIGS. FIG. 3 is a vertical cross-sectional view of the liquid level detection device 20, and the mounting case 21 is fixed on the top plate 2c of the casing 2. Reference numeral 22 denotes an ultrasonic sensor head, which is fixed to the fixed plate 23 by lock nuts 24, 24 with its detection surface 22a facing downward. Further, a compressed air injection nozzle 27 is disposed and fixed to the mounting case 21, and the compressed air sent from the compressed air source from the nozzle 27 is blown toward the detection surface 22a of the sensor head. The water droplets and the like generated on the detection surface 22a are continuously wiped off.

In FIG. 3, 25 is a sensor cover and 26 is a cable. The cable 26 includes a sensor head 22 and a liquid supply control panel (not shown) including an amplifier unit outside the machine. The connection is made to perform signal transmission between the transmitter and receiver of the sensor head 22 and the amplifier unit. Further, in this embodiment, the UD type ultrasonic displacement sensor manufactured by Keyence Corporation is used as the ultrasonic sensor head and the amplifier unit. Of course, it may be of the form.

Next, the operation of the present invention will be described. First, when the slurry is dehydrated, the lifting cylinder 17a of the charge valve lifting device 17 is actuated to lower the charge valve 16 in the basket 1, and as shown in FIG. The discharge part 1c is closed. Next, the basket 1 is stopped or is rotated at a very low speed (10 to 150 rpm) to open a liquid supply valve (not shown) outside the machine, and the slurry is supplied from the liquid supply pipe 18 into the basket 1.

The supplied slurry is sequentially deposited on the lower surface in the basket 1, and the liquid level of the slurry is gradually raised. On the other hand, when the liquid supply surface in the basket 1 rises to a certain height, ultrasonic waves are emitted from the sensor head 22 of the liquid surface detection device 20 toward the liquid supply surface and reflected on the liquid supply surface. The reflected wave is incident on the receiving portion through the detection surface 22a, converted into an electric signal, and then input to the amplifier unit in the liquid supply control panel.

There is a difference in the traveling distance of ultrasonic waves between the empty state before the liquid supply and the state where the slurry is accumulated by the liquid supply, and when the liquid supply surface rises, the sensor head 22 and the slurry upper surface are increased. The distance between them becomes shorter, and the time it takes for the ultrasonic waves to be reflected and reach the receiving side becomes shorter. In the amplifier unit to which the reflected wave signal from the receiver is input, the time from the transmission of the incident wave signal to the reception of the reflected wave signal is continuously measured, and the height of the liquid supply surface is increased from that time. The position is continuously calculated and displayed.

When the detected height position of the liquid supply surface reaches the height position set in advance, the valve control signal is transmitted from the amplifier unit, and the liquid supply valve provided in the liquid supply pipe is sent by the signal. Will be closed. Further, when the liquid supply valve is closed, the basket 1 is continuously switched to the high speed rotation, and the slurry is dehydrated. Further, when the processing is completed, the basket 1 is once stopped, the charge valve 16 is raised to open the dehydrated cake discharging portion 1c, and the scraping device 15 is operated while the basket 1 is rotated at a slight speed to scrape. The dropped dehydrated cake is scraped off and discharged from the machine through the discharge port receiver 12 through the discharge port receiver 12.

[0016]

[Effect of device]

 In the vertical basket bottom discharge centrifuge according to the present invention, the slurry liquid supply surface in the basket is detected by using the ultrasonic sensor head arranged downward on the casing top plate. The liquid level can be detected with extremely high accuracy and continuously, and more stable liquid supply control can be performed as compared with the conventional separator equipped with the liquid level detection device of the detection rod system.

Further, in the liquid level detection device used in the present invention, the compressed air is continuously jetted from the nozzle toward the detection surface of the sensor head during the detection period of the liquid supply surface. The water droplets and the like adhering to the detection surface are completely and easily wiped off, and the detection accuracy of the liquid supply surface is always maintained with high accuracy.

Further, in the vertical basket bottom discharge type centrifuge of the present invention, since the liquid is supplied while the basket is stopped or in the state of very low speed rotation, it is possible to control the liquid supply surface with high accuracy. There is no excess or deficiency in the amount of the slurry charged inside. As a result, it is possible to perform the centrifugal separation process of the slurry with high efficiency without causing abnormal vibration. As described above, the present invention has excellent practical utility.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a vertical basket bottom discharge type centrifuge according to the present invention.

FIG. 2 is a plan view of a vertical basket bottom discharge centrifuge according to the present invention.

FIG. 3 is a vertical cross-sectional view showing a state in which the liquid level detection device used in the present invention is mounted on a top plate.

[Explanation of symbols]

1 is a basket, 1a is a basket barrel, 1b is a basket upper plate, 1c is a discharge port, 2 is a casing, 2a is a frame, 2b is a side plate, 2c is a top plate, 15 is a scraping device, 16 is a charge valve, and 17 is Charge valve lifting device, 17
a is a lifting cylinder, 18 is a liquid supply pipe, 20 is a liquid level detection device, 21 is a mounting case, 22 is a sensor head, 23 is a fixing plate, 24 is a lock nut, 25 is a sensor cover, 26 is a cable, 27 is a nozzle.

Claims (1)

[Scope of utility model registration request] 1. A vertical basket provided with a liquid supply pipe on a top plate of a casing, a lifting device for a charge valve for opening and closing an opening at the bottom of the basket, and a liquid level detecting device for detecting a liquid supply surface in the basket. In a bottom-discharging centrifuge, a sensor cover in which the liquid level detection device is erected on a top plate, an ultrasonic sensor head fixed in the sensor cover, and a detection surface of the ultrasonic sensor head A vertical basket bottom discharge centrifuge characterized in that it is formed of a nozzle that ejects compressed air, and that a liquid supply valve provided in the liquid supply pipe is controlled to open and close by a detection signal from the liquid level detection device. .