Scope of application
The spring damper is a vibration control device that is sensitive to displacement; it is mainly used for anti-vibration of pipelines and equipment in nuclear power plants, thermal power plants, chemical plants, steel plants, etc. It is often used to control the piping vibration of continuous fluid vibration (such as fluid pulsation, two-phase flow, high-speed flow and wind vibration, etc.).
The spring damper can effectively control the vibration and swing of various frequencies, but to a certain extent limits the normal thermal displacement of the pipeline. The design should fully consider the additional force generated by the spring damper on the pipeline.
1. The load of the shock absorber should include the total weight of the shock absorber (equipment + frame + equipment accessories) W (kg). It is better to choose an even number of supporting points, and the minimum should be no less than four. A single shock absorber Bearing static load P0=W/N(kg); single shock absorber bearing dynamic load P=P0+(1.5R(kg))/9.8;
N—the number of support points of the vibration reduction equipment system; R is the equipment disturbance force (N);
When the general vibration requirements are not strict and it is difficult to obtain the preparation disturbance force, the static load P0 of the equipment can be approximated by the dynamic load coefficient p instead:
Dynamic load: P=pP0;
The dynamic load coefficient p is generally taken as p=1.1-1.4; it can be determined according to the total weight of the equipment W and the size of the equipment interference frequency f, the value of p can be larger when W is larger than f, and the value of p can be smaller when W is smaller and f is larger; Example: For fans, water pumps and central air conditioning units, the speed is 1450 rpm, when the static load of the damping equipment is less than 400kg, the p value can be 1.2, and when the static load of the damping equipment is greater than 400kg and less than 1000kg, the p value can be 1.3.
2. Determine the shock absorber model: According to a single shock absorber carrying the P1<=P<=P3, select the shock absorber; you should first select the shock absorber with the P value and the P2 value close to the model;
P1—the minimum load of the shock absorber (kg), P2–the optimal load of the shock absorber (kg), P3—the ultimate load of the shock absorber (kg);
3. In order to meet the damping effect, resonance checking calculation is required for high-speed rotating type shock absorbers subjected to cyclic load; the checking calculation tool formula is: the frequency ratio f/f0 of the equipment interference frequency f and the natural vibration frequency f0 of the shock absorber should be greater than 2. That is: f/f0>=2; equipment interference frequency: f=n/60(Hz); n– equipment speed (rev/min).