An article Monday incorrectly identified a Washington alternative-energy consulting firm. The company is The Synectics Group.

At a time when most of the federal government is frozen in place, the government's only pure science agency, the National Science Foundation, has some of the biggest proposed increases in President Reagan's fiscal 1984 budget request.

The proposed increase for the agency is about 18 percent above the agency's fiscal 1983 appropriation; funding for certain parts of the agency would increase as much as 60 percent over this year's budget.

The new budget reverses the cuts of earlier years, and completes the transformation of the NSF to an agency reflecting the Reagan administration's goals. It would heap extra money onto the areas most closely related to industry and defense, chiefly physics, mathematics and engineering.

But it would let several of the social sciences lose even more ground to inflation following research cutbacks in the past two budgets. And the administration has not replaced the tens of millions of dollars cut from science education programs in the earlier Reagan budgets.

NSF sources said part of the deal to gain major increases for the agency in austere times was an arrangement in which the agency's top managers would be replaced with people who better reflected the administration's point of view.

That purge occurred shortly after Edward A. Knapp stepped in as the agency's new director. It was made clear to the deputy director and the four assistant directors that they would have to leave.

Knapp says the idea to clear out all the agency's top management--a move unprecedented in the history of the relatively nonpolitical agency--was his as much as the White House's.

So far, no replacements have been selected. The procedure for appointment begins when the National Science Board, the NSF's policy arm, submits a list of acceptable candidates to the White House--a list that still is being prepared. Then the White House, in consultation with Knapp, will choose the final nominees from the list--or elsewhere. The whole process is expected to take months.

The biggest boost in the $1.3 billion agency budget would come in funds for new scientific instruments. NSF estimates the amount authorized will jump from $67.9 million to $180.2 million.

The move comes after years of panicked warnings from scientists that aging instruments are hurting both research and science education. However, two years ago, the Reagan administration erased from the budget a science instrumentation program proposed by President Carter's science adviser, Frank Press.

Program by program, one of the biggest increases--21.5 percent--would come in the mathematical and physical sciences. The biggest chunk of that increase would come in industry-oriented "materials research."

The physics component of the budget would increase by 21 percent--and this doesn't include the additional big increases in the Energy Department budget to build the huge particle-accelerating machines at Stanford University and the federal government's Fermilab in Illinois. The substantial new funds to construct the big machines of physics may help the United States leapfrog past the Europeans, who have taken an undisputed lead in high-energy physics after 40 years of domination by the United States.

The budget would give an even larger percentage increase to engineering, a field beyond the original mission of the NSF--to encourage pure, not applied, science.

The NSF fared better than any other science agency in the 1984 budget, and administration officials are giving the credit to the increasingly persuasive George A. Keyworth, the former weapons physicist who is the president's science adviser.

The $4 billion budget of the National Institutes of Health would virtually hold steady, with an increase of less than 4 percent. The National Institutes of Mental Health would continue to be redefined--from an agency handling social, behavioral and biological research to one concerned with research that is more strictly biological.

At the Energy Department, general science programs supporting basic physics would get a hefty 16 percent increase, while the administration would continue to reduce funding for research into alternative energy sources.