DE2365748C3 - Cast inner part of a tubular body - Google Patents

Description

It is known that the inner parts of pipe bodies, in particular elbows, are subject to more wear and tear when flowing through Conveyed goods such as sand, ash, hard minerals or gases mixed with such substances or * 5 Liquids are subject to high wear, especially at the flow deflection points. The tubular body or elbows are attacked quickly until the pipe wall is broken through at one point. Thereupon In most cases, the operation of the entire pipeline must be shut down, the pipe (elbow) removed and through new parts are replaced. There are operational shutdowns, production failures, repair work and Costs.

It has already been proposed to prevent pipelines for flushing or blow-off in mining Excessive wear and tear to protect the inner surfaces of the same from pavement Broken or shaped pieces made of corundum, silicon carbide or other suitable materials of great hardness, which are melted into the pipeline with simultaneous hardening of the material. Additionally it has been proposed to insert bits of hard stone into the inner surface of such flushing or blow-off lines Pour in the pipeline, for example made of corundum or silicon carbide Broken or shaped stone pieces glued to the corresponding surface of the casting mold, attached by means of wire nails or wire mesh and then poured over.

In these older proposals, the hard material particles are arranged in a "pavement-like manner"; H. with very small joints between the same, such that the greater part of the inner pipe surface to be protected is covered with such hard material particles. This results in many manufacturing disadvantages and during operation. The pouring stream cannot pass through such narrow gaps quickly enough; he will cool down and solidify before reaching its end position. The cast webs between the hard material particles are so thin that they cannot withstand greater forces and break easily, whereupon the Break out hard particles long before they are worn out. The secure attachment of the particles in the mold before casting is difficult due to lack of space; as a result, there is a risk of Displacement of the hard material particles by the casting flow. The clasping of the hard material after Cooling of the casting is insufficient. Cracks in the cast material are favored, the risk of underwashing increases All these disadvantages cause a reduction in the service life and de. · Economy. The practical application according to the known methods is very limited

The present invention has the task of overcoming the disadvantages outlined above. In particular A displacement-proof storage of the hard material near the inner surface of the pipe should be achieved, an avoidance of premature cooling of the inflowing liquid cast material, firm grip of every single hard material particle through the cast material, avoidance of cracks in the cast material and in the hard material particles, reduction of the risk of underwashing, maximum possible service life, high economic efficiency and versatile practical application possibilities

These tasks in their entirety are optimally achieved in that the cast inner part of a tubular body, in particular the elbow, is armored at its wear-exposed zone by hard material bodies immovably embedded in their surface, in such a way that the hard material grains have an individual area size of between 0.1 projected onto the adjacent wear zone and 10 cm ² , preferably 0.5 and 3 cm ² and spaced apart in such a position. the wear zone surface of the casting are arranged so that their area proportion, projected onto this surface, is 5-50%, preferably 10-40%

The way of application is described and shown in more detail below, namely shows

F i g. 1 shows a section through a manifold according to the invention, for. B. Displacement elbow,

F i g. 2 some parts of a concrete pump that come into contact with one another, including 2 elbows.

In Fig. 1, an elbow with chilled cast iron inserts for the promotion of mineral-containing operating materials is shown. The manifold 140 is protected on the outer circumference by hard cast inserts 141, 142, 143 , which are arranged interchangeably. These inserts contain carriers 144, 145, 146 curved in parallel on their inside, on which urea particles 147, 148, 149 are fastened to the inside and 150, 151, 152 to the outside. Appropriately is - if the Hartgußeinlagen not in any case have the same shape and can therefore be exchanged - the highest unclaimed funds deposits 142 Reinforce particularly strong. Since the hard material reinforcement means that the use of a larger "wear volume" can be dispensed with, the inserts can be built lighter, more manageable, cheaper and more economical.

In Fig. 2 various parts of a concrete pump that are important for operation are pulled apart and shown in perspective so that their interaction is easy to understand. In particular, it is the armoring of the manifold housings 311, 312 on the inner surface of the manifold outer half, which is mainly stressed according to experience, possibly also at the inlet or outlet, as described in the previous example.

Elbows of the type described here have considerable technical and economic advantages and also serve to provide better protection against accidents.

The advantages achieved by the present invention are set out above.

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: 1. Cast inner part of a tubular body, in particular an elbow, the zone of which is subject to wear and tear is armored by hard material bodies immovably embedded in its surface, characterized in that the hard material bodies (150,151,152) have ^{an individual surface size between 0.1 cm 2} and 10 cm ² projected onto the adjacent wear zone, preferably 0.5 cm ² and 3 cm ² , and are arranged at a distance from one another in such a position on the wear zone surface of the casting that their area proportion, projected onto this surface, is 5-50%, preferably 10-40%. 2. Inner tubular body part according to claim 1, characterized in that the wear-resistant zone consists of exchangeable inserts (141, 142, 143)