Jaw crusher is often used for coarse crushing of bulk materials. It consists of two jaw plates, a movable jaw and a static jaw, which form a crushing cavity. It imitates the movement of two jaws of animals to complete the material crushing operation. During the jaw crushing process, If the material is not crushed by extrusion by the jaw plate, it will fly out from the feed port, which is called return material.

The phenomenon of no material discharge refers to the situation that due to some reasons, the material cannot be discharged or the material discharge is slowed down, causing the discharge port to be blocked, thus causing the material that already meets the discharge specifications to be unable to be discharged out of the machine in time.

The phenomenon of returning materials will not only reduce production efficiency, but also pose certain safety risks to relevant workers. Failure to discharge materials will not only affect the normal operation of the equipment, but in severe cases may cause damage to the jaw crusher, as well as cause the recurrence of jaw crushers. The reason for the failure to cut the material is not single, but multifaceted.

Therefore, only by fully understanding the causes of the jaw crusher's material return and non-feeding problems can we solve them in a timely and effective manner. Material return and failure to unload are one of the common faults during the operation of the jaw crusher, which can be prevented from the following aspects. 

Reason analysis and solutions for returned materials

1. Body problem

The jaw crusher parts do not match the dimensions of the drawings, such as the length and thickness of the jaw plate, the length and angle of the toggle plate, the size of the inner cavity of the frame, etc., resulting in inferior machinery. After long-term use, the angle between the two jaw plates exceeds twice the friction angle, so that there is no sufficient friction between the material and the jaw plate to overcome the upward component of the crushing force, and the material is extruded under the influence of the vertical upward force. , the phenomenon of material return occurs.

Solution: According to the material conditions, choose a jaw crusher of appropriate specifications from a large manufacturer, and weld a guard plate above the jaw crusher feed port to prevent materials from flying out of the feed port and endangering the operator's personal safety.

2. The force on the material is unbalanced

Under the action of the up and down force of the movable jaw plate, if the friction angle between the movable jaw plate and the movable jaw plate is greater than twice the angle between the material and the jaw plate, sufficient friction will not be generated to overcome the vertical extrusion of the components and materials. Under the crushing force, the vertical force of the material to be crushed in the crushing cavity is easily unbalanced. Under the action of the upward component force, the phenomenon of material return is prone to occur.

Solution: In order to reduce the angle between the two jaw plates, a wedge-shaped backing plate can be added at the joint surface of the movable jaw and the movable jaw plate to ensure that the angle between the two jaw plates is less than twice the friction angle and eliminate the phenomenon of material return. .

3. Discharge port problem

For jaw crushers of the same specifications, the outlet width should be adjusted appropriately, because the larger the width of the outlet, the greater the possibility of material return.

Solution: Although the size of the discharge port of the jaw crusher determines its processing capacity, the size of the discharge port should be based on the feed particle size of the secondary crushing, and the size of the discharge port cannot be increased or reduced arbitrarily.

4.Jaw plate problem

During the crushing process, the material is in direct contact with the jaw plate, causing friction. The more serious the wear of the jaw plate, the greater the possibility of material return.

Solution: When the jaw plate is worn and material returns, the jaw plate should be repaired or replaced with a new one in time.

5. Material size issues

Generally speaking, the feed size of the jaw crusher is about the same, so as to ensure uniform discharging. However, when the size of the materials to be crushed is very different, the phenomenon of material return is easy to occur.

Solution: When the particle size difference of the materials is too large, the materials should be screened first, pre-processed by the coarse jaw crusher, and then fine-processed by the fine jaw crusher, so as to ensure the processing requirements of the materials.

Analysis and solutions for reasons of non-cutting

1. The humidity of the object to be broken is relatively high

When the jaw crusher encounters materials with a large surface moisture, or the crushed materials are mixed with mud, it is very easy to get stuck, causing the minerals to be unable to come out. After the ore is crushed, it will become blocked in the cavity and cannot be discharged.

Solution: Strictly control the nature or composition of the material, and carry out pre-screening, washing, and ore blending to control moisture before crushing to ensure the dryness and purity of the material to be crushed. Degree (removal of dust and dust).

2. Feeding speed is too fast

Since the processing capabilities of different types of jaw crushers are also different, during the production process, when all parameters have been set, only the feeding speed is set faster. If too much or uneven feeding is done at one time, it is very easy to cause damage. As a result, too much material accumulates in the lower cavity of the jaw crusher, blocking the discharge port, and then the material does not discharge.

Solution: When purchasing equipment, understand in advance the basic requirements for materials of the selected model of jaw crusher, such as: incoming and outgoing material particle size, crushing capacity, etc. If the equipment still has materials stuck during the crushing process, the material will not be discharged. , the spindle speed can be adjusted to slow down the crushing speed. At the same time, the discharge port can be enlarged to make less in and more out, and improve the material passing rate. However, when adjusting the discharge port, the adjustment angle cannot be too flat to ensure continuous and even feeding. material.

3. The feed contains iron blocks and other foreign matter

If the iron blocks and other unbreakable raw materials are not picked out when adding raw materials, it will cause certain damage to the jaw plate of the jaw crusher, thus affecting the discharge of materials.

Solution: Check from the source, conduct a preliminary pre-screening of the materials to be crushed, and remove objects that do not meet the crushing standards, such as iron blocks, before adding materials to reduce the phenomenon of stuck materials.

4. Low voltage in the workplace

The voltage is too low and cannot provide the power required for the normal operation of the host, resulting in too slow material discharging or even no material discharging.

Solution: Before work, debug the voltage of the construction site according to the equipment requirements to adapt it to the heavy load requirements of the host.