CN115646665A - Spiral structure of horizontal decanter centrifuge - Google Patents

Abstract

The invention relates to the field of decanter centrifuges, and discloses a helical structure of a decanter centrifuge, which includes a straight spiral cylinder, on which spiral blades are fixed, and on which a plurality of annular control plates are sheathed in the axial direction. The annular control plate is fixed on the spiral straight cylinder body. The present invention prolongs the residence time of the fine particles in the settling area through the annular control plate, the average height of the liquid flow line drops rapidly, and the fine particles can also complete the settlement before reaching the overflow port, reducing the critical particle size and making the solid content of the liquid phase decreased, the clarity increased.

Description

A decanter centrifuge spiral structure

technical field

The invention relates to the field of decanter centrifuges, in particular to a helical structure of a decanter centrifuge.

Background technique

The horizontal screw centrifuge is referred to as the horizontal screw centrifuge, which is a kind of high-efficiency centrifugal separation equipment. The drum and the feeding screw rotate at a high speed in the same direction at a certain differential speed, and the material is continuously introduced into the inner cylinder of the feeding screw through the central feeding pipe. , under the action of the centrifugal force field, the heavier solid phase is deposited on the drum wall outside the conveying screw to form a sediment layer. The conveying screw continuously pushes the deposited solid phase to the cone end of the drum, and is discharged out of the machine through the slag discharge port. The lighter liquid phase forms an inner liquid ring, continuously overflows the drum from the overflow port at the large end of the drum, and is discharged out of the machine through the liquid discharge port. During the working process of the existing decanter centrifuge, the material flows rapidly from the inside to the outside on the surface. Most of the solid phase is separated from the liquid phase and enters the cone end of the drum, but some fine particles are still mixed in the liquid phase. It is found that the maximum particle size of the solid particles separated from the overflow liquid phase is 1 micron, and the small particle size solid particles are discharged along with the liquid phase, and there is a large loss of small particle size solid phase materials. The reason is that the existing conveying screw is a single screw blade. When the liquid phase is transported to the overflow port through the settling area, the residence time of the material in the drum is insufficient, and the screw blade is difficult to effectively remove the fine particles mixed in it. Settling makes the fine particles settle incompletely, the material does not completely rotate and settle with the centrifuge, and the fine particles are discharged from the overflow port along with the liquid phase from the surface, so that the discharged liquid phase has a high solid content, resulting in material loss.

Contents of the invention

The present invention intends to provide a helical structure of a decanter centrifuge to solve the problem of incomplete settling and separation of fine particles by the conveying screw of the single helical blade of the decanter centrifuge in the prior art, resulting in material loss.

In order to achieve the above object, the present invention adopts the following technical scheme: a helical structure of a decanter centrifuge, including a straight spiral cylinder, on which a helical blade is fixed, and a plurality of annular control plates are sleeved on the straight spiral cylinder along the axial direction , the annular control plate is fixed on the spiral straight cylinder body.

The principle and advantages of this scheme are: in actual application, the spiral structure is used as the main structure to drive the material flow and centrifugal separation inside the decanter centrifuge. During the rotation of the spiral structure, the solid phase in the material is centrifugally deposited from the liquid phase and separated. Moving to the slag outlet, the fine particles are conveyed by the spiral blades while following the liquid phase flow, and are guided by the annular control plate at the same time, the liquid phase containing fine particles is forced to flow radially by the annular control plate, and the material is rotating The drum must be fully accelerated to flow from the root of the annular control plate to the outer drum, prolonging the residence time of the fine particles in the settling zone, making the fine particles more in contact with the inner wall of the drum and easier to settle on the inner wall of the drum. The solid content of the liquid phase discharged from the overflow port is reduced, and the clarity is improved. Under the same conditions, the maximum particle size of the solid particles in the overflow liquid after separation by the technology of this scheme is 0.3 microns, which effectively improves the effect of material solid settlement compared with the prior art.

Preferably, as an improvement, the annular control plate is perpendicular to the axis of the spiral straight cylinder. In this way, the annular control plate has a better radial guide effect on the suspension containing fine particles, and is more conducive to the settlement of fine particles.

Preferably, as an improvement, the diameter of the annular control plate is smaller than the diameter of the helical blade. In this way, the annular control plate has a better guiding effect on the suspension, and the mutual interference between the annular control plate and the spiral blade is smaller, which is more conducive to the settling and separation of fine particles.

Preferably, as an improvement, the diameter of the annular control plate is 0.6-0.95 times the diameter of the helical blade. In this way, the ring-shaped control plate has the best diversion effect on the suspension, better sedimentation effect of fine particles, lower solid content of the obtained liquid phase, and higher clarity.

Preferably, as an improvement, the pitch of the annular control plate is 1-3 times the pitch of the helical blades. In this way, the number of annular control plates is related to the helical blades. Under such a ratio, the residence time of the material in the drum is more appropriate, and the settlement of the fine particles in the material is more complete and thorough.

Description of drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a liquid streamline diagram of the liquid phase passing through the settling zone in the prior art.

Fig. 3 is a liquid streamline diagram of the liquid phase passing through the settling zone in an embodiment of the present invention.

Detailed ways

The following is further described in detail through specific implementation methods:

The reference signs in the accompanying drawings of the description include: a spiral straight cylinder 1 , a spiral blade 2 , and an annular control plate 3 .

The embodiment is basically shown in Figure 1: a helical structure of a decanter centrifuge, including a straight spiral body 1, on which a helical blade 2 is welded and fixed, and on the straight spiral body 1, five The annular control plate 3 is welded and fixed on the spiral straight cylinder body 1 . The annular control plate 3 is perpendicular to the axis of the spiral straight cylinder 1, the diameter d of the annular control plate 3 is 0.6-0.95 times of the diameter D of the helical blade 2, and the spacing of the annular control plate is 1-3 times of the pitch of the helical blade.

The specific implementation process is as follows: During the working process of the horizontal screw centrifuge, the drum and the screw blade 2 rotate at a high speed in the same direction at a certain differential speed. 1 surface hole enters between the rotating drum and the spiral straight cylinder 1. Under the action of the centrifugal force field, heavier solids are deposited on the drum wall outside the spiral blade 2 to form a sediment layer. The spiral blade 2 continuously pushes the deposited solid phase to the cone end of the drum, and is discharged out of the machine through the slag discharge port. The lighter liquid phase forms an inner liquid ring, which is mixed with fine particles. The liquid phase passes through the settling zone and overflows the drum from the overflow port at the large end of the drum continuously. The diversion of the annular control plate 3 is set between the position where the material enters the centrifuge drum and the liquid phase discharge port, which enhances the radial flow, thus increasing the residence time of the material liquid in the drum and prolonging the fine particles in the centrifuge. The residence time in the settling zone reduces the settling distance of solids in the liquid, making it easier for fine particles to settle on the inner wall of the drum. As shown in FIG. 2 , in the prior art, only the average height of the streamline of the liquid treated by the helical blade 2 is relatively high, and the fine particles cannot settle effectively before reaching the overflow port. As shown in Figure 3, after the treatment of the annular control plate 3, the average height of the liquid flow line drops rapidly, and the fine particles can also complete the settlement before reaching the overflow port, reducing the critical particle size, so that the liquid phase discharged outside the machine contains solids The rate is reduced and the clarity is improved. This structure is different from the solid control plate (BD plate, used to control the dryness of slag discharge) set at the junction of the cone and straight end on the screw of the traditional decanter centrifuge; it is also different from the liquid control plate set near the liquid outlet. (FD board, used to eliminate foam in the liquid discharge), verified by the actual machine, can effectively further settle the fine solid phase particles in the overflow liquid in the prior art, reduce the solid content of the discharged liquid phase, and increase the solid phase The amount of material separation can reduce the loss of material separation.

What is described above is only an embodiment of the present invention, and common knowledge such as specific technical solutions and/or characteristics known in the solutions are not described here too much. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, some modifications and improvements can also be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation of the present invention effect and utility of patents. The scope of protection required by this application shall be based on the content of the claims, and the specific implementation methods and other records in the specification may be used to interpret the content of the claims.

Claims (5)

1. The utility model provides a spiral structure of decanter centrifuge, includes the straight barrel of spiral, is fixed with helical blade, its characterized in that on the straight barrel of spiral: a plurality of annular control panels are axially sleeved on the spiral straight cylinder body and fixed on the spiral straight cylinder body.

2. A decanter centrifuge screw structure according to claim 1, characterised in that: the annular control plate is perpendicular to the axis of the spiral straight cylinder body.

3. A decanter centrifuge screw structure according to claim 2, characterised in that: the diameter of the annular control plate is smaller than that of the helical blade.

4. A decanter centrifuge screw structure according to claim 3, characterised in that: the diameter of the annular control plate is 0.6-0.95 times of the diameter of the helical blade.

5. A decanter centrifuge screw structure according to claim 4, characterised in that: the distance between the annular control plates is 1-3 times of the pitch of the helical blades.

Images